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Safety signals set at danger

作者:宰父咳    发布时间:2019-02-28 08:04:06    

By Mick Hamer IN MARCH 1989 a train went through a red signal near the south London suburb of Purley, and crashed into another. Five people died. Within days, another train driver passed a red signal near Glasgow. This time two people died. Rail crashes were already in the news. Four months earlier, 35 people had died in a triple train pile-up near Clapham Junction. Faced with the new accidents the transport secretary, Paul Channon, asked the public inquiry into the Clapham disaster to widen its investigations to include the Purley and Glasgow crashes. Even before the Clapham accident, British Rail had been examining a system called automatic train protection which would have prevented the Glasgow and Purley crashes – though not the one at Clapham. Nevertheless, at the Clapham inquiry, British Rail gave a commitment that it would install ATP “on a large percentage of its network”. Anthony Hidden, the High Court judge who headed the inquiry, welcomed this pledge. “After the specific type of ATP system has been selected, ATP shall be fully implemented within five years, with a high priority given to densely trafficked lines,” he said. That was five years ago. Today Britain has two trials of ATP, on the lines out of London’s Paddington and Marylebone stations. Neither is yet fully working, and no system of ATP has yet been selected. In addition, British Rail is no longer responsible for maintaining the track and signalling on the railways. These duties now fall to Railtrack, which is pencilled in for privatisation next year. Promises, promises So what of the promise made on ATP? Within the next few days, Railtrack is due to send a report to the Health and Safety Commission (HSC), which is responsible for railway safety, laying out the options for tackling accidents that ATP could prevent. Railtrack declines to say what is in the report until it is finalised, but signs from the industry suggest that the company does not want ATP to be installed widely across the rail network. Railtrack’s report and the commission’s recommendations will land on the desk of the new transport secretary, George Young, who will also have the not entirely unrelated problem of judging when to float Railtrack on the stock market. Cost will inevitably be a major consideration. British Rail estimates that the bill for installing ATP across the whole network will be £750 million. This would be a large sum for a private company to spend on an investment that will generate no income. Railtrack is widely expected to fetch less than £3 billion when it is sold. To complicate matters, ATP requires equipment to be installed in the locomotive as well as on the track, and this will have to be paid for by the collection of soon-to-be-privatised companies that now make up British Rail. ATP is a sophisticated system which prevents drivers making dangerous mistakes. It automatically applies the brakes if a train passes a red light, it slows speeding trains, and it prevents a driver accelerating away from a section of track covered by a temporary speed limit until the last carriage is clear. ATP is designed to prevent three types of accidents. Those caused by speeding, such as at Morpeth, Northumberland, in 1994, when a train took a curve at 40 kilometres an hour above the speed limit; buffer stop crashes, such as the Cannon Street accident in 1991, when two people died; and those caused by trains passing red signals. About 900 trains pass signals set at danger every year – although in most cases the overrun is not serious. Britain may be hesitant about ATP but other countries are not. Trains in Sweden are protected by ATP, and the new highspeed lines in France and Germany have the system built into their signalling. When a Eurostar train sets out from the Gare du Nord in Paris it is protected by ATP until it reaches British rails. France has also installed the system at black spots. Instead of ATP, Britain’s railways rely largely on a technology called the automatic warning system to prevent trains passing red lights. This system is a relic of the steam age. It was first tested by the Great Western Railway in 1906. AWS rings a bell in the driver’s cab whenever the train passes a green light. But at an amber signal, which warns drivers to slow down, a horn sounds. The driver must cancel the horn by pressing a button, otherwise the system automatically applies the brakes. The same happens if the train passes a signal set at red. A critical drawback with this system, recognised at the Clapham inquiry, is that on congested commuter lines drivers often pass through a series of amber lights. Pressing the cancel button becomes a habit, and a driver can unwittingly cancel a red signal. It is like computer programs that put up an “Are you sure?” message when you try to delete a file. Mostly, the answer is yes, but on rare occasions you say yes when you mean no. Losing a computer file is rarely a matter of life and death, but train drivers who make the same mistake can end up dead, and their passengers with them. Tight restrictions on public spending have starved the railways of new equipment for years, even before the drive to cut costs in the run up to privatisation. After the Hidden report had been