Archive for October, 2008

Flight Centre

Friday, October 31st, 2008

Flight Centre Limited (ASX:FLT) is Australia’s largest travel agent. It is listed on the Australian Stock Exchange with a market capitalisation of $1.145 billion as at March 2006. It has 1000 stores in eight different countries with over 8000 staff.

Flight Centre was founded by Graham Turner in 1981. Turner had previously run a successful budget bus trip company in Europe called Topdeck. Turner retains 18% of Flight Centre. By 1990, Flight Centre had opened stores in New Zealand, the UK and US. The UK and US offices were closed in 1991 in the face of the Gulf War. Expansion began again with a move to South Africa in 1994, Canada in early 1995, and the UK later that year. US operations recommenced in late 1999 It has been claimed that

“Flight Centre revolutionised the retailing of international air-travel in Australia by shifting to a model where profitability was driven by volume rather than margins. Initially they built a price advantage by bypassing ticketing wholesalers, seeking out less well-known airlines, and also by arbitraging price differentials across markets.”

The company grew rapidly, establishing different brands to cater for different parts of the travel market. It owns FCm Travel Solutions for the corporate market,Student Flights, Overseas Working Holidays for the student market and also runs related businesses in the discount holiday organiser Escape Travel, travelthere.com, quickbeds.com, luxury holiday company Travel Associates, retail cruise specialist Cruiseabout and Campus Travel aimed at the academic and university markets. Its website flightcentre.com has been the most popular Australian travel agency website for several years. It has operations in Australia ($4.4 billion 2004/5 sales), New Zealand ($639 million 2004/5 total transactions), South Africa ($365 million 2004/5 total transactions), United Kingdom ($909 million 2004/5 total transactions), United States ($65 million 2004/5 total transactions) and Canada ($415 million 2004/5 total transactions).

After decades of rapid and consistent growth in revenues and profits, Flight Centre flew into trouble in 2005 with its first ever decline in annual profit. For the year ending June 30 2005, on a total revenue of $6.9 billion, its net profit was $67.9 million. Profit announcements for the half year ending December 31 2005, showed a continuing fall in net profits to $33.6 million, a decline of 7.7% on the previous year.

It followed Graham Turner’s departure from day-to-day operations when he stood aside from being Chief Executive Officer in 2002, allowing a senior manager Shane Flynn to replace him. He corrected this in July 2005, resuming his previous role as a hands-on manager as Executive Chairman.

The one time darling of the stock market, normally showing strong profit growth, was punished severely with it being the second worst performing stock in the Australian Stock Exchange’s Top 200 companies. Its share price is down 57% from its peak in 2002. This reflected not only concerns about the company’s management but also its long-term prospects.

The company faces serious challenges, with disintermediation occurring in the travel industry. In 2006, Qantas announced that it would no longer pay base commissions to travel agents for domestic and New Zealand flights and that it would reduce international commissions from 7% to 5% . An increasing number of customers are following the lead of many of Flight Centre’s suppliers and dealing with them directly through their own websites rather than going through travel agents. Some financial analysts are very concerned about this, with one issuing a sell recommendation on the stock in a report titled Flightless Centre.

November 2006: A company associated with the founders and a private equity firm is offering $17.20 a share (and somewhat less to current “controlling” shareholders) to take Flight Centre back into private hands.

February 2007: The privatisation of Flight Centre failed when investment bank Lazard rejected the deal even though the majority of minority shareholders agreed with the privatisation bid. Flight Centre shares tumbled soon after the trading halt was lifted to around $15.

References

  1. ^ a b André Sammartino (2007), ‘Retail’, in Dick, H. & Merrett, D. (eds.), The Internationalisation Strategies of Small-Country Firms: The Australian Experience of Globalisation, Edward Elgar: Cheltenham, UK, pp.175-194.

External links

Retrieved from “http://en.wikipedia.org/wiki/Flight_Centre
Categories: Companies listed on the Australian Securities Exchange | Travel

Interstellar travel

Friday, October 31st, 2008


Artist’s depiction of a hypothetical Wormhole Induction Propelled Spacecraft, based loosely on the 1994 “warp drive” paper of Miguel Alcubierre. Credit: NASA CD-98-76634 by Les Bossinas.

Interstellar space travel is unmanned or manned travel between stars. The concept of interstellar travel in starships is a staple in science fiction. Interstellar travel is tremendously more difficult than interplanetary travel. Intergalactic travel, the travel between different galaxies, is even more difficult.

Many scientific papers have been published about related concepts. Given sufficient travel time and engineering work, both unmanned and generational interstellar travel seem possible, though representing a very considerable technological and economic challenge unlikely to be met for some time, particularly for crewed probes. NASA has been engaging in research into these topics for several years, and has accumulated a number of theoretical approaches.

Contents

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The difficulties of interstellar travel

The main difficulty of interstellar travel is the vast distances that have to be covered and therefore the time it takes with most realistic propulsion methods - from decades to millennia. Hence an interstellar ship would be much more severely exposed to the hazards found in interplanetary travel, including hard vacuum, radiation, weightlessness, and micrometeoroids. The long travel times make it difficult to design manned missions, and make a primarily economic justification of any interstellar mission nearly impossible, since benefits that do not become available for decades or longer have a present value close to zero.

It has been argued that an interstellar mission which cannot be completed within 50 years should not be started at all. Instead, the money should be invested in designing a better propulsion system. This is because a slow spacecraft would probably be passed by another mission sent later with more advanced propulsion. if one calculates the journey time to a given destination as the rate of travel derived from growth (even exponential growth) increases, there is a clear minimum in the total time to that destination from now. This is significant because voyages undertaken before the minimum will be overtaken by those who leave at the minimum, while those who leave after the minimum will never overtake those who left at the minimum. Any civilization traveling to an interstellar destination can look forward to a unique date that is best to leave, and one that is the most efficient in terms of cost and time.

Intergalactic travel involves distances about a million-fold greater than interstellar distances, making it radically more difficult than even interstellar travel.

Interstellar distances

Astronomical distances are often measured in the length of time it would take a beam of light to travel between two points (see lightyear). Light in a vacuum travels approximately 300,000 kilometers per second or 186,000 miles per second.

The distance from Earth to the Moon is 1.3 light-seconds. With current spacecraft propulsion technologies, a trip to the moon will typically take about three days. The distance from Earth to other planets in the solar system ranges from three light-minutes to about four light-hours. Depending on the planet and its alignment to Earth, for a typical unmanned spacecraft these trips will take from a few months to a little over a decade.

The nearest known star to the Sun is Proxima Centauri, which is 4.23 light-years away. The fastest outward-bound spacecraft yet sent, Voyager 1, has covered 1/600th of a light-year in 30 years and is currently moving at 1/18000 the speed of light. At this rate, a journey to Proxima Centauri would take 72,000 years. Of course, this mission was not specifically intended to travel fast to the stars, and current technology could do much better. The travel time could be reduced to a few millennia using lightsails, or to a century or less using nuclear pulse propulsion (Orion). A better understanding of the vastness of the interstellar distance to one of the closest stars to the sun, Alpha Centauri A (a sun-like star), can be obtained by scaling down the earth-sun distance (150,000,000 km) to one meter. On this scale the distance to that star would be 271 kilo-meters or about 169 miles.

No current technology can propel a craft fast enough to reach other stars in under 50 years’ time. Current theories of physics indicate that it is impossible to travel faster than light within a flat region of space-time, and suggest that if it were possible, it might also be possible to build a time machine using similar methods.

However, special relativity offers the possibility of shortening the travel time: if a starship with sufficiently advanced engines could reach velocities approaching the speed of light, relativistic time dilation would make the voyage much shorter for the traveler. However, it would still take many years of elapsed time as viewed by the people remaining on Earth, and upon returning to Earth, the travelers would find that far more time had elapsed on Earth than had for them. (For more on this effect, see twin paradox)

General relativity offers the theoretical possibility that faster than light travel may be possible without violating fundamental laws of physics, for example, via wormholes, although it is still debated whether this is possible in the real world. Proposed mechanisms for faster than light travel within the theory of General Relativity require the existence of exotic matter.

Prime targets for interstellar travel

There are 59 stellar systems within 20 light years from the Sun, containing 81 visible stars. The following could be considered prime targets for interstellar missions:

Stellar System
Distance (ly)
Remarks

Alpha Centauri
4.3
Closest system. Two stars, (G2, M5). Component A almost identical to our sun (a G2 star).

Barnard’s Star
6.0
Small, low luminousity M5 red dwarf. Next closest to Solar System.

Sirius
8.7
Large, very bright A1 star with a white dwarf companion.

Epsilon Eridani
10.8
Single K2 star slightly smaller and colder than the Sun. May have solar system type planetary system.

Tau Ceti
11.8
Single G8 star similar to the Sun. High probability of possessing a solar system type planetary system.

Manned missions

The mass of any craft capable of carrying humans would inevitably be several orders of magnitude greater than that necessary for an unmanned interstellar probe. For instance, the first space probe, Luna 1, had a payload of 361 kg; while the first spacecraft to carry a living passenger (Laika the dog), Sputnik 2, had a payload over 20 times that at 7,314 kg. This in fact severely underestimates the difference in the case of interstellar missions, given the vastly greater travel times involved and the resulting necessity of a closed-cycle life support system.

Proposed methods of interstellar travel

If a spaceship could average 10 percent of light speed, this would be enough to reach Proxima Centauri in forty years. Several propulsion systems are able to achieve this, but none of them is reasonably affordable.

