Forty years ago, on Tuesday 1 May 1984 at 5.30 in the morning, Bill (Willie) Taylor, a signaller at Carlisle Power Signal Box (PSB) realised that 4S55, a Liverpool (Garston) to Glasgow (Gushetfaulds) freightliner train had become divided south of Carlisle and both portions of the train were rolling downhill towards Carlisle Citadel station. The freightliner train was carrying dangerous, highly-explosive chemical goods, including toxic tetraethyl lead compound – the treatment used in leaded petrol, and 750 bags of oxalinic acid. Using his signaller’s knowledge and experience, Bill switched the uncoupled wagons onto the empty Carlisle Goods Avoiding Line and avoided disaster. Four decades later, what has changed in the industry and what can we learn from incidents of the past?
The freightliner had stopped earlier at Preston with dragging brakes. The train received attention, but after closing the air brake valves half-way down the train and rectifying the problem, the valves were not reopened, nor was a continuity brake test undertaken. It is believed that the screw couplings between Wagons 5 and 6 were also not stowed away properly and were left swinging. Once over the top at Shap Summit, the coupling between Wagons 5 and 6 probably went slack and the swinging coupling struck an AWS magnet in the four-foot. The coupling was lifted upwards and the train divided with no brakes on the rear 10 wagons of the 15-wagon train.
Bill Taylor spotted the irregular indications on his panel and realised he had a divided runaway train. The locomotive and the front part of the freight train were allowed to run forward safely into Carlisle station and signalled to a stop. After seeing that the leading part of the train had passed Upperby Bridge Junction, Bill switched the points to divert the runaway portion onto a freight-only line bypassing the station. The rear divided wagons made it around the sharp right curve onto Denton Holme Bridge before crashing through the bridge and into the River Caldew. If you search on YouTube for ‘Carlisle Crash’, Rail Engineer’s Graeme Bickerdike has produced an excellent video report of the incident.
There was significant wreckage with much of the train in the river, but nobody was hurt. It did take weeks to clear the route, and the bridge was so badly damaged that the route was closed. Probably because there was no one hurt, the main railway through Carlisle was not affected, and there were no main passenger service disruptions, the incident is not as well-known as other more harmful incidents. However, it is important that the rail industry retains its corporate memory and learns from the past. So, what has changed since 1984?
Counselling
After the incident, Bill finished his shift as normal in the morning and was sent home. He spent most of the day being interviewed by TV and newspapers and then was back on his shift that same night. Thankfully, the post-incident counselling and therapy processes in place today are much improved.
Signallers have to remain calm and concentrate at all times. They have to know and apply the operational rules ‘to the book’, hour after hour, day after day. But in the event of an incident such as Carlisle they have to think quickly, assertively, and calmly put control measures in place.
Bill was able to take the action he did in May 1984 because he had what we know today as ‘non-technical’ skills. For a signaller, these include outstanding communication skills, a strong sense of responsibility, and the ability to work under pressure and make systematic decisions in a timely fashion.
Bill also had extensive local knowledge of the Carlisle area. Having started his railway career as a ‘knocker up’ moving on to be a ‘box lad’ booking train movements, he then became a relief signaller and had worked at most of the 46 mechanical signal boxes in the Carlisle area, which proceeded Carlise Power Signal Box (PSB). So, he knew the area like the back of his hand. With signallers today looking after huge signalling areas and not having the opportunity to work locally like Bill did, it’s unlikely they would be able to acquire and retain the level of local knowledge that he had.
Carlisle PSB was constructed in the 1970s and the signallers control interface is known as a NX or ‘Entrance- Exit’ panel. To clear a signal the signaller presses and releases a button at the Entrance (N) of the route followed by another button at the next signal ahead, known as the Exit (X) of the route. The panels are typically a few metres long so, in 1984, Bill could see the route set for the train and its movement along the line, as well as the train dividing, by observing the track circuit indications on the panel.
While Carlisle PSB still operates using an NX panel for the time being, other more modern signalling control centres use far smaller electronic displays, and they cover a much larger area. Therefore, should a similar incident occur today, it’s unlikely a signaller would be in a position to take the action Bill Taylor did at Carlisle.
Swiss cheese model
When managing safety risk and hazards the important principle is to eliminate hazards well before other controls are required, such as diverting a divided train onto an empty line.
