Home |
Search |
Today's Posts |
#1
![]() |
|||
|
|||
![]()
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 |
#2
![]() |
|||
|
|||
![]()
"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 |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
tyvek (long) | Boat Building | |||
Life in Congo, Part V: What a (long) strange trip its being.... | General | |||
Red over green mast light for sailboat | Boat Building | |||
Red over green mast lights for sailboat | Cruising | |||
long vs. extra long shaft | Cruising |