Product introduction
A mooring winch warping head drum is the rotating drum section of a ship’s mooring winch that takes multiple turns of mooring rope or synthetic tail to heave a vessel alongside. It runs under high, shock-loaded line tension in salt-laden air, so it must combine a generous wall section with an accurately machined bore, keyway and rope groove profile. Casting produces the flanged drum body, webs and internal ribs close to net shape, avoiding the cost and weld risk of fabricating from rolled plate and bar. CNC turning and milling then finish the shaft bore, brake-path seat, bolt circle and groove root radius to the concentricity the winch brake and gearbox demand.
Specifications
| Parameter | Specification |
|---|---|
| Materials | Nickel-aluminium bronze C95800 / CuAl10Fe5Ni5; duplex stainless 2205 (UNS S32205); super-duplex 2507 (UNS S32750); CF8M / 316L; ductile iron QT450-10 |
| Process | Investment casting or resin sand casting + CNC turning, boring, milling and drilling |
| Dimensional tolerance | ISO 8062 CT6–CT8 (CT6 on machined fits, CT8 on unmachined outlines) |
| Machining allowance | 2–4 mm on seating faces; boring allowance per drawing |
| Surface finish | Ra 3.2 um as-cast / shot-blasted; Ra 1.6 um on bore, keyway and brake seat; Ra 0.8 um on bearing journals |
| NDT | Ultrasonic testing (UT) on hub and rim sections; dye penetrant testing (PT) on all machined surfaces and groove roots; radiographic testing (RT) on critical weld-free sections where specified |
| Pressure testing | Not applicable (non-pressure part); optional water-film / chalk test on split-line faces when specified |
| Heat treatment | Solution anneal and quench for C95800 and duplex grades; stress relieving for QT450-10; ferritescope and hardness verification |
| Balancing | Static balancing to ISO 1940 G6.3 or per drawing; dynamic balancing on request |
| Size range | 200–1,600 mm outside diameter; up to 1,500 kg finished weight |
| Documentation | EN 10204 3.1 or 3.2, dimensional report, NDT report, material heat and heat-treatment records |
Key features
- One-piece cast drum body with integral end flanges and internal ribs — no fabricated welds in the rope-load path.
- Rope groove profile cast near net shape and CNC finish-machined to protect synthetic tails from abrasion.
- Ni-Al-bronze C95800 and duplex 2205 options give outstanding seawater corrosion and cavitation resistance.
- Bore, keyway and bolt circle machined in a single set-up to hold concentricity below 0.05 mm TIR.
- Optional hard-facing or sprayed overlay on the brake-path seat for extended service life.
- Interchangeable with existing OEM drums — we reverse-engineer from a sample part or legacy drawing.
Applications
- Shipboard mooring winches on bulk carriers, tankers and container vessels.
- Offshore support vessel and platform supply vessel mooring and towing winches.
- Harbour tug and escort tug towing winch warping heads.
- Dockside and shipyard capstans and shore mooring installations.
- FPSO and single-point mooring winch refurbishment and spares programmes.
Quality and compliance
Every mooring winch warping head drum is produced under Ningbo Ruican’s IATF 16949 certified quality management system, from controlled melting and spectrographic chemistry verification through heat treatment and final machining. Material certification to EN 10204 3.1 is issued as standard and EN 10204 3.2 certification is available when the buyer or its representative countersigns. Witness testing by the buyer’s nominated class society surveyor (LR, DNV, ABS, BV, CCS, NK or other) can be arranged on request, together with ultrasonic, dye penetrant and radiographic NDT reports and a full first-article dimensional inspection report. Type approval of the finished winch remains the responsibility of the equipment maker — Ningbo Ruican supplies the casting and machining package and the supporting documentation to help you obtain it.
FAQs
What information do you need to quote a mooring winch warping head drum?
A 2D drawing with tolerances and a 3D model if available, the specified material grade, rope groove dimensions, required NDT level, annual quantity and the target delivery port. Photographs and a sample part are helpful for replacement orders.
Which material is best for a seawater-cooled winch drum?
Nickel-aluminium bronze C95800 / CuAl10Fe5Ni5 is the traditional choice for seawater service because it resists dezincification, erosion-corrosion and biofouling. Where higher strength or chloride pitting resistance is required, duplex 2205 or super-duplex 2507 is specified.
Can you machine the brake-path seat and keyway to our drawing?
Yes. The bore, keyway, brake-path seat and split-line bolt circle are finish-machined on CNC vertical lathes and machining centres after heat treatment, so the machined geometry is not affected by subsequent thermal distortion.
How do you verify the drum before shipment?
Each drum receives 100% dye penetrant inspection of machined surfaces, ultrasonic testing of hub and rim sections to the agreed acceptance level, dimensional verification against the drawing, and static balancing to ISO 1940 G6.3 or the specified grade.
Do you supply spare drums for existing winches?
Yes. We regularly rebuild spares from legacy drawings or from a measured sample, including reproduction of obsolete groove profiles and non-standard bore and keyway dimensions.
