How do I adjust mast rake and rig tension on a Hallberg-Rassy 31?

On a Hallberg-Rassy 31, set the mast straight athwartships, establish a slight aft rake, then tension the shrouds evenly and check the result under sail. Aim for light weather helm with roughly 2 to 3 degrees of rudder angle when sailing steadily close-hauled; the correct rake depends on the fitted rig, sails and loading.

Check the fitted rig

Identify the mast, spreader arrangement, wire diameters and any changes from the original installation. An HR 31 with replacement spars or standing rigging may need different settings. Follow the instructions for the fitted mast and rig rather than copying another owner's turnbuckle measurements.

Inspect chainplates, mast heel, spreader roots, terminals and turnbuckle threads before tightening anything. Investigate cracked fittings, damaged wire or movement at the mast support first. Extra tension cannot correct a structural fault.

Work afloat in sheltered water, with normal cruising equipment aboard and tank levels representative of sailing trim. Keep people off the side decks while measuring.

• Use a steel tape, a suitable wire-tension gauge, spanners and fresh split pins.
• Record exposed turnbuckle threads, wire diameters and existing gauge readings.
• Check that each turnbuckle has adequate thread engagement at both ends.
• Establish whether forestay adjustment is accessible beneath the furling drum or requires dismantling according to the furler instructions.

Secure the mast with properly led halyards before disconnecting any stay. Never release a loaded fitting.

Centre the mast, set rake

Hoist the steel tape on the main halyard and measure to matching fixed points on the port and starboard sides, preferably corresponding chainplate positions. Keep the tape tension consistent. Equal measurements establish that the masthead is centred. Then sight up the mainsail track for sideways bends lower down.

To measure rake, suspend a weight from the main halyard into a bucket of water to damp its movement. Measure the horizontal distance from the halyard to the mast at a recorded height near the boom. Keep the halyard clear of the boom and other obstructions. Repeat in calm conditions, as wind and fore-and-aft boat trim affect the reading.

No single rake measurement in millimetres applies reliably to every HR 31 installation. Preserve a known satisfactory setting, or obtain the starting figure for your particular spar before making substantial changes.

Forestay length normally controls rake. Lengthening it allows more aft rake; shortening it brings the mast forward, with corresponding adjustment elsewhere in the rig. Ease the backstay adjustment first and work in small, recorded increments. Do not move the mast heel unless the step is designed for adjustment and the spar instructions specify the procedure.