Station footbridge - step depth/ tread depth

[Martino]

I know this has been asked before either here or on another forum, but I can't find it!

I want to build an over the tracks station footbridge ("passenger must not cross the line etc") and wondered if there is a standard or usual riser height and tread depth for such stair cases.

I'll be doing mine 16mm/ft, but wondered what the 1:1 measurements might be.

 

[Ian_S]

Riser height and tread depth.
Stair riser heights shall be 7 inches (178 mm) maximum and 4 inches (102 mm) minimum. The riser height shall be measured vertically between the leading edges of adjacent treads. Rectangular tread depths shall be 11 inches (279 mm) minimum measured horizontally between the vertical planes of the foremost projection of adjacent treads and at a right angle to the tread's leading edge. Winder treads shall have a minimum tread depth of 11 inches (279 mm) measured between the vertical planes of the foremost projection of adjacent treads at the intersections with the walkline and a minimum tread depth of 10 inches (254 mm) within the clear width of the stair.

See - http://publicecodes.cyberregs.com/icod/ibc/2009/icod_ibc_2009_10_par140.htm

 

[Martino]

Thank you Ian. VERY much appreciated!