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Drogues on Monohulls

D/M-19 Monohull, Sparkman & Stephens

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D/M-19

Monohull, Sparkman & Stephens

39' x 8 Tons, Fin Keel

Seabrake MK I

Force 10+ Conditions

 

File D/M-19, obtained from W.R. Allen, Milson's Point, NSW, Australia - Vessel name Adele, hailing port Sydney, monohull, Superstar sloop designed by Sparkman & Stephens, LOA 39' x LWL 35' x Beam 12' x Draft 6' x 8 Tons - Fin keel - Drogue: Seabrake MK I on 200' x 5/8" nylon braid rode - Deployed in cyclone Bola in deep water about 50 miles NW of the North Cape of New Zealand with winds of 60 knots and seas of 40 ft. - Vessel could be steered through a wide arc in the proximity of land - Speed was reduced to about 3-5 knots during 36 hours of deployment.

Seabrake Mk I
Seabrake Mk I

The Seabrake used in this file was the same model used by Peter Blake in D/T-1, the more expensive MK I, with the spring-loaded gate mechanisms. The mechanism is adjustable and can be set to open the gates at a certain speed, instantly increasing drag by about 70%. Refer to inventor John Abernethy's explanation of the workings of the spring-loaded mechanism in File D/M-10. The earlier versions (likely this one) had ballasted nacelles to help keep them submerged, while later versions relied on a length of chain in the rode. Transcript:

Since purchasing the Seabrake I have made four Tasman crossings - Sydney to Auckland and return. The first two crossings were reasonably monotonous. The third included my involvement as a competitor in the Trans Tasman Transfield Challenge Race [Feb/March 1988]. In this race competitors were savaged by cyclone Bola in the vicinity of Three Kings Island and the North Cape of New Zealand. We ran into Bola on the approaches to the northern tip of New Zealand. There was no race warning and the first advisory we had was a weather forecast from a shore-based NZ radio station! Needless to say this warning was passed rapidly through the fleet! We passed through Bola whilst it was centered in the area of Three Kings Islands, Cape Reinga and North Cape. Retrospectively the weather maps indicated that Bola had three centers concentrated in the area at the time.

We had to make an important decision regarding our course across the top of NZ, a particularly treacherous piece of water in bad weather. Even in settled weather the NZ pilot advises that small vessels should approach no closer than fives miles to land. In rough weather fishing boats and even large vessels have been lost, in some cases without trace. This is largely due to strong currents flowing up and down the West and East coasts, and shallow waters (120-130 meters). In bad weather the safer course is to keep northward of the Three Kings and proceed via the Three Kings Trough in deep water (more than 1000 meters). This is the course we adopted.

At 2200 hrs on the 7th March at 33° 36' S, 169° 17' E, we were under bare poles and had set the Seabrake. Shortly thereafter we suffered a 90 degree knockdown, but apart from a few bruises there was no damage. However through this incident we were made very much aware of the confused nature of the seas and that we were catching the odd rogue cross sea. On the 8th, 9th and 10th March we proceeded in a SE direction following the Three Kings Trough, towing the Seabrake. During this period of heavy breaking seas with winds in excess of 60 knots the Seabrake was in continuous use, doing a marvelous job steadying our progress and giving us a strong feeling of security regardless of the conditions. At no stage did Adele show any tendency to broach and it was always possible to maintain a measure of control, despite the extreme conditions.

With the wind generally NW we streamed the Seabrake from the starboard primary winch, which meant the brake was mainly on the quarter, though when the occasion demanded with a particularly big sea we would run straight before. I am not aware of any period when the brake was not on the back of the next wave. On the crest of a wave we would occasionally pull the brake clear [out of a wave face] but it always dug in to hold us for the next one. We made no adjustments to the spring-loaded mechanism which was set to operate [kick in and generate 70% more drag] at 5 knots, and generally we were able to maintain that speed.

