Drives for shipyards: gantry cranes, dry docks, slipways and assembly lines
A shipyard is a unique complex of heavy-duty equipment in which drives operate under a marine climate, on open ground, and at loads atypical for general industry. Goliath gantry cranes with a lifting capacity of 600–2,000 tonnes hoist entire ship sections; trolleys and ship transporters move hulls weighing tens of thousands of tonnes; dry dock caissons must seal off basins 350–500 meters long. At every one of these stations, a drive failure means halting the construction of a vessel worth hundreds of millions of dollars, so reliability and redundancy requirements here are exceptionally high.
Industry-typical tasks
- Main hoist drives of 600–2,000 t shipyard goliath gantry cranes — dual brake systems and redundant drives on every reeving
- Travel drives of portal trolleys and ship transporters with payloads up to 30,000 t — synchronization of dozens of geared motors
- Dock gate drives (Mitre, Caisson, Flap) of dry docks — sealing and holding head differences up to 18 m
- Launching winch and capstan drives for hulls of 5,000–80,000 t on inclined slipways
- Floating dock and lock gate drives — ballast pumps, outfitting jib cranes, swing sections
- Block turning devices and positioners for welding hull sections and blocks in assembly halls
- Outfitting jib and overhead cranes 50–250 t for installing main engines, azimuth thrusters and large equipment
- Emergency and storm-hold systems for goliath gantry cranes on open slipways at gust winds up to 40 m/s
Gearboxes
At shipyards the gearbox is a critical component, and CGC holds a special position here: the sole supplier of marine gearboxes within China State Shipbuilding Corporation (CSSC), with an installed base of more than 30,000 wind-turbine gearboxes of comparable heavy-duty class. For shipyard applications CGC offers both heavy specialized hoist-winch gearboxes (600–2,000 t lifting), industrial travel units for portal trolleys, and large planetary gearboxes for dock gate drives. The portfolio is rounded out by BONENG and HUALI industrial geared motors for auxiliary drives of assembly lines, block turning devices and outfitting equipment.
Main hoist gearboxes of 600–2,000 t shipyard goliath gantry cranes
Two- and three-stage parallel-shaft gearboxes of the CGC ZSY/JST heavy-duty series with a herringbone output stage and forced circulation lubrication. Each crane is fitted with two or four independent gearboxes across the reevings, providing redundancy when lifting hull sections of 600–2,000 tonnes. As the sole supplier of marine gearboxes within CSSC, CGC tailors calculations to the seismic, wind and marine-climate conditions of the shipyard.
- — Output torque 500 kN·m – 4 MN·m per reeving
- — Service factor ≥ 2.5 for heavy-tonnage lifting
- — Forced lubrication with oil cooler and standby pump
- — Compatibility with a dual brake system (service + emergency brake)
- — Marine-grade housing with C5-M anti-corrosion coating
Travel gearboxes for portal trolleys and ship transporters
BONENG K-series (helical-bevel) and HB-series (parallel-shaft) industrial geared motors on every bogie of a multi-axle ship transporter. A 1,500–3,000 t transporter carries up to 40–80 travel bogies, and the gearboxes must be matched with minimal scatter in gear ratio so that motion stays synchronized — without slipping or jamming on the shipyard rails.
- — Gear ratio 40–125 with tolerance of no more than 0.5%
- — Power per bogie 7.5–55 kW
- — Reinforced bearings for radial load from the rail wheel
- — Compatibility with an electromagnetic brake for synchronized stopping
- — IP66 — operation on the open shipyard apron
Gearboxes for dry dock caissons and gates
Low-speed planetary or helical-planetary CGC gearboxes for opening and closing dock gate sections (Mitre Gate, Caisson, Flap Gate). They run in a duty of rare but heavy loaded starts — dry dock gates weigh 1,200–3,000 t. The housing is rated for partial submersion and seawater contact on the seals.
