MARLOW-HUNTER MH31, Operator'S Manual

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Sails and Rigging
12.2
The mast features a double swept-back spreader arrange-
ment. Spreaders are horizontal spars used to spread the
supporting mast shrouds to provide the desired stability
and strength to the mast. This rig arrangement, known
as the B&R rig (named after its designers Lars Bergstrom
and Sven Ridder), sweeps the spreaders aft 30 degrees,
thereby creating an equidistant 120 degree angle between
each rigging point. This tripod arrangement is the same
as used with radio towers, providing excellent strength
and stability without the need for an aft stay (backstay).
The elimination of the backstay allows a more efficient
mainsail shape utilizing a full roach design.
After the mast has been stepped and standing rigging
installed (see below), it should be properly tuned before
serious sailing begins.
12.2 Standing Rigging
Standing rigging is the collection of fixed cables and hard-
ware which provide stability and strength to the mast.
Cables can be either stays or shrouds. Stays run fore
and aft from the mast to the hull. Your Marlow-Hunter
only uses the forestay and is integrated into the roller
furling jib (see sections on the Jib and Running Rigging
below). Shrouds run symmetrically port and starboard of
the mast. In addition to vertical and diagonal shrouds, the
B&R rig includes reverse diagonal shrouds which allow a
mast prebend providing additional rigidity. Shroud con-
nection points can be either the mast or a spreader and
terminate at the deck chainplates. Chainplates are sub-
stantial metal components tied into the hull with attach-
ment points extending into the deck. Chainplates can
be classified as outer or inner, depending on their hull
attachment point.
Refer to Figures 12.16 and 12.17 for the location, descrip-
tion and specification of individual components of the
standard rigging. Refer also to the Rigging the Boat sec-
tion below for installation instructions. Finally, refer to the
rigging manufacturer’s OEM manual for further details on
standing rigging installation.
NOTE: Standing rigging will stretch slightly when initially
loaded. Therefore, the rigging may have to be further tensioned
slightly after a few sails in a strong breeze to compensate for
this initial stretch. Once the mast is tuned and initial stretch is
taken out, the rig should need retuning only at the beginning of
each season.
12.3 Boom
The boom is a horizontal aft-facing spar attached to the
aft mast. It provides control of the shape and angle of
the mainsail and provides points of attachment for control
lines.
The boom is attached to the aft mast at the gooseneck.
The end-cap of the forward boom has a casting (Fig.
12.2) which is bolted into the mast fitting (Fig. 12.3). This
hardware configuration will allow the boom to pivot port
and starboard (and up and down) allowing the mainsail to
harness the wind power.
The type of boom on your boat will correspond to the
type of mast, either the standard conventional mast or
the optional in-mast roller furling mast. Both booms will
have common and some unique control points for the
corresponding lines used. The conventional boom will
have a slot on the top where an optional sail cover can
be installed. The roller furling boom will use the slot on
the top as the traveling path for an outhaul car used to
facilitate the furling process.
Figure 12.2 Figure 12.3
12.4 Mainsail
The mainsail is a triangular shaped sail located behind
the mast and is the largest sail on your boat and main
source of propulsion by wind. Marlow-Hunter provides
the conventional mainsail as standard and the in-mast
roller furling mainsail as optional. The shape of the
respective sails will be slightly different. The convention-
al mainsail will have a larger sail area than the roller furl-
ing mainsail and will include a larger roach. The smaller
size of the furling mainsail derives from the constraints of
the furling method and corresponding mast weight (see