The wrong kind of snow - dealing with transport chaos in the UK

Children across Britain will have been eagerly awaiting an announcement of a 'snow day' and school closures this morning, whilst many office workers will be lamenting their ability to work from home in the post-COVID era of hybrid working. 

However, for those that do decide to brave the wintery conditions, snow equals chaos for commuters. Roads become slushy skid zones and ice rinks, and unfamiliar driving conditions are likely to lead to a large number of accidents.

Whilst rail travel might be safer it is not immune to the impacts of snow. Some may be familiar with the phrase 'the wrong kind of snow', coined in 1991 in an interview with British Rail's Director of Operations. The phrase subsequently covered the front pages  the following day and continues to be a euphemism for a poor excuse to this day. 

However, the powdery, dry, snow that was experienced in '91 caused havoc for electrical systems and air intakes on rolling stock which were not sufficiently encapsulated or had downward facing inlets which sucked up the fine powder. Perhaps it would have been more appropriate to say that we have the wrong kind of trains. Snow is also the enemy of other infrastructure, causing adhesion issues on track - leading to trains skidding through stations - blocking moving parts and weighing down other equipment. 

The primary issue we are likely to see today will be caused by blocked points, the junction where trains move from one track to another. Where snow has been allowed to settle it will compact between the moving parts and prevent the switch rail at the switch and crossing from moving. If temperatures drop after snow has fallen this can be particularly bad as the compacted snow will turn into a solid icy blockage. Once upon a time this problem was addressed with gas fuelled heating elements that prevented snow from settling and ice from forming, these days we have electric point heaters, but these are not infallible and often fail.

Once the snow stops falling and temperatures rise the misery does not stop. Fallen snow melts rapidly overwhelming drainage systems with a sudden influx of water. This can lead to flooding of tracks and destabilising earthworks causing further problems on the network.

Whilst there are winter weather preparation plans in place to limit the negative consequences of wintery weather it is still advisable to avoid travel wherever possible. You may be wondering why Canada, Sweden or Russia don't stop moving when it snows. The reason is that hey are much better prepared for these conditions - both in policy and equipment, as snow is much more frequent in these locations.

In Britain we see these conditions with much less frequency and it is not financially or practically viable to always be prepared. Due to climate change and consequent warmer winters, we are likely to see snow even less frequently in the future. Snow and extreme cold will still happen but our preparedness for these conditions is likely to reduce even further over time. Consequently, it is still important for winter weather plans to be in place to prepare for these infrequent, but extreme, weather events so that we are not beholden to the whims of Jack Frost.

The wintery weather has coincided with visits of researchers from Sweden and Japan to Birmingham Centre for Rail Research and Education to work with our resilient systems research group. The work we undertake is building a clearer picture of the impact of different weather on railway and other transport infrastructure. By identifying hazards and key risks this can inform extreme weather preparation. By quantifying the current impact of weather on railway infrastructure, we can improve our understanding of the risks of future climates to railways - this can then inform adaptation strategies to create a resilient railway for the future.