- — Gear ratio 200–500
- — Output torque 50–800 kN·m
- — Seawater-rated seals, IP68 on the output shaft
- — Replaceable lip seals serviceable without disassembly
- — Anti-corrosion primer per ISO 12944 C5-M Long
Gearboxes for inclined-slipway launching winches
Heavy specialized CGC gearboxes for launching winches with a wire-rope braking system. When launching a 30,000–80,000 t hull, the gearbox is sized not for acceleration but for holding back and controlled descent under gravity; brake-system loading reaches 150–300% of rated torque. The standard layout uses two gearboxes on a single drum winch with balanced torque.
- — Twin operation on a common drum shaft
- — Service factor ≥ 3.0 for holding duty
- — Redundant oil pump station
- — Compatibility with a large-diameter disc brake on the high-speed shaft
- — Bearing temperature and vibration monitoring
Geared motors for block turning devices and section positioners
In assembly halls, hull sections are welded on 100–500 t block turning devices fitted with HUALI K-series and BONENG R-series geared motors with high reduction ratios. The slow rotation (0.2–1 rpm) and precise position holding are required for quality automated welding of horizontal seams in the downhand groove ("boat") position.
- — Gear ratio 250–1,000
- — Self-locking stage or built-in electromagnetic brake
- — Motor-mounted encoder for synchronizing a pair of turners
- — Reinforced bearings against the bending moment from the workpiece
- — Stepped positioning capability
High-power electric motors
Main drives of shipyard goliath gantry cranes and floating docks belong to the domain of medium-voltage induction motors rated 500–2,000 kW at 6 or 10 kV. At a large shipyard a single crane draws up to 8–12 MW of total power split between hoisting, portal travel and trolley travel. Motors must meet marine-duty requirements: heavy-duty anti-corrosion protection, anti-condensation heaters during standstill, additional drain plugs, and operation at relative humidity up to 95%.
Hoist motors for 600+ t shipyard goliath gantry cranes
WOLONG YHTM/WD3000 medium-voltage induction motors rated 500–2,000 kW with water-to-air cooling (IC81W). They run through a medium-voltage VFD in four-quadrant mode with energy regeneration on lowering. On 1,200–2,000 t cranes 2–4 motors per reeving are typically installed with electronic torque synchronization.
- — Power 500–2,000 kW, voltage 6/10 kV
- — Marine-duty design, C5-M anti-corrosion coating
- — Anti-condensation winding heater for standstill
- — Insulated bearing on the coupling side against shaft currents
- — IP55 enclosure, Pt100 RTDs on windings and bearings
Portal travel motors of goliath gantry cranes
WOLONG YE3/YBX3 mid-power induction motors (37–250 kW) with a brake on the rear shaft end, driven through INVT VFDs with a portal-side synchronization algorithm. The key requirement is uniform motion of both crane legs over a 120–180 m span; misalignment beyond 50 mm causes the rail bogies to bind and trips the crane.
- — Power 37–250 kW, IP55, marine-duty
- — Built-in electromagnetic brake on the rear shaft end
- — Encoder with resolution not less than 2,048 ppr for synchronization
- — Compatibility with INVT Goodrive crane-duty VFDs
- — Class H insulation, S4 thermal reserve up to 60 cycles per hour
Motors for dock gate and lock drives
WOLONG YE3 general-industrial induction motors rated 30–250 kW for opening dock gates and locks. The duty is rare but heavy: 2–4 open/close cycles per day with starting torque of 1.8–2.2 times rated. They are installed in protected gate machinery rooms with additional forced ventilation.
- — Power 30–250 kW, IP55
- — Tropicalized, moisture-resistant winding impregnation
- — Starting torque ≥ 1.8 times rated
- — Additional anti-condensation heating at standstill
- — Compatibility with a soft starter or VFD
Motors for launching winches and capstans
WOLONG WD3000 medium-voltage induction motors rated 250–800 kW through a medium-voltage VFD with regenerative braking. Launching a vessel is a controlled deceleration in which the motor operates in generator mode, returning energy to the grid through the VFD's active front end. This eliminates the need for a high-power passive braking resistor.
