S/T-15 Trimaran, Cross

S/T-15

Trimaran, Cross

42' x 23' x 7 Tons

18-Ft. Dia. Sea Anchor

Force 12 Conditions

 

File S/T-15, obtained from Andrew Cserny, Eldorado, IL. - Vessel name Gold Eagle, hailing port Raleigh, IL, trimaran ketch, designed by Norman Cross, LOA 42' x Beam 23' x Draft 4' x 7 Tons - Sea anchor: 18-ft. Diameter Para-Tech on 400' x 5/8" nylon braid tether and bridle arms of 80' each, with 5/8" stainless steel swivel - No trip-line - Deployed in an unnamed hurricane in deep water in the Gulf of Mexico, about 200 miles WSW of Tampa, with winds of 100 knots and seas of 30-50 ft. - Vessel's bow yawed 10° - Drift was estimated to be 30 n.m. during two days at sea anchor.

Dr. Andrew Cserny purchased Gold Eagle (File S/T-8) from Daniel York in 1992. In March 1993 he and his wife set off from Mobile Bay, Alabama, for Cape Sable at the southern tip of Florida - six hundred miles as the crow flies across the Gulf of Mexico. En route they were hit by an unforecast, unnamed hurricane that did considerable damage to the Florida peninsula, sinking one freighter (30 people rescued, a number missing), driving another freighter aground, and sinking a number of small craft, among them a 39-ft. monohull, whose owner and wife were lost at sea. Here is a transcript of Dr. Cserny's harrowing experience - a sobering reminder of what the unpredictable sea is capable of:

We departed Mobile Bay the afternoon of March 10, 1993, on a rhumb line from the sea buoy off the entrance to Mobile Bay heading toward Cape Sable at the southern tip of Florida. The weather was fine, the forecast on the VHF called for possible thunder showers that night along the southeast coast of Alabama and the Florida panhandle, with winds gusting to 17 knots, choppy inland waterways and seas rising to 6-8 feet from the coast to 50 miles offshore...

We sailed under a club footed jib, main sail and mizzen, this being a rather conservative sail plan for our boat, with the winds being anywhere from 8 to 18 knots during the night. Sea and wind conditions continued the same on the 11th and at daybreak we doused the club footed jib and raised the genoa instead, and continued on the rhumb line. Toward the latter part of the afternoon the wind started to head us and we kept going farther west of our rhumb line, so that by around five in the afternoon we were approximately fifteen nautical miles west of our rhumb line.

At this point rather than tacking back toward land, which would have put us in a northeasterly direction and amounted to almost going backwards rather than toward Cape Sable, we decided to deploy the sea anchor and so to speak "park" the boat for the night, rather than trying the motor or trying to sail and really pinch the boat close-hauled. I was not expecting deteriorating conditions, I just wanted to rest for the night and to see if the wind would perhaps change and come from a more favorable direction so we could continue on the rhumb line. I was not aware that the storm was coming, therefore I did not lash down the sails as I would have. Matter of fact, I probably would have taken the sails off if I had known the storm was coming.

After deploying the sea anchor successfully, and watching the boat ride with an easy motion up and down the waves while tethered to the sea anchor, in roughly 6-8 foot waves, we decided to go to bed for the evening. All sails were furled and tied down with bungee straps. I awoke sometime after dark to a rhythmic crunching noise in the aft portion of the boat, which did not sound normal. When I went to investigate, I found that the sea state and the wind had built up considerably and occasional waves were slamming into the open cockpit area. When I lifted the hatch covering the steering compartment, I saw that the Morse cables attached to the steering quadrant had ripped loose from the wooden supports that were used to anchor them, and the steering quadrant was swinging wildly about. We secured the steering quadrant with lines 5/8 inch and 3/4 inch diameter, two of these lines on each side of the quadrant. Within half an hour these had chafed completely through.

