Atmospheric railroad
An atmospheric railroad is a railroad in which the trains are powered by atmospheric pressure .
In all historical and operational systems, the air pressure acts on a piston that slides in a pipe with a slot at the top near the rails and is connected to the locomotive . Fixed pumps suck air in front of the piston or press it into the pipeline. The difference in pressure on the two sides of the piston exerts the force on the locomotive, which is used for locomotion.
In the early days of the railway, the atmospheric railway was used on various routes in England and France, each for a short period of time. The stationary drive machines were often expensive to operate and maintain, and in particular the sealing of the slot on the pipeline could not be solved in a technically satisfactory manner. The leather often used to seal the slot became brittle and the sebum and beeswax used as a lubricant and sealant liquefied at higher temperatures.
At the beginning, atmospheric propulsion was often used to overcome inclines, for which the steam locomotives of the time developed too little propulsion power. In individual cases a speed of up to 160 km / h was reached.
There was a revival towards the end of the 20th century: In an Indonesian theme park there is a 3.2 km long ring route and an atmospheric train has been running in the airport of the Brazilian city of Porto Alegre since August 2013.
Definition of terms
Especially in English-speaking countries, the term atmospheric railroad sometimes also includes the pneumatic railroad . With this system, the pressure difference required for propulsion does not act on a piston connected to the vehicle , but on the entire vehicle, which is traveling in a correspondingly narrow tunnel. The American Hyperloop concept initially relied on propulsion using air drawn in by the railcar.
Historical railways of the 19th century
The English engineer George Medhurst, who invented the pneumatic tube , made the first proposals for an atmospheric railway. The slot on the top of the pipe would have been sealed with the help of water, which would have required an exactly horizontal route without inclines and thus made the system uninteresting for practical applications. It was not until the British engineer Samuel Clegg and the Samuda Brothers made the idea a reality in 1838/39 by introducing a leather flap as a seal for the slot. The first tests took place in Paris in 1838 and in 1839 on an 800-meter-long test section of the West London Line, which was not yet completed at the time, in the Wormwood Scrubs near London. This system was then also applied to the four courses that were carried out. Hallette later suggested closing the pipe with inflatable sealing lips, but this was never put into practice.
Executed paths
Dublin & Kingstown Railway
In 1844 the first atmospheric runway opened for commercial operations in Ireland . The 2.7 km long route connected Kingstown with Dalkey and overcame a ramp with a 17.5 ‰ gradient. The tube for the drive was composed of three meter long cast iron tubes and had a diameter of 38 centimeters.
The route ran in a nearly three meter deep cut and had a tunnel. The clearance profile was only eight centimeters larger than the vehicles, so that it was extremely dangerous for passengers to stick their heads out of the car . The atmospheric drive was only used on the uphill drive to Dalkey, the return trip to Kingstown was made by the car without drive. The ascent was already over half a kilometer before the train station , so that the rest of the route had to be driven through with momentum. If the wagons stopped on the route, third- class passengers were asked to push the train into the station while the other passengers covered the rest of the route on foot. After the pump of the propulsion system suffered a defect, operation on the line was maintained for a month with a steam locomotive before it was completely stopped on April 12, 1854.
Croydon Atmospheric Railway
The railway engineer William Cubitt proposed the construction of an atmospheric railway to the London & Croydon Railway along the already existing line from London Bridge station to Croydon with an extension to Epsom , which would have resulted in a thirty kilometers long atmospheric railway. However, the project could not be implemented due to technical defects.
history
In 1844 Parliament gave the London & Croydon Railway permission to build an additional track for the atmospheric railway along the existing line. The track was laid from London to Croydon east of the existing facilities, with a flyover structure having to be built between Norwood and Croydon for the first time in railway history because the tube of the atmospheric railway did not allow level crossing with locomotive-operated lines. The overpass led the atmospheric railway to Croydon over the tracks to Dover and Brighton , with a gradient of 20 ‰ selected for the ramps.
The first test drives took place in the summer of 1845 and in January 1846 regular operations between Croydon and Forest Hill began. Compared to trains hauled by locomotives, the smooth ride was praised, with remarkably high speeds of up to 160 km / h being achieved for the time. Due to technical inadequacies, the railway was switched to operation with locomotives after two and a half years .
technology
Four pumping stations were built for the railway:
- Croydon
- Jolly-Sailor Station - this station was named after a nearby pub and was located near what is now Norwood Junction
- Dartmouth Road, near Forest Hill
- New Cross
The New Cross pumping station was never used because the atmospheric railroad did not run north of Forest Hill. The structures had a high tower that was reminiscent of a cathedral and housed the chimney of the boiler system and the exhaust pipe of the pumps.
The trains consisted of up to 16 cars, which were pulled by a motor vehicle consisting of two coupled cars. The piston was attached to the first carriage, while the second carriage was provided with a device that resealed the seal on the pipe. The pipe between the rails was 38 centimeters in diameter. To make it easier for the trains to get there, the tracks led out of the stations with a slight gradient.
business
The precise stopping was difficult, in particular the trains could not be reset if they had driven past the desired stopping point. When the trains are full, the drive force was sometimes insufficient to pull them over the flyover. In such cases, the first three to four cars were unhooked and driven to the start of the slope, while the rest of the train was left standing on the slope. The two parts of the train were then connected with a long rope and transported to the terminus. Another problem was the seal on the top of the pipe, which did not work in extreme weather because it was either too hard or too soft.
