What is the meaning of "Over head line" and " Third Rail" in Rails?

Question

What is the meaning of "Over head line" and " Third Rail" in Rails?

Answer 1

Overhead trains get the power from cables suspended over the train.

Third rail trains get their power from an electrified rail running adjacent to the tracks.

Answer 2

They're both means of delivering electricity to trains.

Overhead line, also called catenary, is a wire suspended above the track. The train picks up electric current from the wire via a device called a pantograph, attached to its roof. The voltage is typically 25000V AC for mainline trains, or up to 1500V DC for light rail and trams.

Third rail is a metal rail running alongside the track; the train picks up current from this via a so-called "shoe" device. The supply is typically low voltage DC (750V max).

In Britain, for historic reasons, the third rail system is used in Southern England, Merseyside, and on the London Underground and Glasgow Subway, whereas overhead lines are used pretty much everywhere else.

Answer 3

Basically it's how electric trains get their electricity.  In some cases they pick it up from cables running along the track above the trains, in others there are no overhead cables but instead an electrified rail alongside the two the train runs on.

Answer 4

third rail is when an electrical powered train has to pick up power from either a second source other than disel and it gets it power from electric wire that runs overhead and picks the power from a pantograph that is on the car or locomotive the third rail is next to the track with a pick up shoe on the truck or close by

Answer 5

Over head line means that the electricity supply to power electric trains is carried by over head cables. Third rail means that the electricity suppy is carried by a third rail that runs along side the track.

Answer 6

Overhead line is where power lines follow the track to provide electricity to locomotives. However third rail provides electricity by an extra rail which is electrified. The locos that use third rail have special adjustments so they can pick up the power.

I hope this helps you.

Answer 7

From what i know, I think that overhead line is how the electricity gets into the train, aswell as third rail.... thats why when theres a third rail, you are told not to touch them cause they are electricified...

Answer 8

An overhead line is where the power supply to electric trains is carried in wires which run above the roof of the train, supported by a structure of masts, gantries, etc. known as catenary.

The train has a retractable arm or frame attached to the roof which makes contact with the wire. This is known as the pantograph.

Most electric trains use the overhead power system, with very high voltages of alternating current (AC) being converted to direct current (DC) on board the train for use in its traction motors. The train picks up through the pantograph and earths through the running rails.

Some electric rail systems, e.g. that operated by Network South East on suburban lines south of London, England, use the third rail. The third rail is fitted on either side of the running rails and carries DC which is picked up by the train using a device known as the 'shoe', which is attached to one or more bogies (trucks) on the train. The train then earths through the running rails.

The London Underground btw uses a 'four rail' system where there is an outer conductor rail beside the running rails and an inner conductor rail between them. The train picks up through the outer rail and returns through the inner one.

Answer 9

It's a means of power transmission to electric trains.  Overhead lines refer to the string of power lines the rails.  A train that moves underneath them has something called a "pantograph" on it's roof that can be raised and lowered to make contact with the line.  This is similar to how bumper cars in an amusement park get their power from overhead.

The third rail is literally a 3rd rail that runs parallel to the standard rails and there's an electric current running thru it.  It's typically placed a little higher than the other two rails.  An element sticking out from underneath the train makes contact to get power.  This is the method most subway systems use (like in NYC Subway, London Undergound/Tube, Chicago El, etc).