Crane Load Test and Acceptance Procedure: What B2B Buyers Must Verify Before Sign-Off
For any overhead crane, gantry crane, or jib crane installation, the load test is the single most important milestone before your equipment enters service. It is also the step where inexperienced buyers most often accept inadequate documentation or skip protocol. This guide covers the 125% static test, the 110% dynamic test, and the documentation package you should demand — whether you are importing an LD single-girder crane, a QD double-girder unit up to 150T, or a KBK light rail system.
Why the 125% Test Exists
Design standards such as GB/T 3811, FEM 1.001, DIN 15018, and CMAA #70 all require proof that a crane can carry more than its rated capacity. The 125% static test verifies structural integrity — girders, end trucks, bolted connections, and the runway interface. The 110% dynamic test verifies that the hoist, brake, and travel drives function correctly under load. These are not optional formalities; they are the legal basis for putting the crane into service in most jurisdictions, and they are a core requirement for CE, EAC (TR CU 010/020), and GCC/SASO conformity.
The Static Test: 125% Rated Capacity
The procedure is straightforward but must be executed precisely:
- Test load: 125% of rated capacity. For a 20T QD double-girder crane, that is 25T. For a 50T LH hoist double-girder, 62.5T.
- Lift height: Raise the load 100–200 mm clear of the ground and hold for at least 10 minutes.
- Inspection: With the load suspended, inspect girders for permanent deflection, check all bolted and welded connections, and verify the runway and rail alignment.
- Deflection limit: Measure mid-span deflection under load. For most overhead cranes, the allowable is L/800 to L/1000 depending on the applicable standard. Permanent deformation after unloading must be zero.
For gantry cranes such as the MG double-girder or RMG rail-mounted container crane, the same 125% principle applies, but the test must also confirm rail travel, skew, and, for RMG units, container spreader alignment. Shipbuilding gantry cranes often require a tailored test plan because of their span and cantilever geometry.
The Dynamic Test: 110% Rated Capacity
After the static test passes, perform the dynamic test at 110% of rated capacity. This validates the complete drive train:
- Raise and lower the load through the full hoist range.
- Travel the trolley and bridge across the full runway length.
- Test all limit switches — upper, lower, and travel end stops.
- Verify brake holding performance, especially for metallurgical cranes (YZ series) where brake reliability is safety-critical.
For light systems such as KBK light rails, jib cranes (BZD pillar, BX wall-mount), and DHP electric chain hoists, the test is scaled down but the principle is identical. A 2T jib crane still gets a 125% static and 110% dynamic test, with the same documentation.
Documentation Package: What to Demand
The test certificate is only one document. A complete acceptance package should include:
- Load test certificate — signed and dated, listing test loads, hold times, deflection readings, and pass/fail results.
- Material certificates — Q345B or Q235B steel mill certificates for girders and structural components.
- Component certificates — Schneider, Siemens, ABB, or SEW component documentation for drives and controls.
- Conformity documents — CE declaration, EAC certificate, GCC/SASO, SONCAP, or KEBS as applicable to your market.
- Operation and maintenance manual — in your language, with lubrication schedules and spare parts lists.
- Warranty statement — 12-month coverage terms and contact details.
Insist on third-party witness or a qualified engineer's signature for cranes above 20T. For QD universal double-girder cranes up to 150T, or QDS smart unmanned cranes, an independent inspection adds credibility and protects you in any future liability dispute.
Practical Advice for Importers
First, confirm the test is performed at the factory before shipment, not on site after delivery. Factory testing at Hefei Chunhua Hoisting Machinery Co., Ltd is standard, and it avoids the cost and delay of resolving issues overseas. Second, ask for video documentation of the test — this is increasingly common and gives you a verifiable record. Third, check that the test load is calibrated; an uncalibrated load cell invalidates the certificate. Fourth, for multi-crane orders, ensure each unit is tested individually, not as a batch.
Finally, plan your acceptance timeline. Production runs 30–45 days, and the load test is typically scheduled in the final week. If you require a specific third-party inspector, book them early. With no MOQ and a 4-hour quote SLA, Chunhua Crane can accommodate single-unit and mixed orders, but inspection scheduling still needs lead time.
Contact for Test Documentation and Quotes
To request a sample load test certificate, discuss acceptance criteria for your specific crane model, or get a quote, contact the export team directly:
- WhatsApp: +86 193 9277 7259
- Email: yuhua0095@gmail.com
- Website: chinacraneexporter.com
Whether you are importing a single MD electric hoist or a 125T YZ metallurgical crane, the load test and acceptance procedure is your final quality gate. Treat it as a technical negotiation, not a formality — and demand the documentation to match.