The winds and seas continued to build in the dark, and by two in the morning I thought we were probably in a Force 10 gale. Sometime during the night we were hit by an immensely strong burst of wind which I presumed must have been a twister, because the pressure inside the pilot house fluctuated rapidly, the windows rattled, the doors to the pilot house rattled, and the sliding hatches tried to come off the top of the boat [lift off their rails]. The front windshields flapped wildly up and down, the wind shrieked horribly with pitch and intensity I have never heard before although I have been in an automobile traveling at 135 miles per hour. It lasted maybe a minute to a minute and a half and it was during this time that the sails tore loose and began flapping wildly from the front to the back of the boat. The main sail was torn loose from its track in places. It was torn from the bolt rope, flopped wildly over the starboard side of the boat and self-destructed. In the same extremely high wind or twister that hit us, the mizzen sail was torn loose. The speaker for the loud hailer was torn loose from its mounting and carried away. The club-footed jib tore loose. It was shredded, and the boom flailed wildly about, causing holes and damages....

The seas continued to build, the wind shrieked, the sails continued to flog wildly, the spray was driven it seemed horizontally across the surface of the water and was leaking in around the top of the windshield and the left pilot house door fairly profusely. Waves were probably 25 to 30 feet in height, maybe higher, with breaking crests which regularly broke over the bow. One had to literally hold on all the time just to exist. Even sitting down, one had to hold on.

Then we were struck by what I would consider to be a rogue wave. I was holding on to the steering wheel in the pilot house at the time. I was thrown across the pilot house and crashed through the door on the right side and landed outside the cockpit on the right side of the boat. At the same time everything that was loose flew from the left side of the boat to the middle of the boat or over to the right side. For example, the toaster sitting on the left side of the boat on top of the kitchen cabinet flew across the boat and landed on the right side on top of the nav station, approximately two feet higher than where it was sitting on the kitchen counter. Everything in the boat literally got scrambled. Rest was possible only on the floor of the main salon, wedged between the icebox on the right and the dinette and the galley cabinets on the left.

I am not sure exactly when, but I suspect probably when the rogue wave hit, the sea anchor also tore loose a bridle leg, carrying with it the hardware for mounting the trampoline, because, sometime after daybreak we noted that the bridle for the right side of the sea anchor was totally gone. There was a hole in the bow on the right side [starboard ama], and the boat was riding to the sea anchor from one line, which was cleated off to the left side of the main bow. And sometime during the course of the day, this line chafed in two. But before it chafed in two, it periodically caught the [steel] anchor and flipped it out of its mounting on the bow, breaking part of the anchor bracket and bending another part - actually lifting the stainless steel plate that the anchor bracket and the pulpit were welded to. Eventually, the line to the sea anchor, now no longer being protected from chafe by the snatchblock on the float bow, chafed itself to destruction on the anchor bracket. I am not sure at what point the last attachment of the sea anchor parted, but after this, we were mostly broadside to the waves, and in a most vulnerable position for being flipped over.

Gold Eagle of Raleigh, showing damaged starboard ama after the trimaran survived a freak storm in the Gulf of Mexico. "I am not sure exactly when, but I suspect probably when the rogue wave hit, the sea anchor also tore loose a bridle leg, carrying with it the hardware for mounting the trampoline, because, sometime after daybreak we noted that the bridle for the right side of the sea anchor was totally gone. There was a hole in the bow on the right side [starboard ama], and the boat was riding to the sea anchor from one line, which was cleated off to the left side of the main bow." (Andrew Cserny photo).
Gold Eagle of Raleigh, showing damaged starboard ama after the trimaran survived a freak storm in the Gulf of Mexico. "I am not sure exactly when, but I suspect probably when the rogue wave hit, the sea anchor also tore loose a bridle leg, carrying with it the hardware for mounting the trampoline, because, sometime after daybreak we noted that the bridle for the right side of the sea anchor was totally gone. There was a hole in the bow on the right side [starboard ama], and the boat was riding to the sea anchor from one line, which was cleated off to the left side of the main bow." (Andrew Cserny photo).
gold_eagle2The storm continued to rage. The boat laid most of the time broadside to the waves which were breaking over the port float. The wind continued to shred the sails and I considered it almost suicidal to go outside and try to stow the sails which were basically destroyed by this time anyway.