Nuclear pulse propulsion

Since the 1960s it has been technically possible to build spaceships with nuclear pulse propulsion engines, i.e. ships driven by a series of nuclear explosions. This propulsion system contains the prospect of very high specific impulse (space travel’s equivalent of fuel economy) and high speed, and therefore of reaching the nearest star in decades rather than centuries; construction and operational costs per unit of payload were expected to be similar to those of ships using chemical rockets.

Proposed interstellar spacecraft using nuclear pulse propulsion include Project Orion and Project Longshot. Using miniature nuclear bombs as fuel, Orion would be able to reach a velocity of 10% of the speed of light. It is one of very few known interstellar spacecraft proposals that could be constructed entirely with today’s technology.

Fusion rockets

Fusion rocket starships, using foreseeable fusion reactors, should be able to reach speeds of approximately 10 percent of that of light. These would “burn” deuterium. One proposal using a fusion rocket is Project Daedalus.

The problem with all traditional rocket propulsion methods is that the spacecraft would need to carry its fuel with it, thus making it quite heavy. The following three methods attempt to solve this problem.

Interstellar ramjets

In 1960 Robert W. Bussard proposed the Bussard ramjet, a fusion rocket in which a huge scoop would collect the diffuse hydrogen in interstellar space, “burn” it on the fly using a proton-proton fusion reaction, and expel it out of the back. Though later calculations with more accurate estimates suggest that the thrust generated would be less than the drag caused by any conceivable scoop design, the idea is attractive because, as the fuel would be collected en route, the craft could theoretically accelerate to near the speed of light.

Antimatter rockets

An antimatter rocket would have a far higher energy density and specific impulse than any other proposed class of rocket. Assuming that energy resources and efficient production methods are found to make antimatter in the quantities required, theoretically it would be possible to reach speeds near that of light, where time dilation would shorten perceived trip times for the travelers considerably.

Beamed propulsion

A light sail or magnetic sail powered by a massive laser or particle accelerator in the home star system could potentially reach even greater speeds than rocket- or pulse propulsion methods, because it would not need reaction mass and therefore would not need to accelerate that as well as the payload. In theory a lightsail driven by a laser or other beam from Earth can be used to decelerate a spacecraft approaching a distant star or planet, by detaching part of the sail and using it to focus the beam on the forward-facing surface of the rest of the sail. A magnetic sail could also decelerate to its destination without fuel, by interacting with the plasma found in the solar wind of the destination star and the interstellar medium.

Beamed propulsion seems to be the best interstellar travel technique presently available, since it uses known physics and known technology that is being developed for other purposes, and would be considerably cheaper than nuclear pulse propulsion.

The following table lists some example concepts using beamed lased propulsion as proposed by the physicist Robert L. Forward

Mission
Laser Power
Vehicle Mass
Acceleration
Sail Diameter
Maximum Velocity (% of the speed of light)

1. Flyby
65 GW
1 t
0.036 g
3.6 km
0.11 @ 0.17 ly

2. Rendezvous

outbound stage
7,200 GW
785 t
0.3 g
100 km
0.21 @ 2.1 ly

deleceration stage
26,000 GW
71 t
0.2 g
30 km
0.21 @ 4.3 ly

3. Manned

outbound stage
75,000,000 GW
78,500 t
0.3 g
1000 km
0.50 @ 0.4 ly

deleceration stage
17,000,000 GW
7,850 t
0.3 g
320 km
0.50 @ 10.4 ly

return stage
17,000,000 GW
785 t
0.3 g
100 km
0.50 @ 10.4 ly

deceleration stage
430,000 GW
785 t
0.3 g
100 km
0.50 @ 0.4 ly

Further speculative methods

Light speed travel

Interstellar travel via transmission

Main article: Teleportation

If physical entities could be transmitted as information and reconstructed at a destination, travel precisely at the speed of light would be possible. Note that, under General Relativity, information cannot travel faster than light. The speed increase when compared to near-light-speed travel would therefore be minimal for outside observers, but for the travelers the journey would become instantaneous.

Encoding, sending and then reconstructing an atom by atom description of (say) a human body is a daunting prospect, but it may be sufficient to send software that in all practical purposes duplicates the neural function of a person. Presumably, the receiver/reconstructor for such transmissions would have to be sent to the destination by more conventional means. Tachyons could not be used for communication.

Faster than light travel

Main article: faster-than-light

Scientists and authors have postulated a number of ways by which it might be possible to surpass the speed of light. Even the most serious-minded of these are speculative.

Warped spacetime

According to Einstein’s equation of General Relativity, spacetime is curved:

General relativity may permit the travel of an object faster than light in curved spacetime. One could imagine exploiting the curvature to take a “shortcut” from one point to another. This is one form of the Warp Drive concept.

In physics, the Alcubierre drive is based on an argument that the curvature could take the form of a wave in which a spaceship might be carried in a “bubble”. Space would be collapsing at one end of the bubble and expanding at the other end. The motion of the wave would carry a spaceship from one space point to another in less time than light would take through unwarped space. Nevertheless, the spaceship would not be moving faster than light within the bubble. This concept would require the spaceship to incorporate a region of exotic matter, or “negative mass”. As a practical means of interstellar transportation, this idea has been criticized; see Alcubierre Drive.

Wormholes

Wormholes are conjectural distortions in space-time that theorists postulate could connect two arbitrary points in the universe, across an Einstein-Rosen Bridge. It is not known whether or not wormholes are possible in practice. Although there are solutions to the Einstein equation of general relativity which allow for wormholes, all of the currently known solutions involve some assumption, for example the existence of negative mass, which may be unphysical.

Methods for slow manned missions

Slow interstellar travel designs such as Project Longshot generally use near-future spacecraft propulsion technologies. As a result, voyages are extremely long, starting from about one hundred years and reaching to thousands of years. Crewed voyages might be one-way trips to set up colonies. The duration of such a journey would present a huge obstacle in itself. The following are the major proposed solutions to that obstacle:

Generation ships

A generation ship is a type of interstellar ark in which the travellers live normally (not in suspended animation) and the crew who arrive at the destination are descendants of those who started the journey.

Generation ships are not currently feasible, both because of the enormous scale of such a ship and because such a sealed, self-sustaining habitat would be difficult to construct. Artificial closed ecosystems, including Biosphere 2, have been built in an attempt to work out the engineering difficulties in such a system, with mixed results.

Generation ships would also have to solve major biological and social problems. Estimates of the minimum viable population vary - 180 is about the lowest, but such a small population would be vulnerable to genetic drift, which might reduce the gene pool below a safe level.

A generation ship in fiction typically takes thousands of years to reach its destination, i.e. longer than most human civilizations have lasted. Hence there is a risk that the culture which arrives at the destination may be incapable of doing what is needed - in the worst case it may have fallen into barbarism. Also they may forget that they are on a generation ship. Stephen Baxter’s story “Mayflower II” (in the collection Resplendent) explores both of these risks as does Robert A. Heinlein’s two-part 1941 novel Orphans of the Sky. The_Starlost was a Canadian produced science fiction television series devised by writer Harlan Ellison and broadcast in 1973. The setting is a huge generational colony spacecraft which has gone off-course. Many of the descendants of the original crew and colonists are unaware, however, that they are aboard such a ship.

Suspended animation

Scientists and writers have postulated various techniques for suspended animation. These include human hibernation and cryonic preservation. While neither is currently practical, they offer the possibility of sleeper ships in which the passengers lie inert for the long years of the voyage. However, even assuming all relevant space-faring and suspended animation technologies could be developed, an automated means of guiding the ship to its destination with little or no human influence would be required.

Extended human lifespan

A variant on this possibility is based on the development of substantial human life extension, such as the “Strategies for Engineered Negligible Senescence” proposed by Dr. Aubrey de Grey. If a ship crew had lifespans of some thousands of years, they could traverse interstellar distances without the need to replace the crew in generations. The psychological effects of such an extended period of travel would potentially still pose a problem.

Frozen embryos

A robotic space mission carrying some number of frozen early stage human embryos is another theoretical possibility. This method of space colonization requires, among other things, the development of a method to replicate conditions in a uterus, the prior detection of a habitable terrestrial planet, and advances in the field of fully autonomous mobile robots and educational robots which would replace human parents (see embryo space colonization).

NASA research

The NASA Breakthrough Propulsion Physics Project identified two breakthroughs which are needed for interstellar travel to be possible :

  1. A method of propulsion able to reach the maximum speed which it is possible to attain
  2. A new method of on-board energy production which would power those devices.

In other words, any engine short of the best conceivable engine won’t work, and that engine cannot be powered by currently known energy sources. Analogies for ‘breakthroughs’ in technology are steam engines supplanting sailing ships, and jet aircraft replacing propeller aircraft.

Geoffery A. Landis, of NASA’s Glenn Research Center, says that a laser-powered interstellar sail ship could possibly be launched within 50 years, utilizing new methods of space travel. “I think that ultimately we’re going to do it, it’s just a question of when and who,” Landis said in an interview. Rockets are too slow to send humans on interstellar missions. Instead, he envisions interstellar craft with gigantic sails, propelled by laser light to about one tenth the speed of light. It would take such a ship about 43 years to reach Alpha Centauri, if it passed through the system. Slowing down to stop at Alpha Centauri could increase the trip to 100 years.

