Furrer+Frey is an engineering company like no other, with electrification experience accumulated from the development, construction and maintenance of overhead contact line systems since 1923…

Passing this knowledge on from one generation of engineers to the next, building an understanding through the capital of the company: the engineers and staff. The company understands that experience and competency need to be aligned with the requirements of the project. Here, we look at a project in India that Furrer+Frey has successfully delivered.

Furrer+Frey has a long and successful relationship with Delhi Metro Rail Corporation Limited (DMRC). DMRC operates a modern mass rapid transit system in the National Capital Region (NCR) of India. With the commencement of first service in December 2002, the DMRC network has now expanded to 377 kilometres which include ten corridors. The system is fully electrified and utilise 25kV overhead equipment for the entire network.

Overhead equipment on some of the DMRC corridors faces challenging conditions: excessive pollution, significantly high number of pantograph passages, low headway between trains, longer service hours, increasing service load and interference from external elements such as birds and kites. After almost 15 years in service, the overhead equipment on these corridors is facing reliability problems originating because of a number of factors.

Furrer+Frey worked with DMRC to review the overhead equipment on these corridors for restoring the reliability of the system and improving maintainability. Furrer+Frey collaborated with TÜV SÜD who reviewed and modelled the traction power supply equipment along these corridors.

Furrer+Frey was chosen for the task of improving DRMC’s electrification performance for two key reasons. Firstly, Furrer+Frey has almost one hundred years of electrification experience. Secondly, the work was undertaken by the Furrer+Frey UK team, who have expertise in maintaining, renewing and improving the UK’s ageing Network. The experience from the UK was critical; maintaining performance on a densely operated network is a key skill in demand around the world.

The first task involved reviewing the existing operation and maintenance processes and manuals of DMRC for these corridors. Furrer+Frey’s UK team then spent several weeks on-site with the DMRC maintenance teams looking at specific recurring issues on overhead equipment and interacting with DMRC personnel to understand their real maintenance regime. As a company that has worked in over 30 countries, Furrer+Frey was also able to utilise its international experience, specifically not only from the UK, but also from other metro projects to make specific recommendations for system improvement. Furrer+Frey also reviewed DMRC maintenance practices against industry benchmarks from the UK and across Europe.

Component lifespan

A significant issue in Delhi is the extremely high level of pollution, and this is also a major factor affecting life of certain components of the overhead equipment. Excessive pollution coupled with high electrical load leads to reduced component life and led to unexpected early failures. Furrer+Frey carried out metallurgical and metallographic examination of samples recovered from polluted sections, which helped it in making recommendations based on extent of material loss due to accelerated corrosion and levels of surface contaminants such as sulphur-containing compounds. In the long run India’s electrification programme, will also partially help to reduce this pollution.

DMRC has also been considering the use of different conductor sizes and tensions, that could potentially have a positive impact on the reliability and availability of the overhead equipment. Furrer+Frey created a digital twin of the DMRC electrification system and was able to model scenarios for DMRC, and what outcome changes would make on long-term performance. Furrer+Frey used its dynamic simulation software PCaDA, a simulation tool accredited to EN 50318. Based on the modelling outcomes validated against the requirements set in EN 50119, DMRC was able to understand the impact of change in conductor tension and configuration on system performance. Variable pantograph pressure was also simulated as part of this exercise.

A review of the adequacy of existing traction power supply system for these corridors was carried out by TÜV SÜD Schweiz AG, along with power supply simulations for future traffic scenarios. The output of these simulations i.e. electrical load on various overhead conductors was then utilised by Furrer+Frey to review the adequacy of existing conductors and making recommendation on conductor sizing in case the existing conductors are not suitable.

Another area of importance for DMRC is to reduce maintenance and repair times due to short maintenance windows. Furrer+Frey owns an extensive construction and maintenance plant fleet in Switzerland and Germany and has also worked with a number of modern railroad plant in the UK. Based on this experience, the company was able to provide a recommendation to DMRC on a variety of modern railway plant that can help in efficient maintenance planning and also significantly reduce time on track.

When it comes to adopting new, improved railway equipment; DMRC is at the forefront among the Indian rail asset owners and operators. But this could also result in a number of new components in the system without proper training and tools to maintain them. Jointly DMRC and Furrer+Frey identified such components where hands-on training would improve performance. Furrer+Frey then delivered the training at Delhi Metro Rail Academy in Shastri Park Depot. Having a hands-on maintenance academy is also part of DMRCs long term plans to improve reliability.

Furrer+Frey GB’s Engineering Manager and lead for the project Ankur said: ‘Working with DMRC is always collaborative, and everyone is aligned to a common goal of improving the network. It was also good to be able to give hands-on training, too often consultancy work is about writing reports that people don’t read. To see straight away a light switch in someone’s mind and they realise they can improve working practices and improve reliability is a delight.’

The collaborative efforts of DMRC, Furrer+Frey and TÜV SÜD Schweiz AG are expected to boost the reliability of DMRC’s overhead electrification system, paving the way towards efficient maintenance regime for DMRC personnel. Ultimately the purpose of the whole work is to improve operational performance and make travelling better for the 6 million people who use DMRC network daily.

Noel Dolphin, Director at Furrer+Frey GB said: ‘It is always exciting working on projects in India. There is a can-do attitude on all projects, and the huge growth in urban metros shows there is a desire for sustainable development. India is also pioneering electrification and plans to have a one hundred per cent electrified network.’

Furrer+Frey has been creating innovative overhead line solutions for almost one hundred years and has become synonymous with all things electrification from battery charge stations to high-speed overhead line, working around the world on a multitude of interesting and challenging projects.

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