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April 18, 2017

Stairways and Platforms: Stairways – Terms and Definitions

The flight of a stairway

uH

Climbing height

is the vertical distance between the horizontal ground level and the horizontal platform or landing.

g

Going

is the horizontal distance between he nosing* of two consecutive steps.

e

Headroom

is the plumb-vertical distance between the nosing* of two consecutive steps.

h

Rise

is the height difference between two consecutive steps.

l

Platform length

r

Overlap

is how far a step extends over the step below. This is based on the difference between the depth of step and the going.

alpha

Pitch

is the angle between the pitch line and the horizontal ground level.

w

Width of flight

is the distance between two strings.

p

The pitch line

is produced by laying a ruler across all the nosing* in a stairway.

t

Depth of step

is the total depth of a step from the nosing* to the rear top edge of the same step.

c

Clearance

is the distance above the pitch line – as measured at a right angle to the pitch line – that should, if possible, be kept free of all obstacles.

* The nosing is the front upper edge of a step.

 

GuardRail2

The guard-rail

The hand-rail is the uppermost part of a guard-rail that is close to hand. The knee-rail runs in parallel with the hand-rail. Vertical columns or balusters can also be used for this purpose, but are uncommon and unnecessary in an industrial environment. Foot-rails stop objects from falling off platforms. They are not required on stairways. The vertical components used to secure a platform or stairway are called stanchions.

Categorizing by pitch

Stairways have a pitch of up to 45º. They are required as a means of accessing stationary working platforms.

Machine steps and stepladders have a pitch from upwards of 45º to a maximum of 70º. The use of these steps is permitted only when it is not possible to install a stairway due to operational reasons, e.g. because a stairway would narrow a traffic route, adjacent workstations of different heights are connected, or a stairway would prevent access to resolve a malfunction.

Ladders have a pitch of 70º to 90º and may be used only when the use of stepladders is not possible for technical and operational reasons.

DefinedPitch2

 

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