
https://abs.twimg.com/emoji/v2/... draggable="false" alt="β‘οΈ" title="High voltage sign" aria-label="Emoji: High voltage sign">Overhead lines, OLE or &
#39;wires&
#39;...

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β" title="Red question mark ornament" aria-label="Emoji: Red question mark ornament">We get a lot of questions on what that means, how do they work and how long it takes to fix etc.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Thumbs up" aria-label="Emoji: Thumbs up"> Here&
#39;s a thread which we hope will be useful to passengers.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π§΅" title="Thread" aria-label="Emoji: Thread">Thread
#DelaysExplained

https://abs.twimg.com/emoji/v2/... draggable="false" alt="πΌ" title="Tokyo tower" aria-label="Emoji: Tokyo tower">Overhead line equipment β OLE β is the wiring and other equipment you can see above electrified railway lines. They look similar to electric pylons you see across the country.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β οΈ" title="Warning sign" aria-label="Emoji: Warning sign"> Our overhead wires carry 25,000 volts of electricity to power electric trains.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Battery" aria-label="Emoji: Battery">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π€" title="Thinking face" aria-label="Emoji: Thinking face"> OK - so I know electricity powers my train and how itβs carried, but HOW does my train get power from the overhead wires above it?
A Pantograph!

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">Scroll below

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Railway car" aria-label="Emoji: Railway car"> A pantograph is fitted on the roof of electric trains. It acts like a spring and pushes a conductive "head" onto the underside of overhead lines.
This allows electricity to flow into the train.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β‘οΈ" title="High voltage sign" aria-label="Emoji: High voltage sign">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π‘" title="Pouting face" aria-label="Emoji: Pouting face"> Delays occur when a problem affects the overhead wires or train equipment, requiring us to either slow down or stop services.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π«" title="Tired face" aria-label="Emoji: Tired face">
The disruption can be caused by just some of the following:

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β¬οΈ" title="Downwards arrow" aria-label="Emoji: Downwards arrow">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β¬οΈ" title="Downwards arrow" aria-label="Emoji: Downwards arrow">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β¬οΈ" title="Downwards arrow" aria-label="Emoji: Downwards arrow">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Electric plug" aria-label="Emoji: Electric plug">Power supply failures.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π¬" title="Wind blowing face" aria-label="Emoji: Wind blowing face">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π²" title="Evergreen tree" aria-label="Emoji: Evergreen tree">High winds blowing the overhead wires out of alignment, or vegetation onto OLE.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Station" aria-label="Emoji: Station">The trainβs equipment due to a faulty component.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π¦" title="Owl" aria-label="Emoji: Owl">Birds landing on the equipment and causing a short circuit.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="βοΈ" title="Sun with rays" aria-label="Emoji: Sun with rays">Extreme heat causing the wires to expand and sag

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π€" title="Thinking face" aria-label="Emoji: Thinking face"> Problems trigger an alert in our control centre of an electrical &
#39;trip&
#39; advising us to investigate.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β‘οΈ" title="High voltage sign" aria-label="Emoji: High voltage sign">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β" title="Cross mark" aria-label="Emoji: Cross mark"> If necessary, electricity is turned off while the cause of the "trip" is investigated. This can potentially take up to an hour depending on location. Not a quick job!

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π·ββοΈ" title="Man construction worker" aria-label="Emoji: Man construction worker">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π·ββοΈ" title="Woman construction worker" aria-label="Emoji: Woman construction worker"> Engineers arrive out on site and begin repair, usually in a specialised MEWP (Mobile Elevated Work Platform) that allows us to work quickly at height.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π«" title="Tired face" aria-label="Emoji: Tired face"> If the wires have fallen down, the solution is more complicated and a lot longer to resolve.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Thumbs up" aria-label="Emoji: Thumbs up"> When the repairs are completed, careful measurements are taken to check itβs safe and compliant. The teams and equipment then leave the site and report the repairs.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β
" title="White heavy check mark" aria-label="Emoji: White heavy check mark">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Electric plug" aria-label="Emoji: Electric plug">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β
" title="White heavy check mark" aria-label="Emoji: White heavy check mark"> We then switch the electricity back on, services are restored and electric trains are able to run as normal.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β±" title="Stopwatch" aria-label="Emoji: Stopwatch">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π§" title="Wrench" aria-label="Emoji: Wrench"> Due to the nature of the repair work, it can take some time for services to recover and return back to normal.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="β" title="Red question mark ornament" aria-label="Emoji: Red question mark ornament">How can we prevent OLE failures?

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π
" title="High-speed train with bullet nose" aria-label="Emoji: High-speed train with bullet nose">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Banana" aria-label="Emoji: Banana">The New Measurement Train, A.K.A &
#39;Flying Banana&
#39; regularly takes measurements of the OLE, while travelling at speeds of up to 125mph.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π³" title="Flushed face" aria-label="Emoji: Flushed face">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π·ββοΈ" title="Man construction worker" aria-label="Emoji: Man construction worker">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π·ββοΈ" title="Woman construction worker" aria-label="Emoji: Woman construction worker">Any faults detected are picked up and fixed by engineers before thereβs an issue.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Thumbs up" aria-label="Emoji: Thumbs up">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π‘" title="Electric light bulb" aria-label="Emoji: Electric light bulb">One of the most recent innovations weβre using is a pantograph camera.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π·" title="Camera" aria-label="Emoji: Camera">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π
" title="High-speed train with bullet nose" aria-label="Emoji: High-speed train with bullet nose">Theyβre mounted on top of passenger trains and our engineers review the footage to check for faults in the OLE.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π₯" title="Desktop computer" aria-label="Emoji: Desktop computer">

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π€" title="Hugging face" aria-label="Emoji: Hugging face"> Pretty cool!

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Battery" aria-label="Emoji: Battery">Each OLE delay is different β but we do everything we can to fix it as quickly, and as safely as possible.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π€" title="Face with look of triumph" aria-label="Emoji: Face with look of triumph"> We know delays are frustrating and we do everything we can to avoid them.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Thumbs up" aria-label="Emoji: Thumbs up">Thank you for bearing with us while we get you moving again.

https://abs.twimg.com/emoji/v2/... draggable="false" alt="π" title="Right pointing backhand index" aria-label="Emoji: Right pointing backhand index">
https://www.networkrail.co.uk/running-the-railway/looking-after-the-railway/delays-explained/">https://www.networkrail.co.uk/running-t...
Tip: mention @twtextapp on a Twitter thread with the keyword βunrollβ to get a link to it.