Friday, 20 November 2020

Hitachi to Re-assess Design of the Intercity Express Trains to Improve Crashworthiness Standard

Following the collision of an empty LNER Intercity Express Train, and a LNER High Speed Train at low speed when entering Neville Hill Depot, the Rail Accident Investigation Branch has recommended that Hitachi re-visit the assessment of the design of the Intercity Express Train against the requirements of the crashworthiness standards.

The incident occurred at 21:41 hrs on 13 November 2019, when an empty LNER Intercity Express Train, approaching the maintenance depot at Neville Hill in Leeds, caught up and collided with the rear of an empty LNER High Speed Train moving into the depot. 

The leading HST train was travelling at around 5 mph (8 km/h) and the colliding train at around 15 mph (24 km/h). No one was injured in the accident, but the trailing bogie of the second and third vehicles and the trailing wheelset of the fourth vehicle of the new Intercity Express Train derailed to the right, by up to 1.25 metres.

The derailment occurred because the design of the Intercity Express Train is susceptible to derailment in low speed collisions. This susceptibility is related to the use of high-strength couplers with large freedoms of movement in pitch and yaw. 
These features were part of the train’s design. However, the impact of these features on the train’s resistance to derailment and lateral displacement in low speed collisions, was not considered by the train’s designers.

The crashworthiness standard used to design the Intercity Express Train did not specifically require consideration of the likelihood of derailment during collisions at lower than the 22.5 mph (36 km/h) specified design speed, nor did it include specific criteria for assessing the derailment performance. As such, the assessment and validation of the design did not identify any issues with these design features.

Following a full investigation the RIAB have made the following recommendations.

Hitachi to revisit the assessment of the design of the Intercity Express Train against the requirements of the crashworthiness standard

LNER to assess the risk of a derailment of an Intercity Express Train involved in a low speed collision

RSSB to consider whether it is appropriate for the crashworthiness standard to be modified.

The RIAB have also issued two recommendations which are addressed to LNER and relate to correcting its understanding of the setup of the train management system and ensuring that the documentation provided by Hitachi has not led to any other safety issues.

43300 was badly damaged in the collision and has been written off

It was found that the collision occurred because the driver of the Intercity Express Train was focused on reinstating an on-board system which he had recently isolated, instead of focusing on the driving task. This was exacerbated by him unintentionally commanding too much acceleration due to his lack of familiarity with the new train.

See our original report here