Tube Carrages

[admarlow]

How come different tube lines have different carrages on their trains?

[JudgeJ]

There are two basic types of Underground carriages in London – Sub surface and deep level. (Carriages on the Underground are, incidentally, termed “cars”. This stems from the influence of American engineer Charles Tyson Yerkes, who built a number of the early tube lines including the Bakerloo and the Piccadilly).

Sub service trains (the District, Circle, Metropolitan, Hammersmith and City and East London lines) generally travel in tunnels no more than a few feet below the surface and usually in twin track large tunnels. The other lines (the “tube” lines) travel in much smaller, usually single track tunnels of only 12 feet diameter.

Within these two basic types there are a large number of variations. These have come about because the different lines had their rolling stock replaced at different times from a number of suppliers. Currently the oldest sub-surface stock is the “A60” stock used on the Metropolitan and East London lines. This dates back to the early 1960s when the last part of the Metropolitan Line (beyond Rickmansworth to Amersham and Chesham) was electrified.

The oldest Tube stock runs on the Victoria Line. Although it has been refurbished it dates from 1967 when the line was first opened.

However, for a really retro experience travel to the Isle of Wight. Here former London Underground trains operate the eight-mile long Island Line from Ryde Pier Head to Shanklin. These trains date from 1938, and one of them has been restored to red “London Transport” livery. (All London Underground trains were, like the buses, painted red until the "silver" ones started appearing in the mid 1960s)

[iwbus]

Slightly off opic but in reply to the above answer I live on the IoW and there are 2 red trains. I work for the bus company and they take grat pride in their 1939 open to bus even though it's a year younger than any of the trains in daily use!

[dzug]

They were originally built by different private companies to different specifications without thought of interworking.

JudgeJ has more of the detail