How do I adjust the mast rake and rig tension on a Hallberg-Rassy 42?
I've recently bought a 1995 Hallberg-Rassy 42 and the helm feels a bit heavy upwind, plus the leeward shrouds seem quite loose in a blow. I want to reset the rig tension and check the mast rake from scratch. How do I go about setting the correct rake and tensioning the Seldén rig properly?
Answer
To adjust the mast rake and rig tension on a Hallberg-Rassy 42, start by setting the forestay length to achieve a 1 to 2-degree aft rake, which typically translates to the masthead sitting 300mm to 400mm aft of the mast base. Once the rake is set, use the Seldén folding rule method or a Loos gauge to tension the cap shrouds to 15-20% of the wire's breaking load before bringing the lowers and intermediates into line.
Setting Mast Rake
The older Enderlein ketch and the post-1991 Frers sloop both feature a Seldén rig requiring a slight aft rake for helm balance. A rake of 1 to 2 degrees aft induces a touch of weather helm. This gives the helmsman better feel upwind. A heavy helm suggests the mast leans too far aft.
Check the current rake using a main halyard as a plumb bob. Tie a heavy spanner to the shackle. Wait for a dead calm day. Let the spanner hang just above the deck. Measure the distance from the aft face of the mast at the gooseneck to the halyard wire. A gap of 300mm to 400mm is ideal.
To adjust this measurement, slacken the backstay and alter the forestay turnbuckle. HR 42s often carry a Furlex 300S or 400S reefing system. Undo the lower toggle screws and slide the drum upwards to expose the rigging screw.
Cap Shroud Base Tension
Before tensioning the caps, entirely slacken the lower shrouds, intermediate shrouds and the baby stay. The mast should rely only on the forestay, backstay and cap shrouds. Tighten the backstay to a medium working tension.
HR 42s generally use 10mm or 12mm 1x19 stainless steel wire for the cap shrouds. These attach to 5/8-inch or 3/4-inch bronze Hasselfors turnbuckles. Seldén specifies a resting cap shroud tension of 15% to 20% of the wire's breaking load.
Sailors without a Loos PT-3 gauge can use the highly accurate Seldén folding rule method.
- Tape a 2-metre folding rule securely to the cap shroud. Align the bottom edge exactly with a reference tape mark placed on the wire.
- Tighten the turnbuckle evenly using two spanners.
- Monitor the gap opening between the bottom of the rule and the tape mark.
- Every 1mm of stretch over 2 metres equals 5% of the breaking load. Tighten until a 3mm gap appears, equalling 15% tension.
Apply this tension evenly on both port and starboard sides to keep the masthead perfectly centred.