New generation of cantilever system dedicated for lightweight railway and tramway overhead traction lines

Acronym: MABTECH
No.: TECHMATSTRATREG2/409939/6/NCBR/2019
Program: TECHMATSTRATREG2
Financing unit: NCBR
Project leader: dr Joanna Zdunek at Warsaw University of Technology
Function: consortium
Timeframe: 2019-2021

As part of this project, a new version of the cantilever system will be developed and implemented for production, dedicated to the so-called light rail and tramway overhead contact line, whose commercialization is planned both in Poland and in Europe. Currently used national railway traction systems use the so-called the upper network traction, which in Poland is powered by 3kV DC. The construction of such a network must be continuous contact between the contact wire and the pantograph contact patch of the moving trainset, which in practice is ensured by the use of a number of structural components arranged along the length railway tracks, starting from supporting structures and finishing on the last immovable element of this network, suspended directly above the track axis, i.e. the contact wire. Thanks to the continuous contact of the contact wire with the pantograph is closed by the electric circuit enabling the flow of electricity from the traction substation to the upper traction network, specifically to the carrying rope and through properly spaced current bridges up to contact wire, traction motors of the rail vehicle and then through wheels, rails and so-called return network from back to the traction substation.

One of the components of this complicated system is the so-called cantilever of the traction network, being in its essence a multi-element spatial structure with rope lifts, which in most cases is manufactured on the basis of standard structural steels susceptible to corrosion. Its production is mainly based on the process of cutting, bending, welding and mechanical processing available commercially sections and processes of their anti-corrosion protection, i.e. mainly hot-dip galvanizing and painting spray. This method is in many cases very imperfect, which was observed on the basis of research allowing to show that this type of healing is not sufficient and leads to a rapidly occurring corrosion of structural components of the suspension system.

In addition, some of the elements used in native tram and railway suspensions of traction networks, i.e. mainly handles, clamps or joints it is produced using traditional gravity casting technology. This method has a number of disadvantages leading to products with low surface quality, internal defects and resulting from them low operating properties. Therefore, more and more often in Poland and abroad our country is observed that these elements are often in terrible technical condition after the period of 10-15 years exploitation depending on the place of installation, which is associated with numerous corrosion centers, cracks or loosening of screwed elements. In addition, tests of the overhead contact line have shown that the traditional ones suspension system of the overhead contact line have a very unfavorable effect on its parameters, i.e. mainly on the coefficient uniformity of network flexibility, directly affecting the speed limits of running trains rail. On this basis, in the context of the current state of knowledge and responding to the actual the demand for the railway and tram market has been undertaken conceptual and research works carried out in a comprehensively selected consortium consisting of Mabo Sp. z o.o .; Faculty of Non-Ferrous Metals, AGH University of Science and Technology Stanisława Staszica in Kraków; Institute of Non-Ferrous Metals, Metal Division in Skawina and the Faculty of Materials Science at the Warsaw University of Technology.

The purpose of these works is designing from scratch a new structural solution of the suspension system, made of a new one material that will be adapted to the so-called light traction networks. Innovation and originality of this The project is located both in the new design of individual components of the traction network cantilever system and development and selection of the most advantageous construction material for their production. Geometry and the design of the new suspension system will be developed using the extensive individual experience members of the consortium in consultation with experts from the Railway Institute and PKP PLK S.A. and based on analysis of the advantages and disadvantages of the solutions currently used.

At the same time, research will be carried out on selection and creation of the most advantageous construction material for individual elements of the new cantilever system, guaranteeing its adequate mechanical strength (load-bearing capacity), deformability at the processing stage, weldability and corrosion resistance. After the research phase activities aimed at implementing the designed technology and launching production will be carried out the developed structural solution of the suspension system in industrial conditions of Mabo Sp. z o.o.