Delays explained – overhead line equipment

Delays explained – overhead line equipment

Published 6 July 2020 | Average read time
3 min read
Stories Delays explained Infrastructure insights

We know delays caused by OLE failures are frustrating and do all we can to minimise them.

What is OLE?

Overhead line equipment – or OLE – is the name for the overhead wires and other equipment you can see on electrified railway lines.

It carries 25,000 volts of electricity to power electric trains.

It’s a critical part of the railway that allows us to run faster and greener electric services instead of diesel.

Watch this video to find out more:

How can it cause delays?

Delays can occur when a problem affects the OLE, requiring us to either stop or slow down services through the area.

There are lots of different components that make up our overhead line equipment, and lots of different ways that a delay can occur including:

  • Power supply failures, which can cover very small to very large areas
  • High winds blowing the overhead wires out of alignment, or blowing vegetation onto the equipment
  • An impact with the train’s equipment due to a faulty component
  • Wildlife such as birds landing on the equipment and causing a short circuit
  • Or extreme heat causing the wires to expand and sag.
Renewing OLE to improve reliability

How do we resolve an OLE delay?

If a problem occurs:

  1. We first receive an alert in our control centre of a fault, advising us to investigate.
  2. If necessary, electricity to the area is turned off and isolated.
  3. A team with the necessary equipment is mobilised from a depot
  4. Engineers arrive out on site and begin repair, usually in a specialised Road Rail Vehicle that allows us to work quickly at height.
  5. When the failure is serious, for example, if the wires have been brought down, the solution is more complicated and takes more time.
  6. Where possible, diesel trains will be mobilised to move any affected trains to the nearest station
  7. When the repairs are completed, careful measurements are taken to check it’s safe and compliant
  8. The teams and equipment leave the site and report repairs complete
  9. The electricity is switched back on
  10. Services are restored and electric trains are able to run as normal. It may take some time for service to recover to normal.
  11. Following the incident, investigations are undertaken to identify the root cause and the lessons that can be learned to prevent re-occurence.

Every OLE delay is different – but we do everything we can to get there and get it fixed as quickly, and as safely as possible.

Find out more about electrification.

Read more:

Delays explained – signals

Delays explained

Broken rail explained

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