Parts of a Boat

The restraint of cargo so it cannot shift, tip, roll or break free during a voyage. Securing arrangements account for vessel accelerations, cargo properties, friction, stowage and the strength and angles of lashings and fittings. Checks continue during the passage because settlement, vibration and weather can reduce restraint.

A fitting that grips or restrains anchor chain independently of the windlass. It transfers anchoring or sea loads to the vessel’s structure and relieves the windlass brake and gearing. The stopper must match the chain, be correctly engaged and be released under controlled conditions.

The area through which a boom can travel as it moves across a vessel. Crew, passengers, rigging and equipment should be kept clear because the boom may cross rapidly during a tack, gybe or accidental wind shift. The danger includes the mainsheet and tackle as well as the spar itself.

The length of rope tail buried inside another part of a rope to form a splice. Required bury depends on rope construction, fibre, diameter, splice type and loading. An inadequate or poorly tapered bury can slip or concentrate stress, so the rope manufacturer’s splice instructions should be followed.

A principal standing-rigging shroud running from the mast or masthead to the chainplate, commonly over spreader tips. It provides major lateral support to the mast and helps control mast bend. Correct tension must be balanced with the other shrouds and stays without exceeding the rig designer’s limits.

The maximum load that lifting or load-handling equipment is authorised to carry in normal service. It is set below the breaking load using design and safety factors and applies only under the specified configuration and conditions. The lowest-rated component, side loading, wear, shock and altered lead angles can govern the safe limit of an assembly.

The radius of the curve through which a rope, cable, hose or other flexible component is bent. A bend that is too tight can reduce rope strength, damage fibres, kink wire or restrict a hose. Manufacturer limits and an appropriate sheave or fairlead diameter should be used, especially under load.

A watertight tube or bearing housing through which a propeller shaft passes through the hull. It supports and aligns the shaft and incorporates bearings and sealing arrangements that keep seawater out and lubricant in where applicable. Wear, alignment and seal condition require regular inspection because failure can cause vibration, leakage or shaft damage.

The reinforced clew point that becomes the after lower corner of a reefed sail. It is pulled down and aft to the boom so the reefed foot and new leech can be tensioned. The reef clew carries substantial load and must be secured by the reefing line or a suitable strop, not by intermediate reef…

A reinforced eye in a sail used as an attachment point when reefing. Tack and clew cringles take the principal loads of the shortened sail, while intermediate reef-point cringles gather loose cloth. Their construction, leads and fittings must avoid chafe and distribute load into the sail structure.