Written evidence submitted by the Minister of State for Transport


I am writing to you in response to a question raised at the Joint Committee on National Security Strategy oral evidence session held on 18 July.


During the evidence session, you enquired why during the recent heatwave it was possible for trains to run between Euston and Glasgow, but not between London Kings Cross and Edinburgh, despite both railways being electrified.


It may be helpful to explain that Network Rail (NR) is responsible for the operational management of the railway, including managing the effects of any weather-related incidents on the railway. In anticipation of extreme weather conditions, industry works together to implement the necessary mitigations to ensure both passenger and staff safety and to minimise disruption.


My officials have spoken to Network Rail to establish the operational factors considered when making the decision to close the southern section of the East Coast Main Line (between London King’s Cross and south of Leeds and York) on Tuesday 19 July. Network Rail provided the following explanation.


NR Risk Assessment Process


To safely manage the forecasted extreme weather on 18 and 19 July, NR Route Engineering Team carried out a detailed line by line review of rail infrastructure, to assess the safety risk to passengers during the forecast weather conditions.


Where deemed necessary, the decision was made to implement speed restrictions or line closures in places. These decisions were independently reviewed by NR’s Regional Engineering Team and NR Technical Authority to ensure decisions were safe, consistent, and not overly risk averse. The Office of Rail and Road Chief Inspector of Railways was consulted on the arrangements and endorsed NR’s plans.


In terms of the East Coast Main Line (ECML), air temperatures on 19 July were forecast to be between 38 and 40 degrees Celsius for the full section of the route between King’s Cross to Leeds and York, which was typically 2 degrees warmer than air temperatures on the West Coast.


In line with these temperatures, NR deemed that trains could run with speed restrictions between York to Newcastle, and at line speed north of Newcastle due to temperatures being cooler. However, NR deemed the risk profile was different south of York and Leeds due to the higher forecast temperatures, and the expected impact the heat would have on rail infrastructure.


East Coast Main Line Infrastructure Design


On the East Coast, the 2 degrees of additional heat put a lot of equipment beyond its design limit. Some of the particular challenges during the extreme heat included:


Track challenges – As several parts of track between York and King’s Cross are supported by timber, this means the route would have been subject to significantly more 20mph Emergency Speed Restrictions than comparable routes. To operate above 20mph on this route required several hundred additional staff to be located next to the track which could not be resourced. Further, the route would have seen an increased risk of track buckling.


Overhead line – The overhead line is designed and maintained to be safe and reliable up to 38C. However, with air temperatures of 40 degrees Celsius, NR anticipated multiple failures of the overhead line system leading to dewirements and unacceptable delays and risk to passengers. Due to the design of the wire suspension on the ECML, it’s possible that dewirement on one line could have brought down the wires on the adjacent lines which would make it very difficult to operate a rescue train alongside any stranded trains to recover passengers.


Passenger and Staff Welfare


Given the increased risk of overhead line failures, the likelihood of trains being stranded without power was greater. As trains on this route are indeed electrified, a power failure would mean loss of air conditioning too, posing a significant welfare risk to any passengers and staff stuck on stranded trains.


Given the length of route affected, NR could not provide a robust process to manage stranded trains in sufficient time. This put passengers at unnecessary risk and increased the chances of them trying to self-evacuate.


In terms of NR staff safety considerations, NR deemed it an unnecessary risk to ask staff to work in such high temperatures dressed in PPE. It was estimated over 500 operations and maintenance staff would be needed to run trains during the most extreme conditions, and previous experience of extreme heat events led NR to conclude there was a very high likelihood of multiple significant issues to deal with concurrently.


I hope this letter has reassured you that Network Rail has very robust procedures in place to inform their operational decisions, and these decisions ensure the safety of both passengers and staff is prioritised at all times.


Wendy Morton MP, Minister of State for Transoport


8 August 2022