Angle picks the family
Each access type owns a slope band; hybrid compromises between bands tend to perform worse than either neighbour.
Access screening · AS 1657
Stair, ladder or walkway?
The angle usually decides the access type — but the angle people have and the access people need are often different things. This check screens slope, frequency of use and what workers carry, then points to the access family to design around.
Pathway at a glance
AS 1657 access-angle spectrum
The angle normally selects the access family, but frequent use and carried loads push the choice toward flatter, safer access.
How to use this summary
- Near-level to about 20 degrees is walkway/ramp territory.
- About 20 to 45 degrees is stairway territory.
- The 45 to 60 degree compromise band should usually trigger a layout redesign.
- Steeper access may be step-type or rung ladder territory only when the task suits a ladder family.
Confirm exact band edges, preferred angles and detailed geometry against the current AS 1657 edition.
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Choose the access family
Screen scope, slope, actual use and height or edge exposure before accepting a stair, step ladder, rung ladder or walkway.
ScopeSlopeUseResult
Scope
What is the access for?
Start by confirming that the route is fixed workplace access to plant or equipment, not public building access or temporary task access.
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The selection ladder
The most useful access decision is often discovering that the layout needs to change before a product can be selected.
Use overrides angle
Frequent access and carried loads push the design toward flatter, more walkable access even where a steeper option physically fits.
The 45–60° trap
Brownfield layouts often force this compromise band. Treat it as a redesign trigger, not a product-selection problem.
Falls hierarchy sits above all of it
Eliminating the need to access the area, or providing safe collective protection, beats any ladder detail.
03
Worked screening examples
01
Conveyor access
Conveyor drive platform
Context: Daily greasing round with space initially shown as a 65° access route.
Screening view: Frequent use pushes the result toward a stair or layout change rather than accepting a steep maintenance ladder.
02
Tank access
Tank top inspection
Context: Quarterly inspection, no carried loads, steep access is available.
Screening view: A rung ladder may screen as the correct family, but the landing and fall-protection decision still needs to be made deliberately.
03
Retrofit access
Mezzanine plant room
Context: A 50° ship-ladder style compromise is proposed because nothing else seems to fit.
Screening view: The tool treats the layout as the problem and recommends changing the route rather than forcing a hybrid.
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Reference basis
This page paraphrases the access-selection logic and does not reproduce the standard's selection figure.
AS 1657Selection, design and installation of fixed platforms, walkways, stairways and laddersWHS RegulationManaging the risk of falls and applying the falls hierarchyNCC / AS 1428 boundaryNon-plant public access and accessible-building pathways
Important limitation
Screening guidance for choosing an access family, based on the published structure of AS 1657. Band edges, preferred angles and detailed requirements must be confirmed against the current edition of the standard, and layout decisions on real plant may need engineering review. This page does not reproduce the standard.
Get Engineering Help
Ask an engineerIs the layout forcing the wrong access?
XPO Engineers can review brownfield access layouts, platform constraints, clearances and structural interfaces before a non-compliant compromise gets built.