On the morning of the 14th the wind had subsided sufficiently to enable us to get outside of the pilot house and at this point I rigged the mizzen sail, using the reef points in the mizzen to lash the upper part of the sail, which had shredded away from the lower part. I repaired the clew of the genoa. We used sails to steer the boat and were able to set a course heading toward Ft. Meyers, which was the nearest approach to land. We still had no steering. Once we got underway with the sails and were able to steer with the adjustments in the sails, the seas no longer broke over the transom and we were able to bail out the rear compartment, which gave us access to the steering quadrant. Fortunately I had numerous tools on board, as well as a good assortment of fasteners, and by cutting up some of the floor boards, and after hours and hours of jury rigging, we were able to effect a workable repair of the steering quadrant.... While I was effecting the above mentioned repairs, my wife June was able to make contact with a passing tanker, which was rather surprised to see us still out there afloat and under sail, and told us that they had been beaten up fairly badly, and we had just lived through a Force 12 storm with 30-50 ft. seas and 100 knot winds.

For the next three days we beat into seas ranging anywhere from 8-12 feet. The waves were coming directly at us, and at a normal cruising RPM of 1500 to 1700 RPMs we were making anywhere from two to four knots over ground as measured by the GPS. While beating into the wind and waves we took water in over the main bow where the trampoline attachment had torn loose, as well as where the cap for the anchor chain was torn loose, and everything in the front part of the boat got soaked. The starboard part of our float took on a considerable amount of water through the hole ripped out by the bridle. However, I used rags and fiberglass impregnated cloth to repair this defect, and was able to bail out the water from the right float. We dropped anchor in a bight just north of Matanzas Pass on the 17th. It was the first time we had been able to sleep in our bunks since the 10th.

Comments: The sea anchor was eighteen (18) foot diameter, manufactured by Para-Tech Engineering, with a 5/8" nylon rode 400 feet long and bridle arms of the same material, 80 feet long, with stainless steel swivels. There was a trip line at the apex of the parachute. Actually, the initial part of the trip line consisted of a nylon strap, maybe 10-12 feet long, possibly slightly longer than that, to which was attached a plastic float, possibly 8-10 inches long, maybe 4-5 inches in diameter. Then attached to this was a length of nylon line maybe about 30 feet long.

I made my first mistake here by taking the float off from the nylon strap, tying the nylon strap to the 30 foot nylon line, then attaching the float to the end of the nylon line. In retrospect, this was the wrong thing to do, and I suspect that the trip line kept fouling the parachute, causing the parachute to periodically collapse, then the parachute would unwind itself and it would hold again for a while and then it would collapse again, allowing the boat to surge backward to a much greater extent than it would have if the parachute had been fully opened out all the time. While riding to the sea anchor, at times we would head into the wind and waves and take the waves just fine, then all of a sudden we would start slipping and turning sideways with respect to the wind and waves. I'm sure at these times, the parachute anchor was collapsing. I went out on the bow and tried to pull the sea anchor in but this was impossible, even with the chute collapsed and taking the waves on the port beam, there was enough tension on the line that it made it impossible to pull it in. At times, the sea anchor would undoubtedly unwind and fully deploy itself and we would be riding quite securely on the bridle, heading into the waves again.

I suspect that when the rogue wave hit, the chute was collapsed, because the rogue wave hit us pretty much broadside on the port side of the boat. I suspect that at this time we came close to being capsized, and quite possibly the parachute anchor, even though it was collapsed and allowing us to lie broadside to the waves, probably kept us from going over. I do not know for a fact, but I suspect that the attachment points of the bridles were torn loose from the bows at this time, thereafter, the bridle was then attached to the bow of the main hull and really no longer acted as a bridle, chafing at times against the anchor and the anchor bracket. As a result of this, the lines eventually chafed through and we lost the sea anchor altogether. From then on we were lying a-hull, but always presented the port side and sometimes the port front quarter of the boat throughout the rest of the 1½ days that the storm lasted after this.