References

  1. ^ Yoji Kondo: Interstellar Travel and Multi-generation Spaceships, ISBN 1896522998 p. 31
  2. ^ Interstellar Travel: The Wait Calculation and the Incentive Trap of Progress, JBIS V 59 no 7 July 2006
  3. ^ Bob Forward: Ad Astra, in Journal of the British Interplanetary Society (Vol. 49, pp. 23-32, 1996)
  4. ^ General Dynamics Corp. (Jan 1964). “Nuclear Pulse Vehicle Study Condensed Summary Report (General Dynamics Corp.)”. U.S. Department of Commerce National Technical Information Service.
  5. ^ Forward, R.L. (1984). “Roundtrip Interstellar Travel Using Laser-Pushed Lightsails”. J Spacecraft 21 (2): 187–195. doi:10.2514/3.8632. 
  6. ^ Bob Forward: Ad Astra, in Journal of the British Interplanetary Society (Vol. 49, pp. 23-32, 1996)
  7. ^ Forward, R.L. (1984). “Roundtrip Interstellar Travel Using Laser-Pushed Lightsails”. J Spacecraft 21 (2): 187–195. doi:10.2514/3.8632. 
  8. ^ Geoffrey Landis, The Ultimate Exploration: A Review of Propulsion Concepts for Interstellar Flight, in: Yoji Kondo: Interstellar Travel and Multi-Generation Spaceships, ISBN 1-896522-99-8, pp. 52-62
  9. ^ Remote Sensing Tutorial Page A-10
  10. ^ (http://www.nasa.gov/centers/glenn/research/warp/ideachev.html#worm)
  11. ^ John G. Cramer, Robert L. Forward, Michael S. Morris, Matt Visser, Gregory Benford, and Geoffrey A. Landis, “Natural Wormholes as Gravitational Lenses,” Phys. Rev. D51 (1995) 3117-3120
  12. ^ M. Visser (1995) Lorentzian Wormholes: from Einstein to Hawking, AIP Press, Woodbury NY, ISBN 1-56396-394-9
  13. ^ a b Malik, Tariq, “Sex and Society Aboard the First Starships.” Science Tuesday, Space.com March 19, 2002.
  14. ^ Warp Drive, When? Breakthrough Technologies
  • Eugene Mallove and Gregory Matloff (1989). The Starflight Handbook. John Wiley & Sons, Inc. ISBN 0-471-61912-4
  • Zubrin, Robert (1999). Entering Space: Creating a Spacefaring Civilization. Tarcher / Putnam. ISBN 1-58542-036-0
  • Eugene F. Mallove, Robert L. Forward, Zbigniew Paprotny, Jurgen Lehmann: “Interstellar Travel and Communication: A Bibliography,” Journal of the British Interplanetary Society, Vol. 33, pp. 201-248, 1980.
  • Geoffrey A. Landis, “The Ultimate Exploration: A Review of Propulsion Concepts for Interstellar Flight,” in Interstellar Travel and Multi-Generation Space Ships, Kondo, Bruhweiller, Moore and Sheffield., eds., pp. 52-61, Apogee Books (2003), ISBN 1-896522-99-8.
  • Zbigniew Paprotny, Jurgen Lehmann: “Interstellar Travel and Communication Bibliography: 1982 Update,” Journal of the British Interplanetary Society, Vol. 36, pp. 311-329, 1983.
  • Zbigniew Paprotny, Jurgen Lehmann, John Prytz: “Interstellar Travel and Communication Bibliography: 1984 Update” Journal of the British Interplanetary Society, Vol. 37, pp. 502-512, 1984.
  • Zbigniew Paprotny, Jurgen Lehmann, John Prytz: “Interstellar Travel and Communication Bibliography: 1985 Update” Journal of the British Interplanetary Society, Vol. 39, pp. 127-136, 1986.

See also

  • Alcubierre drive
  • Spacecraft propulsion
  • Bussard ramjet
  • Relativistic rocket
  • Antimatter rocket
  • Spacewarp
  • Wormholes
  • Interstellar communication
  • Interstellar travel and the Wait Calculation
  • Project Daedalus
  • Project Orion
  • Fusion rocket
  • Spaceship
  • Starwisp
  • Eugen Sänger
  • Robert Bussard
  • Robert L. Forward
  • Freeman Dyson
  • Carl Sagan
  • Tau Zero
  • Gliese 581c

External links

  • Links gathered by Mark Tomion, including Practical Design of a Spacewarp, by Mohammad Mansouryar
  • NASA Breakthrough Propulsion Physics Program
  • Centauri Dreams
  • “Atomic rockets” SF spacecraft fan site
  • Sex and Society Aboard the First Starships
  • Bibliography of Interstellar Flight
  • Extensive list of sources Science and Science Fiction for Interstellar Flight

v • d • e

Spaceflight

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History (Space Race, Accidents and incidents) · Astrodynamics · Lists and timelines

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Earth observation satellites (Spy satellites, weather satellites) · Space exploration · Space tourism · Communication satellites · Satellite navigation · Space colonization

Human spaceflight

General

Astronaut  · Life support system

Hazards

Weightlessness (space adaptation syndrome)  · cosmic radiation

Major projects

Mercury · Gemini · Apollo · Shenzhou · Mir · ISS

Other

Extra-vehicular activity

Spacecraft

Launch vehicle · Space Shuttle · Robotic spacecraft · Self-replicating spacecraft · Spacecraft propulsion · Rocket

Destinations

Sub-orbital · Orbital (Geosynchronous orbit, Geocentric orbit)  · Interplanetary spaceflight · Interstellar travel · Intergalactic travel

Space launch

Expendable and Reusable systems · Escape velocity · Direct ascent · Non-rocket spacelaunch · Spaceport · Launch pad

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Other

Private spaceflight · Space weather · Lagrangian point · Space and survival

Retrieved from “http://en.wikipedia.org/wiki/Interstellar_travel
Categories: Interstellar travel | Space exploration | Space colonization | Spaceflight

Transcontinental railroad

Friday, October 31st, 2008


“First Transcontinental Railroad” is the name of the railway completed in 1869 between Omaha, Nebraska/Council Bluffs, Iowa to Sacramento, California which connnected to other railways going respectively to the Atlantic and Pacific to establish the first coast-to-coast U.S. transcontinental rail route. Shown is the ceremony for the driving of the “Last Spike” signifying the joining of the tracked CPRR and UPRR grades at Promontory Summit, Utah, on May 10, 1869. Photograph by Andrew J. Russell.

A Transcontinental Railroad is a railroad that crosses a continent from “coast-to-coast”. Terminals are at or connected to different oceans. Because Europe is criss-crossed by railways, railroads within Europe are usually not considered transcontinental, the Orient Express perhaps being an exception.

Contents

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The Americas

Panama

The world’s first inter-oceanic railroad was the Panama Railway, completed in 1855. Built near the narrowest point of the Central American isthmus in modern-day Panama (then part of Colombia), the railroad was 48 miles / 77.25 km long, and it was the first railroad to cross the Americas to connect the Atlantic with the Pacific Ocean. Given the tropical rain forest environment, the terrain, and diseases such as malaria and cholera, its completion was a considerable engineering challenge. The construction took 5 years, 8 million dollars and thousands of workers from the United States, Europe, China and Africa.

This railroad was built to satisfy the need for a shorter and more secure path between the United States’ East and West Coasts, a need triggered mainly by California Gold Rush. However, the railroad continued its activity over the years, and it played a key role in the construction and the subsequent operation of the Panama Canal, due to its proximity with the water way. Currently, the railway operates under the private administration of the Panama Canal Railroad Company, and its upgraded capacity allows it to complement the cargo traffic through the Panama Canal.

United States

In the United States, the area of the Mississippi River has always been a transfer point between systems in the East and West. No single company ever controlled a route all the way from one coast to the other (though several had lines between the Pacific Ocean and the Gulf of Mexico). The reason for this is fairly simple: if an eastern company were to ally itself with a western company, it would no longer have the choice to send traffic over the other western lines. This is still true—two of the major Class I railroads have systems east of the Mississippi, while the other two major ones are mainly west of the Mississippi.

In the United States, the term transcontinental railroad usually refers to a line over the Rocky Mountains (and on several routes also the Sierra Nevada Mountains) between the Midwest and Pacific Ocean. Some of the eastern trunk lines are covered in railroads connecting New York City and Chicago.

  • The rails of the “First Transcontinental Railroad” were joined on May 10, 1869, with the ceremonial driving of the “Last Spike” at Promontory Summit, Utah, after track was laid over a 1,756 mile (2,826 km) gap between Sacramento and Omaha, Nebraska/Council Bluffs, Iowa)
  • In 1882, the Atchison, Topeka and Santa Fe Railway connected Atchison, Kansas with the Southern Pacific Railroad at Deming, New Mexico, thus completing a second link to Los Angeles.
  • The Southern Pacific Railroad linked New Orleans with Los Angeles in 1883, linking the Gulf of Mexico with the Pacific Ocean.
  • The Northern Pacific Railway, also completed in 1883, linked Chicago with Seattle.
  • The Great Northern Railroad was built without federal aid by James J. Hill in 1893; it stretched from St. Paul to Seattle.
  • In 1909, the Chicago, Milwaukee & St. Paul (or Milwaukee Road) completed a privately built Pacific extension to Seattle. On completion the line was renamed the Chicago, Milwaukee, St. Paul and Pacific.
  • John D. Spreckels completed his privately funded San Diego and Arizona Railway in 1919, thereby creating a direct link (via connection with the Southern Pacific lines) between San Diego, California and the Eastern United States. The railroad stretched 148 miles (238 km) from San Diego to Calexico, California.
  • In 1993, Amtrak’s Sunset Limited was extended to the Atlantic Ocean, making it the first transcontinental passenger train route operated by one company. Hurricane Katrina temporarily cut the route in 2005.

See also: Gould transcontinental system

George J. Gould attempted to assemble a truly transcontinental system in the 1900s. The line from San Francisco, California to Toledo, Ohio was completed in 1909, consisting of the Western Pacific Railway, Denver and Rio Grande Railroad, Missouri Pacific Railroad and Wabash Railroad. Beyond Toledo, the planned route would have used the Wheeling and Lake Erie Railway, Wabash-Pittsburgh Terminal Railway, Little Kanawha Railroad, West Virginia Central and Pittsburgh Railway, Western Maryland Railroad and Philadelphia and Western Railway, but the Panic of 1907 stopped the plans before the Little Kanawha section could be finished. The Alphabet Route was completed in 1931, providing the portion of this line east of the Mississippi River. With the merging of the railroads, only the Union Pacific Railroad and the BNSF Railway remain.

