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What's more dangerous in a terminal station, braking to a halt or powering towards the buffers?
Has that heading got your attention? Then consider this classic example of an unintended consequences.
When the Train Protection & Warning System (TPWS) was developed it was intended to protect junctions where a SPAD could result in a collision. As you all know, in speed trap mode, the train-mounted TPWS equipment measures the time between passing the two ‘grids' on the track.
At each location, the grids are spaced so that the time interval is always the same at the ruling speed. For example the grids at a 30mile/h trap will be twice as far apart as those for 60mile/h. If the timer measures less than the bogey time – on come the brakes and the train should stop in the signal overlap.
Then Her Majesty's Railway Inspectorate got in on the act. TPWS was also to be fitted where a Permanent Speed Restriction required a major reduction in speed – Morpeth curve is a good example and probably inspired the move. This was quite sensible.
But they also wanted to use TPWS to protect terminal platforms, since trains occasionally run into the buffers. This was probably inspired by the Cannon Street accident, the results of which were atypical since, as my good chum Andred revealed, the rolling stock was pre-Mk 1 by several decades and thus lacking in crashworthiness.
But, safety is paramount, and with the HSE/HMRI in CYA mode TPWS was mandated in terminal station platforms. Including Kings Cross suburban side which I frequent. And I noticed that trains coming into the platform were suddenly running literally, at walking speed – in my case 4mile/h.
Now even in leaf fall season this seemed like taking defensive driving a tad too far. It was obviously associated with the TPWS since after passing the grids in mid platform, the driver had to apply power to get the train up to the buffer stops. A similar situation was noted at Brighton , including the notching up after passing the grids.
Clearly, TPWS protecting buffer stops at the HSE/HMRI's instruction was actually making the railway more dangerous. Instead of approaching the platform end with the brakes on, and some retardation in hand, after passing the grids, drivers were accelerating – gently, but still accelerating – towards the buffers under power with the brakes off.
Totally bonkers. So how could this happen in a 21 st Century railway?
Answer, TPWS was designed for the open railway, because there was no way a case could be made for fitting it at buffer stops. But Railway Safety legislation decreed it must be done, whatever the cost benefit analysis.
So fitted it was. But when you have an aerial producing electro magnetic radiation, you get a phenomenon known as ‘side lobes' and when the grids were in platforms, the on-train receiver could detect a side lobe, instead of the main transmission, and trigger the TPWS, putting on the brakes. Even though the grids are spaced for 15mile/h and drivers had been instructed to run in at 10mile/h, trains started stopping when the buffer stop TPWS installations were commissioned.
Now, a modified type of grid has been developed, with smaller side lobes in the radiation and seems to work. As a result, the 5mile/h crawl will revert to a 10mile/h crawl with the speed trap set at 15mile/h.
Perversely, buffer stop TPWS should give the greatest benefit where slam door stock is still in use, but in fact it creates more risk. Suppose a 12 car train of slam door stock gets a TPWS brake application half way down the platform. Half the train is sticking out into the station throat and the next thing you know, Alan Williams and his Southern chums are opening the doors and jumping down onto the track.
And even if the commuters don't take direct action, the tail of the train would still blocking the throat.
And while I'm at it, there's another risk to commuters from platform TPWS. Remember that many of the injured at Cannon Street were people standing up ready to alight, some holding slam doors open ready for a quick exit.
In the sudden deceleration they were hurled forward or had doors slam on their extremities. Perhaps we need a new PA announcement ‘As we are approaching a TPWS equipped terminal station, please remain seated until the train has stopped'
Back in 1998, consultants for Irish Rail found ‘large sections of track in unacceptable condition'. The report by International Risk Management Services warned, ‘a high proportion of the facilities are in poor condition and much of the mechanical signalling is in an unacceptable state'. An Irish Government report in November 1998 recommended ‘a 15 year safety investment programme costing in the broad order of I£590m'.
According to IE Informed Sources, years of under spending on track and signalling were triggered by report from consultants McKinsey in 1981. This favoured reducing passenger and freight services because an increase in traffic would raise the cost of retaining the railway.
In 1984, an Irish Government White Paper followed, titled ‘Building on reality' ( a title I commend to Richard Bowker for next year's Strategic Plan) . It said that ‘retrenchment measures', would be implemented ‘in the context of the McKinsey Report'. It added that retrenchment would mean ‘that there will be no substantial investment in railways and there will be strict cash limits on other expenditures'. According to a former CIE Corporate & Business Planning manager, ‘patching and minimum renewal became the order or the day'.
Hang on a minute, wasn't it McKinseys who came up with Railtrack's Project Destiny? This was based on a policy of extending asset life and renewing only when equipment became life expired. It resulted in 57% of track renewals being deferred for a year or put into maintenance. The pejorative term for this is ‘patch and mend', and while we can't blame McKinsey's for Railtrack's lack of knowledge of the condition of its assets, they might have noticed that the client was a bit vague about the state of things.
Anyway, the wreckage of Project Destiny is strewn across the desks of Stephen Byers and Richard Bowker.
So what's to be afraid of? Well, just before Christmas the Transport Specialist in the 10 Downing Street Policy Unit, a career civil servant, moved on to greater things, which was shame, because Brian Hackland was nicely up to speed. His replacement, Matthew Ellson comes from an international firm of consultants.
As James Bond remarked, once is happenstance, twice is coincidence, three times is enemy action