Trains can travel faster and more efficiently if they’re electric – but how do you electrify the network?
Diggers, wires, pylons, cranes – all of this machinery and equipment has a lot to do with it.
Railway electrification is a great thing. It enables faster, more environmentally friendly, and more reliable trains.
As well as being better for passengers, electric trains are lighter and cause less wear and tear to the track.
However, to make these amazing changes, there is going to be some short-term disruption whilst overhead lines are installed…
When the Victorians built the railways, they built them for steam trains. Many things they built weren’t designed with electric trains using overhead lines in mind.
Things like tunnels and bridges might not have enough room to fit both the trains and the new overhead wires that need to be installed.
To create room, engineers might need to excavate and lower the track bed. Bridges might need to be jacked up or even rebuilt if they are too low…
Changes might also need to be made around stations to make sure there’s enough of a gap between buildings and the overhead wires to keep everyone at a safe distance and prevent people accidentally electrocuting themselves!
It can cost a lot of money to make these changes but safety is the top priority. Platforms themselves might need to be lengthened to accommodate the longer, higher capacity electric trains.
Once engineers have created enough space to accommodate the overhead wires, they then can start to build the infrastructure that will supply the trains with the electricity.
This includes electricity sub-stations that provide the 25,000 volts of power to the wires, and masts and pylons that hold the wires high above the trains.
Overhead line masts need strong foundations to ensure they don’t sway when trains pass.
These foundations are created by either ‘piling’ – that’s when hollow steel tubes are first vibrated into the ground and then struck repeatedly with a large hydraulic hammer until they are deep enough – or by pouring concrete into excavated holes to create a solid base onto which the masts are attached.
Masts are placed approximately every 50 metres to keep the electrified wires running between them under the correct tension for trains to pass safely.
Attached to the masts are cantilevers – structure that hold the electrified wires above the tracks. These may reach across one, two or more lines.
To help electrify new lines, Network Rail has a state of the art High Output Factory Train that helps engineers electrify more tracks more quickly.
This train has 23 vehicles – 5 dig the foundations and fill them with concrete, while another 5 drive the steel tube piles into the ground.
3 vehicles install the main steelwork for the OLE structures, whilst a further 5 install ‘small parts steelwork’ to the masts, and 3 hang up the wires.
The train carries everything it needs to install the overhead wiring and the structures that hold the electrical equipment, so as well as piling tubes and steel gantry sections, it carries drums of electrical wire!
Find out more about Britain’s railways!
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