- — Power 250–800 kW, 6 kV
- — Four-quadrant generator-mode operation
- — Encoder for precise launch-speed control
- — Thermal reserve for sustained holding torque
- — IP55 enclosure, marine-duty design
Industrial brakes
Brake systems on shipyard cranes are a matter of safety for an entire vessel under construction. A 1,200 t goliath gantry crane holding an 800 t hull section above an open slipway must carry at least two independent brake systems on each hoist drive, with each one rated to hold the full load on its own. Goliath cranes on open slipways are additionally equipped with storm rail clamps that hold the crane in place at gust winds up to 40 m/s.
Dual hoist brakes on 600+ t goliath gantry cranes
Each hoist drum carries a pair of HUAWU YPZ2/YWZ5 disc brakes: the service brake is electro-hydraulic with proportional control, and the emergency brake is a spring-applied fail-safe type. On normal stops only the service brake operates; the emergency brake closes only on loss of power, rope break or overspeed. Each brake is sized for 1.75–2.0 times the rated load.
- — Braking torque margin 1.75–2.0 times rated hoist torque
- — Emergency brake response time ≤ 0.15 s
- — IP55 enclosure, marine-duty design
- — Pad wear and disc temperature monitoring
- — Marine-society certification (CCS/RMRS)
Storm rail clamps for goliath gantry cranes
An open-slipway goliath gantry crane with a 120–180 m span and 60–80 m steelwork height carries an enormous wind load. JINGU CWZ rail clamps are mounted on each leg and engage automatically when wind reaches 20 m/s (in service) or 35–40 m/s (out of service, storm). Engagement is mechanical via spring, with hydraulic release.
- — Hold the crane at wind speeds up to 40 m/s
- — Automatic engagement on anemometer signal
- — UPS backup against loss of power
- — Compatibility with rails per GOST R 51685 / DIN 536
- — Remote release from the operator cabin
Explosion-proof brakes for paint docks
Paint and shot-blasting chambers of dry docks contain solvent vapors and abrasive dust — an Ex II 2G T3 zone under ATEX. Jib cranes and manipulators in such rooms are driven through ZHONGHAI SB explosion-proof shoe brakes with intrinsically safe electro-hydraulic thrusters. Only certified "Ex motor + Ex brake" sets are used.
- — Ex II 2G T3 certification (ATEX/IECEx)
- — Intrinsically safe thruster with non-flammable hydraulic fluid
- — Antistatic brake linings
- — Remote wear monitoring without opening the housing
- — Stainless-steel housing for corrosive atmospheres
Brakes for launching winches and anchor capstans
Inclined-slipway launching winches use large-diameter HUAWU band and disc brakes sized for sustained holding torque during launch. A backup spring-hydraulic brake with an independent power unit is fitted as well, capable of stopping the winch even on a total loss of electrical power and oil in the main system.
- — Braking torque 200 kN·m – 2 MN·m per winch
- — Proportional control of the descent
- — Backup brake with a stand-alone power unit
- — Forced cooling of the brake discs
- — Marine-society certification
Couplings and power feeds
Shipyard drives use three coupling families: drum-type gear couplings on the main hoist drives of heavy cranes and launching winches; flexible pin couplings on industrial geared motors of assembly lines; and busbar trolleys as the "electrical coupling" of mobile cranes. Separately, conductor lines and cable reels feed the cranes along rail tracks up to 800 m long.
Gear couplings on main hoist drives
YONGJING GIICL drum-type double-engagement gear couplings connect the output shaft of the heavy CGC gearbox to the hoist drum at torques of 200 kN·m – 2 MN·m. The barreled tooth profile compensates for angular misalignments up to 1.5° and thermal elongation after extended loaded operation. The same couplings are used to connect large propeller shafts and main engine drives during afloat outfitting.
