Improving safety on our trams

By - Monday 12th December, 2016

A look at the interim report into the Sandilands tram accident

The terrible tram crash that occurred on 9th November at the Sandilands junction is still fresh in the memory. This was a dark day for Croydon. Our thoughts and sympathies at this time must be with those affected.

With the publication of the interim report of the Rail Accident Investigation Board (RAIB), we should start to look at how such an accident can be prevented from happening in the future. The report concludes that the cause of the disaster was excess speed through the sharp ninety-degree bend just before Sandilands station. The maximum permitted speed through this turn is 12.5mph, yet the recording device in the tram showed that it was travelling at 43.5mph – more than three times the limit.

So far there is no indication of why the speed was so high, although no problems have been found with either the track or the tram. We should not speculate as to the cause, which will come out in the final report.

On much of Croydon’s tram network, they operate in conditions more akin to a train

The 12.5mph limit starts at a reflective warning board just 30 metres from the bend. There is currently no requirement for advanced notice of speed limits. This is similar to the requirements for Croydon road users, who are also not given advanced notice of speed restrictions.

Yet on the road, a speed limit sign is sited to be visible from some distance, on a road where a car may be travelling at 50 or 60mph. A tram is much slower to brake than a car. According to the report, at Sandilands a tram travelling at 50mph needs to brake at its full service rate from 180 metres before the board in order to be travelling at 12.5mph at the board. The mitigating factor for trams is that they travel a very restricted route. The driver is expected to know where he is on the route, to be intimately acquainted with the speed requirements, and to proceed appropriately.

But trams do not only operate on the roadway. On much of Croydon’s network, they operate in conditions more akin to a train. Indeed, the route in from New Addington is in a dedicated corridor much like the railway environment. The tram does not encounter road conditions until after the Sandilands stop.

Additional speed restrictions and associated signage have now been installed

What is also different about a tram is that paying attention to the route ahead is in one sense less critical than for an ordinary road user because a tram runs on rails. There is no need to steer. In the rail-like environment, there is even less incentive to pay attention as – unless there is a fallen tree or a land slip – there is little chance of encountering an obstruction on the route ahead.

Looked at in this light, the Sandilands bend is a particularly high-risk situation. A long section of high speed track where minimal attention is demanded of the driver is followed by an abrupt transition to a very slow speed section where excess speed has disastrous consequences. Little wonder that the RAIB interim report concluded that the trams could not be brought back into service until ‘measures to reduce the risk of trams approaching Sandilands Junction from the direction of New Addington at an excessive speed’ had been introduced.

Additional speed restrictions and associated signage have now been installed. Similar measures have been implemented at three other locations on the tram network. Essentially, these additional speed restrictions give advanced warning of a very low speed restriction, and an associated hazard, further ahead.

The full report will be published next year

The fact remains that this all relies on the driver paying visual attention to the environment ahead. Irrespective of what occurred in the Sandilands accident, I would hope that the RAIB is at least considering some kind of audible warning for the rare situations, such as at Sandilands, where a long railway-like high speed section ends abruptly with a section requiring a very low speed manoeuvre.

The audible warning must be part of the safety system, as otherwise the driver would be tempted to rely on it as the trigger to pay attention, increasing the risk of an accident should the horn fail. This may not be cheap or quick to install, but it needs at the very least to be considered.

The full report will be published next year. Until then, we must ensure that the RAIB’s initial recommendations are followed through to the letter, and that all parties involved in the operation of our trams remain vigilant against the risks posed when trams – statistically a very safe means of urban transport – travel at high speeds. Those who have suffered deserve no less.

A book of condolence for victims of the accident is available at the town hall. Donations can be made here.

Robert Ward

Robert Ward

Engineer and project manager specialised in helping businesses make better strategic decisions and improve safety, quality and effectiveness. Conservative Party Councillor representing Selsdon and Addington Village on Croydon Council. He tweets as @moguloilman.

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