The furler is the boat-side system. The anti-torsion cable is normally supplied as part of the finished Code Zero and built into its luff. The two must be specified together before the final dimensions are approved.
What is normally supplied with the sail
The anti-torsion cable runs through the full luff and performs two jobs:
It carries the luff tension. The cable takes the high load between the tack and head so the laminate can remain light and the leading edge can stay straight.
It transmits rotation. Turning the furling drum rotates the cable, allowing the sail to roll evenly around it.
For a new Code Zero, this cable is normally sized and incorporated into the sail during production. Its construction, diameter, finished length and terminations follow from the sail area, expected tension and furling system. Reusing an existing cable is a special constraint and must be agreed before design.
What we need from your furler
The furler determines how the head and tack connect and how much of the available hoist is occupied by hardware. In most cases, the manufacturer and exact model give us the necessary interface dimensions.
Enter the system in Furler Model. If the model is unknown, or the equipment has non-standard adapters, send clear photographs showing:
- the complete furling drum at the tack;
- the top swivel at the head;
- the pins, shackles, thimbles or adapters at both ends;
- manufacturer names, model numbers and other markings;
- the connection dimensions and the distance between load-bearing pin centres, with a ruler or tape visible where necessary.
A distant photograph of the furler is not enough. We need to see the exact surfaces and pins the sail will connect to.
Why these dimensions come before the luff
The straight-line distance between the tack point and halyard exit is not the finished sail luff. The drum, swivel, shackles and end connections consume part of that distance. Their combined stack height must be allowed for before the cable and sail luff are cut.
Where a known furler model is supplied, its published dimensions normally provide the starting point. Photographs and measured connection dimensions are needed when the model cannot be confirmed or the installation differs from the standard arrangement.
Cable Type in the configurator
Cable Type records the cable or torsion construction being built into the sail. It is not an invitation to choose an arbitrary diameter. Select an existing requirement when one is already known; otherwise the sailmaker confirms the suitable construction from the completed sail and furler specification.
Luff tension and operation
A Code Zero works at tight angles because its luff remains straight. The halyard is tensioned before furling or sailing so rotation travels through the cable rather than being absorbed as twist.
The masthead, halyard, tack fitting and bowsprit all carry this load. The sail specification can define the cable and connections, but the boat’s load capacity must be confirmed separately where there is any doubt.
With the furling system identified, continue to Dimensions.