Canada


Lord Strathcona driving the last spike of Canada’s first transcontinental railroad, the Canadian Pacific Railway, in 1885

The completion of Canada’s first transcontinental railroad is an important milestone in Canadian history. Between 1881 and 1885, the Canadian Pacific Railway (CPR) completed a line between Ontario and the Pacific coast, fulfilling a condition of British Columbia’s 1871 entry into the Canadian Confederation. The City of Vancouver, incorporated in 1886, was designated the western terminus of the line. The CPR became the first transcontinental railway company in North America in 1889 after its International Railway of Maine opened, connecting CPR to the Atlantic coast.

The construction of a transcontinental railroad had the effect of establishing a Canadian claim to the remaining parts of British North America not yet constituted as provinces and territories of Canada, acting as a bulwark against potential incursions by the United States.

Subsequently, two other transcontinental lines were built in Canada: the Canadian Northern Railway (CNoR) opened another line to the Pacific in 1912, and the combined Grand Trunk Pacific Railway (GTPR)/National Transcontinental Railway (NTR) system opened in 1917 following the completion of the Quebec Bridge, although its line to the Pacific opened in 1914. The CNoR, GTPR, and NTR were nationalized to form the Canadian National Railway, which remains Canada’s “other” transcontinental railway.

Guatemala

Main article: Rail transport in Guatemala

A second Central American inter-oceanic railroad began operation in 1908 as a connection between Puerto San José and Puerto Barrios in Guatemala, but ceased passenger service to Puerto San José in 1989.

Costa Rica

Main article: Rail transport in Costa Rica

A third Central American inter-oceanic railroad began operation in 1910 as a connection between Puntarenas and Limón.

South America

Main article: Trans-Andean Railways

There is activity to revive the connection between Valparaíso and Santiago in Chile and Mendoza, Argentina, through the Transandino project. Mendoza has an active connection to Buenos Aires. The old Transandino began in 1910 and ceased passenger service in 1978 and freight 4 years later. Technically a complete transcontinental link exists from Arica, Chile, to La Paz, Bolivia, to Buenos Aires, but this trans-Andean crossing is for freight only.

Mexico - Panama

  • FERISTSA - a proposed north-south line.

Eurasia

  • The first Eurasian transcontinental railroad was the Trans-Siberian railway (with connecting lines in Europe), completed in 1905 which connects Moscow with Vladivostok on the Pacific coast. There are two connections from this line to China. It is the world’s longest rail line at 9,289km (5,772 miles) long. This line connects the European Railroad System with China, Mongolia and Korea. Since the former Soviet Countries and Mongolia use a broader gauge, a break of gauge is necessary either at the Eastern frontiers of Poland, Slovakia, Hungary and Romania or the Chinese border. In spite of this there are through services of passenger trains between Moscow and Beijing or through coaches from Berlin to Novosibirsk. Almost every major town along the Trans-Siberian railway has its own return service to Moscow.
  • A second rail line connects Istanbul in Turkey with China via Iran, Turkmenistan, Uzbekistan and Kazakhstan. This route imposes a break of gauge at the Iranian border with Turkmenistan and at the Chinese Border. En route there is also a train ferry in Eastern Turkey across Lake Van. The European and Asian parts of Istanbul are currently linked by a train ferry, but an undersea tunnel is under construction. There is no through service of passenger trains on the entire line. A uniform gauge connection was proposed in 2006, commencing with new construction in Kazakhstan.

Other

  • The Trans-Asian Railway is a project to link Singapore to Istanbul and is to a large degree complete with missing pieces primarily between Iran and Pakistan (under construction in 2005), and in Myanmar, aside from political issues. The project has also linking corridors to China, the central Asian states, and Russia. This transcontinental line unfortunately uses a number of different gauges, 1435 mm, 1676 mm and 1000 mm.
  • The TransKazakhstanTrunk Railways project by Kazakhstan Temir Zholy will connect China and Europe at a gauge of 1435 mm. Construction is set to start in 2006. Initially the line will go to western Kazakhstan, south through Turkmenistan to Iran, then to Turkey and Europe. A shorter to-be-constructed 1435 mm link from Kazakhstan is considered going through Russia and either Belarus or Ukraine.
  • The Baghdad Railway connects Istanbul with Baghdad and finally Basra, a sea port at the Persian Gulf. When its construction started in the 1880s it was in those times a Transcontinental Railroad.
  • The proposed trans-Himalayan railway from Pakistan to China via the Khunjerab Pass could count as a transcontinental railroad due to the size of the mountains in the way.

Australia

East-West

  • The first Trans-Australian Railway was completed in 1917, between Port Augusta and Kalgoorlie, and crosses the Nullarbor Plain. This line completed the link between the mainland state capitals of Brisbane then Sydney via Melbourne and Adelaide to the western state capital of Perth. This route suffered from a number of breaks-of-gauge, using 1435 mm twice, 1600 mm once, and 1067 mm thrice, with five breaks-of-gauge in all.

The Trans-Australian Railway was the first route operated by the Federal Government.

In the 1930s, 1960s, and 1990s steps were taken to rationalise the gauge chaos and connect the mainland capital cities mentioned above with a streamlined 1435 mm uniform gauge system. Since 1970, when the direct line across the country was all completed as standard gauge, the passenger train on the Sydney to Perth line has been called the Indian Pacific.

North-South

  • The first north-south trans-Australia railway opened in January 2004 and links Darwin to Adelaide through the Ghan. This line uses the 1435 mm gauge, though it started out as 1067mm gauge.
  • In 2006, proposals for new lines in Queensland that would carry both intrastate coal traffic and interstate freight traffic would see standard gauge penetrate the state in considerable stretches for the first time. (ARHS Digest September 2006). The standard gauge Inland Railway would ultimately extend from Melbourne to Cairns.
  • Starting in 1867, Queensland built several railways going inland from several ports in a westerly direction. From the 1920s, steps were taken to connect these lines by the North-South North Coast line.

Africa

East-West

  • There are several ways to cross Africa transcontinentally by connecting west-east railroads. One is the Benguela railway that was completed in 1929. It starts in Lobito, Angola and connects through Katanga to the Zambia railways system. From Zambia several ports are accessible on the Indian ocean: Dar es Salaam in Tanzania through the TAZARA, and, through Zimbabwe, Beira and Maputo in Mozambique. The Angolan Civil War has made the Benguela line largely inoperative, but efforts are being taken to restore it. Another west-east corridor leads from the Atlantic habours in Namibia, either Walvis Bay or Luderitz to the South African rail system that, in turn, links to ports on the Indian Ocean ( i.e. Durban, Maputo).

North-South

  • A North-South transcontinental railroad had been proposed by Cecil Rhodes: the Cape-Cairo railway. This system was seen as the backbone for the African possessions of the British Empire, and was not completed. During its development, a competing French colonial project for a Trany line from Algiers or Dakar to Abidjan was abandoned after the Fashoda incident.
  • An extension of Namibian Railways is being built in 2006 with the possible connection to Angolan Railways.
  • Libya has proposed a Trans-Saharan Railway connecting to say Nigeria.

African Union of Railways

  • The African Union of Railways has ambitious plans to connect the various railways of Africa.

References

  1. ^ Executive Order of Abraham Lincoln, President of the United States, Fixing the Point of Commencement of the Pacific Railroad at Council Bluffs, Iowa. dated March 7, 1864. 38th Congress, 1st Session SENATE Ex. Doc. No. 27
  2. ^ The Official “Date of Completion” of the Transcontinental Railroad under the Provisions of the Pacific Railroad Act of 1862, et seq., as Established by the Supreme Court of the United States to be November 6, 1869. (99 U.S. 402) 1879
  3. ^ Omaha’s First Century Installment V. — The Proud Era: 1870-1885
  4. ^ UPRR Museum, Council Bluffs, IA
  5. ^ “Canadian Pacific Railway”. Retrieved on 2008-01-18.
  6. ^ “Canadian National”. Retrieved on 2008-01-18.

External links

  • The Old Transandino
  • Trans-Asian Railway Project

Retrieved from “http://en.wikipedia.org/wiki/Transcontinental_railroad
Categories: Rail transportHidden categories: All articles with unsourced statements | Articles with unsourced statements since August 2008 | Articles with unsourced statements since July 2008

Fifth wheel coupling

Friday, October 31st, 2008


already coupled

“Fifth wheel” redirects here. For other uses, see Fifth wheel (disambiguation).

The fifth wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some recreational vehicles RVs are in a fifth wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle. The coupling consists of a coupling pin (or king pin) on the front of the semi-trailer and a horseshoe-shaped coupling device called a fifth wheel on the rear of the towing vehicle.

The term fifth wheel comes from a similar coupling used on four-wheel horse-drawn carriages and wagons. The device allowed the front axle assembly to pivot in the horizontal plane, to improve turning.


