Overhead Crane Load Testing and Commissioning Requirements: A Practical Guide

Load testing and commissioning is the last gate between a newly installed or modified overhead crane and safe production use. Get it right and the crane is documented, code-compliant and ready to run for decades. Get it wrong and you inherit a latent structural, electrical or brake defect that will surface at the worst possible moment.

This guide summarizes what CSA B167, ASME B30.2 / B30.17 and OSHA 1910.179 actually require, and how a proper commissioning package should be structured. It pairs with our Crane Inspection Program Consultant and Crane Service Program Consultant pages.

When a load test is required

A rated load test is triggered by any of the following:

• New installation — before first production use.
• Relocation or re-erection of an existing crane on a new runway.
• Structural alteration or repair to load-bearing members (bridge girders, end trucks, trolley frame, hoist load block, hooks).
• Major electrical or control modification that affects hoist braking, limits or overload protection (VFD retrofit, new brake, new upper limit).
• Replacement of load-bearing components — hoist unit, rope drum, load block, hooks.
• Periodic re-certification on a schedule set by the owner, insurer or jurisdiction.

Routine wire rope, brake or contactor replacement typically does not require a rated load test, but a functional test is always required.

Proof load values by code

• CSA B167-16 / B167-26 — 125% of rated capacity for new cranes and for cranes after structural alteration. Repairs to load-bearing parts are tested at 100–125% depending on the scope.
• ASME B30.2 (top-running) and B30.17 (under-running) — test load not less than 100% and not more than 125% of rated capacity unless the manufacturer specifies otherwise.
• ASME B30.16 (below-the-hook hoists) — 125% of rated capacity for new or altered hoists.
• OSHA 1910.179(k)(2) — before initial use, all new and altered cranes shall be tested at not less than 100% and not more than 125% of rated capacity.

The 125% number is the working ceiling for almost every overhead crane load test in North America. Testing above that value is not a "safety margin" — it can permanently deform structure and voids the manufacturer warranty.

Commissioning sequence

A proper commissioning package runs in this order. Skipping steps is the single most common cause of failed sign-offs.

1. Pre-energization checks — runway alignment, rail sweep, bolt torque, grounding, cable management, limit-switch installation, nameplates, fall arrest and access.
2. No-load functional tests — bridge, trolley and hoist in both directions, all speeds, all pendants/radios, e-stops, mainline disconnect, upper and lower geared limits, weightless block-operated limit, anti-collision, warning devices.
3. Brake tests, no load — hoist holding brake, control braking (VFD), bridge and trolley brakes, coast distances against manufacturer spec.
4. Rated load test — 100% — lift, hold, traverse the full runway, stop, hold suspended for a minimum time (typically 10 minutes) while inspecting girder deflection, brake slip and structural response.
5. Proof load test — 125% — same sequence with a certified test load. Measure deflection at mid-span and compare against the manufacturer's allowable (typically L/888 to L/1000).
6. Overload device test — verify the hoist overload cuts out before the mechanical rated-load limiter engages.
7. Post-test inspection — full visual and NDT where required, torque check on critical fasteners, brake wear check.
8. Documentation — signed test report, deflection measurements, calibration certificates for the test load, operator qualifications, drawings marked "as-built."

Choosing the test load

Solid weights, water weights and load cells all have a place. The right choice depends on capacity, headroom, floor loading, availability and risk.

• Solid weights — simple, cheap for small capacities, but hard to source, hard to rig safely and impossible to fine-tune above ~10–20 t.
• Water weights (suspended water bags) — the industry standard for cranes above ~5 t. Fill/drain in place, incremental loading, no swinging solid mass overhead. See our dedicated post on water weights and Unique Group.
• Hydraulic pull testers / load cells — used when there is no headroom for a suspended load, or on davits and monorails where a suspended bag will not clear.
• Existing plant loads — acceptable for functional verification, never acceptable as a certified proof load unless independently weighed and certified.

Every test load must be independently certified. "We think it's about 10 tons" is not a test.

Documentation that must exist at handover

A commissioning package that will survive an insurance audit, a Ministry of Labour visit or an OSHA inspection includes:

• Manufacturer data report, general arrangement drawings and electrical schematics
• Runway survey (rail alignment, span, elevation, camber)
• Erection and installation checklist signed by the installer
• Load test procedure and signed test report with the certified test load value
• Deflection readings vs. allowable
• Brake, limit and overload test results
• Operator training records (theoretical and practical — see our operator training post)
• Recommended preventive maintenance program and initial spare-parts list

Where owners get burned

The pattern we see on projects we're brought in to rescue:

• Test load not certified — the crane "passed" 125%, but no one can prove what the bag actually weighed.
• Deflection never measured — bridge is sagging under service load and no one has a baseline.
• Overload device never proved out — the setpoint drifted and no one caught it.
• No signed commissioning report — insurer refuses to cover a subsequent incident.
• Operators trained on a different crane — pendant layout, limit behaviour and brake feel are all different.

A vendor-neutral commissioning witness costs a fraction of one lost production day.

How CAG helps

Crane Advisory Group writes owner-side load test and commissioning procedures, witnesses the test, reviews the OEM's documentation package and signs off — or refuses to sign off — on behalf of the owner. Talk to us about your next new crane, modernization or repair project.