Winter 2016

Replacing the present train doors of the London underground with alternatives based on TenCate Cetex® thermoplastic composites means a shorter time between stops and greater capacity. These are just two of the benefits that such a replacement would provide. One train is currently being monitored to validate the potential savings.  

London currently has 10 million inhabitants – a figure expected to reach 13 million in 2020. Reason enough for Transport for London to embark on exploring the possibilities for expanding capacity two-and-a-half years ago. Running more trains on the present network is not an option; adaptation is. Replacing the present metal-coated doors with doors based on thermoplastic composites means they would be lighter. Thanks to these weight savings, the time involved in opening and closing the doors can be reduced by 0.7 of a second, and TfL calculates that this equates to running 2.5 more trains on the circuit each day.

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Farringdon Station (Wikimedia Commons)
 

‘The lower weight of the doors will achieve faster actuation times,’ says John Darlington, head of product management for TenCate Advanced Composites UK. ‘This leads to a shorter time between stops and increased capacity due to faster passenger throughput. Transport for London has also calculated that the 25-30% weight savings achievable with the new composite doors would mean that the trains will be around one ton lighter overall, resulting in less wear on the tracks. The doors will also be more durable and corrosion-resistant than the metal and honeycomb core construction currently used.’

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London currently has 10 million inhabitants – a figure expected to reach 13 million in 2020 (photo: independent.co.uk) 

TfL has estimated that the net benefit of replacing a total of 12,000 current doors with composite alternatives based TenCate Cetex®, at a replacement cost of € 25 to € 29 million, would be approximately € 116 million over their lifetime. TenCate Cetex® thermoplastic composites are valued for their toughness and impact resistance. Furthermore, they are fire-retardant, as well as resistant to moisture and solvents. ‘Trains for the London Underground must last for forty years. After twenty years, major maintenance and refurbishment are carried out. As far as Central Line is concerned, it’s a question of 300 to 400 new doors for trains destined to replace those scheduled to be taken out of service.’

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The net benefit of replacing a total of 12,000 current doors with composite alternatives based TenCate Cetex®, at a replacement cost of € 25 to € 29 million, would be approximately € 116 million over their lifetime

To fully validate potential savings, a composite door equipped with a range of sensors has been mounted on a London Underground train and is currently undergoing a test programme. These sensors measure the vibrations, acoustics and material fatigue. The door was developed by a consortium composed of Atkins (engineering & design consultancy), Wabtec (manufacturer of locomotives and components for lorries), University College London and the National Composites Centre (NCC). TenCate Advanced Composites UK is a member of the NCC.

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Replacing metal doors with composite doors means savings in maintenance and faster actuation times, which would enable 2.5 extra trains to run each day (image by PriestmanGoode)

‘A composite door requires less maintenance, and the weight savings deliver time and energy savings. Over the coming twenty years, it would be possible to run one or even two and a half extra trains a day, with weight savings of one ton per vehicle. When it comes to maintenance of doors in service, time savings are expected to amount to £100 million (€ 87 million).’
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Working on a door (photo: NCC)

John Darlington expects thermoplastic composites to become increasingly accepted by the railway industry over time. Opportunities exist in such areas as new products, retrofit and repair. 

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(Photo: NCC)

‘If you look at the composite fuselage of a modern plane, there’s no reason why the roof of a train couldn’t be made from exactly the same materials – with all the advantages that would bring.’ 

Blue fabric (Tecawork Blue 65287)