This article may contain excessive or inappropriate references to self-published sources. (May 2017) (Learn how and when to remove this template message)
String Transport (also known as "SkyWay", Yunitskiy String Transport and Rail Sky Way) is a concept of an elevated light rail transportation system using prestressed rails with prestressed cables ("strings") and concrete inside them. It is designed for both freight and passenger services and has two main types of track structure and rolling stock — standard and suspended.
Theoretical foundations and modelsEdit
The project was conceived by Belarussian engineer and inventor Anatoly Yunitskiy from the beginning of the 1980s. The first 1/10 scale models of track structure and rolling stock were constructed in 1990-s. Different models were built either with one or two strings. The dynamic and wind behaviour was tested by using a single-string 1/10 scale model in 2006-2007.
In 2016 the Expert Council under the Russian Ministry of Transport evaluated the SkyWay string technology and called it "innovative but only in theory". There were no any information about the result of this acknowledged and/or any Government Purchases or contracts with SkyWay.
First samples of urban railcar U4-210 and personal light railcar U4-621 were revealed at an international railway exhibition Innotrans 2016 in September 2016. Plans of implementing technology in Indonesia were announced after RailwayTech 2017 exhibition. Implementing SkyWay lines in Indonesia with “Surabaya - Jakarta” line.
The first full-scaled string rail test track was constructed in Russian town Ozyory (Moscow Oblast, Russia) in 2001. This test track had tube rails supported with a wire rope and spreaders, unlike the monolithic string as proposed now. The length of this test track was about 150 meters. Due to lack of funding the inventors did not produce any railcars for this test track, but used a modified truck ZiL-131 with steel wheels instead of normal road wheels. Later this test site was abandoned and deconstructed.
A prototype test site with three test tracks (light rail, cargo rail and high-speed urban rail), is currently being built in the town of Maryina Horka, Belarus since 2015 and is due for completion in 2018.
In 2007 and 2008 the pilot string railway lines was planned to built in some Russian cities. But specialists of Moscow State University of Railway Engineering gave a negative assessment of the project and it was not implemented.
In 2010, it was planned to build a test site in Australia, but the project was not implemented because of a quarrel between Yunitskiy and his business partners.
In 2014 the company planned to built its first test site in Lithuania, but this project was cancelled in the end of 2014 due to suspicions of financial frauds from the Bank of Lithuania, which warned investors that unidentified individuals invited Lithuanian residents to invest in "next-generation string transport" by acquiring on-line shares of the private limited company without a prospectus approved by a competent authority. Lithuanian Bank’s Supervision Department announced that having acknowledged there aren’t signs of a financial pyramid scheme in the proposed business.
On May 26, 2017, the Vilnius Regional Prosecutor's Office decided to stop the pre-trial investigation aimed at revealing signs of illegal financial activity in the work of the organizations created by Anatoly Yunitsky in Lithuania. The decision of the Executive body recognized that no evidence confirming suspicions in unfair practices of the management of companies that intended to create a demonstration and certification center of string transport on the territory of Lithuania, had been collected during the investigation. All applied temporary restrictions of the ownership rights to the funds, securities and other property on the accounts of these organizations have been removed.
In May 2017 Memorandum of Understanding was signed by Himachal Pradesh government with Sky Way Technology Corporation. Himachal Pradesh Urban Development Minister Sudhir Sharma said the facility would be started in the next three years.
In July 2017 the Economic Times reported that the project ran into controversy when doubts were raised over the credential of Belarus-based Skyway Technologies along with concerns over the suitability of the means of transport for the region. The congress government was criticised for "the decision to sign a memorandum of understanding with a company with no operational projects anywhere in the world" and doubts were raised over the safety and viability of the project.
The track structure design is based upon the use of strings built with high-tensioned steel wires inserted into a concrete/resin core and enveloped within a steel shell.
It differs from traditional cable ropeways by using a perfectly flat rolling way to limit the wear, rolling resistance and noise. The functions dedicated to rope tension and rolling way are handled by separate parts. Narrow span intervals (~50m) coupled with tension much higher than common ropeway allow for low sag, permitting high speed operation.
The string attachments are fixed and there is no tensioning system. The steel thermal expansion over the seasons is absorbed by the modification of the tension stress in the string. As such there are no junction gaps in the rail except for switches, which are built similarly to railway switches. According to inventors, the system can utilize the most direct possible route, but it is possible to create curves by using intermediate supports which locally replace the string with steel structures.
Fatigue handling of the rail, which is an integral part of the string is being studied. As for pre- or post-tensioned beams mixing steel and concrete, fatigue studies are also being carried out. The designer proposes low overall fatigue, considering that the variation of the string tension due to vehicle weight is relatively low.
