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STRUCTURES & INFRASTRUCTURE
Resilience by design The dramatic scene at Dawlish following the storms of February 2014.
GRAHAME TAYLOR
The first section of sea wall along Marine Parade was completed in July 2020.
R
ailway structures have seen their fair share of violent weather over the years. Now, some of them are nearly 200 years old and yet the weather makes no concessions at all to their age. Storms continue unabated, the heavens open and inundate already saturated soils. There is no let-up. Understandably, some structures have had enough and fail. When they fail, the railway is interrupted. In our technological world, passengers and freight customers have high expectations. They expect no interruptions; they expect railways to be resilient no matter what is thrown at them by the weather. But perhaps it’s worth sorting out what ‘resilience’ means, particularly in the context of railway engineering. According to the internet so it must be true! - the word has been around since the early 17th Century, coming from the Latin ‘resiliens’, the present participle of ‘reilire’ - ‘to rebound or recoil’ - which, in turn, is related to ‘re-’ - meaning ‘back’ - and ‘salire’ - ‘to jump or leap’. These days, the meaning has become either (a) ‘the ability of a substance to return to its usual shape after being bent, stretched, or pressed’ or (b) ‘the ability to be happy, successful, etc’, again after something difficult or bad has happened.
Rail Engineer | Issue 189 | Mar-Apr 2021
The whole system In a railway engineering context, given that structures are rarely imbued with happiness, we have a cocktail of both (a) and (b) with ‘the ability of a substance to return to its usual shape after something difficult or bad has happened’. But even then it’s not quite right as railway structures rarely deform sufficiently for us to be relieved that they’ve returned to their original shape. It is more meaningful to consider the resilience of the whole railway system to return to its usual shape - or state - after something difficult or bad has happened. In the end, the ‘usual state’ must refer to the timetable - to the planned and predictable running of trains to form a service for passengers and freight customers. Resilience has to extend to a multitude of railway operating tasks - locating rolling stock, train crew, rescuing stranded passengers, feeding trains back into the network in a logical manner