published, British Rail began to have second thoughts about the cost of ATP, partly because the cost had escalated following the devaluation of the pound in September 1992. In July 1994, British Rail and Railtrack released a cost benefit analysis which concluded that every life saved by installing ATP across the rail network would cost £14 million. It said that investment in safety measures only paid off if it cost less than £4 million to save a life. The conclusion, that ATP was poor value for money, was seen in media reports as an attempt to soften up public opinion for a retreat from British Rail’s commitment to ATP. John MacGregor, the then transport secretary, asked the HSC for its views on the report. While praising the analysis and agreeing that installing ATP across the whole rail network was impracticable, the HSC disagreed with the final figures. It estimated the cost of installing ATP at £11 million for every life saved. The commission also said that if ATP was fitted just at high-risk locations this figure would fall to just over £5 million. Railtrack told the HSC that it agreed with these figures. The costs would come down even more if the railways looked at cheaper versions of ATP than those being tested on the Paddington and Marylebone lines. Well-placed sources in the railway industry say the original specification for ATP was unnecessarily elaborate and expensive. They put the cost of saving a life with a cheaper version of ATP closer to £2 million. On 31 March last year – the day before Railtrack took over responsibility for safety on the railways – the chairman of British Rail wrote to MacGregor to say that if it was up to him, ATP would be adopted on new high-speed lines. It should also be considered whenever a line needed major resignalling work. This advice was endorsed by Frank Davies, the HSC’s chairman. “The commission regards this as the minimum response to the need and expects Railtrack to carry forward that undertaking,” he said in a letter to the transport secretary last December. But Railtrack has shown little sign of urgency over ATP. In his letter, Davies outlines talks on safety between HSC officials and staff at Railtrack. “These discussions have not so far produced any firm indication from Railtrack of their intentions as regards reducing or preventing the incidence of signals passed at danger, overspeed and buffer stop collisions,” he wrote. “The issue of alternatives to the piloted ATP systems … remains unresolved.” Davies concludes that ATP should not be dropped: “It would in our view be unreasonable to rule out the possibility that particular applications of ATP … on parts of the network might yield good value in terms of reduced loss of life.” In March, Brian Mawhinney, who had taken over from MacGregor as transport secretary, wrote in a Parliamentary answer that he accepted this advice. Railtrack and British Rail are looking at a series of alternatives to ATP. Some of these measures are already being used, including better screening of drivers for psychological problems and regular tests of their competence. Railtrack is also examining technical alternatives to ATP. One of the more common times at which a driver can pass a red signal is after stopping at a station. When the guard gives the all-clear at a platform, drivers sometimes forget to check the signal in front of them. A new system would prevent a train from moving off until the signal turned green. But the system is passive, and drivers would have to press a button to prime it when they stopped at a station. Cheap capital Railtrack is also looking at an enhanced version of the automatic warning system. This would stop trains that passed a red signal within a safe distance, before they had a crash. The system has the advantage that it would be simple and cheap to install. But it would not prevent other types of accidents, such as those caused by speeding. These days, when the government is faced with bank-rolling large transport projects such as the Dartford Bridge across the Thames, it resorts to a “private finance initiative”. This is a device in which the government and the private sector share the costs and the risk of an investment. For Railtrack this would be a cheap way to raise capital, and could make ATP more palatable. Ironically, this device is open only to organisations in the public sector. If the HSC recommends a wider role for ATP, says one railway industry source, the funding issue “will be a real dilemma for the government”. After the Clapham inquiry, the then transport secretary Cecil Parkinson told MPs: “I can assure the House that finance will not stand in the way of the implementation of the report.” This pledge should still be honoured today, says a spokesman for the Central Transport Consultative Committee, the statutory body that represents rail passengers. “I can’t see why if ministers said at the time that finance wouldn’t stand in the way that finance should now stand in the way,” he says. “At the very least, you should have [ATP] at high-risk locations, where double track goes into single line, for instance.” The head-on collision at Cowden in Kent last October took place on just such a stretch of single line. The report into that accident renewed the call for ATP. Had it been in place,

 

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