A summer afternoon in Scotland and the sun shines on the scene serene. It’s shortly after 17:45, and the 17:15 Glasgow–Edinburgh has slowed to 30 mph, thanks to restrictive aspects just beyond Falkirk. Routine stuff – frustrating, maybe – but routine…until, that is, the driver catches sight of a cow from the corner of his eye. The beast has got itself up the bank, and is doing what cows do best – chewing grass.

When the train pulls in to Polmont shortly after, the driver tells his secondman to inform the station staff. As the secondman crosses the platform, the 17:30 Edinburgh–Glasgow powers by on the Down. If the cow had actually been on the track, or if there’d been a whole herd on the bank, the driver would’ve stopped sooner, put down detonators, used track circuit clips, phoned the signalman….but it was alright, there was no real danger…

The 17:30 reached 85 mph as it passed Polmont Signal Box and began to take the gentle curve into the cutting beyond. Its driver, controlling the train from the DBSO, could see a cow on the line ahead. He rammed on the emergency brake, but it was too late…The coach struck the animal and dragged its carcass along before the leading left-hand wheel flange lifted and rode the top of the rail. When the right-hand wheel lost purchase, the coach clattered along the sleepers before striking the cess rail and veering up the bank.

Forward momentum caused it to slide, twist and collide with the third coach. The second was pushed up the opposite side of the cutting, where it divided from the train and turned end-for-end. Thirteen people were killed, and 14 passengers, the driver and two other members of staff were injured.

The official investigation found that there was a chance element involved, in that a specific part of the cow had to have been struck at a specific moment, on a specific trajectory, to lift the wheel with sufficient force to derail the train. But as the cow had accessed the line via a vandalised fence at an abandoned level crossing, it recommended a review of the way fences were inspected, and the way damage was reported. It also recommended that the Rule Book be changed to make sure large animals within the boundary fence were treated ‘as an immediate danger to trains’, and that driver-to-shore communication be fitted in the cabs of all trains travelling at 100 mph and over. As a result, BR improved its management of fencing, amended its rules and invested some £3 million in the National Radio Network (NRN), which was introduced from 1986. It also fitted obstacle deflectors to its DBSO’s and went on to improve the structural integrity of the later Mark III and IV driving van trailers. All these measures make it easy to see why we haven’t had a Polmont since Polmont. Indeed, the risk from a derailment after striking an animal is just 0.42 per cent of all train accident risk, which itself is only 6 per cent of the total system risk. How do I know? It all comes down to horizon scanning….

Dangers of complacency

Statistics show that we have the safest railway in Europe, and as I’ve said before, numbers are good: they give context, and the trend lines that you get when you join all the dots (sorry, data points) can help you focus resource where it’s most needed. But we’re all aware of the dangers of complacency; we all know that one SPAD, one failed set of points, one error could see us back in the late 90’s again. And that’s why we always keep an eye on the international scene – something that grew in pertinence last July, when – in the space of just 22 days – we saw four major accidents: a runaway and explosion in Quebec (6th), a derailment in Paris (12th), a high-speed derailment in Spain (25th) and a collision in Switzerland (29th).

At RSSB, we took stock and assessed each of the ‘July four’ in light of GB operations. The Quebec accident is particularly interesting, of course, as the circumstances that created it include the huge upturn in rail-borne oil traffic seen in North Dakota and Canada. Indeed, analysts expect up to 40 times more oil to be transported by trains there over the next five years. However, it wasn’t just the events of July 2013 that took us down this path – considering, analysing and reporting on events overseas is a regular RSSB activity. Indeed, it was an accident in Germany in January 2012 that led to a reassessment of the risk from animals on the line.

Like Polmont, this incident involved a push-pull service running in ‘push mode’ derailing when it struck cattle. One passenger was killed; the driver and one further passenger were injured. When I presented this information to a group of cross-industry operational safety decision makers, the obvious question was: ‘Have we learned from Polmont?’

Re-evaluation of potential risk

In light of this – and a non-fatal incident at Letterston Junction in July 2012 – we recommended a re-evaluation of the potential risk from animal strike incidents. A special topic report was the result, which demonstrated the work done by BR post-Polmont and showed that, while the total reported number of animal-on-the-line incidents had fallen by 42 per cent since 2003/04, reported cases of animals being struck by trains had tripled, and that this rise was mainly down to deer. At two million, the deer population is reportedly higher now than at any time in the last 1000 years, thanks (inter alia) to milder winters, the planting of winter crops, increased woodland cover and greater connectivity between green spaces in urban areas.

While deer are able to jump fences of varying heights, the derailment risk is considered to be less than with a cow or horse, although the withdrawal of the lightweight DBSOs, the fitment of obstacle deflectors and a general improvement in train crashworthiness means that it is now low for all animal types.

RSSB’s report highlighted a number of diverse deer deterrents – ranging from the bizarre and erratic (like the use of creosote and moth balls as barrier repellents) to the bizarre and rather more effective (like spreading a concentrated extract of lion dung along the perimeter). That said, the best way to deter deer remains properly erected and maintained fences. With this – and recent incidents like Letterston Junction – in mind, Network Rail has put standards in place to mitigate the different types of fence-related risk evident at different locations. The latest standard for managing the boundary uses the likelihood of unauthorised access, the consequences of unauthorised access, adjacent land use and the condition of existing boundary measures to determine the initial level of fencing required and the subsequent level of inspection, repair or replacement needed.

Furthermore, animal incursions are a standing item at Network Rail’s regular boundary risk management liaison meetings, and will be covered by an ‘objects on the line’ deep dive review, which is due to start in July and end in September 2014.

In addition, the importance of reporting large boned animals seen within the railway boundary – not just on the line – was re-briefed to the front line via a feature in ASLEF’s Locomotive journal and a discussion piece in the RED 39 safety briefing DVD programme.

To sum up, the industry can have a degree of confidence that the risk from animal incursion has been reduced by industry improvements in fence management, cab-to-shore communications, the rules for reporting incidents and the robustness of trains to collision. But while we will continue to monitor the situation, we know that the occasional incident can still cause harm, and delays to passengers and goods.

That’s why we sometimes need to look beyond the trendlines and – occasionally – beyond our own borders when considering where to aim limited safety budgets.

Greg Morse is RSSB’s operational feedback specialist and the Rail editor of Right Track magazine. The views expressed in this article are his own.

RSSB’s special topic report on the risk from large boned animals may be found at www.rssb.co.uk.

Follow Greg on Twitter: @GregMorseAuthor