Blog IronAxis Technical Team 27 Oct 2026 views ( )

Marine Electric Hoists: Rack-and-Pinion Trolleys and Salt-Fog Protection

Marine hoists face two problems rarely seen onshore: when a vessel lists or trims, the trolley can slip or creep along the rail because wheel friction is no longer enough; and salt fog and high humidity attack both hoist body and load chain.

Zhejiang Vertex International Trade Co., Ltd. builds marine hoists with two targeted upgrades — a rack-and-pinion trolley drive, and two-layer corrosion protection combining marine-grade paint with Dacromet-coated chain.

Rack-and-pinion trolley: traction without friction

A standard trolley transmits travel force through wheel-to-rail friction. On a damp or oily rail, with gravity acting along the rail as the hull inclines, adhesion drops — the trolley slips or shifts after stopping.

Here a rack is fixed along the rail and a pinion on the trolley meshes with it, so drive force passes through tooth engagement rather than friction. The trolley keeps travelling and positioning even on an inclined hull. Rail profile and mounting dimensions must match, so please confirm rail section, rail length and headroom when enquiring.

Corrosion protection in two layers

The hoist body uses heavy-duty marine coatings from established suppliers such as Jotun and Hempel; coating grade, number of coats and dry-film thickness are confirmed per order, and ISO 12944 marine systems or salt-spray reports can be supplied on request.

The load chain receives Dacromet treatment — a zinc-aluminium flake coating with better salt-spray resistance than conventional blackening and no hydrogen-embrittlement risk from electroplating.

Built for shipboard maintenance

Pinion, rack and chain are replaceable without special tooling; brake and electrical components are positioned for inspection on board.

Information needed for selection

Installation location and duty — engine room or open deck

Rail section, length, headroom, hull inclination

Capacity, lift height, working class

Shipboard power — voltage, frequency, phase (60 Hz is common)

Coating system and salt-spray test requirements

Class inspection — CCS, BV or DNV certificates

Note: a paint brand is not a class approval. Certificates are applied per model, configuration and delivery batch.

Zhejiang Vertex International Trade Co., Ltd. Parent Companies:

1. Zhejiang Boneng Lifting Technology Co., Ltd. (Former Name: Taizhou Boneng Lifting Machinery Equipment Co., Ltd.)