GB/T 14406-2011 Gantry Crane Technical Requirements and Parameters
GB/T 14406-2011 "General-Purpose Gantry Cranes" is the core national standard governing the design, manufacturing, and acceptance of gantry crane products. The standard specifies technical requirements, test methods, and inspection rules for general-purpose gantry cranes with rated lifting capacities from 3t to 320t. Compared with the bridge crane standard, the gantry crane standard imposes additional requirements for wind resistance, outrigger stiffness, and cantilever deflection. This article provides a clause-by-clause interpretation of the standard's key provisions and highlights the differences from the bridge crane standard.
GB/T 14406-2011 "General-Purpose Gantry Cranes" was issued and implemented in 2011, superseding GB/T 14406-1993. This standard is applicable to general-purpose gantry cranes with rated lifting capacities from 3t to 320t and spans from 12m to 50m, covering a variety of structural types including single-girder gantry cranes, double-girder gantry cranes, lattice-frame gantry cranes, and offset-suspension gantry cranes. All MG, MH, and MHhs series gantry cranes manufactured by Kelude Heavy Industry are designed and built according to this standard.
Scope of Application and Product Types
GB/T 14406-2011 applies to general-purpose gantry cranes with rated lifting capacities from 3t to 320t and spans ranging from 12m to 50m. Compared with the bridge crane standard GB/T 14405-2011, the gantry crane standard has a lower lifting capacity ceiling (320t vs. 500t) but accommodates a wider span range and supports cantilever configurations.
Applicable structural types: Gantry cranes come in a wide range of structural configurations, including single-main-girder gantry cranes (MH type), double-girder gantry cranes (MG type), lattice-frame gantry cranes (MHhs type), and offset-suspension gantry cranes (MHL type). Each structural type differs in outrigger design, main girder cross-section, and travel mechanism configuration.
Non-applicable products: Similar to the bridge crane standard, this standard does not apply to explosion-proof gantry cranes, metallurgical gantry cranes, or gantry crane products covered by dedicated standards. Gantry cranes intended for outdoor use shall additionally meet wind-resistant design requirements.
Core Technical Requirements
Main girder stiffness requirements: Under full static load, the mid-span deflection of the main girder shall not exceed 1/700 of the span (for duty classifications A4 to A5) or 1/800 of the span (for A6 to A7). For gantry cranes with cantilevers, the deflection at the cantilever end under rated load shall not exceed 1/350 of the cantilever length. The recommended pre-camber of the main girder is 1/1000 of the span.
Outrigger design requirements: Outriggers are the core structural components that distinguish gantry cranes from bridge cranes. Outriggers shall be designed with strength and stiffness calculations, and under combined rated load and wind load conditions, the maximum stress in the outriggers shall not exceed 1/1.33 of the material's yield strength. The verticality tolerance for outrigger installation is H/1000, with an absolute value not exceeding 5mm. The span difference between the two sides of the outriggers shall not exceed 5mm.
Wind protection safety requirements: Gantry cranes with a work duty classification of A6 and above shall be equipped with wind rail clamps or anchor devices. The clamping force of the rail clamp shall meet the anti-sliding requirements under the maximum local wind pressure. The anchor device shall be interlocked with the crane travel mechanism — the crane bridge shall not be able to start until the anchor is released. The manual/electric dual-mode rail clamp supplied as standard by Kelude Heavy Industry is rated to withstand wind force up to Beaufort scale 12.
Anti-overturning stability: Due to their high center of gravity and large windward area, gantry cranes shall undergo an anti-overturning stability check in accordance with GB/T 3811 Crane Design Standard. Under three operating conditions — no-wind condition, maximum wind in working condition, and maximum wind in non-working condition — the stability factor shall not be less than 1.5, 1.33, and 1.15, respectively.
Test Methods and Inspection Rules
The static load test and dynamic load test requirements for gantry cranes are essentially consistent with those for bridge cranes, with the addition of cantilever-end load tests and wind protection device interlock tests.
Cantilever-end load test: The cantilever end shall undergo a 1.25-times static load test and a 1.1-times dynamic load test. During the static load test, the deflection measured at the cantilever end shall not exceed 1/400 of the cantilever length. The counterweight arrangement for cantilever-end load tests differs from that for mid-span tests — a basket or a dedicated counterweight frame is typically used.
Wind protection device test: After the rail clamp is engaged, a horizontal thrust equivalent to 1.5 times the calculated wind load shall be applied, and the rail clamp shall not slide. The interlock function between the anchor device and the travel mechanism shall be verified through no fewer than three consecutive test cycles to confirm reliable operation.
Inspection rules: Factory acceptance tests are performed unit by unit, with inspection items consistent with those of the bridge crane standard. For type tests, two units are randomly selected from a qualified batch (three for bridge cranes), and the acceptance criterion is the same: zero accepted out of one rejected.
Comparison Table: GB/T 14406 vs. GB/T 14405 — Overhead vs. Gantry Type Standards
| Comparison Item | GB/T 14405overhead type | GB/T 14406gantry type |
|---|---|---|
| Lifting Capacity Scope | 3~500t | 3~320t |
| Span Limitation | General≤40m | 12~50m |
| structural features | Main Girder+End Carriage, None Outrigger | Main Girder+Outrigger, Optional Cantilever |
| main girder deflection | S/700~S/800 | S/700~S/800, Cantilever L/350 |
| Wind Protectionrequirements | None(Indoor Predominant) | A6Mandatory Above Rail clamp/anchoring |
| Anti-overturningverification | Not Required | Mandatory(Three Typesoperating conditions) |
| Outriggerrequirements | None Outrigger | Perpendicularity H/1000And≤5mm |
| type test Sampling Inspection | 3Unit(s) | 2Unit(s) |
Frequently Asked Questions
Q: What are the main differences between gantry crane and bridge crane standards?
A: The most significant structural difference is that gantry cranes have outriggers and cantilevers, which is why the gantry crane standard includes three dedicated sections covering outrigger stiffness, anti-overturning stability, and wind protection devices. In addition, the type test sampling requirement for gantry cranes is 2 units (compared to 3 for bridge cranes). The rated capacity ranges also differ: 3–500 t for bridge cranes and 3–320 t for gantry cranes.
Q: Why is the deflection limit for gantry cranes more lenient than for bridge cranes?
A: Gantry crane main girders typically span longer distances and are supported by outrigger structures. While the absolute deflection at a given span is greater, the higher self-weight and inertia of the structure mean that deflection has less impact on operating stability. The L/350 deflection limit for the cantilever end accounts for the actual load-bearing characteristics of cantilevered structures — during cantilever operation, operators are more concerned with horizontal displacement at the tip than with absolute deflection.
Q: What types of wind protection devices are available for outdoor gantry cranes?
A: The standard recommends three options: ① Manual or electric rail clamp — clamps onto the rail head; ② Anchor device — uses anchor pins inserted into ground-mounted anchor seats; ③ Windproof cable — connects the outriggers to ground anchor points. Rail clamps are sufficient for classes up to A6, while classes A7 and above should use a combination of anchoring and rail clamps.
Q: Is the camber requirement the same for gantry cranes and bridge cranes?
A: Essentially yes — the main girder pre-camber is set at 1/1000 of the span in both cases. However, for gantry cranes with cantilevers, the upward camber at the cantilever end is controlled at 1/200 to 1/350 of the cantilever length. If the gantry crane has a cantilever on only one side, the load on that side's outrigger will be significantly higher than on the opposite side, so the design must account for unequal outrigger cross-sections.
