What to Watch When Specifying a Double Drum Mooring Winch (and Why LBS-Grooved Drums Are Quietly Winning)

If you’re weighing up a double drum mooring winch for a refit or a newbuild, here’s the short version: the drum surface engineering matters as much as the motor on the nameplate. In fact, many customers say grooved sleeves are where rope life is won or lost. That’s been my experience on quay visits, too—fewer hockles, fewer rewinds, calmer crews.

Trend check

Electrification (VFDs), condition monitoring, and OCIMF MEG4-aligned brake settings are now normal. The quieter revolution is LBS/Lebus-style groove sleeves. They’re retrofit-friendly and, surprisingly, they bridge the gap between steel wire and HMPE lines. On a double drum mooring winch, that translates into predictable spooling, fewer crushed wraps, steadier line tension.

Typical specification snapshot (with LBS-grooved sleeves)

How the LBS sleeve is made (short version)

• Materials: Q345B/S355 base drum, 42CrMo forged sleeve ring, hardness ≈ HB 230–260.
• Methods: CNC turning, multi-start helical-parallel LBS groove machining, stress relief, shot blasting Sa 2.5.
• Testing: UT/MT on welds; groove gauge check ±0.2 mm; spooling test with wire Ø verification; brake static test at ≈1.25× rated; noise ≤85 dB(A).
• Standards referenced: ASME B30.7 (winches), OCIMF MEG4 (mooring), ABS/DNV rules, EN 10204 3.1 certs.
• Service life: 10–15 years design with periodic recoating; rope life uplift many operators report ≈25–40%.

Applications and real-world notes

Bulkers, tankers, Ro-Ro ramps, offshore supply vessels—anywhere a double drum mooring winch handles mixed rope inventories. I’ve seen sleeves retrofitted pier-side in a day, which keeps superintendents happy and stevedores friendlier than usual.

Vendor landscape (quick, practical view)

Case file: Bulk carrier mooring refit

An operator swapped plain drums for LBS sleeves on a forward double drum mooring winch. After six months: rope life up ≈35%, reported mooring time down ≈12%, and zero slippage incidents in squalls. To be honest, the bosun just liked that the line “stayed where it should.”

Customization and procurement notes

• Groove pitch matched to rope Ø and construction (EN 12385 wire or ISO 10325/10425 offshore). HMPE-friendly radii available.
• CT (constant tension) and auto rendering set to MEG4 line design parameters.
• Docs: EN 10204 3.1, NDT reports, coating TDS, FAT protocol. Pricing can start low per sleeve and scale with size—ranges widely, honestly.
• Supply capacity quoted ≈10,000 pcs/month for sleeves—handy for fleet rollouts.

Testing highlights (FAT)

Functional run at 1.1× rated pull; brake static test at ≈1.25× rated; spooling test with full drum; gearbox oil temp monitoring; noise survey. Results are logged to class witness where required.

References

1. OCIMF, Mooring Equipment Guidelines (MEG4), 2018.
2. ASME B30.7, Winches, latest edition.
3. ABS, Guide for Towing and Mooring, latest revision.
4. DNV, Offshore Standard DNV-OS-E301 Position Mooring (now DNV-ST series), latest.
5. EN 10204:2004, Metallic products — Types of inspection documents.