GB/T 29561-2013 Portal Crane Standard Specifications
GB/T 29561-2013 "Portal Cranes — Technical Specification" is the governing technical document for the design, manufacturing, and acceptance of portal cranes. The standard defines the technical requirements, safety requirements, test methods, and inspection rules for portal cranes used in ports and shipyards. It refines and supplements GB/T 17495-2009 for harbor portal cranes and is applicable to general-purpose and harbor portal cranes with a rated load of ≤100 t.
GB/T 29561-2013 is the product technical specification for portal cranes, covering technical requirements, test methods, and inspection rules. Portal cranes are among the most essential cargo-handling machines in ports and shipyards, and their technical specification directly affects operational efficiency and job-site safety.
Whole-Machine Technical Requirements
GB/T 29561-2013 sets out systematic requirements for the overall performance of portal cranes. A portal crane consists of the portal frame structure, slewing platform, jib system, hoisting mechanism, luffing mechanism, slewing mechanism, and travel mechanism. The standard specifies that the work duty of the crane (per GB/T 3811 Crane Design Standard) must be no lower than A6 for port handling service or A5 for shipyard installation service. For overall stability — with the crane supported on four outriggers in working condition — the anti-overturning stability factor must be ≥1.33 under working wind load and ≥1.25 under maximum non-working wind load. In the non-working condition, the crane must be able to retract the boom to the minimum radius position and raise the hook to its highest point to minimize the wind load area. For the metal structure under full load, the static stiffness requirement at the main boom tip is: the vertical deflection of the boom tip under rated load must not exceed 1/200 of the boom length, and the horizontal displacement must not exceed 1/400 of the boom length.
Mechanism Technical Requirements
The standard specifies technical requirements for each crane mechanism. Hoisting mechanism — dual-motor or dual-brake configuration (on larger-capacity models); hoisting speed is split into a high-speed range (lifting speed loaded ≥12 m/min) and a low-speed range (≤2 m/min) to suit different duty cycles. Hoisting height — harbor portal cranes typically require a hoisting height of ≥22 m (sufficient for stacking four layers of containers), while shipyard portal cranes require ≥35 m (for lifting large ship sections in dry docks). Luffing mechanism — driven by rack-and-pinion or screw-type luffing, with a derricking speed of 5–15 m/min. Changes in the boom center of gravity during luffing must be automatically compensated by a counterweight or rope-compensation system to minimize luffing power consumption. Slewing mechanism — driven by a slewing bearing (three-row roller or crossed-roller type) or a large slewing ring, with a slewing speed of 1–2 r/min. The standard requires that the slewing brake be capable of reliably stopping the boom at any slewing angle while carrying a rated load at maximum working radius. Travel mechanism — long-travel speed is typically 15–25 m/min for port service or 10–20 m/min for shipyard service, and the crane must be equipped with a rail clamp or anchor device to ensure wind safety in the non-working condition.
Jib System and Luffing Compensation
The standard sets detailed requirements for the jib system and luffing compensation. Boom types — portal crane booms are classified as straight booms (simple structure, easy to manufacture, suited to small- and medium-capacity cranes) and combination booms (main boom plus jib forming an "elephant-trunk" configuration that maintains near-horizontal load travel across a wide radius range, suited to harbor portal cranes). Luffing compensation — the combination boom or moving-counterweight system must achieve horizontal load displacement during luffing, meaning the hook height variation at any working radius must not exceed ±200 mm. This ensures the load does not rise or fall unintentionally during luffing operations, improving handling efficiency and reducing energy consumption. Boom balancing — the jib system (including boom dead weight, lifting spreader, and load) must be properly force-balanced through counterweights or spring systems — the difference in luffing drive force between full-load and no-load conditions must not exceed 30% of the full-load drive force; otherwise, luffing power consumption becomes excessive. Boom limiting — a radius limit switch (controlling maximum and minimum radius) and a radius indicator (displaying the current working radius in real time in the operator cab) must be fitted.