Exeter – Newton route on the South Devon Railway
history
The British engineer Isambard Kingdom Brunel extended the Great Western Railway with the 84 km long South Devon Railway from Exeter to Plymouth . Of this route, 32 km between Exeter and Newton Abbot were completed and put into operation as an atmospheric railway. The line was opened in 1846 with locomotive-hauled trains, with the installation of the pipeline for the atmospheric railway being carried out in parallel with the timetable operation. The first piston wagons for the atmospheric railroad were delivered in February 1847, and from September 1847 the first trains with travelers ran in trial operation. From February 1848, regular traffic was handled entirely by the atmospheric railway, but in September 1848 its operation was stopped again and the trains were transported with locomotives.
technology
The pump houses were set up about five kilometers apart along the route. They were located in Exeter St Davids, Countess War, Turf, Starcross, Dawlish, Teignmouth, Bishopsteignton, and Newton Abbot. Two vertical 41.5 HP steam engines were installed in each pump house, which were supplied with steam at a pressure of 2.8 bar. The pipe between the rails was originally intended to be 30 cm in diameter, but after the first attempts it had to be enlarged to 38 cm. The seal of the slot in the pipe was made of ox leather, which was initially lubricated with lime soap and later with cod liver oil and soap .
business
After initial problems with moisture and dirt in the pipes as well as poorly built steam engines, the line was put into operation. The trains reached an average speed of 103 km / h. However, operations could not be maintained for long because the seal in the slot in the pipe was leaking and the steam engines were using too much coal.
The leakage of the seal on the pipe originated on the one hand from the fact that it froze and became brittle in the cold, and on the other hand from the fact that it was eaten by rats that were attracted by the lubricants used. In order for the railway to be able to operate at all, a group of railway employees was assigned full-time to lubricate the seal and fix leaks.
The high coal consumption of the steam engines came from the fact that they were dimensioned for the originally intended smaller pipe and therefore had to be operated longer and faster than intended. In addition, there was a lack of suitable communication facilities, so that the pump houses worked according to the schedule and were often operated in vain when trains were delayed.
After half a year of operation, Brunel found that the operating costs of the steam engines were three times as high as he had calculated. In order to get the operating costs under control, the pipe seal would have had to be replaced along the entire length of the route and the steam engines that were too weak had to be upgraded. The management of the railway therefore decided on Brunel's recommendation to discontinue the operation of the atmospheric railway and to return to the locomotive hauled trains.
Le Pecq – St. Germain the Chemin de fer de Paris à Saint-Germain
history
In France , the first exclusively steam-powered railway line was inaugurated on August 24, 1837. The trains ran between Gare Saint-Lazare and Le Pecq about twenty kilometers west of Paris. The actual destination of the railway was Saint-Germain-en-Laye , which is located on a terrace above the Seine , but could only be reached via a 35 ‰ ramp with several engineering structures. The locomotives of the time were not able to accept this incline, which is why an atmospheric railway was set up on this 2.5-kilometer section, which began operation on April 15, 1847. After a railway accident occurred on September 6, 1858 at the Le Pecq station because a train had escaped from the Saint-Germain station, the atmospheric railway was stopped on July 2, 1860. Originally it was planned to operate the atmospheric railway from the Nanterre station. Engine houses were therefore also built in Nanterre and Chatou , but they never received steam engines and were partially destroyed in the riots in 1848.
technology
The pipe for the drive, which lay between the rails, was half buried and consisted of 850 individual cast pipes with a diameter of 63 cm. The pipe was evacuated to approx. 0.6 bar for train journeys.
business
Atmospheric propulsion was only used on the ascent to Saint-Germain. In Le Pecq, the locomotive of the trains coming from Paris was uncoupled and the train cars of the atmospheric railway were presented. After the steam engine had evacuated the line for about four minutes, the train could be brought to the beginning of the pipeline with a winch , where the pull piston could be inserted into the pipeline after opening the inlet valve and the train was sucked in the direction of Saint-Germain. The pipeline came to an end two hundred meters from the terminus. The train left them through an exit valve and rolled the rest of the way to the station without any drive.
For the return journey, the trains in Saint-Germain station were pulled to the beginning of the slope with a winch until they rolled towards Le Pecq station, driven solely by gravity. The towing vehicle of the atmospheric railway was specially equipped with strong brakes in order to be able to control the speed of the train on a slope.
19th century projects not carried out
In the middle of the 19th century, an atmospheric railway was proposed for several railway projects that were to overcome steep inclines:
- Stuttgart , 1843/44: Charles Vignoles , whom the Württemberg state hired as a consultant for the design of its first railway lines, recommended atmospheric steep ramps for the ascent of the Eastern Railway via the Geislinger Steige and for a descent of the Northern Railway into the Enztal between Tamm and Bissingen .