- — Torque 200 kN·m – 2 MN·m
- — Angular misalignment up to 1.5°
- — Grease lubrication with a 6-month service interval
- — G6.3 balancing at peripheral speeds above 15 m/s
- — Marine-grade seals
Flexible pin couplings on assembly lines
LONGXUAN LX (LMC) and YONGJING couplings with elastic bushings damp start-up shock loads and compensate for shaft misalignments of BONENG/HUALI geared motors on hull-section conveyors, block turning devices and feed tables of automated welding stations. The elastic elements can be replaced without removing the coupling — critical for uninterrupted assembly-line operation.
- — Torque 5–125 kN·m
- — Radial misalignment compensation 0.2–1.0 mm
- — Elastic element service life not less than 30,000 h
- — Pin replacement without uncoupling the shafts
- — Compatibility with a brake pulley for jib cranes
Busbar trolleys for goliath and portal cranes
Goliath and portal cranes are fed along 400–800 m rail tracks by ANNENG heavy-duty busbar trolleys with copper or copper-clad-aluminium conductors rated for 800–4,000 A. On open slipways the busbar carries enhanced IP65 insulation, ice protection, and contact-surface heating in the winter version.
- — Rated current 800–4,000 A
- — IP65 enclosure, marine-duty design
- — 6 m section length with straight-line splicing
- — Conductor heating for winter operation
- — Compatibility with 4-pole / 5-pole current collectors
Propeller shafts and main-drive couplings on afloat outfitting
During afloat outfitting at the quay, the main engine, reduction gear, shafting and azimuth thruster are installed. YONGJING gear couplings connect the thrust shaft, intermediate shafts and propeller shaft; correct sizing and balancing are critical for vibration-free behavior on sea trials. SDS supplies complete coupling sets for outfitting of CSSC and other shipyard projects.
- — Torque 100–800 kN·m on the propeller shaft
- — G2.5 balancing for shaft lines above 100 rpm
- — Compatibility with the main-gear thrust bearing
- — Marine certification (CCS/RMRS/Lloyd's Register)
- — Anti-corrosion coating on exposed surfaces
Applications gallery
Our solutions for this industry
SDS portfolio brands that cover typical applications in this industry.
- CGCindustry flagship — the sole supplier of marine gearboxes within CSSC, 30,000+ wind-turbine gearboxes of heavy-tonnage class; heavy gearboxes for 600–2,000 t crane hoists, dock gates and launching winches
- WOLONGmedium-voltage motors for main crane drives 500–2,000 kW (YHTM, WD3000), marine-duty design, IC81W water-to-air cooling
- BONENGgeared motors for portal trolleys and ship transporters (K, HB series), industrial drives for assembly-line conveyors
- HUAWUdual brake systems for heavy 600+ t goliath gantry cranes (YPZ2, YWZ5) — service + emergency, brakes for launching winches
- JINGUstorm rail clamps for goliath gantry cranes on open slipways, holding at gust winds up to 40 m/s
- ZHONGHAIexplosion-proof brakes for paint and shot-blasting docks (Ex II 2G T3), intrinsically safe thrusters
- ANNENGbusbar trolleys 800–4,000 A for large shipyard goliath and portal cranes, marine-duty IP65 with conductor heating
- YONGJINGGIICL gear couplings for main hoist drives and propeller shafts, marine certification CCS/RMRS
- LONGXUANflexible pin couplings LX/LMC for assembly lines, block turning devices and outfitting jib cranes
- HUALIgeared motors for block turning devices and section positioners (K series), drives for automated welding stations
- INVTGoodrive crane-duty VFDs with portal-side synchronization and regenerative braking for launching winches
- DONLYhydraulic power units for dock gate drives, launching winches and floating-dock ballast systems
Image credits: Wvdp (CC0) · Andrew (CC BY 2.0) · Public Record Office of Northern Ireland (No restrictions (public domain)) · Wikimedia Commons (Public domain) · IMessmer (CC BY-SA 3.0)