If we had been running downwind in these waves, I suspect that we might have been pitchpoled, and I'm certain that had we been running when the rogue wave hit we would have been pitchpoled. I also suspect that had the sea anchor been properly deployed and properly attached, that we would have survived the storm with only our sails blown out.

Lessons Learned: 1) I believe the weather forecast on the VHF is unreliable. Next time I venture offshore I will be listening to the weather forecast on the single side band. 2) When deploying the parachute anchor, next time the float will be attached at the end of the trip float line or the strap that comes directly off the apex of the parachute, then the longer trip line will be attached to the float. This float line will be fairly short and made of polypropylene line with float attached to it, making sure that it will not sink down and foul the parachute anchor. 3) I have replaced the sea anchor with another 18 foot parachute by Para-Tech. This one is now in a pack which can be deployed without taking the chute out of the bag. You can just throw the whole thing into the water, which I think is an improvement. The tether is 5/8" nylon, 500 feet long. There is an oversized stainless steel swivel. The bridle arms are longer now, made of 3/4" Dacron, which is less stretchy than nylon and hopefully better resistant to abrasion. The geometry of the attachment of the bridle to the boat is now different. I believe that it is significantly better. The two legs of the bridle now come through the points on the bows of the amas where the stainless steel plate holding the snatchblock is much more substantial than what was there before. The snatchblocks are considerably more substantial than the ones they are replacing. The bridle is led straight back onto the deck of the ama and tied off to a cleat which is through bolted to the main deck, and underneath is attached and through bolted to an L-shaped steel backing plate, in turn through bolted to the main crossbeam. With this geometry, all the strain will be taken by this oversized cleat and the snatchblock on the point of the ama will only act as a fairlead to be subjected to very little strain, and nothing like the forces that this same point was subjected to before, that being the reason why things pulled out. 4) The jacklines I had rigged before were of 1 inch nylon strap with 4800 breaking strength. I religiously used the harness and the tether whenever I ventured outside the pilot house. At the end of the storm the port jackline had chafed completely in two where it had been riding against the babyshroud on the port side. There were no cotter pins or rough or jagged edges on the babyshroud or on the turnbuckle. I'm sure that any round line would have also chafed in two. The new jacklines will be made out of stainless steel wire covered with plastic coating that will not chafe in two. 5) The Morse pushpull cables have been replaced with hydraulic steering. The attachment points are much more substantial than before. Previously, the anchor points for the cables were secured to a sheet of 3/4" plywood by four 1/4" stainless machine screws. The whole attachment point just literally ripped a 2 x 4" rectangle of the 3/4" plywood completely out and rendered the steering useless. The new steering parts are much more massive.

During the entire storm we moved approximately 30 nautical miles according to our GPS. However, during at least half of the storm, the anchor was totally gone and during the first half the storm the sea anchor worked off and on, so you can't really say that we drifted 30 miles at sea anchor. Having observed how the boat reacted to the sea conditions when she was being held by the sea anchor, and comparing the actions of the boat without the sea anchor, there is no doubt in my mind that the sea anchor is the ultimate survival tool in heavy weather offshore. I am also certain that had our sea anchor been deployed and attached properly we would have had a much easier time, and felt much more secure. The motion of the boat and therefore our comfort level inside the boat would have been much better. It is quite possible that the steering quadrant would not have torn up because we would not have surged backwards so much with each wave. I believe that with the sea anchor properly deployed, we would have had a frightening but manageable experience, instead of the almost three days of sheer terror that we lived through, not knowing from one wave to the next if we were going to be capsized.