Fifth Wheel Caravan and Double Cab Pick Up Truck

It was invented in the UK by Clive Henderson


The fifth wheel on a semi truck

See also

  • Tow hitch
  • Semi-trailer truck construction
  • Kingpin (mechanics)
  • Semi-trailer fifth wheel coupling

Links

  • Fontaine International
  • Fifth Wheel Company
  • Jost Couplings
  • Holland Hitch company history

Retrieved from “http://en.wikipedia.org/wiki/Fifth_wheel_coupling
Categories: VehiclesHidden categories: All articles with unsourced statements | Articles with unsourced statements since May 2008

Rockoon

Friday, October 31st, 2008

A rockoon (derived from the terms rocket and balloon) was an extension to the rocket, which allowed the rocket to achieve further distance. The rockoon was a solid fuel rocket that, rather than being immediately lit while on the ground, was first carried into the upper atmosphere by a gas-filled balloon, and then separated from the balloon when it had reached its maximum height and automatically ignited. This would allow the rocket to achieve a higher altitude, since the rocket did not have to move through the lower thicker air layers.

The original concept of “Rockoons” was developed by Cmdr. Lee Lewis, Cmdr. G. Halvorson, S. F. Singer, and James A. Van Allen during the Aerobee rocket firing cruise of the U.S.S. Norton Sound on March 1, 1949.

A disadvantage of a rockoon is that balloons cannot be steered and consequently neither the direction the rocket moves in nor the region where it will fall is easily adjustable. Therefore, a large area for the fall of the rocket is required for safety reasons.

As TIME reported in 1959, “Van Allen’s ‘Rockoons’ could not be fired in Iowa for fear that the spent rockets would strike an Iowan or his house.” So Van Allen convinced the U.S. Coast Guard to let him fire his rockoons from the icebreaker Eastwind that was bound for Greenland. “The first balloon rose properly to 70,000 ft., but the rocket hanging under it did not fire. The second Rockoon behaved in the same maddening way. On the theory that extreme cold at high altitude might have stopped the clockwork supposed to ignite the rockets, Van Allen heated cans of orange juice, snuggled them into the third Rockoon’s gondola, and wrapped the whole business in insulation. The rocket fired.” It Sounds like ‘Raccoon’.

See also

  • Loki (rocket), last flight in 1957
  • JP Aerospace
  • CU Spaceflight
  • Da Vinci Project

External links

  • Details of Rockoon launches made in 1956 from the USS COLONIAL in the Pacific Ocean Stratocat website
  • Details of Rockoon launches made between 1952 and 1954 in the Arctic by the USCGC EASTWIND Stratocat website
  • High Altitude Research Corporation

References

  • Astronautix


 This rocketry article is a stub. You can help Wikipedia by expanding it.

Retrieved from “http://en.wikipedia.org/wiki/Rockoon
Categories: 1953 in space exploration | Spacecraft propulsion | Spaceflight | Rocket stubs

Porter (railroad)

Friday, October 31st, 2008

A porter is a railroad employee assigned to assist passengers aboard a passenger train or to handle their baggage; it may be used particularly to refer to employees assigned to assisting passengers in the sleeping cars.

In Australia, a Railway Porter had various roles. A Baggage Porter assisted with luggage; an Operating Porter assisted with Safeworking duties; a Station Porter assisted with general station duties and a Lad Porter was a junior Station Porter.

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Railroad porters in the United States

Until desegregation had its effect in the United States in the 1960s, the occupation of porter was almost the exclusive province of African American men. It was the Civil War policy of George Pullman, head of the Pullman Company, who wished to tap into a huge potential work force that was also non-unionized. Until the latter 20th century the occupation included providing a variety of on-board personal services, such as shoe shining. (Tye, 2004) This eventually changed with the organization of the Brotherhood of Sleeping Car Porters under the leadership of A. Phillip Randolph.

See also

  • Rail transport
  • Rail terminology
  • Pullman Porters
  • Society for the Prevention of Calling Sleeping Car Porters “George”

References

  • Rising from the Rails: Pullman Porters and the Making of the Black Middle Class, By Larry Tye, Published 2004, Macmillan, 314 pages ISBN:0805070753

External links

  • A. Philip Randolph Pullman Porter Museum

Retrieved from “http://en.wikipedia.org/wiki/Porter_(railroad)
Categories: Rail transport | Passenger rail transport | Rail transport in the United States

Roll-on/roll-off

Friday, October 31st, 2008

Main article: Merchant ship


Loading a ro-ro passenger car ferry

Roll-on/roll-off (RORO or ro-ro) ships are ferries designed to carry wheeled cargo such as automobiles, trucks, semi-trailer trucks, trailers or railroad cars. This is in contrast to lo-lo (lift on-lift off) vessels which use a crane to load and unload cargo.

RORO vessels have built-in ramps which allow the cargo to be efficiently “rolled on” and “rolled off” the vessel when in port. While smaller ferries that operate across rivers and other short distances still often have built-in ramps, the term RORO is generally reserved for larger ocean-going vessels. The ramps and doors may be stern-only, or bow and stern for quick loading.

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Types


Spirit of Vancouver Island, a Canadian RORO ferry


Another Canadian RoRo Ferry, the MS Chi-Cheemaun operating on Lake Huron


The Pride of Burgundy, a P&O Ferries passenger car ferry on the Dover-Calais English Channel route which can carry 600 cars.

Various types of RORO vessels include ferries, cruiseferries, cargo ships, and barges. A true RORO’s ramps can serve all of the vessel’s decks; otherwise it is a hybrid type. New automobiles that are transported by ship around the world are often moved on a large type of RORO called a Pure Car Carrier (PCC) or Pure Car Truck Carrier (PCTC).

Unlike elsewhere in the shipping industry where cargo is normally measured by the metric tonne, RORO cargo will typically be measured in the more convenient unit of lanes in meters (LIMs). This is calculated by multiplying cargo length in meters by the number of decks and by its width in lanes (lane width differs from vessel to vessel and there are a number of industry standards). Aboard PCCs cargo capacity is often measured in RT or RT43 units which is based on a 1966 Toyota or by car equivalent units (CEU).

The largest RORO passenger ferry is MS Color Magic, a 75,100 GT cruiseferry that entered service in September 2007 for Color Line. Built in Finland by Aker Finnyards, she is 223.70 m (733 ft 11 in) long, 35 m (114 ft 10 in) wide and can carry 550 cars as well as 1270 lane meters of cargo.

The RORO with the greatest car-carrying capacity is the Ulysses (named after a novel by James Joyce) which is owned by Irish Ferries. She entered service on 25 March 2001 and operates between Dublin and Holyhead. The 50,938 GT ship is 209.02 m (685 ft 9 in) long and 31.84 m (104 ft 6 in) wide, and can carry 1342 cars and 4101 lane meters of cargo.

History

At first, wheeled vehicles carried as cargo on oceangoing ships were treated like any other cargo. Automobiles had their gas tanks emptied and their batteries disconnected before being hoisted into the ship’s hold, where they were chocked and secured. This process was tedious and difficult, vehicles were subject to damage, and could not be used for routine travel.

The first RoRo ships were ferries carrying steam trains across rivers. One of the earliest was Firth of Forth ferry in Scotland which started in 1851 and operated for nearly forty years, until the completion of the Forth Bridge.

Ferries hauling rail cars were used after the US Civil war in New York harbor, the Great Lakes and the St. Clair River in Detroit. By the latter quarter of the century, car ferries were a common sight in San Francisco and Puget Sound. A car ferry worked the Columbia River for many years at Kalama for the Northern Pacific Railway. By the turn of the century, car ferries became important adjuncts to railway systems particularly those which were discontinuous due to geography. Montreal, Newfoundland and Labrador, Prince Edward Island, and the Islands of Japan were all cut by water, and thus needed ferries. Russians used car ferries on Lake Baikal to move rail cars while the line was finished.


Carrier Princess, Seaspan Coastal Intermodal ferry in Active Pass, March, 2007

The first automobile roll-on roll-off ship was the Suhulet and her 3 sisters Sahilbend, Saadabad and Sultanahmet. They were commissioned in the Ottoman Empire during 1871 in Istanbul to enable Trans-Bosphorus automobile and horse-car crossings.

During WWII, landing craft were also among the first ships enabling road vehicles to roll directly on and off. Post war, the idea was adopted for merchant ships and short ferry crossings. The first RoRo service crossing the English channel began from Dover in 1953.

In 1957 the US military issued a contract to the Sun Shipbuilding and Dry Dock Company in Chester, PA for the construction of a new type of motorized vehicle carrier. The ship, Comet, had a stern ramp as well as interior ramps which allowed cars to drive directly from the dock, onto the ship, and into place. Loading and unloading was speeded dramatically. Comet also had an adjustable chocking system for locking cars onto the decks, and a ventilation system to remove any exhaust gases that accumulated during vehicle loading.

The Atlantic Conveyor was requisitioned during the Falklands War to ferry Helicopters and STOVL Harrier fighters which flew to their assigned fleet carriers before it was sunk after being hit by two Argentine Exocet missiles. In September 1983 Soviet Yakovlev Yak-38 pilots operated from the civilian ‘Ro-Ro’ vessel Agostinio Neto, they conducted further tests from another ‘Ro-Ro’, Nikolai Cherkasov. ‘Ro-Ro’ and other types of container ships have been suggested as emergency STOVL escort carriers with pre-fab ski jump, air control tower, and defensive systems.

Car carriers


Skaugran


The Cetus Leader, a 6500 unit PCTC


A PCC ship’s starboard side showing side ramp

Since 1970 the market for exporting and importing cars has increased dramatically and the number and type of RO/ROs has increased also. In 1973, Japan’s K Line built the European Highway, the first Pure Car Carrier (PCC), which carried 4,200 automobiles. Today’s pure car carriers and their close cousins, the Pure Car/Truck Carrier (PCTC) are distinctive ships with a box-like superstructure running the entire length and breadth of the hull, fully enclosing and protecting the cargo. They typically have a stern ramp and a side ramp for dual loading of many thousands of vehicles, as well as extensive automatic fire control systems.

