Line Speed Calculations

[LucaZone]

How exactly do the designers come up with the permissible speeds of railway lines? I know this isnt exactly a common thing as speed limits dont change much, as well as the fact that there is an awful lot of factors involved when calculating the speed limit of track and curves.

However there MUST be a chart somewhere referencing curve radius + cant > common permissible speed. :P

Any ideas?

 

[TheSlash]

They also have to take into account signal spacing, signal sighting, braking curves, track maintenance etc

 

[LucaZone]

Arent signals built in conjunction with the required line speed?

 

[paul1609]

Sometimes, The Coastway line from Brighton to Portsmouth Actually has signals spaced for 90 mph although the line speed is 70-75 mph basically because of the sighting of the level crossings.

The Portsmouth Area resignalling supposedly opening at the new year is replacing all the signals in the area with 4 aspect signals to improve capacity between Havant and Portsmouth. as the signals are closer together differential speed limits will apply for the first time. Emus will be basically subject to the same limits as now but the few loco hauled trains will have lower limits. A diagram appears in the latest edition of modern railways.

 

[Dennis]

Seem to rememebr seeing something about this in one of the group standards, don't rememember which one though...http://www.rgsonline.co.uk/rail/search.html