S/T-14 Trimaran, Cross

S/T-14

Trimaran, Cross

46' x 25' x 10 Tons

24-Ft. Dia. Sea Anchor

Force 6 Conditions

 

File S/T-14, obtained from Ron Clisby, Grants Pass, OR. - Vessel name Nonchalant, hailing port Portland, trimaran ketch, designed by Norman Cross, LOA 46' 6" x Beam 25 ' x Draft 52" x 10 Tons - Sea anchor: 24-ft. Diameter Para-Tech on 100' x 3/4" nylon braid tether and bridle arms of 100' each, with 1" stainless steel swivel - Partial trip-line - Deployed in a low system in deep water about 450 miles NE of Tahiti with winds 25-35 knots and seas of 10-15 ft. - Vessel's bow yawed less than 10° - Drift was 12.7 n.m. in 38 hours at sea anchor.

The family of Ron and Sue Clisby sailed Nonchalant, a big, comfortable Cross trimaran, around the world in 1994. En route to Tahiti they ran into a blow. The weather fax was down and rather than take any chances they anchored her to the surface of the Pacific from 1330 hrs on 4/23/94 to 0330 hrs on 4/25/95. Here is a transcript of Ron's feedback, handwritten sometime during those two days:

Yesterday we deployed our 24' Para-Tech sea anchor for the first time, and are very impressed with the results. We were en route from the Marquesas to the Tuamotus when we encountered nasty weather, thunderstorms, lightning, etc., two nights ago. Our SSB and therefore weather fax are inoperative so we have been depending on a buddy boat for wx info. Yesterday they said we had been in a tropical depression during the night. We had winds around 20-25 k with gusts to 35 k and seas confused and around 10-15 feet.

It was still daylight and the kids were napping so we decided to deploy the chute. It worked beautifully and after some small adjustments we were inside baking bread. Today, our friends (hove-to 10 miles away) said the weather service is calling it a gale with winds to 43 k. They had wind gusts to 50 last night, but we had less (max 35 k) only 10 miles to the north.

This morning 0945 the seas are calm (gentle roll) and we have only 4 k wind at present. There are still lots of rain clouds in the area but I can see little holes of blue sky popping up to the west. After further clearing, we'll retrieve the chute and continue to Takaroa or Ahe.

P.S. With more complete weather fax info we likely would have continued on. But this has been a great learning experienced and we won't hesitate to use the chute when needed in the future.

S/T-3 Trimaran, Cross

CROSSS/T-3

Trimaran, Cross

50' x 27' x 16 Tons

28-Ft. Dia. Parachute Sea Anchor

Force 10 Conditions

 

File S/T-3, obtained from the owner of the boat, residing in Durban, South Africa - Vessel name withheld by request, hailing port Yarmouth, England, trimaran ketch, designed by Norman Cross, LOA 50' x Beam 27' x Draft 6' x 16 Tons - Sea anchor: 28-ft. Diameter C-9 military class parachute on 500' x 3/4" nylon braid tether and bridle arms of 80' each, with 5/8" galvanized swivel - Full trip line - Deployed in an Atlantic storm in deep water south of Tristan Da Cunha with sustained winds of 50 knots and seas of 30 ft. - Vessel's bow yawed 20° - Drift was estimated to be 12 n.m. during 36 hours at sea anchor.

 

South African safety expert, yachtmaster, instructor and Intec Maritime Academy principal Henton Jaaback had heard about the Casanovas' pioneering work. He acquired a military parachute, which he ended up loaning to the owner of this passage-bound trimaran. On her way to Rio from Cape Town the trimaran ran into a horrendous storm south of the island of Tristan da Cunha. Exhausted, the owner and his wife deployed the parachute according to the Casanovas' guidelines. It pulled the three bows into the huge seas and kept them there for 36 hours - through the worst part of the storm. After the 36 hours there was a jerk, the bows fell off the wind, and the big multihull lay beam to the seas, drifting downwind. It is the owner's opinion that the galvanized swivel in the system seized - failed to rotate, though the 3-strand rope used for the bridle arms is suspect as well (3-strand will torque under load). At any rate when he pulled the lines back on board, all that remained were the two bridle arms of about 60 ft. each, twisted around each other and their ends unraveled. The full trip line had snapped at the same time, so they lost everything, hardware, swivel, tether, parachute and all.

