A = 5m maximum for gradients between 1 in 12 and 1 in 15
A = 10m maximum for gradients between 1 in 15 and 1 in 20
B = 1.2m, with at least 1m unobstructed for the whole length.
c = 1.2m for landing lengths at the top and bottom and 1.5m if any intermediate landings are needed.

A raised kerb 100mm high is needed against the side of any drop.

Handrails are needed on both sides of any ramp which is longer than 2m.
Handrails should be easy to grip, say 45 to 50mm diameter mop handle type.
D = 1000mm height of handrail above a landing.
E = 900mm height of handrail above the surface of a ramp.
F = 300mm length of overrun of handrail from bottom riser and back of top tread.

Ends of handrails should be closed so that they do not project into a route of travel.