How do I adjust mast rake and rig tension on a Hallberg-Rassy 39?
I want to check the mast rake and standing rigging on my Hallberg-Rassy 39 before the season. How do I establish the right starting point, and how tight should the shrouds be before checking the boat under sail?
Answer
Set your Hallberg-Rassy 39's mast rake from the drawing for its actual mast, then centre the mast and tension the shrouds evenly before checking the result under sail. Aim for a mast that is straight athwartships, controlled forestay sag and light weather helm; there is no reliable universal HR 39 rake measurement or turnbuckle torque setting.
Identify and inspect the rig
Identify the mast section, standing-rigging arrangement and whether the mainsail is conventional or in-mast furling. Original equipment, replacement spars and later modifications can require different settings, particularly for mast bend. Find the Seldén identification number near the mast heel and obtain the corresponding rig drawing and tuning instructions.
Before tightening anything, inspect the chainplates, terminals, spreader roots, turnbuckles and mast support for cracks, corrosion or movement. Extra tension cannot correct a moving chainplate or a settling mast support. Keep the mast supported throughout adjustment. Never disconnect a loaded stay or shroud.
- Photograph each turnbuckle and record its exposed thread or pin-to-pin length.
- Check that both threaded ends have adequate engagement and that the locking arrangements are sound.
- Use a steel tape, suitable spanners and a rig-tension gauge calibrated for your wire diameter and construction.
A Loos gauge can suit wire rigging, but check its measuring range. One model does not cover every shroud size.
Measure rake and centre the mast
Measure with the boat afloat in calm conditions, carrying its normal cruising load, with nobody moving around the deck. Uneven loading changes the boat's trim and therefore the apparent rake.
Suspend a weight from the main halyard and let it settle. Measure horizontally between the halyard and a clearly recorded point on the mast near boom height. Keep the weight just above a bucket of water to damp movement. Record the reference height and backstay setting so you can repeat the measurement.
Do not adopt the 600 to 750 mm figures sometimes discussed for the HR 37 or HR 40. These are not an established HR 39 specification. Measurements taken at different heights are not directly comparable.
Forestay length principally determines rake, with the other stays adjusted to suit. Access to an adjuster inside a furling system depends on the fitted gear; follow its instructions before disturbing it. Centre the mast by taking the same halyard, under equal tension, to matching port and starboard reference points. Then sight up the mainsail track for sideways curvature.
Set tension and mast bend
With the backstay at the maker's specified initial setting, take up the cap shrouds evenly, alternating sides in small increments. Adjust the lower shrouds and any intermediates to keep the mast straight sideways while establishing the specified fore-and-aft bend.