A new or modified truck-mounted crane is handed over to operations only after a documented three-phase commissioning sequence: no-load trial, static load test at 125% of rated capacity, and dynamic movement load test [S1][S2].
OSHA requires that "prior to initial use all new and altered cranes shall be inspected to insure compliance" [S2]. The practical effect is that no crane, including truck-mounted units covered under ASME B30.5, enters service until mechanical, structural, electrical, and load-test records are signed off by a competent person [S2][S3].
Pre-Commissioning Mechanical and Structural Inspection
Inspection before any power-on trial covers the bridge frame, end trucks, welds, anchor bolts, and runway alignment, with misaligned rails identified as a direct cause of skewing and binding [S2].
Wire-rope checks require the rope to be securely fastened to the drum with at least two wraps remaining on the drum when the hook is in its extreme low position, per OSHA [S2]. Hooks, latches, sheaves, pins, shafts, and bumpers are visually inspected for wear, cracks, or deformation, and any damaged crane is to be immediately taken out of service [S2][S3].
For truck cranes specifically, the outrigger pads, boom pivot pin, slewing ring bolts, and counterweight retention fasteners sit on the same mandatory checklist as the lifting mechanism, since the chassis is the foundation of the test load [S1][S3].
Electrical, Brake, and Safety-Device Verification
With the main isolator open, insulation resistance of motors and cables is measured with a megohmmeter, and every circuit is checked against the wiring diagram before re-energising [S1][S2].
Brake verification is mechanical: with power off, the brake is tested by hand for firm grab and positive hold; twin brakes on the same drive are adjusted to act together within the manufacturer's tolerance band [S1][S2].
Limit switches (hoist upper/lower, travel end-stops), emergency-stop, warning gong, overload relay, and any load moment indicator (LMI) or rated capacity indicator (RCI) are functionally exercised, with LMI/RCI accuracy verified by a test lift using a certified test weight [S2][S3].
No-Load Trial Run
The no-load test exercises every motion at operating speed, without a hook load, to confirm direction, smoothness, brake response, and limit-switch cut-off [S1][S2].
For a truck crane this stage covers hoist up/down, boom elevate, telescope extend/retract, slewing left/right, and outrigger deployment, with the operator selected for the trial on the basis of documented experience [S1][S2].
Any grinding, abnormal noise, hunting, drift under hold, or limit-switch overrun at this stage sends the crane back to maintenance, not forward to load testing [S1].
Static Load Test at 125% Rated Capacity
A certified test load not exceeding 125% of the rated capacity is suspended for a defined hold period, and the crane is observed for structural deflection, brake drift, and hook-seating behaviour [S1][S5].
Per OSHA-aligned practice, "a certified and rated load test means that test loads cannot exceed 125 percent of the rated load," and the test load is pre-weighed, with sling and shackle certificates on file before lift [S1][S5].
For a truck crane, the static test is repeated over the working arc (front, side, and rear) and at minimum and maximum boom radius, since lifting capacity is radius-dependent and a single-angle test is not representative of on-site duty [S1].
Dynamic (Movement) Load Test
The dynamic test runs the same 125% test load through full operating motions: hoist, lower, traverse, and slew, at rated speed, to validate the drive train and brakes under working stress [S1][S2].
Acceptance criteria include smooth acceleration, no motor overload trip, no brake slip, hook alignment on the load centre, and confirmation that all safety devices still function at the test load [S1][S2].
On truck cranes the test also covers travel on outriggers at low speed with a partial load, since road-class travel is a separate duty cycle not exercised in the no-load or static phases [S1].
Documentation, Standards, and Periodic Re-Test
Load-test reports are filed at the site of the crane for review by designated employees, and a written report is produced after every inspection cycle, with replacement parts required to meet the original specification [S3][S5].
Reference frameworks in active use are OSHA 1910.179 for overhead/underhung cranes, ASME B30.2 for overhead and gantry cranes, ASME B30.5 for mobile and truck-mounted cranes, CMAA specification 70/74 for duty classification, and Safe Work Australia's Guide to Inspecting and Maintaining Cranes (Dec 2015) for inspection frequency [S2][S3].
Routine re-inspection is scheduled at intervals set by service class, commonly weekly, monthly, or quarterly, and never less than annually where manufacturer intervals are not available [S3]. For comparison across lifting equipment categories, the criteria set used here (rated load, duty class, brake redundancy, limit devices, documentation) maps directly to the selection logic in a truck crane working principle brief, where the same parameters determine both design and acceptance [S1][S3].
Spec-level background on the components involved: tensile testing machine, and construction machinery and equipment.