Galvanized swivels have always been a source of concern to your author, though one looks at the Casanovas' file and sees that they never had a problem with theirs in eighteen years of cruising and storm use. The problem with these swivels lies in the galvanic process, which results in an acid-etched coarse surface, liable to stick or "gall" under load. Even so, the swivel - if of good American or Japanese make - usually gets a chance to rotate during slack cycles, as born out by many other files in this database. Moreover there are excellent stainless steel swivels on the market today.

Why do parachutes rotate under load? They may do so because of inconsistencies in fabrication, or shroud lines that are not precisely equal in length. But mostly they rotate because of the ratchet effect produced by the overlapping of the panels. These panels, shaped like pie wedges, have to be sewn together to form the circular shape of the canopy. The edge of the first panel is laid over the edge of the second and sewn, the edge of the second panel is laid over the edge of the third, etc., the radial seams being over, over, over, and this is where the ratchet effect crops up. To do away with this built-in cause of rotation one has to stagger the fit of the seams. The edge of the first panel is laid over the second and sewn, but the edge of the second panel is laid under the third, etc. Over, under, over, under. The parachutes that are used to slow down supersonic aircraft on the runway are of staggered fabrication. You won't see them spin.

CANOPY
Canopy panels

The panels on Para-Tech sea anchors are now sewn in such a way as to be spin-neutral, although swivels are still a good idea. Here is a transcript of the DDDB feedback provided by the owner and his wife:

 

Swivel on bridle galvanized iron 16 mm - swivel on parachute 16 mm also. The bridle was attached to the swivel of the main line with two shackles. Main line 20 mm "multiplait." Bridle was 25 mm nylon 3-strand rope. After recovering the remains of the bridle we saw we had lost the two shackles and the swivel. The remains of the arms of the bridle were unraveled & twisted around each other - everything else was lost. We have been informed that galvanized swivels apparently lock under strain....

The trip line also snapped when we lost the para-anchor. This was at about 3 pm (we felt a jerk). We rushed into foul weather gear and on deck.... When we started up the engine and tried to find the "rig," the wind was so strong the boat could make no headway - also the seas were white, so the [white] buoy was impossible to see! A red buoy would perhaps show up better, even though we could not have motored to get it....

Some hours after we lost the para-anchor, after broaching dangerously south of Tristan da Cunha, we decided to use a drogue to slow the boat and eliminate broaching. We were bare-pole doing 5-6 knots and descending the slope of waves at 12-13 knots. The drogue consisted of 150 ft. of "multiplat" 20 mm. rope plus 33 ft. of 1/2" chain with 4 knots to make more vortex [turbulence]. All the above was attached to a bridle of 30 ft. [each arm].... We used the engine [in conjunction with the drogue] at the minimum, about 1000 revs, that gave us a speed of approx 4-5 knots and maximum speed in descending wave slope of 7-8 knots and no more broaching.

We needed the engine to keep enough steering power. We had a 3-blade fixed prop that spoiled the efficiency of the rudder; I think we lost about 50% efficiency! But we used the autopilot without any problem and we really appreciated the work of the drogue in straightening the boat each time at the beginning of a broach. The bridle was fixed to two sampson posts of 4" square oak, fixed to the keel of each float. The wind was then about 40 knots, with big breaking seas for about 24 hours.

We were very surprised by the efforts [loads] imposed by the drogue and also by the parachute anchor and we don't think that normal cleat-type fitting would have lasted under the strain....

We now have two para-anchors.... We honestly feel we would not sail without one now. Our experience around Tristan, and the knowledge that we were safe and could ride out a storm, has made this indispensable.