The hazard and incident at Carlisle occurred because: (i) the air brake valves were not reopened after the train had received attention at Preston; (ii) a brake test was not undertaken; and (iii) the screw couplings between the wagons had not been stowed away properly and were left swinging. This is a classic ‘Swiss cheese’ model of incident causation.
The Swiss cheese model likens systems to multiple slices of Swiss cheese, which has randomly placed and sized holes in each slice, stacked side by side. The principle of this is that lapses and weaknesses in one defence (a hole in the cheese) do not allow a risk to materialise. The other defences are represented by the other slices of cheese and only when a hole in each slice of the stack aligns with holes in all other slices have all the defences failed and an incident occurs.
So, in the case of the incident at Carlisle, the lack of a brake test when the train was stopped at Preston was the main and most important defence to prevent the train dividing and the wagons running away to Carlisle. This is very much the same today.
Brake continuity testing
The testing of a train’s braking system before a train moves remains an extremely important defence against a runaway train. The Rail Accident Investigation Board (RAIB) says that even when a braking system is functioning correctly, a failure to operate it properly can lead to safety problems. With any work involving a train’s braking system, or following the addition or removal of vehicles forming a train, a brake continuity test should always be carried out. Train drivers are also required to carry out a running brake test to check that adequate retardation can be achieved.
At Edinburgh in 2019, the driver of an overnight sleeper train was unable to stop their train which ran 650 metres past its intended station call. The RAIB investigation found that when the train was split earlier in the journey a valve in the brake pipe was inadvertently closed, causing the brakes on the coaches to be inoperable, which was also the cause of the Carlisle crash in 1984. A brake continuity test had been carried out, but before the train’s brake pipe valve was closed. RAIB recommended changes to the operating rules so that the brake continuity test is always carried out after all other duties.
The need for brake continuity tests to be the final duty undertaken before departure was further demonstrated in an incident at Crofton West Junction in 2020. In this incident, a freight train was prepared for departure, including a brake continuity test. However, after the train preparation was completed, a group of trainees and an instructor visited the sidings and used the train to practise train preparation procedures.
This led to the brake pipe valves between the locomotive and the wagons being closed, rendering the air brakes on the wagons non-operational, just like the incident at Carlisle in 1984. This was not detected before the train moved off and the driver was unable to stop the train when they encountered restrictive signals. The train passed two signals at danger and crossed a junction which was being protected by one of the signals.
Corporate memory
The rail industry is a complicated system that is constantly changing and improving, and the industry must always look forwards to innovate and find new ways of doing things. It is also important that the industry remembers and learns from the past, as we have hopefully demonstrated in this article.
Learning is difficult enough on a personal basis and in an industry like rail it can be even harder. The companies and organisations involved are many and it’s difficult to retain the corporate memory as people move on or join the industry. When someone with 30 years’ experience retires, the industry doesn’t just lose 30 years’ knowledge and experience, it also loses what the person retiring has learned from those who retired soon after they started. This makes it more like 50-60 or more years of knowledge and experience lost.
To help rail’s corporate memory, RSSB has a number of things which can help. The quarterly update on progress against the Leading Health and Safety on Britain’s Railway (LHSBR) allows trends to be monitored from sources such as the Safety Management Intelligence System (SMIS), daily incident logs and other information sources. It also provides a forum for updates on the work being done to address risk areas highlighted by the safety indicators and investigation reports.
RSSB provides learning via its series of safety films and Right Track magazine. It also tracks overseas rail incidents through the monthly Rail Accident and Incident News and Rail Investigation Summary documents. The relevant incidents and report findings from each are added to the regular risk papers used by the various cross-industry risk groups. These cover topics such as train accidents, level crossings, station safety, and freight operation.
Rail Safety Review helps those with an overview of safety consider the points raised with regards to their safety management system arrangements. This is not limited to rail as there is much that can be learned from other industries, such as the Nimrod air crash of 2006, the Boeing 737 MAX incident of 2019, and the Deepwater Horizon oil rig explosion of 2010.
It is not unheard of to find that an overseas situation in rail has been seen in Britain before, and that the industries hazard control mitigations are adequate. But the rail industry in Britain must never stop checking itself against other industries, other railways, or learning from the past.
A lot has changed since 1984 and the Carlisle crash, and the actions of Bill Taylor resulted in it being a largely forgotten incident. However, as we have shown, the need to always carry out a brake continuity test as the final duty before departure of a train has not changed.
Image credit: Cumbrian Railways Association
