Mast down (long)
 

This weekend I was participating in a 225 mile (naut) race
that turned out more dramatically than expected.

Crew incl. skipper 6 (3 two-man teams).
Watch : 6h on deck 3h below starting at 15:00, 3 hours
after racestart.
Expected race time in average conditions 40-50 hours.

The weather forecast for the first 24 hours were 270-300
degrees 10-15 m/s.
235 boats were registered but 46 did not start, probably due
to the weather forecast.
17 boats finished the race.

Our start was at 12.00. The wind was 9-15 m/s 270-295
degrees.
The course for the first 30 miles (naut) was. ca 175
Main and Genoa. 1.reef in main when wind 270 reefing out
when
wind from 285 Wind increasing to average 13 m/s (10-17) Reef
in and out several times during first hour. Speed average
8.5 knots ( 9-10 over ground)
Spirit high. Doing well: 3. 4. or 5. in start and maybe
leading on handicap. Only 2 surfing boats were pulling away
a bit.
Squalls or small thunderstorms shifting with sunshine.

After the first hour the average wind seemed to increase to
16m/s (11-19) but the wind were staying in 285-300 so wee
kept
full main and genoa now doing 9 - 11 knots through the
water. Less current now. In some of the gusts we had to
slacken the genoa to be able to fall of to the course. The
main were as far out as it could come most off the time the
apparent wind being abaft the beam. The log showing 12
knots when going slightly under the course in the gusts.
The seastate were not worrying since the seas were from
maybe 40 degrees abaft the beam and we were only a few
miles off a windward shore and the current going south now
less than 1 knot.
The helm had to work the wheel but were able to control the
boat fairly well except for in the most powerful gusts were
we had to let out the genoa sheet.

2 hours out we were hit by a prolonged gust that were
slightly stronger the helm were still controlling the boat,
but slowly it luffed and the rudder couldn't turn the boat.
The genoa were let out and the rudder won the battle
and got the boat back on a low course.
But the sails were acting strange and I thought that the
genoa was let out way to much and the main looked strange
too as if the kicking strap (boom-vang ?) were loosened. But
before I reached any conclusion as to what was going on the
mast came down. Fairly slowly it seemed. It was broken
somewhere close to the upper spreaders and just above or at
the decklevel. The boom were in the air and some on almost
were hit when it came down over the companionway/cockpit.
Another crew were hanging in the slack leeward lifelines and
were pulled in by to others and nearly fell overboard on the
windward side instead.
Now everything seemed to happen slowly. The mast was in
the water at a angle of maybe 45 degrees held by the leeward
shrouds and grinding at the leeward rail the lover spreaders
being in a reasonable distance to the hull but with a
spreader pointing dangerously in the direction of the
hullside. And getting closer when the boat is rolling
(more violently without the mast)

We tried first to save the rig, but quickly gave up getting
the mast on board. Then gave up the mainsail. Tried to save
genoa, but gave up. We did loosen (and save) the boom and
vang from the mast while cutting the stays and shrouds (some
shrouds vere slack and were loosened by removing the splits)
A strange moment when looking at the mast rig and sails
disappear into the dark

We were relieved that there were no person damage, and we
could motor back to our homeport in less than one hour.

Boat: 34' Cruiser racer.
Length 10.23 m
Width 3.25 m
Draft 1.85 m
Displacement arround 4.5 - 5.0 ton (4.2 ton light I think)
Balast 1.950 kg
Masthead 2 spreader rig'. All shrouds in line with mast.
Adjustable babystay. Adjustable checkstays on genoa rail.
Mast-section: not slim.

--
Peter S/Y Anicula

Mast down (long)
 

"Knot." wrote:

Thanks for the article. I enjoyed the details. A couple of
questions. What does course ca 175 mean? Is this a
corrected heading of 175?

"Ca" should have been "ca." short for "circa" meaning about.
A course was never calculated since it was familiar coastal
waters.

meaning essentially due south. If that is the case, I
understood winds were abeam and behind you when the
mask broke. Also if my math is correct, winds were
21 knots (25 mph) to 37 knots (42 mph) and then you
were hit with a "prolonged gust".

Yes, short time before the mast broke we read a windstrength
of 24.4 m/s (47 knots) - the highest figure we saw, and we
reached a speed of 13 knots through the water.

You were sailing with full main and a full 135 Genoa in
this gust, which incidentally may register as a gale. The
main was against the shrouds and you had trouble
controlling the boat (wheel).
This tells me sails trim was not balanced or you were
constantly on the edge of broaching, which would
indicate to me that the boat was severely overpowered.
Do you think that you had a bit too much sail out for this
air?

Well, yes apparently. The reason being that we wanted to win
the race and that we thought the gear would take the
beating.
Five of the people onboard were fairly experienced - both as
sailors in general and with this boat.
We were all a bit surprised, and though we knew that we
stressed the boat heavily, we thought of the boat as being
fairly strong, and we were not worried until the last gust
when it was to late.
I suppose you could call it a calculated risk, though our
calculations were apparently too "optimistic".
If on a cruise or on a passage we would not take the same
chances if it could be avoided.
Stressing the gear like this is not good seaman-ship, but
our attitude, I guess, is to try to get pretty close to the
limit when racing.

Unless you surf, you will never exceed hull speed anyway,
not with the length/displacement ratio you have. So having
excessive sail out only stresses the rig.

Well, right and wrong. 13 knots is well above "hull speed",
whether "surfing" or not. And we were sailing faster when we
carried full main than when reefed.

What was the status of your backstay? I have seen masks
break because backstay tension was not properly set and
balanced with the forestay. This would make sense in
gusty conditions to me.

The backstay (no runners) were fairly tight but not as tight
as when beating in heavy conditions. The babystay were set
by hand (3-purchase) - not as hard as when beating in heavy
air. The windward checkstay were set by hand (3-purchase)
but the attachment-point were not mowed more than maybe 2
feet back. The leeward checkstay were not set.

We haven't reached any conclusion as to exactly what
happened or why - except off course that we were stressing
the gear to - and apparently over - the edge.
What I think happened is that the middle section of the mast
oscillated forward-aft to much, and that this oscillation
was created by the flapping sails. When the boat bore away
the mast was either already damaged or were "caught in a
extreme position" with no strength, so when the wind filled
the sails, the vertical compression made the mast bend and
break at the upper spreaders, and then when the backstay no
longer could hold the mast back, it swung forward and broke
at the base at decklevel. So what I think was the problem
was more the movement than the stress/pressure in itself.
What I think would have improved our chances would have been
to move the attachment-point of the leeward checkstay well
aft and maybe tightening it a bit more.

No stays or shrouds broke (I am convinced, but not certain).
I cannot exclude some material fault (oxidation) in the area
around the upper spreaders, but I have no reason the assume
that this was the case.

--
Peter S/Y Anicula