RIGS
The rigs are Plan B specific.
All three rigs use 11 mm diameter x 0.6 mm wall black, high-tensile aluminium mast sections and Sailsetc black rectangular boom sections.
The A rig mast has 15 mm forward pre-bend rolled evenly from the head to 900 mm below, the B rig mast has 10 mm forward pre-bend rolled evenly from the head to 600 mm below and the C rig mast is without prebend. The pre-bend is measured with the mast laid on its side, as the distance of the head from a straight edge in contact with the straight lower mast. With all three rigs, the back-stay can be tightened without or with the mainsail mounted, removing this pre-bend or any induced bend, to achieve a perfectly straight mast. With the mainsail mounted, further tightening of the backstay will bend the upper mast aft and progressively reduce mainsail camber in the mainsail upper sections. The mast ram can be extended or retracted to increase or reduce mainsail camber in the mainsail lower sections. The shrouds exit from a single hole at the front of the mast. On Plan B yachts, A and B masts generally use the forward shroud attachments at the deck with the more steeply raked C mast using the aft deck attachments. The aft attachments can be used with all rigs, to promote more mid-mast rear bend, needing more backstay for correction and hence increasing the jib-boom lift tension.
Spreaders of the A and B rigs are bespoke from 3 mm diameter aluminium. The C rig is without spreaders.
Plan B jackstay-style mainsails are cut to suit a straight mast or one with only very little aft bend to reduce sail camber at the head. The mast ram can be adjusted to give more or less sail camber in the lower sections.
Shroud heights, jib-boom pivots, mast pre-bend and mast rake are combined to give a rig that will automatically adjust to wind gusts, freeing and flattening both jib and mainsail in harmony. This allows the correctly trimmed yacht to sail close-hauled to windward, in balance, needing only minimal helm correction.
The mast has a plain, cylindrical plastics step. In the hull, the mast-step base is flat and parallel to the waterline. This allows the mast step angle to be tuned to the rake used, helping to keep the lower mast in column.
B and C rigs have internal mast corrector weights, to bring them to a nominal A rig weight.
Fittings are a selection of Sailsetc commercial and Plan B bespoke.
