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Sea Anchors on Trimarans

S/T-9 Trimaran, Condor

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triple_shockS/T-9

Trimaran, Condor

40' x 28' x 3 Tons

18-Ft. Dia. Sea Anchor

Force 10 Conditions

 

File S/T-9, obtained from Phil Herting, Coconut Grove, FL. - Vessel name Triple Shock, hailing port Norfolk VA, trimaran designed by Condor Ltd., LOA 40' x Beam 28' x Draft 8' (20" board up) x 3 Tons - Sea anchor: 18-ft. Diameter Para-Tech on 400' x 5/8" nylon braid tether (no bridle) with 5/8" stainless steel swivel - Full trip line - Deployed in a gale in deep water about 120 miles west of Miami with winds of 50 knots and seas of 15-20 ft. - Vessel's bow yawed 45° (without bridle) - Drift was estimated to be 15 n.m. during 7 hours of deployment.

Triple Shock was on her way back to Miami from Jamaica, after participating in the Miami-Montego Race. The wind had been building for some time when the aluminum rudder cage split, leading to complete loss of steering control. The para-anchor was deployed to stabilize an emergency situation. No bridle was used, just a single rode leading off the main hull, as a result of which the bow would yaw considerably off the wind. With the weather deteriorating, a nearby Coast Guard vessel was asked to render assistance. Delivery skipper Phil Herting said that the seas were so large that the 110' CG cutter, Madagorda, would periodically disappear from view in the troughs. Transcript:

 We were NNE of Great Issacs in deteriorating conditions when the aluminum fabricated rudder cage split. Upon breaking, the boat rounded up and then stalled. We immediately dropped the main and rolled up the balance of the jib. At that point we deployed the para-anchor. This device was utilized to stabilize an emergency situation and was deployed to ride out some bad weather. Because of the immediacy created out of the breakage we had to deploy it as fast as we could and with what line we had immediately available. For this reason the first line tied to the para-anchor was a 1/2" pre-stretched Dacron backup spinnaker halyard.

This immediately proved to be a mistake. The shock load transmitted back through the line was unbelievable. Realizing our mistake we then attached 250' of 3/4" three strand nylon. Though the nylon reduced the shock loading, it created another problem. I elected not to attach the second rode to a bridle because I wanted to save that for the tow from the CG cutter. So we led the rode through the bow chock to a primary winch. This enabled us to adjust the line when replacing chafing gear. And the chafe was the problem. Because the distance from the winch to the chock was so great, it created a longer spring and chafe area on the line. In retrospect, I should have deployed the nylon rode first and then had a Dacron tail. This would have minimized the chafe at the chock.

The Madagorda, the 110' cutter that came to our assistance, said that our rescue was done in the worst weather in which they had ever attempted one. They did a phenomenal job, though it did take 3 hours to get us a heaving line. One reason for this was the fact that the parachute was sitting right where they wanted to position themselves when getting us the towline.

What are you going to do? I hate to think of the situation if we had not had the para-anchor with us. It should be considered a vital piece of gear when making any substantial offshore passage.

Sea Anchors on Trimarans

S/T-5 Trimaran, Newick Derivative

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VALS/T-5

Trimaran, Newick Derivative

30' x 25' x 2 Tons

5-Ft. Dia. Sea Anchor

Force 9 Conditions

 

File S/T-5, obtained from the owner of the boat, residing in Falmouth, MA. - Vessel name withheld by request, hailing port Falmouth, design derived from the Newick Val 31 concept (lightweight, open wing ocean racing trimaran), LOA 30' x Beam 25' x Draft 8' x 6" (2' 3" board up) x 2 Tons - Sea anchor: 5-ft. Diameter Shewmon on 200' x 5/8" nylon three strand tether and bridle arms of 50' each, with 1/2" galvanized swivel - No trip line - Deployed in a gale in deep water within the Gulf Stream with winds of 45-50 knots and seas of 12 ft. - Vessel's bow yawed 10° - True drift was undetermined due to the Gulf Stream.