The PCTC has liftable decks to increase vertical clearance as well as heavier decks for “high and heavy” cargo. A 6500 unit car ship with 12 decks can have three decks which can take cargo up to 150 tons with liftable “panels” to increase clearance from 1.7 meters to 6.7 meters on some decks. Lifting decks to accommodate higher cargo reduces the total capacity.

With the building of the Wallenius Wilhelmsen Logistics’s 8000 CEU car carrier Stockholm Faust in June 2007 the car carriers entered a new era called the LCTC (Large Car & Truck Carrier).

Risks

The seagoing RORO car ferry, with large external doors close to the waterline and open vehicle decks with few internal bulkheads, has a reputation for being a high risk design (to the point where the acronym is sometimes derisively expanded “Roll On/Roll Over”.

Benefits

While the characteristics of seagoing RORO car ferries have inherent risks, there are benefits to its seaworthiness. For example the car carrier Cougar Ace listed 80 degrees to its port side in 2006 but did not sink, since its high enclosed sides prevented water from entering.

Variations of RORO

ROPAX

The acronym ROPAX (roll on/roll off passenger) describes a RORO vessel built for freight vehicle transport but also with passenger accommodation. Technically this encompasses all ferries with both a roll on/roll off car deck and passenger-carrying capacities, but in practice ships with facilities for more than 500 passengers are often referred to as cruiseferries.

ConRO

The ConRo vessel is a hybrid between a RORO and a container ship. This type of vessel has a below-decks area used for vehicle storage while stacking containerized freight on the top decks. Examples of ConRo ships such as those in the fleet of Atlantic Container Line can carry a combination of 1,900 twenty-foot-equivalent-units (TEUs) of containers, up to 1,000 TEUs of heavy equipment, as well as project and oversized cargo on three decks and up to 2,000 automobiles on 5 decks. Separate internal ramp systems within the vessel segregate automobiles from other vehicles, mafi trailers and breakbulk cargo.

RoLo

A RoLo (roll-on lift-off) vessel is another hybrid vessel type with ramps serving vehicle decks but with other cargo decks accessible only by crane.

See also


Nautical portal

  • List of RORO vessel accidents
  • Konkan Railway Corporation
  • Train ferry
  • Car float
  • Ferry

References

  1. ^ Unknown author. “Pride of Burgundy“. Retrieved on 2007-12-01.
  2. ^ Asklander, Micke. “M/S Color Magic (2007)” (in in Swedish). Fakta om Fartyg. Retrieved on 2008-03-05.
  3. ^ Asklander, Micke. “M/S Ulysses (2001)” (in in Swedish). Fakta om Fartyg. Retrieved on 2008-03-05.
  4. ^ “Stockholm Faust“. Wallenius Lines.
  5. ^ Bill Bryson (1995). Notes from a Small Island. London: Doubleday. ISBN 978-0385405348
  6. ^ Emmanuel Makarios, The Wahine Disaster: a tragedy remembered, page 50 (2003, Grantham House, Wellington) ISBN 1869340795

External links

  • IMO and ro-ro safety
  • Atlantic Ro-Ro Carriers, company employing ro-ro vessels
  • Atlantic Container Line, vessel specifications
  • Royal Haskoning, RoRo and Criuse Terminal
  • Cut-away of PCC


Wikimedia Commons has media related to:
RoRo ships


Wikimedia Commons has media related to:
Car carriers

v • d • e

Modern merchant vessels

Dry cargo:

Bulk carrier · Container ship · Hopper barge · Reefer ship · RORO ship · Heavy lift ship

Tankers:

Oil tanker · Chemical tanker · LNG carrier · Coaster · FPSO unit

Passenger:

Cruise ship · Cruiseferry · Ferry · Ocean liner

Support:

Dive support · Fireboat · Supply ship · Tender · Tugboat

Other:

Cable layer · Crane vessel · Drillship · Dredger · Fishing vessel · Icebreaker · Merchant submarine · Research vessel · Semi-submersible

Sizes, smallest to largest: Handysize · Handymax · Panamax · Aframax · Suezmax · Capesize · VLCC · ULCC

Retrieved from “http://en.wikipedia.org/wiki/Roll-on/roll-off
Categories: Ship types | Commercial item transport and distribution

Reversible lane

Friday, October 31st, 2008


The Lions Gate Bridge from the south end in Stanley Park, Vancouver.

A reversible lane (called a counterflow lane or contraflow lane in transport engineering nomenclature) is a lane in which traffic may travel in either direction, depending on certain conditions. Typically, it is meant to improve traffic flow during rush hours, by having overhead traffic lights and lighted street signs notify drivers which lanes are open or closed to driving or turning. Some people refer to non-physically-separated reversible lanes as “suicide lanes” due to many fatal accidents occurring when drivers failed to pay attention to the lights and lane markings and got into head-on collisions.

Reversible lanes are also commonly found in tunnels and on bridges, and on the surrounding roadways — even where the lanes aren’t regularly reversed to handle normal changes in traffic flow. The presence of lane controls allows authorities to close or reverse lanes when unusual circumstances (such as construction or a traffic accident) require use of fewer or more lanes to maintain orderly flow of traffic.

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Signals and markings

In the United States, reversible lane markings are typically a dashed or broken double yellow line on both sides. Most often done on three-lane roads, the reversible lane is typically used for traffic in one direction at morning rush hour, the opposite direction in the afternoon or evening, and as a turning lane at most other times. There is also a transition period (typically 30–60 minutes) between reversals prohibiting traffic of any kind in the reversing lane, in order to prevent collisions. Sometimes, lane control signals are placed over the roadway at regular intervals (within sight of each other) indicating which lanes are allocated to which travel direction; a red X indicates the lane is closed or reserved for the opposite direction; a green arrow indicates a permitted travel lane. The center lane is marked with either one of those (depending on time of day), and often a flashing yellow X at other times, becoming solid yellow before turning red. Other setups had double-turn-lane signs backlit with white fluorescent lighting instead of the flashing yellow X.

Other streets with reversible lanes (including several in Washington, D.C.) simply have signs posted indicating what lanes are open to which direction when.

Separation of flows

Some more recent implementations of reversible lanes use a movable barrier to establish a physical separation between allowed and disallowed lanes of travel. In some systems, a concrete barrier is moved during low-traffic periods to switch a central lane from one side of the road to another; some examples are the Coronado Bridge in San Diego, California, the seven lane Tappan Zee Bridge on the Hudson River in New York and the 8 lane Auckland Harbour Bridge across the Waitemata Harbour in Auckland, New Zealand. Other systems use retractable cones or bollards which are built into the road, or retractable fences which can divert traffic from a reversible ramp. The two center lanes of the six-lane Golden Gate Bridge are reversible; they are southbound during morning rush hour and northbound at evening rush hour, and are demarcated by vertical yellow markers placed manually in sockets in the roadway.

Many urban freeways have entirely separate carriageways (and connecting ramps) to hold reversible lanes (the reversible lanes in such a configuration are often referred to as “express lanes”). Generally, traffic flows in one direction or another in such a configuration (or not at all); the carriageways are not “split” into two-lane roadways during non-rush periods. Typically, this sort of express lane will have fewer interchanges than the primary lanes, and many such roadways only provide onramps for inbound traffic, and offramps for outbound traffic.

Passing lanes


Typical striping on an old-style suicide lane setup in the United States.


Markings for reversible lanes in Sweden.

Historically, a “suicide lane” has also referred to a lane in the center of a highway meant for passing in both directions. Neither direction had the right-of-way, and both directions were permitted to use the lane for passing. Head-on accidents were common. Very few of these setups are left (at least in the United States), though sometimes a similar layout exists, where three lanes are striped with two in one direction and one in the other, but traffic in the direction with one lane is allowed to cross the centerline to pass. However, this is not as dangerous, because one direction has clear right-of-way. They still however have 2-lane roads with 4-lane right-of-way where only the oncoming traffic in the opposite lane has to be checked as opposed to risking in a center lane.

Turn lanes


This is a typical 5-lane arterial equipped with a center-turn lane. These are often found in cities, towns and developed areas near cities. In the United States, the broken line is located on the inside of the lane. In Canada (except British Columbia), the broken line is located on the outside.

Another type of center two-way lane is a center left-turn lane (for countries which drive on the right), center turn lane or median turn lane, a single lane in the center of the road into which traffic from both directions pulls to make a left turn. It is also used by drivers turning left onto the main road. While this is sometimes also called a “suicide lane”, it is actually far safer, as car accidents occur at far lower speeds.

These roads are very common in suburban areas, and rather less common in rural areas. Many were divided highways before the median was demolished or otherwise filled with the turn lane.

This center lane can be used by emergency vehicles like police cars, ambulance, and fire trucks to avoid traffic travelling in either direction. Drivers are never allowed to use the center lane of such a highway for passing slow-moving vehicles.

Examples

No (or minimal) lane controls

  • Connecticut Avenue in Washington, D.C.
  • Chain Bridge in Washington, D.C.
  • Bailey Bridge, in Coquitlam, BC.

Lane controls and no (or minimal) physical separation

Trans-national

  • The Peace Bridge between the U.S. and Canada, connecting Fort Erie, Ontario to Buffalo, New York. 3 lanes total, all marked reversible, 1 reversed in the direction of rush hour flow with the possibility of all lanes flowing in the same direction based on traffic needs.
  • The Lewiston-Queenston Bridge connecting Niagara-on-the-Lake, Ontario to Lewiston, New York. 5 lanes total, all marked as reversible, 1 to 4 lanes marked daily in the same direction depending on traffic needs. In addition to the directional signals, special signals are also fitted to specify what type of vehicle may use the lane.