Electrical System and Safety Devices
The standard specifies requirements for the electrical system and safety devices. Power supply — harbor portal cranes typically use a cable reel power supply that automatically pays out and retrieves the cable as the crane travels, with a supply voltage of 380 V/415 V (low voltage) or 6 kV/10 kV (high-voltage incoming). Electrical protection — overcurrent protection, overvoltage/undervoltage protection, phase loss protection, earthing protection, and leakage protection must be provided. Safety devices — a portal crane must be equipped with the following safety devices: a load limiter (automatically cuts off hoisting-up and radius-increasing motions when the load exceeds 110% of the rated capacity), a load moment limiter (LML) (alarms and automatically stops dangerous-direction motions when the load moment exceeds 105% of the rated value), a hoisting height limit switch (automatically stops hoisting-up when the hook reaches the upper limit), a lowering limit switch (stops lowering when the hook reaches the set lowest position), a radius limit switch (limits the maximum and minimum working radius), a slewing angle limit switch (limits the slewing range to prevent cable twisting), an anemometer (alarms when wind speed reaches ≥20 m/s), plus travel limit switches and buffers on each mechanism. Kelude can design and manufacture harbor and shipyard portal cranes in accordance with the GB/T 29561 standard.
| mechanism | drive mode | speedrange | safety device |
|---|---|---|---|
| Hoisting mechanism | Motor+Reducer / Gearbox+Drum | high speed≥12, low speed≤2m/min | Double Brake+overload limiting |
| Luffing mechanism | rack/screw drive | 5~15m/min | Working radiuslimit switch+balance compensation |
| Slewing mechanism | Motor+Reducer / Gearbox+Slewing Bearing | 1~2r/min | slewing limit+Brake |
| travel mechanism | Motor+Reducer / Gearbox+travel Crane wheel | 10~25m/min | Rail clamp+Anchor device |
FAQ
Q: What are the main working mechanisms of a portal crane?
A: A portal crane consists of four primary mechanisms: 1) Hoisting mechanism — handles vertical lifting of the load, comprising an electric motor, reducer, drum, wire rope, and hook block; 2) Luffing mechanism — changes the boom angle to adjust the working radius, available in wire rope luffing and rack-and-pinion luffing configurations; 3) Slewing mechanism — enables 360° rotation of the boom around the slewing center, consisting of a slewing bearing, slewing reducer, and drive unit; 4) Travel mechanism — moves the entire crane along the rails via motorized and idler bogies. The coordinated operation of these four mechanisms allows the portal crane to achieve precise positioning of loads in three-dimensional space.
Q: What operating conditions are considered in the stability verification of a portal crane?
A: The stability verification covers the following conditions as required by the standard: 1) Stability under working conditions — with the maximum rated lifting capacity combined with the maximum radius, accounting for wind load (working wind speed ≤ 20 m/s) and inertia load, the stability factor must be ≥ 1.15; 2) Stability under non-working conditions — the crane must withstand storm wind loads (based on the 50-year return period maximum wind speed for the region) with a stability factor ≥ 1.25; 3) Stability during erection and dismantling — stability verification at each stage of assembly and disassembly, requiring that the overturning moment does not exceed the stabilizing moment; 4) Rope breakage condition — considering the impact load resulting from the sudden fracture of either the hoisting or luffing wire rope.
Q: What are the wind protection safety requirements for portal cranes?
A: Due to their large windward area and high center of gravity, wind protection is a critical safety priority for portal cranes. The standard requires: 1) Dual wind protection using both rail clamps and an anchor device; 2) A working wind speed limit of ≤ 20 m/s (Beaufort scale 7) — operations shall be stopped and the crane moved to its anchoring position when this limit is exceeded; 3) An anemometer for real-time wind speed monitoring, with an audible and visual alarm triggered when wind speed exceeds the alarm threshold (17 m/s); 4) Both the rail clamps and anchor device must be engaged simultaneously in non-working conditions; 5) In coastal regions, windproof cables must also be installed, with the crane designed to withstand wind speeds of up to 55 m/s. Kelude portal cranes come standard with an anemometer, electric rail clamps, and an anchor device.
Q: What are the key inspection points for daily maintenance of a portal crane?
A: Daily inspection: verify proper brake operation on all mechanisms, check wire ropes for broken wires and wear, and listen for abnormal noise from the slewing bearing. Weekly inspection: check lubrication and wear of the luffing rack and gear, verify shaft alignment of all mechanism couplings, and inspect the contact condition between wheel flanges and the crane rail. Monthly inspection: verify the torque of slewing bearing connection bolts (must reach 100% of the design value), and inspect critical weld seams of the metal structure for cracks — with particular attention to the boom root and the connections between portal legs and cross beams. A comprehensive load test and stability verification shall be performed every six months.