 

This lightweight Val-class racing trimaran was sailing back from Bermuda to her home port of Falmouth when she ran into a gale within the Gulf Stream. The skipper deployed a 5-ft. diameter Shewmon sea anchor, which pulled the three knife-like bows into 12-ft. confused seas, and kept them safely there for a period of 18 hours. Several snatch blocks were used to bring the bridle ends to cockpit winches. This enabled the skipper to work the bridle from the safety of the cockpit. He found it necessary to freshen the nip once every hour or so - two turns on the winches to shift the wear points and reduce localized chafe. The large daggerboard - drawing 8' 6" when fully lowered - was raised about two thirds of the way up, leaving about three feet of board sticking out of the bottom to keep the hull's center of lateral resistance sufficiently forward. The tiller was lashed amidships.

The bridle was led off the main hull and the tip of the port float only. The beam of the yacht being 25 ft., this "half-bridle," extending from a 12½ ft. base, was evidently enough to provide the leverage needed to keep the trimaran facing into the seas. In general your author is opposed to "half-bridles," however. Along with other safety experts, your author feels that the multihull bridle should make full use of the leverage afforded by the maximum beam of the yacht. The wider the base of the bridle, the greater the leverage - and the more positive its influence in terms of vessel alignment.

Sea Anchors on Trimarans

S/T-4 Trimaran, Condor

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CONDORS/T-4

Trimaran, Condor

40' x 28' x 3 Tons

18-Ft. Dia. Sea Anchor

Force 7-8 Conditions


File S/T-4, obtained from Jack Hunt, Apollo Beach, FL. - Vessel name Crystal Catfish IV, hailing port Apollo Beach - Trimaran, designed by Condor Ltd., LOA 40' x Beam 28' x Draft 8' (20" board up) x 3 Tons - Sea anchor: 18-ft. Diameter Para-Tech on 400' x 1/2" nylon three strand tether and bridle arms of 80' each, with 5/8" galvanized swivel - No trip line - Deployed during passage of low system in deep water in the Gulf of Mexico about 125 miles WNW of Tampa with winds of 30-40 knots and seas of 15 ft. - Vessel's bow yawed 10° - Drift was estimated to be about 2 n.m. during 12 hours at sea anchor.

 

Jack Hunt is a veteran of the 1980 and 1984 OSTARs (Observer Singlehanded Trans-Atlantic Race) in which he sailed a 31-ft. monohull named Crystal Catfish III. After making the switch to a lightweight, fast multihull, Jack ended up using a Para-Tech sea anchor during the 500-mile single-handed qualifying run, in preparation for the 1988 OSTAR. In a related article which appeared in the January/February issue of Multihulls, Jack describes conditions in the Gulf of Mexico in the winter as "a battleground of warm and cold fronts, locked in fifteen-round bare-knuckled battles for supremacy, much like the English Channel in June, except the waves in the Channel have the decency to come from the same direction as the wind." Here is a transcript of the DDDB feedback your author obtained from Jack:

 

Two things caught me by surprise in the twelve hour winter ride [at sea anchor] in the Gulf. First, how much stretch there is in nylon rode. Chafe protection is a must. Second, the "G-forces" which result from the boat being lifted up on a wave top (increased G-force) and then let down into a trough (reduced G-force), much as one would feel on a roller coaster. These forces are a characteristic, I suspect, of the lightweight multihull configuration, having nothing to do with the para-anchor and not at all a problem, just surprise. Because I am alone I do not use a trip line; not enough hands. Instead, I winch the rode in until the para-anchor is within reach with a boat hook and then pick up a shroud line. All of which nets me quite a mess hurriedly stuffed into a bag on a trampoline, so I can get back to tending the suddenly underway boat. Re-folding the chute for its next use presents me with the "one-legged sailor at an ass-kicking contest" scenario. Consequently I have acquired a parachute for use in between the time I haul out the para-anchor and can get it re-folded, if something should develop. The [aerial] parachute is not nearly as rugged as the para-anchor, however, so I remain motivated to work out a more reliable re-folding routine.

The only question remaining for me is, "why didn't I use a para-anchor all those years I had a monohull?" Probably had to do with the false heroism of getting the hell kicked out of me and my boat while hove-to. I should have had this para-anchor years ago.