- Vienna , 1844: Heinrich Sichrowsky proposed a tram from Lobkowitzplatz to Hütteldorf
- Vienna , 1849: Julius Pollak's connecting line from the main customs office to the southern train station
- Semmering Railway , 1848: Suggestion by Adalbert Ritter von Schmid
- Gotthard Railway , 1865: The Italian commission, which dealt with the traction means of the future Gotthard Railway, mentioned an atmospheric railway based on the Coletti system , but this was no longer considered. The system worked with closed tubes without slots, in which pistons ran, which were connected to the trains by wire ropes.
New routes of the 20th / 21st Century
Developments by Oskar Coester
Oskar Hans Wolfgang Coester is a Brazilian inventor and entrepreneur who is applying and improving the principle of the atmospheric railway again: The vehicles are moved with the help of stationary fans. The air flow they generate meets rectangular plates that are attached to the vehicle in a sealed flow channel. Since the transport cabins do not need a drive motor, they are relatively lightweight.
Coester received the first patents in this field as early as 1977. In 1983, a 1000 m long test track was put into operation in Porto Alegre.
Test vehicle at the Hanover Fair in 1980
The vehicle used was built according to the Coester principle and offered space for twelve people. 18,000 people were transported within nine days.
The atmospheric train of the Taman Mini Indonesia Indah theme park
The 100 hectare Taman Mini Indonesia Indah theme park is accessed by a 3.2 km long circular railway with six stops and three trains.
The atmospheric railway of Porto Alegre airport (Brazil)
At Salgado Filho Airport , a 1000 m long line went into operation in August 2013. The first vehicle offers space for 150 passengers, a second vehicle, which is delivered a little later, has twice the capacity.
literature
- Friedrich Becker: The atmospheric railway: edited after the reports of Smith, Mallet, Samuda, Pim etc. and English sources. Frankfurt 1844. Google
- Robert Stephenson, Ch. M. von Weber (transl.): The atmospheric railway, represented by Robert Stephenson. Berlin 1845. Google
- AL Crelle: About the so-called atmospheric railways. Berlin 1846 Google
- Edmund Heusinger von Waldegg: Handbook for special railway technology. Volume 1 (3): Railway construction. Leipzig 1877, pages 911–938 and plate LVIII. Reprint of the original edition from 1877: Archiv-Verlag, Braunschweig 2005.
Web links
- Helmut Lindner: The forgotten train of time - The Atmospheric Railway by Samuel Clegg and Jacob Samuda. (PDF; 1.5 MB) Deutsches Museum , February 1991 (scan from Culture & Technology ).
Individual evidence
- ↑ a b c d e f g A. W. Streane: Croydon in the past: historical, monumental, and biographical. Croydon, 1883 (English)
- ↑ Hallette's atmospheric railway. In: Polytechnisches Journal . 96, 1845, pp. 423-428.
- ^ Victor von Röll: Atmospheric Railway. In: Enzyklopädie des Eisenbahnwesens , Volume 1. Berlin, Vienna 1912, pp. 279–280.
- ^ H. Latham: The Atmospheric Railway. On: Dalkey homepage , accessed June 26, 2011 (English)
- ↑ a b Samuda's Atmospheric Railway. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Illustrated London News, October 11, 1845
- ↑ a b c d e f g h Brunel's Atmospheric Railway. On: Exeter Memories , accessed July 2, 2011
- ↑ a b c d e Atmospheric Railway. ( Memento of the original from August 18, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. On: MyBrunel , accessed June 28, 2011
- ↑ a b c d Le Chemin de fer atmospheric. From: www.histoire-vesinet.org of the Société d'Histoire du Vésinet , accessed on July 3, 2011
- ^ A b Laboulaye, Ch: Les Chemins de fer atmospheriques. On: www.histoire-vesinet.org in Dictionnaires des Arts et Manufactures, de l'agriculture, des mines., Etc. , Volume 1, Paris 1873
- ↑ Les grandes dates de la ligne Paris - St-Germain-en-Laye. From: www.histoire-vesinet.org of the Société d'Histoire du Vésinet , accessed on July 3, 2011
- ↑ Andreas M. Räntzsch: Württembergische railroad history. Volume 1: 1830-1854. Planning phase and implementation of the building project . H&L publications, Schweinfurt 1996, ISBN 3-928786-36-9 .
- ^ The Vienna U-Bahn: Early Planning (1844–1898). Retrieved July 3, 2011
- ↑ Martin Kugler: Atmospheric Railway. DiePresse.com, January 16, 2010, accessed October 20, 2018 .
- ↑ a b G. Dinhobl: The Semmeringerbahn: the construction of the world's first high mountain railway . Vienna 2003
- ^ The Swiss Alpine Railway in the VDI magazine, Volume 14, 1870 Google
- ^ O. Coletti: Sistema di trazione Idro-pneumatlco-automotore pel servizio di locomozione sul plani Inclinati delle strade ferrate. In: Il Poltecnico , 15th year, Milano 1867 Google
- ↑ The Book of Synergy. Retrieved October 9, 2014