Australia

  • The Sydney Harbour Bridge in Sydney, New South Wales (8 lanes total, 3 (formerly 4) potentially reversible, 3 reversed daily. AM peak 6 South 2 North. PM peak 3 South 5 North. Other times, 4 South 4 North),
  • The Spit Bridge, Sydney, New South Wales (4 lanes total. AM peak 3 South, 1 North. PM peak 3 North, 1 South. All other times 2 North, 2 South).
  • The Alfords Point Bridge in the south-western suburbs of Sydney, New South Wales. 3 lanes total, with the centre lane reversible using manual placement of plastic bollards. Originally this bridge was built with two lanes, and was to be part of twin spans, but only the foundations and excavations for approach works were built for the Eastern span, and the bridge was opened with one lane used in each direction. New approach works commenced in January 2007 for the second span, at a cost of $45 million AUD, eliminating the need for a reversible lane. However, a 300-meter reversible centre lane will still remain on Alfords Point Road over Henry Lawson Drive, approximately 500 meters north of this proposed bridge.
  • Flagstaff Road in the southern suburbs of Adelaide, South Australia. 3 lanes total, with the centre lane reversible.
  • Johnston Street, Melbourne, Victoria. 5 lanes total, with the centre lane reversible.
  • Queens Road, Melbourne, Victoria. 5 lanes total, with the centre lane reversible.
  • Coronation Drive, Brisbane, Queensland.
  • Tasman Bridge, Hobart, Tasmania. 5 lanes total, with center lane reversible

Canada

  • The Lions Gate Bridge in Vancouver (3 lanes total, 1 reversible)
  • The Pitt River Bridge in Pitt Meadows
  • The Angus L. MacDonald Bridge and the Herring Cove Road in Halifax, Nova Scotia (3 lanes total, 1 reversible)
  • Jarvis St. in downtown Toronto (5 lanes total, centre lane reversed daily for AM/PM rush hours)
  • Okanagan Lake Bridge in Kelowna, British Columbia (3 lanes total, 1 reversible)
  • The Champlain Bridge in Ottawa, Ontario (3 lanes total; 1 reversible).
  • The George Massey Tunnel in Delta, BC and Richmond, BC (4 lanes total, 2 reversible).
  • Connors Road amongst other roads that enter into the river valley in Edmonton, Alberta. (4 lanes, 3 reversible).
  • Centre Street from 16th Avenue North to 6th Avenue South in Calgary, Alberta. (4 lanes total, 2 reversible; standard configuration is 2 out, 2 in; morning rush is 1 out, 3 in; and evening rush is 3 out, 1 in.)
  • 10th Street North / 9th Street South from 5th Avenue North to 4th Avenue South in Calgary, Alberta. (4 lanes total, 2 reversible; standard configuration is 2 out, 2 in; morning rush is 1 out, 3 in; and evening rush is 3 out, 1 in.)
  • Park Avenue in Montreal, Quebec, five lanes total, centremost lane is reversible, sidemost lanes are reserved for public transport during rush hour. Morning rush is 2 in, one out (not including bus lanes), evening rush is reversed.
  • Champlain Bridge (Montreal), rush hour bus lanes
  • Jacques-Cartier Bridge (Montreal), five lanes total, two for both directions, one rush hour central reversible lane

Croatia

  • State Route 102 near Kraljevica leading southbound to the Krk Bridge used to have a three-lane passing lane combination, blind curves, and a steep grade. It was later changed to a passing lane combination that makes the northbound traffic dominant.

United Kingdom

  • The A61 Queens Road in Sheffield, England, although it is a very short section (4 lanes total, 1 reversible: allowing for either 3 out, 1 in, or 2 out, 2 in).
  • The A470 North Road in Cardiff, Wales, A section of around 1 mile long between the Maindy Road Junction and College Avenue where the road drops from a dual two-lane to a three-lane section. One lane is always dedicated to Northbound (out of town) traffic, and one lane to Southbound (city centre bound traffic) with the centre lane reversing depending on the time of day - i.e. in the morning 2 lanes into the city, 1 lane out, in the evening 2 lanes out of the city, 1 lane in.
  • The A15 in Lincoln (Canwick Road) has a short three-lane section of tidal flow.

United States

Arizona

  • In Phoenix on 7th Avenue between McDowell Road and Northern Avenue, and 7th Street between McDowell Road and Cave Creek Road/Dunlap Avenue. On both roads, the lane configuration is 2 southbound and 3 northbound, with the center lane open for southbound traffic between 6-9am and open to northbound traffic between 3-6pm. No left turns are permitted during these hours for either direction.

California

  • The Golden Gate Bridge (6 lanes total, 2 reversible, vertical median markers provide minimal physical separation) connecting San Francisco, California with suburban Marin County
  • Doyle Drive (U.S. Route 101) in San Francisco, California
  • Lafayette Street in Santa Clara, California - the center lane is used for northbound traffic on weekday mornings, southbound traffic for weekday afternoons, and as a center turning lane at other times.

Georgia

  • Vineville Avenue in Macon, Georgia: the center lane of three is reversed using overhead lane-use control signals.

Kentucky

  • The Clay Wade Bailey Bridge in Covington, Kentucky (3 lanes total, 1 reversible)
  • Nicholasville Road (U.S. Highway 27) in Lexington, Kentucky, has reversible lanes (lane signals, no physical separation) starting at its intersection with Rose Street at the University of Kentucky campus and ending at New Circle Road, the city’s inner beltway. During morning rush hour, southbound traffic (away from the UK campus and downtown) is restricted to one lane between campus and Southland Drive, and two lanes from Southland to New Circle. Northbound traffic faces the same restrictions in the evening rush hour. During off-peak hours, an equal number of lanes are dedicated to traffic in each direction.
  • Baxter Avenue and Bardstown Road (U.S. Highway 31E) in Louisville, Kentucky have reversible lanes (lane signals without any physical separation) for 2½ miles starting at their intersection with Lexington Road and ending at Douglass Boulevard. Southbound traffic leaving downtown Louisville is restricted to one lane during the morning rush hour, with northbound traffic having the same restriction during the evening rush hour. Electronic signs over the roadway alert motorists to the traffic flow dedication of each lane.

Indiana

  • In Indianapolis, Fall Creek Parkway North Drive between Central Avenue and Evanston Avenue has 5 lanes (7 in some sections) with 1 lane marked as reversible. Configuration is typically designed to allow for 3 in 2 out during morning rush hours, and 2 in/3 out during afternoon rush hours. Due to Fall Creek Parkway’s proximity to the Indiana State Fairgrounds, lane configurations change periodically to facilitate traffic flow during events at the fairgrounds.

Maryland

  • The Chesapeake Bay Bridge near Annapolis, Maryland (5 lanes total, all marked reversible, 1 usually reversed for normal peak traffic). However, due to its dual spans, when there are 2 eastbound lanes and 3 westbound the opposing sides are completely divided, this is the usual configuration.
  • The Hanover Street Bridge in Baltimore, Maryland has 5 lanes total marked reversible, with 1 usually reversed for normal peak traffic).
  • Georgia Avenue in Silver Spring, Maryland has 7 lanes. During most hours, the center lane is marked with a yellow lit X as a left turn lane for both directions. During morning and evening rush hours, the lane is marked with a down facing green arrow – southbound in the morning, northbound in the evening – or a red X – northbound in the morning, southbound in the evening – and left turns are prohibited.

New Jersey

  • The access road to Artificial Island in Lower Alloways Creek, New Jersey (home of both Hope Creek Nuclear Generating Station and Salem Nuclear), Alloway Creek Neck Road, has three lanes total. The lanes can be switched direction with overhead signage for either the shift change, auto accidents, or made completely one-way in either direction, depending on the circumstances.

New York

  • Delancey Street in New York, NY has two lanes on the eastbound side adjacent to the median used for westbound traffic in the morning rush hour between the Williamsburg Bridge and Allen Street. All traffic in these lanes must continue to and then turn left onto Allen, during these times left turns are prohibited from the regular westbound roadway onto Allen Street
  • Manhattan Bridge (New York, NY) lower level has three lanes, which can have all lanes used in one direction or reversible with two lanes one way and the other for the opposite direction.
  • The upper level of the Queensboro Bridge in New York, NY has 4 lanes and can have all flowing outbound (PM peak), or two lanes each direction in normal configuration.

North Carolina

  • Tyvola Road in Charlotte, North Carolina
  • U.S. Route 29 in Charlotte, North Carolina
  • High Point Road in Greensboro, North Carolina
  • Asylum Avenue in Hartford, Connecticut
  • Edwards Mill Road in Raleigh, North Carolina

Ohio

  • At least one road in Sandusky, Ohio has reversible lanes, for the purpose of allowing quick departure of Cedar Point guests.

Pennsylvania

  • The Liberty Bridge near the Southern Terminus of I-579 in Pittsburgh, Pennsylvania has 4 lanes, all of which are potentially reversible, and 2 of which are reversed based on rush-hour times.

Texas

  • In Dallas, Texas, two of the major streets leading into downtown (Ross Avenue and Live Oak Street) have five lanes with three different lane configurations. During morning rush hour, three lanes go inbound to downtown, with one lane going outbound and a turn-only lane in between. During evening rush hour, three lanes go outbound, still with the center turn-only lane. All other times, the streets are configured for two inbound lanes and two outbound lanes with a turn-only lane in the center.
  • West Alabama Street and North Main Street in Houston, Texas – both are three-lane streets, which operate in a 2 in 1 out configuration during the morning rush, a 1 in 2 out configuration during the evening rush, and a 1 each way + two-way left turn lane at other times.

