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Running trains during severe weather

Severe winter weather such as snow and ice can cause disruption to all forms of transport, including road, rail and air services.

The South West Trains-Network Rail Alliance and our team of traincrew, engineers, operations and customer service staff work hard to deliver the best service we can to our customers in challenging conditions. We also put significant efforts into planning ahead to prevent these problems affecting our train services and we learn lessons from the disruption of previous winters.

No transport service can operate 100% in all weather conditions, but we understand that any disruption is frustrating for our passengers. Here we answer some of the most frequent questions our customers ask about the impact of the weather on our services – and outline what we are doing to keep trains running and passengers provided with fast and accurate information on their services.


Our network and trains

The Alliance operates one of the most complex commuter rail networks in the UK as well as operating and maintaining the signalling, points and third rail power supply that the trains need to run. We run nearly 1,700 trains a day, covering more than 600 miles of track and serving nearly 180 stations covering South West London, Surrey, Hampshire and parts of Wiltshire, Berkshire, Devon and Somerset. Together, we run a dedicated control centre where we work to keep trains on our network running as smoothly as possible, as well as dealing with any disruption that occurs.

Most of our trains – as well as trains operated by other operators south of the River Thames: Southern, Southeastern and First Capital Connect – are powered by electricity from a track-level third rail DC electrical system. This relatively low-cost system was introduced in the 1920s and 1930s and is different to the system used by trains that draw power from overhead lines. During normal weather conditions, this system works extremely well and we are able to deliver extremely high levels of punctuality to our customers. In addition, we use a small number of diesel trains largely on the London to Salisbury and Exeter route which are powered by fuel and run without any requirement for electrical power.

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Why is it difficult to run trains in snow or icy conditions?

Our trains draw power from the top of the third rail, which is located close to the ground. This is unlike more modern third rail systems, such as the Docklands Light Railway, where the third rail is raised and power is drawn from underneath. As a result, snow and ice can form on the third rail during freezing temperatures. When this happens, it effectively creates a barrier between the rail and the train, interfering with the ability of electric trains to draw power. In these cases, the train can stop and become stuck.  The problem is more serious if freezing ground temperatures are combined with snow, sleet or rain.
Heavy snow and icy conditions can also affect the ability of some of our employees to get to their place of work or to locations where there are problems. It can also make underfoot conditions at stations dangerous. 

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Why don’t you replace the third rail with a more modern system?

The basic design of the electrification system used in South London, Kent and Sussex as well as our area means that it will never work perfectly during icy conditions. Replacing this system would require massive investment and long term planning due to the large area covered by this system.  These investment decisions would need to be taken by the Department for Transport in conjunction with Network Rail.

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So are you doing anything to improve the situation for customers now?

The Alliance recognises that we have to make the best of the infrastructure that is available to us. We have also been working together to learn from the experiences of previous winters and have invested in measures to significantly enhance the resilience of our service.

Firstly, our operations teams constantly monitor the weather to ensure we are up to date with the latest forecasts and can plan our approach accordingly.  We operate a programme of anti-icing trains during the night, where de-icing fluid is sprayed onto the top of the third rail to prevent ice forming.  In addition, we run empty trains during the night to keep routes clear of ice, particularly in areas we know can be vulnerable to the weather.  However, even with these measures, in extreme temperatures ice can still form in between the empty trains that we run over our extensive network.

Additionally, the following track management initiatives have been put in place:

  • Preventative heating of the conductor rail at key strategic locations on the network to try to prevent it freezing and to enable trains to draw power.
  • A new specially-built train for use on the south-east rail network to lay heated anti-icing fluid directly on the conductor rail, and to scrape snow and ice from the tracks.


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Why do you get problems with some of your trains as well as the track?

During extremely cold weather, even when we try to keep trains moving for our customers there can be a problem with ice being picked up from the track. This can cause component failures on our trains, including affecting the systems that power the train. We experienced this problem with some of our electric trains last winter. In situations where there is damage to some train units and unplanned maintenance is required, it can mean that some trains will have fewer carriages than usual.  Along with our train suppliers, we work very hard to minimise the impact this has on passengers. 

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So what are you doing to make your trains more reliable?

Along with our partners, we are investing to make our trains more resilient. In partnership with train manufacturer Siemens, and to add to work done in previous years, we have invested in heated couplers for our class 444 Desiro trains so they can “split and join” more reliably, making trains even more reliable during extreme weather conditions. This allows for trains to easily divide (10 car trains can divide into two and go in different directions).

This investment complements our normal winter maintenance package for our trains where we ensure heating is working, horns are free from ice and snow, screenwash bottles are full of anti-freeze and the anti-slip sandboxes are full.  Much work also goes on to ensure that the depots remain free of snow and ice in order to ensure that trains can continue to be maintained and can leave and enter the depots at the start and end of day.

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Should I be concerned about the safety of travelling by train in these conditions?

We take the safety of our passengers and staff very seriously and we would never operate a train service unless it was safe to do so.  Our focus is to ensure our trains and our stations can be used by our passengers safely and with confidence and to do everything we can to minimise the impact of severe weather on our customers.

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Why do you decide to run special timetables in severe weather?

We would rather avoid severe disruption, but when it happens we know that what our passengers want most is certainty about when and how they are going to reach their destination.  Even after all of the precautions we take, very heavy snow will inevitably make it extremely difficult to operate our normal timetable reliably.

So we have a contingency timetable prepared and ready for use should snow or ice disrupt our normal timetable.  Our snow timetable has a number of features designed to help us deliver a reliable service in challenging conditions:

  • The trains are timetabled to run slower (but typically at maximum possible length), giving more time to cope with poor conditions, but continuing to provide as much capacity as we can for our customers.
  • Trains and traincrew are allocated to particular routes (rather than moving between routes and trains during the day as some do during normal operation).  This helps to minimise instances of disruption on individual routes causing knock-on problems affecting other services.


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What are you doing about stations and car parks?

Customer safety is our top priority and a huge effort goes into keeping the busiest areas of our stations, such as platforms, stations and footbridges, as clear of snow and ice as possible. We have a large stockpile of ice treatment chemicals at stations and at suppliers.  We have also updated all of our station snow and ice-clearance arrangements, buying new equipment where our internal review suggested gaps. Finally, we also have station adoption snow and ice clearance scheme where stations are adopted by back-office staff that live locally.

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What about the information you provide on screens at stations and on the internet?

Communicating fast and accurate information to our customers during disruption – as well as running a safe train service – is a top priority.  We know that in previous years information we put out during the height of the disruption was sometimes not as good as we wanted it to be. 

We have made some significant investments to improve our information provision:

  • Up to date disruption information will be placed on the front page of our website
  • Special weekday and weekend severe weather contingency timetables, which passengers can access the evening before they travel.
  • Blackberry smartphones for on-train staff to receive immediate service updates and pass up-to-date information to passengers.
  • Twitter (@SW_Trains) and dedicated email alerts tailored to passengers’ individual journeys.
  • Dedicated information managers in the Wessex operational control centre at London Waterloo to improve advice for customers.


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So, what should I do?

During periods of severe weather, we suggest that you:


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