Mast Climbing Work Platform Zone Load

Placing the same total load at the outboard edge, or all of it on one cantilevered end, produces a moment the platform and mast were never rated for even though the scale says the load is within capacity. That distinction is the difference between the rated number and a safe load, and it is why manufacturers publish load charts BY ZONE rather than as a single figure -- a platform with a six thousand pound rating does not have six thousand pounds of capacity anywhere on it. MASONRY WORK IS THE CASE THAT STRESSES IT. A platform staged with cubes of block and a mixer is carrying a very large concentrated load, placed by a forklift at whatever spot is accessible, and it is easy to exceed a zone's rating while the total remains comfortably under the platform's. Marking the platform with its zone limits, and staging to them, is what keeps that from being a judgment made by whoever is driving the lift -- and it is why the material delivery sequence on a mast climber job is a safety document rather than a logistics one. THE MAST TIES ARE WHERE THE MOMENT ENDS UP. Everything the platform carries, and everything the wind pushes, becomes a load in the ties to the building at their spacing, so the tie pattern is part of the load path and not an incidental detail. Ties anchored into cladding rather than structure, or spaced beyond the manufacturer's interval, are the failure that no load chart can see. The same load spread evenly across the platform produces essentially no moment about a centre mast and leaves every zone within its rating -- same weight, same platform, entirely different structure. A screening comparison of a load and its position against ratings the reader takes from the manufacturer's load chart. IT IS NOT A LOAD CHART and it does not generate one: zone boundaries and zone ratings are the manufacturer's, they differ between machines and between configurations, and a chart from a similar machine is not this machine's chart. It does not compute wind load on the platform or on any sheeting, evaluate the mast's own capacity or its erected height limits, or address the base, the foundation, or the tie anchorage into the structure. It does not cover twin-mast configurations, bridging, or platform extensions, each of which has its own chart. The manufacturer's load chart and erection manual, the competent person, and the erector's engineering govern.

utilization against the platform's total rating and against the ZONE rating for the load's position; the moment about the mast = load x distance; the tie force = that moment divided by the mast tie spacing.

The cantilever load-distribution relations by name. ZONE RATINGS ARE THE MANUFACTURER'S and are entered: cantilever ends carry a small fraction of the platform's rating, and a load within the total can exceed a zone. It does not compute wind load, mast capacity, erected height limits, or tie anchorage into the structure. The manufacturer's load chart and erection manual, the competent person, and the erector's engineering govern.

Two ratios and one moment on ratings the reader takes from the load chart; no chart is reproduced.

Estimate. AHJ and licensed professional govern.

Field names used by the API: platform_length_ft, cantilever_length_ft, rated_capacity_lb, zone_rated_capacity_lb, load_lb, load_centroid_ft, tie_spacing_ft, tie_capacity_lb, total_utilization_pct, zone_utilization_pct, moment_ft_lb, max_load_at_position_lb, tie_force_lb, tie_utilization_pct

• Zone ratings are the manufacturer's they differ between machines and configurationsthe manufacturer's load chart
• No wind load on the platform or on any sheetingthe erector's engineering
• No mast or anchorage capacity the base, foundation and tie anchorage are separatethe manufacturer's erection manual