Suspended Scaffold Calculator

Not on account of height alone. Building Height has zero effect on Total Suspended Load, Load Per Suspension Point, or Min Rope Breaking Strength across its full 1-1,000 ft declared range. It only drives Total Wire Rope (how much rope length is needed to reach from the roof rigging down to the working height plus safety tail), which is a length requirement, not a strength requirement -- a taller building needs more rope, not stronger rope.

Yes, and it is usually the number that actually governs. Per OSHA 1926.451(a)(4), the wire rope must support 6x the load transmitted "with the scaffold operating at ... the rated load of the hoist" -- not merely 6x whatever is on the platform today. This calculator computes Min Rope Breaking Strength as 6x the GREATER of the actual computed Load Per Suspension Point or Hoist Rated Capacity, so raising Hoist Rated Capacity raises Min Rope Breaking Strength directly once it exceeds the computed load per point (which is true across most of its 100-5,000 lb declared range for a typical platform load).

Yes -- wire rope strength and hoist motor capacity are two independent failure modes, even though both are now sized using Hoist Rated Capacity. A wire rope correctly rated for 6x the hoist's rated capacity says nothing about whether the hoist MOTOR itself can actually lift Load Per Suspension Point -- that is Hoist Utilization, which reads above 100% (flagging Hoist Overloaded) whenever the actual load exceeds what the motor is rated to lift, independent of whether the rope passes its own check.

It always increases Total Suspended Load and Load Per Suspension Point -- each additional worker adds a fixed 250 lb (OSHA's assumed weight with PPE) to Live Load, monotonically across the full 0-8 worker declared range. Min Rope Breaking Strength, though, only rises with worker count once Load Per Suspension Point exceeds Hoist Rated Capacity; below that crossover, Hoist Rated Capacity is the greater of the two and governs Min Rope Breaking Strength on its own, so adding workers has no effect on rope strength (though it still raises Hoist Utilization). At this calculator's default 1,500 lb Hoist Rated Capacity, Load Per Suspension Point never reaches that crossover across the full 0-8 worker range, so Min Rope Breaking Strength stays flat at 6x Hoist Rated Capacity regardless of worker count -- a lower Hoist Rated Capacity is needed to see workers move it.

It's a federal regulatory minimum, not a margin this calculator invented. OSHA 29 CFR 1926.451(a)(4) requires every suspension rope on a powered adjustable suspension scaffold to support at least 6 times the maximum load transmitted at the hoist's rated capacity, or 2 times the hoist's stall load if that's greater, and (a)(5) separately caps stall load at 3 times rated load. This calculator has no stall-load input, so it applies the rated-load branch of the rule directly rather than approximating a stall-load scenario it can't verify.