Lane controls and physical separation by empty lane

  • The A38(M) motorway (otherwise known as the Aston Expressway) in Birmingham, England. The road heads out of the city centre towards Spaghetti Junction on the M6. It is a 7 lane section of motorway with no central reservation, while one lane remains closed to traffic. Overhead lane control signals allow for 4 lanes in, 2 out in the morning rush hour, vice versa in the evening, and 3 lanes either way at other times.
  • The U.S. Route 78 portion in Snellville, GA, United States, has 6 lanes in total. This occurs from the limited access portion through Stone Mountain Park to G.A. State Route 124 (Scenic Highway) for several miles. The middle two lanes are reversible (usually occurring during rush hour) with a varying lane always reserved a center turn lane while the 3 lanes are used for one side and 2 for the other. Example of an intersection on U.S. 78
  • The Caldecott Tunnel between Oakland, California and Contra Costa County, California has three separate bores, with the middle bore switching direction twice daily for rush hour traffic.

Lane controls and physical separation by movable barrier

  • Benjamin Franklin Bridge, Walt Whitman Bridge, Commodore Barry Bridge, and Betsy Ross Bridge in Philadelphia, PA
  • Tappan Zee Bridge in New York
  • Theodore Roosevelt Bridge in Washington, D.C.
  • Auckland Harbour Bridge in Auckland, New Zealand
  • The Coronado Bridge in San Diego, California

Third (reversible) carriageways on freeways

See also: Express lanes

  • Bundesautobahn 7, New Elbe Tunnel, Hamburg, Germany (actually two reversible carriageways, plus two fixed)
  • Warringah Expressway in Sydney, Australia
  • Interstate 5 in Seattle, Washington, and Interstate 90 from Bellevue to Seattle, Washington
  • Interstate 15 in northern San Diego, California
  • Interstate 25 and US-36 in Denver, Colorado
  • Interstate 394 through Minneapolis, Minnesota and its western suburbs
  • Interstate 90/Interstate 94 (Kennedy Expressway portion) in Chicago, Illinois
  • Interstate 70 through St. Louis, Missouri
  • Lee Roy Selmon Crosstown Expressway from Brandon to Tampa, Florida
  • Interstate 64 in Norfolk, Virginia (center carriageway reserved for HOV traffic during rush hour)
  • Interstate 395 and Interstate 95 through Washington, D.C. and its Virginia suburbs (center carriageway reserved for HOV traffic during rush hour)
  • Lincoln Tunnel between Weehawken, New Jersey and New York, New York has three tubes with two lanes each. The center tube carries two lanes in peak direction weekdays (with a reserved inbound bus lane during the AM rush period) and a single lane each direction off-peak (nights, weekends, holidays).
  • Interstate 93 through Boston, Massachusetts

Entire roadway routinely reversed


South and Marion Roads in Adelaide, provide access to the Southern Expressway at its northern end. Here, southbound access to the expressway from South Road is restricted.

  • The Anchieta/Imigrantes highway system in Brazil contains the world’s longest fully reversible road (The Imigrantes variant at a length of 58.5 km). It comprises a total of 10 lanes distributed over 4 separate roadways (3+3+2+2), each of which can be reversed. Traffic flow is unidirectional on up to three roadways at a time, in different combinations, depending on demand. Since this highway system is the only quick route from São Paulo to the beach, the majority of the traffic on Fridays and Sundays are cars on weekend trips, creating highly asymmetrical demand.
  • The Southern Expressway in Adelaide, South Australia is the world’s longest exclusively one-way reversible road, spanning 21 km though the city’s southern suburbs. It changes direction to carry peak hour traffic to the city centre in the morning and away from the city in the evening. On weekends the directions are reversed.
  • In Washington, D.C., the Rock Creek and Potomac Parkway between the Lincoln Memorial and Calvert St. is converted from two lanes in each direction to one-way southbound in the morning and one-way northbound in the evening rush hour Monday through Friday, excluding federal holidays. The P Street exit, usually unavailable northbound, is an allowed left exit in the evening. South of Virginia Avenue, two lanes are closed during rush hours to facilitate the merge to or from Virginia Avenue. There are no overhead markings, but police barricades block wrong-way entrances to the roadway.
  • In Washington, D.C., parts of 15th Street NW and 17th Street NW are one-way during certain hours. There are no overhead markings on either road.
  • Canal Road in Washington, D.C. (between Foxhall Road and Arizona Avenue)
  • Sherman Access in Hamilton, Ontario. 2 lanes total, both marked as reversible, with both lanes flowing in the same direction during rush hour each weekday.
  • The lower deck of the Centre Street Bridge in Calgary, Alberta is fully reversible. It normally allows for two way traffic, but both lanes flow in the same direction during rush hour each day.
  • Victoria Bridge, in Montreal, Quebec, normally allows for two-way traffic. But during rush hours, it only allows one-way traffic, northbound in the morning, and southbound in the afternoon.

See also

  • Barrier transfer machine
  • Contraflow lane reversal
  • Single track road

References

  1. ^ http://maps.google.com/maps?f=q&hl=en&geocode=&q=fall+creek+road+indianapolis,+in&sll=39.884714,-86.033077&sspn=0.059275,0.12394&ie=UTF8&ll=39.806459,-86.148562&spn=0.006989,0.015492&t=h&z=16

External links

  • WTOP: Where are D.C’s Reversible, Rush-Hour Lanes? (as of June 30, 2003)

Retrieved from “http://en.wikipedia.org/wiki/Reversible_lane
Categories: Road infrastructure | Streets and roads | Road transport | RoadsHidden categories: All articles with unsourced statements | Articles with unsourced statements since December 2007 | Articles with unsourced statements since July 2008

Green transport

Thursday, October 30th, 2008

Green transport is a category of sustainable transport which uses human power, animal power and renewable energy. In common usage public transport is considered a green transport option in comparison with private vehicles, as is car pooling. But some people prefer a definition that does not include public transport or vehicle movements which relies on non-renewable energy.

Green transport includes:

  • walking
  • cycling and some other types of human-powered transport
  • Green vehicles
    • solar powered vehicles
    • wind powered vehicles

Often there can be a sliding scale of green transport depending on the sustainabilty of the option. Public transport on traditional diesel buses uses less fuel per passenger than private vehicles so is more green than private vehicles, but is not as green as using a solar powered bus. It can often be useful to talk about moving a community towards the ultimate green mode transport outcomes - instead of declaring that they are there if they cross a particular sustainability threshold. Walking across sensitive environments can often cause considerable damage and so is not always the greenest option.

Green transportation is for reducing the environmental damage originated in individual’s use of cars and light trucks.

See also

  • Alternative propulsion
  • Green bridge
  • Green vehicle
  • Sustainable transport

Retrieved from “http://en.wikipedia.org/wiki/Green_transport
Categories: Landscape | Sustainable transport

Train dispatcher

Thursday, October 30th, 2008

This article is about rail industry occupation. Train Dispatcher is also a computer simulation by Softrail.

A Train Dispatcher is employed by a railroad to direct and facilitate the movement of trains over an assigned territory, which is usually part, or all, of a railroad operating division. In Canada the train dispatcher is known as the rail traffic controller (RTC).

Charles Minot, a Division Superintendent on the Erie Railroad is credited with the first effort to control the movement of a train beyond the rule book and operating timetable, when, in September 1851, he sent a telegram to a railroad employee at another location directing that all trains be held at that point until the train Minot was riding could arrive.

From that beginning, a system of train dispatching evolved. The operating rule book, later standardized for all railroads, contained the basic rules for the operation of trains, such as the meaning of the all fixed, audible and hand signals; the form, format and meaning of train orders; and the duties and obligations of each class of employee. The operating, or official, timetable established train numbers and schedules; meeting points for those trains; showed the length of passing tracks at each station as well as indicating the locations where train orders might be issued and contained a variety of other information which might be necessary or useful to train crews operating trains over the territory covered.

Train orders supplemented the timetable and the rule book. They were addressed to a particular train or trains and directed that train or trains to do whatever the train dispatcher had decided needed to be done: meet another train, wait at specified locations, run late on its published schedule, be cautious under the circumstances described or numerous other actions.

Train dispatchers are required to be intimately familiar with the physical characteristics of the railroad territory for which they are responsible, as well as the operating capabilities of the locomotive power being used. Experienced train dispatchers learned the idiosyncrasies of the locomotive engineers and train conductors and melded that knowledge into the operating decisions made. An efficient train dispatcher could utilize the rule book, timetable, train orders and personal experience to move a large number of trains over the assigned territory with minimal delay to any train, even in single-track territory.

Initially, train dispatchers issued train orders using American Morse code over telegraph wires. Later, after the telephone was invented in 1876 and became common, most railroads constructed their own telephone systems, for internal communications, which the train dispatchers used to issue train orders. The last train order known to have been issued using Morse code was copied at Whitehall, Montana, on May 6, 1982, on the Burlington Northern Railroad.

Beginning before World War II and accelerating after it, most major railroads installed centralized traffic control (CTC) systems to control train movements. Using CTC, a train dispatcher could align track switches anywhere on the territory so that trains could move into and out of sidings without having to stop and hand throw switches. The train dispatcher could also control the trackside signals governing the movement of trains. Satellite radios enabled train dispatchers to communicate directly with train and engine crews. These capabilities eliminated the need for most train orders, but still required the oversight of a train dispatcher.

See also

  • Vince Coleman (train dispatcher)
  • Railroad engineer
  • Railroad Terminology

References

  • Association of American Railroads Standard Book of Rules, 1926 edition.
  • Association of American Railroads Consolidated Code of Operating Rules, 1967 edition.
  • Robert Jones. “Milestones in Telegraphic History” (PDF).

Retrieved from “http://en.wikipedia.org/wiki/Train_dispatcher
Categories: Transportation occupations | Rail transportHidden categories: All articles with unsourced statements | Articles with unsourced statements since March 2008