We had no problems with chafe and we did not use chain or any other means to weigh the brake down. Wind speed was variable between 40 and 60 knots and for shorter periods 60 plus. Difficult to estimate the height of waves. With a fifty odd foot mast we would on occasions be buried in the trough. On the 8th we had periods of heavy rain followed by gusty winds up to 50 kts. On the 9th with storm jib set the log says "from midnight to daybreak ran before heavy breaking seas - Seabrake probably saved us from being rolled in the early hours of the morning. During the day and evening conditions too rough to get sailing so jilled along at 2-5 kts under Seabrake in a SE direction away from North Cape." On 10th March conditions had moderated and we were able to proceed under full sail.

On the return journey, Auckland to Sydney, we experienced peak conditions. A high extended right across the Tasman with a broad front covering most of the North Island of New Zealand with a narrow front bordering the New South Wales coast [of Australia]. We left New Zealand in extremely light conditions having to motor up the East Coast until we cleared the Three Kings. Thereafter we moved in an easterly air flow right across the Tasman.

As we approached Australia the wind steadily increased. This was further exacerbated by low pressure areas developing north and south of the high. During the last five days we experienced winds in excess of 40 knots for most of the time, including a squall which lasted about an hour which was an absolute white out of wind-driven seas, which we estimated in excess of 100 knots.

Throughout the period of five days we towed the Seabrake off the weather quarter. Initially we sailed under trysail and boomed out storm jib. As conditions increased in severity we progressively lowered the trysail then the storm jib. Later the cockpit spray hood and life buoys, to reduce windage.  As you can imagine, with an easterly air stream extending right across the Tasman the seas built up and were breaking dangerously, particularly at times when the winds reached about 50 knots. Adele handled the conditions extremely well with the Seabrake out. It was quite remarkable how in the midst of a breaking wave it would hold the boat momentarily and allow the wave to sweep forward and away from under us.

As you will have gathered from this I have the highest regard for the Seabrake. Even under the worst conditions the brake always gives a measure of control and at the same time enables you to make progress. Not the least virtue is a sense of security and a great boost to your confidence at time when your morale could be at low ebb. The downside is that they are comparatively heavy and they take up room in the cockpit, though this can be overcome to some extent by mounting them on special brackets [on the stern pulpit]. Still, for safety at sea, anything is worthwhile.

I have also had some experience with parachute anchors which are also great, particularly with prolonged periods of heavy weather when you want to get some sleep and rest up for a period. You can really sit back and enjoy a good storm! The main problem is with chafe and this needs constant attention.

 

Drogues on Monohulls

D/M-18 Monohull, Cal T-2

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CALT2D/M-18

Monohull, Cal T-2

27' x 3 Tons, Fin Keel

36" Dia. x 72" Conical Drogue

Force 9-10 Conditions

File D/M-18, obtained from Wes Thom, Brownsville, TX - Vessel name Paper Dragon, hailing port Annapolis, monohull, Cal T-2 designed by Bill Lapworth, LOA 27' x LWL 24' x Beam 10' x Draft 5' x 3 Tons - Fin keel - Drogue: 36" x 72" heavy duty, Coast Guard approved cone made by Cal June, on 125' x 1/2" nylon three strand tether and bridle arms of 10' each, with 1/2" galvanized swivel - Deployed in a whole gale in deep water about 125 miles west of Bermuda with winds of 45-50 knots and seas of 20-25 ft. - Vessel's stern yawed 20-30° - Speed was reduced to about 2 knots during 48 hours of deployment.

