Delays explained - overhead line equipment

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

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:

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.

If a problem occurs:

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