Modern Tramway gauge specification

[melmerby]

Hi all

 

In the days of yore when most towns/cities had a tram system running double deck trams, the track gauge didn't co-incide with the same size used for railways due to different flange/wheel specification.

 

E.G. in Glasgow to enable standard 4' 8 1/2" railway wagons to run in the tram tracks a gauge of 4' 7 3/4" was required due to the differing specifications.

 

Many modern systems have stretches of non-flanged track on long open runs and flanged tramway track in paved areas

 

Does the same variation in flange specifications apply today?

Or are trams now made to railway specification regards the wheel/flange?

 

Cheers

 

Keith

 

 

[PLD]

In fact the effective gauge of a 4' 8 1/2" tramway is exactly the same as a 4' 8 1/2" railway...

Many first generation tramway also featured stretches of open sleepered track and the tram will and always would have run perfectly happily on the railway track, but because of the much greater depth of the flanges, the railway wagon would not run on GROOVED rail of the same gauge.

 

On grooved track the wagons ran on their flanges on the bottom of the groove, the tread that would normally run on the top surface of the rail being 1 - 2" clear of the rail head. It is because of the taper of the flanges that it requires the grooved rails to be narrower to allow this.

 

The modern UK tramways generally have larger flanges than their predecessors, primarily to allow higher speeds (but still not to full mainline size) and the track has a deeper groove to accommodate them.

[Andy Reichert]

In fact the effective gauge of a 4' 8 1/2" tramway is exactly the same as a 4' 8 1/2" railway...

Many first generation tramway also featured stretches of open sleepered track and the tram will and always would have run perfectly happily on the railway track, but because of the much greater depth of the flanges, the railway wagon would not run on GROOVED rail of the same gauge.

 

On grooved track the wagons ran on their flanges on the bottom of the groove, the tread that would normally run on the top surface of the rail being 1 - 2" clear of the rail head. It is because of the taper of the flanges that it requires the grooved rails to be narrower to allow this.

 

The modern UK tramways generally have larger flanges than their predecessors, primarily to allow higher speeds (but still not to full mainline size) and the track has a deeper groove to accommodate them.

 

BTW. That's also a terrific description of how "Electric Avenue" model tram track works. 

 

Andy