From the service manual. Might help.
TUNING THE H41 B&R RIG
PAGE 52
The easiest method for tuning the B&R rig is
to perform step one as follows before the
mast is stepped, with it lying aft side down
on two sawhorses. Begin with all rigging
slack. If the mast is already stepped, loosen
all the rigging, and then proceed to step
one.
1. Start with all the rigging slack. Then
induce the mast bend by tightening the
reverse diagonals (diamonds). Measure
the bend by tensioning a line or the main
halyard between the masthead and the
gooseneck. The maximum amount of
bend should be no more than 8”
[203mm] for the standard rig and no
more than 2” [50mm] for the furling
mast. Measured perpendicular from the
aft face of the mast to the halyard at the
deepest part of the bend. It can be less
than that based on the sail shape and
your own preference. The bend should
also be evenly distributed along the
mast to give a smooth shape. Keep in
mind that bending a furling mast may
make it more difficult to furl and will not
do much to flatten the sail as in a
standard rig. It is very important that
the mast also be straight from side to
side at this time. Tighten or loosen the
reverse diagonals to achieve this.
2. Step the mast with all shrouds attached
but with the turnbuckles completely
loosened (if the mast was not already
stepped).
3. Attach the jib halyard to a cleat on the
bow to support the mast in a raked
position (the masthead should be about
2’-0” [~6cm] behind the step). Attach
the verticals and tighten them until you
can just see the hole for the cotter pin
in the turnbuckle. Tighten the jib halyard
until you can attach the forestay. At
this point the masthead should be raked
so that a weight hung on the main
halyard hangs about 1’ behind the mast
step.
4. Use the main halyard to check that the
mast is centered from side to side. Pull
it tight and mark the halyard next to the
verticals chainplate. Now do the same
to the other side to see if the marks line
up. If not, tighten and/or loosen the
verticals until the marks line up. Once
the masthead is centered, begin
tightening the verticals until the
turnbuckles are approximately half
closed. While tightening the verticals
you may notice the bend in the mast
increasing. Now you can tighten the
lowers, which will tend to straighten the
lower part of the mast. Be sure to
tighten port and starboard sides evenly.
5. Now you should tighten the headstay
until it is approximately half closed as
well. This should induce the appropriate
amount of headstay tension. Never use
anything more than a pair of wrenches
to tighten your rigging. If you use an
extended piece of pipe on the handle of
a wrench you can over tighten the
rigging and do damage to the mast or
rigging.
6. On the Hunter 41 it is necessary to go
up the mast in a bosun’s chair to tighten
the number 2 diagonal shroud (D2 or
intermediate shroud). Always use
caution when “going aloft”. You should
always use a mountain climbing harness
or Bosun’s Chair intended for this use.
Always tie into the harness with the
halyard using a bowline and then secure
the shackle as a back up as the knot is
more reliable than a mechanical
fastener. The person hoisting you aloft
should keep the halyard stopper closed
to prevent falls. Good communication
between the two of you is also
important. Tighten the D2 until it has
just become tight and then add two
complete turns. While at the first
spreader, look up the back of the mast
to see if it is straight (rather than bent
from side to side). If it is not straight
then adjust the appropriate D2 to
straighten it.
7. Have the person on deck carefully lower
you. They should keep the halyard
wrapped at least twice around the
winch and should always have one hand
able to stop the halyard from running
free. Once on deck look up the back of
TUNING THE H41 B&R RIG
PAGE 53
the mast and see if it is straight (rather
than bent from side to side). If not then
adjust the lowers (D1) until it is.
8. If you have the standard rig you need to
attach the struts at this time. Attach
the lower end of the strut to the smaller
hole in the chainplate. Adjust the length
by turning the ball joint bearing in the
upper end of the strut until the holes in
the pin can be attached. It is normal to
have some play between the strut and
the chainplate and strut bracket
9. The final test is to go sailing in 10-15
knots of wind. If when sailing upwind,
the shrouds on the leeward side are
slack then tighten them to remove
about half the slack keeping note of the
number of turns. Then tack and do the
same to the other side. Do this until you
are happy with the tension and the
leeward side does not get loose when
the boat is heeled. Now sight up the
mast to be sure it is still relatively
straight from side to side. If it is not
then adjust to appropriate rigging to
correct it. For example: if the mast is
straight until the upper spreader and
then hooks to the windward side then
you will have to revisit steps 6 and 7
above. Remember to always tighten the
leeward shroud, tack and tighten the
new leeward shroud the same amount.
This prevents damage to the
turnbuckles and is also much easier to
do. Keep in mind it is also possible to
have something too tight such as a
diagonal shroud.
10. At this point you should have adequate
headstay tension. The sails are built for
an average of 14” [350mm] of headstay
sag, possibly more or less depending
upon light or heavy air. The bend in the
standard mast should be about 4”
[100mm] and 1” [25mm] in the furling
mast and it should be nearly straight
from side to side when sailing upwind.
If any of these are not true then revisit
the appropriate step above to correct it.
If the sag in the headstay is too much
then adding tension to the verticals will
fix it.
11. Once the rig is tuned you should make
sure to add the cotter pins to all the
rigging bending back the ends and
taping them to prevent snagged lines,
sails and fingers.
Remember that rigging, like everything else,
can age. As it gets older it may need to be
replaced. The frequency for which this
becomes necessary depends on the climate
and conditions in which the boat is sailed.
For example: if you sail in the Caribbean it
should be replaced every 2-3 years
compared to every 10 for the great lakes.
You should consult a professional rigger for
advice.
