DDDesignDeck
51.9 m2Leg 01 / Plan
BROADSEAM

Sailmakers since 1974

Flat cloth, curved on purpose.

Every sail leaves here flat and arrives at the boat curved. The curve is cut into the seams before a single panel is joined, and it is the reason one sail sets and another one bags.

Mainsail, 11.4 m sloop, full batten

01 / The sail

Mainsail, 11.4 m sloop, full batten

Luff, P

13.2 m

Foot, E

4.6 m

Head

1.15 m

Roach

9 percent

Luff round

2.2 percent

Area

51.9 m2

The area is not a figure we typed in. It is the outline you are looking at, integrated: change the roach and it moves, and so does the cloth the sail costs.

02 / The cut

15 panels off a 915 mm roll.

Cross cut: the panels run square to the leech, which is the cheapest honest way to build a sail and still the right one for most cruising boats.

Cloth
Cruising laminate, 320 g
Weight
320 g/m2
Seams
14
Girth
13.93 m

Every one of those seams is about to be cut wider through its middle than at its ends. That is the next screen, and it is the whole job.

03 / The shape

The curve, and what it costs in cloth

A cambered section is longer than the flat chord under it. That difference is the surplus we cut into the seams: a few millimetres of extra width through the middle of each seam, tapering to nothing at both ends.

12 percent camber at 42 percent aft. Over a 4.58 m chord, that section wants 176 mm more cloth than the chord under it.

The luff is cut with 2.2 percent round. The mast takes up 65 percent of it as it bends, leaving 98 mm, so the two seams either side of that section are broadened 39 mm apiece to make up the rest.

Take the broadseam out and the sail is flat: fast in nothing, useful in nothing. Put in too much and it is a bag that will not point. There is one right answer per boat and it is arithmetic, not taste.

04 / The cloth

64.7 metres on the roll.

SeamLengthBroadseam
012.13 m16 mm
022.68 m17 mm
033.16 m19 mm
043.56 m22 mm
053.90 m25 mm
064.17 m29 mm
074.40 m34 mm
084.58 m39 mm

First eight of 14 seams. 18.9 kg of cloth in total, at 14 percent wastage.

05 / Work

Sails off this floor

34.1 m2

Mainsail, full batten

Rustler 36

Cross cut, 340 g cruising laminate

41.8 m2

Genoa, 135 percent

Rustler 36

Radial head, foam luff

58.6 m2

Gaff main and topsail

Fife 8 metre, 1926

Flax weave polyester, hand roped

26.4 m2

Blade jib

J/109

Radial, taped leech

06 / Service

And the rest of it

Recut

A sail that has stretched out of shape, brought back to its designed section.

Repair

Panel replacement, leech and luff tapes, batten pockets, hand work on old cloth.

Valet and storage

Washed, dried, inspected, logged and hung through the winter.

Covers and canvas

Stack packs, sprayhoods, winch and wheel covers, cut on the same floor.

07 / Enquiries

Send us the boat.

Rig dimensions and what you use the boat for is enough to start. We will send back a drawing, an area, and a price, and you will know what the cloth is before you agree to anything.

loft@broadseam.example

The Old Sail Loft, Quay Road Falmouth TR11 3EA

Cutting floor open to visitors on weekday mornings.

BroadseamFrom $9.99 a month, free for 7 days.Make it yours