16.07.08
Technology transforms Tube
Source: Rail Technology Magazine June/July 2008
The Victoria line is nearly 40 and facing a mid-life crisis. How can she cope with another 48 million passengers a year by 2025? The answer lies in technology
It’s not a sight you see every day of the week – Her Majesty the Queen buying a ticket and catching the Tube. The year is 1969 and our Sovereign is formally opening the Victoria Line, London Underground’s first deep Tube route to be built across the capital since the early 1900s. Now, almost 40 years later, the world’s first automatic passenger railway is in danger of becoming a victim of its own success.
“Already the line is carrying 165 million passengers a year and by 2025 that is forecast to soar to more than 213 million,” said Alistair Kennedy of Metronet Rail. “Unless something is done, the system won’t cope.” Kennedy is vice president of a programme to upgrade the line in time for the 2012 Olympics as part of Transport for London’s £10 billion investment in the Tube. Metronet Rail is owned by TfL and renews and maintains eight of the network’s 12 lines for London Underground.
Kennedy added: “Working as one team with our customer London Underground and our turnkey supplier Bombardier in Derby, we are introducing a new, larger fleet of 47 longer, faster trains, a new signalling and control system, upgraded track and depot improvements. This will give passengers a faster, more frequent and more comfortable ride.” That means a 19 per cent increase in capacity and 16 per cent faster journeys.
The £900 million programme is immensely complex. The Metronet/LU team, works together out of Euston in London and has just strengthened its unified approach to the programme. It has to integrate complicated new systems on to ageing infrastructure without causing major disruption to passengers. Most of this is being achieved in the four and a half hours of engineering hours when the Tube service is suspended overnight. “It’s as technically complex as anything I have been involved in but the real challenge is the logistics of integrating the system in the timescales required.”
The migration from the old trains and signalling to the new requires a period of ‘overlay’ when two signalling systems operate in parallel controlling a mix of old and new trains. Only once the last of the old trains is removed can the signalling system be optimised to take full advantage of the faster trains and capability of the signalling system. But first the trains and signalling have to be proven …
Testing, testing
Deep below ground, Gary Hatfield is on board the first pre-production train as it sprints along the Victoria Line at 80kph. He is monitoring progress of the overnight integration testing regime of which he’s head.
From the outside the train sparkles in its London Underground livery of red, white and blue. Inside, however, cables suspended from the ceiling and rows of cast iron ‘passengers’ (weights used to simulate passenger loading) betray its real purpose. At one end of the train the carriages are stripped of their interiors. Engineers sit at temporary tables beneath exposed ventilation ducts, cable looms and information displays, examining data on their laptops.
“We’ve had the train a year now, testing and proving it as a stable platform with which to set up and test the signalling,” said Hatfield. “Now that the signalling system is controlling the train under ATO (automatic train operation), we’re carrying out validation tests for the signalling system, running scenarios to prove the system performs as it is designed.” One of the tests, for example, simulates the failure of the doppler speed-distance device to check that the back-up unit successfully feeds through information to stop the train correctly at stations.
Reaching the point where the signalling system is controlling the train has been a major achievement and the journey there wasn’t simple. The signalling system, supplied by Westinghouse Rail Systems, was first bench-tested, then fitted to a 1960s Victoria Line train running on Bombardier’s test track in Derby. This special train has since been running on the Victoria Line testing the trackside signalling equipment.
“The next stage will be to take delivery of the second pre-production train this July,” said Hatfield. “This will be fitted with the signalling system so we’ll be running the real train with the real signalling equipment in the real environment. Then we can move up to multiple-train testing with close headways, our ultimate aim being to run a mini service of six trains – four old and two new – in one section to bring the signalling system up to its full envelope.
“That’s all in engineering hours but by the end of the year we’ll have the second new train running empty during the day. Then, next year, we will actually be trialling it with passengers on board, in the off peak, late at night, then progressively at busier and busier times. By then the two trains will have amassed some 20,000km to test their reliability so will it be a significant achievement to finally see passengers on board? Absolutely!”
All aboard
Metronet’s Mark Foster, who is responsible for the design and delivery of the new Victoria Line train, has reason to be pleased: Bombardier has just started its series build of the remaining 45 trains. This follows the intensive testing programme and market testing of a full-scale model which scored a 93 per cent satisfaction rating with the public. “The customer acceptance testing result was a real boost,” he said. “It meant we were vindicated in the product we were delivering.”
This will be the first new train fleet to be introduced on the Underground since the late 1990s. The ‘09 Tube Stock’, as it’s called, will deliver a significant reliability improvement over the existing rolling stock due in part to design improvements and technology enhancements which are, wherever practical, based around proven systems and components.
Foster said: “The new trains will accelerate faster and brake harder, cutting journey times. The traction units are significantly more energy efficient because they use solid-state computer-controlled electronics to convert the traction current to usable train power, instead of electro-mechanical systems. At the same time they are fitted with regenerative braking which returns electrical energy to the conductor rail to be used by a following train.”
Not only will the fleet be boosted from 43 trains to 47, but the new trains will be three metres longer and, inside, two inches taller. This, coupled with wider aisles, will help accommodate extra passengers as well as making conditions more comfortable. There will be automatic voice announcements, linked to visual displays throughout the carriages, giving real-time service information to help passengers plan their journeys.
Foster said: “A real bonus is the way this train meets – well, actually exceeds – the rail vehicle accessibility regulations. We have four designated wheelchair spaces as well as other measures such as low-level alarm buttons and handrail and grab poles that also help reduce crowding in the door areas.”
Sending the right signals
The ‘Distance-to-Go Radio’ signalling system that will shorten the distance between moving trains, again improving journey times, is no less impressive. This fixed-block, transmission-based system will transmit radio signals via a leaky feeder cable suspended on the tunnel walls. Equipment on board the trains will use this information to calculate the limit of movement authority and appropriate operating speed that will, under all circumstances, allow the train to be brought safely to a halt.
Already all signalling installation is complete and the 14 new signalling equipment rooms have been built and fitted out. The interface between these and the 17 interlocking machine rooms is complete and all 565 absolute position reference boxes have been fitted across the line to tell the train exactly where it is.
In all, the programme has installed 560km of signalling cables – enough to go round the M25 three times. The real challenge now remains to run the new system in parallel with the existing system so that the new trains can run in a mixed fleet with the 1967 trains until the last of the old fleet is removed, in 2011.
At your service
All this would be pointless without an upgraded depot to house and support the new trains. Already complete, it boasts extended inspection pits for the longer trains, two new driver simulators, an upgraded power supply and increased stabling. The new trains can even be lifted in one hit using a purpose-built series of 32 synchronised jacks – piling for which had to be buried seven storeys deep because the north London site is built on a marsh.
Finally, a multi-million pound service control centre has been built on the depot. Kennedy picks up the story again: “The building is complete and handed over and the signalling control system is installed and being tested. We also have to link the line management system to the London Underground information systems and this is now under contract and being developed before the centre can be fully commissioned.
“London Underground will use this to better control and regulate the upgraded line. Once we’ve finished, the Victoria Line will once again be the most up-to-date automatic passenger train service in town.”
And very much fit for a Queen.
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