Mastering the map: why route knowledge matters
Editor Greg Morse discusses the importance of route knowledge, accurate reporting, and taking accurate actions.
We’ve talked about the Ladbroke Grove accident of 1999 many times in Right Track. A key element of its causal chain was that the driver of the ‘SPADding’ train had, according to the public inquiry, received inadequate training, which focused more on traction handling than where that traction would be handled.
There are precedents in the past too where poor route knowledge has led to derailment. At Foxhall Junction in 1967, for example, an express came off as the signalling in place at the time made a green aspect with no route indication look like a straight run down the goods loop, when in fact it meant a switch across to the Down Main. This was taken at speed, with fatal consequences. In that case, the whole signal layout had combined with the way that layout had been briefed out.
A lot of the time, it’s down to poor communication. Contributory to the fatal SPAD and collision at Colwich Junction in 1986, for example, was the way a change in the use of flashing yellow aspects ahead of junctions had been briefed, while the Potters Bar accident of 2002, in which 7 people died, is an almost textbook example of how comms can go wrong, with devastating effect.
The incident occurred on 10 May 2002. The train involved was 12:45 King’s Cross–King’s Lynn, which had left the capital on time and made its uneventful way north until it struck 2182A points just south of Potters Bar.
The points had moved under the unit, causing the rear bogie of the third coach and all wheels on the fourth to derail.
The latter became detached and crossed to the adjacent line before flipping into the air, crashing into the station and striking the parapet of a bridge.
The points had been fully inspected on 1 May. A further visual inspection the day before the accident reported no problems. However, that evening, a station announcer heading home from Finsbury Park reported a ‘rough ride’ south of Potters Bar after travelling over the Down Fast.
Tapes of telephone calls recording and responding to this report showed that the relevant protocols between the different parties had not been followed. As a result, the initial message was misunderstood, which led in turn to a Permanent Way team being sent to the UP Fast in error. They found nothing wrong.
There’s a link here to the fatal tram derailment at Sandilands in November 2016. Evidence came to light that there had been a number of customer complaints about harsh, heavy or sudden braking before the day of the accident. These reports were not detailed enough and therefore could not be categorised to identify the risk of overspeeding on curves.
As a result, RAIB’s investigation identified an underlying factor that potential safety learning from customer complaints had not been fully exploited. To help with this, RSSB undertook a project to collect, review and summarise good practice in this area. The report on that work includes information on accurate recording, routing the report to the appropriate responsible parties, taking action, and learning the lessons. There’s a lesson there for all of us.
