Pneumatic transport - an instrument for the next revolution ?

From the very idea to success

The construction of the first line speed trains is scheduled to start this year in the United States. The project will be realized in the HTT company. Among others, the Zhang Yaoping from the Chinese National Traction Laboratory, the researchers from the Chinese University of the South-West Jiaotong and the Chinese Academy of Sciences, who presented the project of a train moving in the tunnel vacuum, will work on the first prototype of such train. Zhang Yaoping ensures that they possess all available technologies, needed for its construction.

The first prototype of train is to be ready in 10 years.

 

The idea of the past, rail of the future

The proposal of the pneumatic railway transport is indeed, not new. The very first idea of this type of transport refers to the 1945 concept of American engineer Robert Goddard. It is known, however, that in that times there was no technology  necessary to implement the idea. Besides, the civilization of fossil fuels was not interested in innovative and low-carbon ideas, that were straight from science fiction. According to the data available in the ET3 company, such a solution will consume 50 times less energy than typical electric trains and will be about 10 times cheaper in use than the high-speed railway vehicle. Therefore, this solution is very prospective. The security measures in the pneumatic transport will have to be at the highest technological level. Monitoring of transportation conditions, acceleration and g-force scale associated with it, will have to be continuous. Similarly,

when it comes to the passengers of this mode of transport, it is demanded that the transport capsule and each of the seats installed, are equipped with the aforementioned Green Logger that provides the possibility of measuring the level of the sound, pressure, position, tilting, g-force and many others. This ensures the ongoing analysis of transportation and the ability to appropriately respond to dangerous situations. In an interview concerning the Hyperloop concept, Elon Musk said that the safety systems would be at the highest level, so as to ensure absolute reliability and the absence of any risk to users and third parties.

Polish accent

The Polish scientists also started to work on the design and build the Hyperloop prototype. A team of engineers from the Warsaw University of Technology, which also joined the experts of Wroclaw University of Technology and the representatives of design firms, is working under the guidance of prof. Janusz Piechna. They intend to win the competition on innovation organized by Elon Musk, and at the moment, they managed to reach the final of that contest. They have a good chance, although the competition is huge. The Poles raised the finance on the crowd funding portal and managed to build a prototype of Hyperloop. Participation or victory in the competition, means that part of the Polish engineering thought will be used in the construction of the project. If they win the contest, they will take part in the creation of perhaps the most interesting mode of transport in this century.

The first ultra-fast train will be built in 2016 and the line will connect Los Angeles with San Francisco, allowing people to cover this 500-kilometer distance in about 35 minutes. Does this mean the beginning of the great railway revolution? The time will give the answer to this question. Who knows, maybe people will travel from Warsaw to Berlin in metal pipes really soon, moving from place to place in an incredibly short period of time

 

Revolutionize the rail market

High-speed rail technology of pneumatic transport has very often caught the interest of the constructors.Currently, one of the originators of its application is Elon Musk from Hyperloop Transportation Technologies (HTT), according to which such mode of transport could revolutionize the existing means of communication. A company called Evacuated Tube Transport Technologies (ET3) has also advocated for the use of similar technologies in transport. Both vehicle concepts assume that the travel speed can be increased by eliminating the rolling resistance.

The transportation capsules could levitate while moving on magnetic as well as air cushions, hovering over a single track. Using this type of technology, acceleration and deceleration of the vehicle would be performed by magnetic cushion. Considering the enormous speed with which the capsules would move, magnetic accelerators could be installed at a distance of a few kilometers from each other. The capsules would be dispersed by compressed air and magnetic force, and inhibited in the same manner. Magnetic levitation technology has already been applied in the project of the Maglev vehicle and has been successfully used on a daily basis. The world speed record of this train constitutes 602 km/h. To reduce air resistance, the system would use the tunnel with vacuum. In the tunnel of this type, the pressure should be artificially reduced in order to minimize friction of the air. Pneumatic and electrical energy consumed during the acceleration of the vehicle, will be able to recover at its braking. Therefore, the energy expenditure on the trip would be small.

 

Technical problems

Each of the concepts used, involves pumping from the tunnels almost all the air, allowing to reduce the pressure about ten times. However, the elimination of the problems with resistance and performance of the system is not so simple; moreover, it constitutes another problem for the engineers. There is a certain ratio of the cross-section of the tunnel and the capsule, after crossing which, the moving capsule would behave like a plunger in the syringe. It means that the resistance, which will be generated, will balance on both sides and the capsule will push ahead a column of air, which will increase the resistance at the front of the capsule. It happens even if

the air pressure would be reduced to the assumed level. To avoid this, the Hyperloop project will pump the air through a special channel and under the capsule. The air flow under the capsule will additionally provide an air cushion, in other words, pillow, on which the vehicle will be able to lift easier. The air, flowing from the top to the sides of the capsule will allow to control its stability more easily. To overcome such technical problems the vehicle should move very quickly, or very slowly. From this perspective the laws of physics cannot be deceived, and the only solution to this problem is to make speed greater than the speed of a sound. Then, the air resistance would be greatly decreased. Unfortunately, no one has tried to exceed the speed of sound in a sealed airtight tunnel. It is therefore difficult to say what effect this attempt may have on potential capsule passengers.The tunnels would be situated above the ground, mounted on very high columns or would be buried deep in the ground. Such a solution would allow to build the tunnel on the shortest possible route in a straight line, eliminating the additional

risk of collision. Another threat occurring at high speeds - is the overload on the corners. To avoid this type of phenomena, tunnels of low pressure should be completely straight. The only thing that could influence the shape of the tunnel is the curvature of the earth’s crust.

 

Between the train and plane

The idea of ultrafast rail transport is a part of the concept of modern transport of the future, which would combine the speed of travel with ecology and low emissions. It should supplement the travel sector over medium distances, which is not cost-effective for aircraft, and too time-consuming for motor vehicles and railways. Using high speeds on intercontinental routes, it would compete with the air transport in the speed area of transport and its environmental performance. The magnetic-pneumatic capsule, aimed at the transportation of people, would fill this gap by reducing travel time and the amount of energy consumed for the trip. The problem of using great amount of energy by the classical form of transport in comparison to the above-mentioned technology, can be traced in the chart below. These is how the operating costs of the Hyperloop project look when compared to other means of transport along the planned route Los Angeles - San Francisco. The following chart shows a comparison of the energy cost of transportation between the two cities in the United States. After reading this chart, one can conclude that covering this distance with the help of Hyperloop is even more effective from the perspective of energy than purely electric travel by Tesla S type car. The Elon Musk project could recover the energy consumed during the journey, which makes it much more efficient than conventional vehicles. So far assumed average travel speed of the capsule constitutes about 1100 km/h at relatively short distances, and  even 6500 km/h at intercontinental distances. Currently, the existing magnetic railway transport is able to accelerate

to the speed below 600 km/h. Increasing this speed is difficult because of the conferred air resistance and generated level of noise inside and outside the vehicle. The only way to exceed these speeds is to remove the air and rolling resistances.

 

Changes to everyday mobility have become, in the last two decades, one of the key problems of European social, spatial and transport policy.

Recently, Polish shipbuilding industry has been held in high esteem. It is not a surprise since Polish shipyards are successfully fighting for the new orders, increase income, employ new workers and commission new vessels. Currently, the private entities of this industry are doing very well and improve their state over the months. One may warily talk about a boom in the shipbuilding industry. Nowadays, the shipyards represent the highest technical and technological quality. The private sector continues to develop and compete with shipyards from the whole Europe.