Independent guide: Trimaran rigs are often designer-specific. The designer's rigging plan and the builder's instructions take priority over general advice.
Quick answer
A trimaran's shrouds usually run to chainplates on the amas (outer hulls) or beams, giving a very wide shroud base. Many performance and trailerable trimarans, including popular folding designs, use rotating wing masts with diamonds. Service priorities are the ama chainplates and beam structure, the mast-base ball and rotation system, diamond tension, and the folding or demountable mechanisms that affect rig tension.
What makes trimaran rigging different
- Wide shroud base — lower compression per unit of sail, but chainplate loads concentrate in the amas and beams.
- Rotating masts — common on performance boats; need a free-turning base and rotation control.
- Diamonds — diamond stays stiffen the mast in place of multiple spreaders; their tension is critical.
- Folding or demountable beams — rig geometry changes with the beams, so pins, hinges and locking systems are part of the rig.
- Light weight — synthetic standing rigging and Dyneema bridles are common.
Inspection priorities
- Ama and beam chainplates, including their bonding to the structure
- Mast-base ball, socket and step
- Diamond wires, spreaders and tangs
- Forestay bridle or bow fitting on the main hull
- Folding hinges, pins and locks
- Rotation spanner and control lines
Services trimarans commonly need
- Standing rigging replacement, sometimes converting to synthetic rigging
- Mast stepping — trailerable trimarans are often stepped by owners with a gin pole
- Rope splicing for bridles, strops and soft attachments
- Mast repair around the rotation fittings and base
Related
Frequently asked questions
What is a rotating mast on a trimaran?
A rotating mast is a wing-shaped section that pivots on a ball at its base so it can align with the mainsail, improving airflow and efficiency. It needs a free-turning mast-base ball and socket, correct diamond and shroud tension, and a rotation control system, all of which require regular inspection.
What should be checked on a folding trimaran?
The folding beams, their hinges and locking pins, the ama chainplates, and how the shrouds and stays behave when the boat folds. The rig must be set up so it stays correctly tensioned when the amas are extended, and pins and locking mechanisms should be checked every time the boat is unfolded.