String rail transport uses special light-weight railcars and multiple units with traction motors for both passenger and freight transportation. Freight transport also uses freight wagons without motors hauled with locomotives or traction rope. All rolling stock have individual suspension for each wheel with side anti-derailment small wheels like a monorail rolling stock.
String rail vehicles have commercial names "unibus" (universal railbus), "unicar", "unitruck" and "unibike" by analogy with conventional transport, where "uni-" means "unification". Creation of rolling stock for string railways is conducted by SkyWay Companies Group. It carries out design and development of the following types of string transport:
Safety and evaluationEdit
An earlier prototype of String transport was tested in Russia. This was subsequently dropped after an assessment by the State Railways University in Moscow in 2008 found that the project was "not viable and unsafe". According to the assessment, string rail technology is filled with a "large number of system defects and (is) almost unrealistic because it doesn’t provide an even path for the traffic". The report also quoted that "Passengers are at altitude from the ground level. Destruction of any string leads to deaths. The system is associated with great risk". Later, in 2017, the State Railways University in Moscow made another conclusion, which stated that “if the issues of rigidity, reliability, safety and maintainability are properly addressed, this technology can be implemented”, and also “the string rail transport technology is innovative and is of undoubted interest for science, engineering and experimental research." 
Notes and referencesEdit
- Venugopal, Vasudha (13 July 2017). "Doubts raised over Belarus company credential for Rs 250-crore skyway transport project in Dharamshala". The Economic Times. Retrieved 15 July 2017.
- "The Expert Council of the Russian Ministry of Transport oacknowledged SkyWay string technology as innovative" (PDF). Innovation and public procurement. Ministry of Transport of Russia. Retrieved 28 August 2016.
- "The Expert Council under the Ministry of transport of the Russian Federation acknowledged SkyWay string technology as innovative (in English)" (PDF). Rsw-systems.com. Retrieved 28 August 2016.
- "SkyWay rolling stock is shown to the public for the first time". SkyWay official website. SkyWay. Retrieved 21 September 2016.
- "SkyWay lures visitors of RailwayTech 2017 with rail-string technology | Republika Online". Republika Online. Retrieved 2017-05-17.
- "Испытательный полигон СТЮ на телеканале РТР". Youtube.com. 15 September 2011. Retrieved 11 April 2018.
- "Аферисты или модернизаторы". Stringer News (in Russian). 2010-02-08.
- "What is EcoTechnoPark". SkyWay official website. Retrieved 28 August 2016.
- "EcoTechnoPark preparatory work has begun". YouTube.com. SkyWay (official youtube channel). Retrieved 28 August 2016.
- "What happens in EcoTechnoPark on 16 March 2016". YouTube.com. SkyWay (official youtube channel).
- "MIIT theme № 98/06". String-fraud.ru. Retrieved 11 April 2018.
- "SkyWay - Страсти по Скайвею: Юницкий создаёт историю струнных дорог, а недобросовестные конкуренты Узлов и Дубатовка её переписывают". SkyWay. Retrieved 11 April 2018.
- "Bank of Lithuania: The Bank of Lithuania warns investors on the public offer of securities in violation of applicable laws". Lb.lt. Retrieved 2017-03-01.
- Černiauskas, Šarūnas. "Lietuvos bankas: "oro traukinius" žadančio A. Junickio veikloje – sukčiavimo požymiai". DELFI. Retrieved 2017-03-01.
- "A genuine investment project? A boondoggle? A scheme? Lithuania: a national security threat first". Baltic News Network - News from Latvia, Lithuania, Estonia. 2014-09-25. Retrieved 2017-03-01.
- курс, The Baltic Course - Балтийский. "Investment project from Yunitskiy in Siauliai – threat to national security?". The Baltic Course | Baltic States news & analytics. Retrieved 2017-03-01.
- "Генпрокуратура Литвы не смогла доказать, что SkyWay – мошенники". Ru.sputniknews.lt (in Russian). Retrieved 2017-08-14.
- "В Литве не смогли доказать, что SkyWay – вне закона". Rzd-partner.ru (in Russian). Retrieved 2017-08-14.
- "Инновации SkyWay: почему струнный транспорт переехал из Литвы в Беларусь?". Lenta.ru (in Russian). Retrieved 2017-08-17.
- "SkyWay Innovations: Why Has SkyWay Transport Moved over from Lithuania to Belarus?" (PDF).
- "SkyWay Technology". Official site of SkyWay group of companies. rsw-systems.com. Retrieved 1 November 2016.