 

Wes Thom has delivered yachts on the east coast and across the Atlantic. En route to Bermuda on his own boat, a 27-ft. Cal T-2 designed by Bill Lapworth, he had occasion to use one of the heavier 36-inch diameter Coast Guard approved cones manufactured by Cal June of Los Angeles. This is quite a large cone, about six feet long, not to be confused with the smaller "fish trolling" ones made by Cal June. It was deployed on 125' of rode and Wes Thom and his wife saw it being repeatedly tumbled by the crests. Thom did not consider the tumbling a drawback at the time because the cone would always recover and re-exert its pull at the needed time. Transcript:

We had been sailing from Cape May to Bermuda. Two days out, on a Wednesday, we talked to a Russian tanker by radio and were warned by an individual, who seemed to be out of breath, to head back for the mainland immediately. Basically he told us that a bad storm was on the way and a small boat like ours had no business being out there. He said they were increasing their own speed to full speed to avoid the storm. We thanked them, but told them we could not get to land that fast. They said "God bless you, we will pray for you."

At 7000 hrs Friday we had a full main and 150 jib up. As the wind increased we rolled in the 150 and hanked on a working jib. At 1100 hrs first reef in main. At 1200 hrs 2nd reef. At 1400 hrs storm jib. At 1500 hours no main. At 1600 hrs bare poles. At this point we were still going in the general direction of Bermuda about 1.5 knots, and a little concerned about the reefs around Bermuda if the storm blew us all the way there. We were 100-125 miles west of Bermuda, our course NE, the wind out of the south. As our speed increased to about 6 knots, occasionally surfing at 10-11 knots, we put out two warps. No knots, no weights, just 150' of 5/8" line [nylon three strand] off the port winch, and 300' of 1/2" [nylon three strand] off the starboard winch. With the warps out our speed came back down to 1.5 to 2 knots, still heading NE. We thought if we needed to we could always use the port winch to pull the warps in and add weights etc. In reality we could never have done that. The strain on each warp, even after the worst part of the storm, was amazing. The 5/8" warp was pulled so tight it would make noises like a cello string, and the 1/2" warp had an even higher pitch, like a guitar string. After putting out the warps we later rigged a 125' piece of 1/2" line, the end securely bridled through corner stanchion bases, with a 2-size larger CAL JUNE conical drogue [36" x 72" Coast Guard Approved "Storm Sea Anchor"]. When our speed got back up to 6 knots [with warps in tow] we deployed the cone, which brought our speed back down to 1.5 knots [the two warps coming off port and starboard winches and widely spaced to right and left, the Cal June cone and its tether in the center].

Most of the waves seemed to be breaking before they got to the boat, but a few would drop 10" of water in the cockpit. At night we also steered by listening for the oddball waves crossing the others. They sounded a bit like a train when they hit, rocking us sideways if we had not turned down wave for them. The main waves were out of the SW. The odd ones from the S or SSE.

In the daylight we could see that the waves were not less than the height of our spreaders (about 25') and about 150-175' from crest to crest. We were in deep water east of the Gulf Stream, WNW of Bermuda, still headed NE. We could look behind and watch the drogue start up a wave as we came over a crest. We could see it tumble on its own crest as we slid down the back side of ours. About the time we were in the trough it would grab again, and up and over the next crest we would go. We could clearly see the yellow cone tumbling repeatedly. It would get rolled, get tossed around, go end over end and everything in between. But it wasn't getting turned inside out, and it seemed to be doing its job when needed.

Most of the time we could let the autopilot steer. We could get 2-3 hours of very good sleep, even with the freight trains coming every once in a while. Once, when I was inside and looking through a port hole I saw the bow get buried by green water, which then turned white, and rolled off, and I could see the bow again. Sunday morning (48 hours later) it starting moderating. By 1600 hrs we had hauled in our CAL JUNE. It had to be winched in, a few feet at a time, when it was tumbling on the crest behind us. The sea was still sloppy when we set sail and the last warp [which was still left out] served to ease our motion.

We believed we had been blown 50-75 miles WNW of Bermuda and set a course for south. Monday morning we got our first celestial sight, and a few hours later a running fix, but something was very wrong. Our intercepts were very long and our sights had never been this far off before. Theory says you don't have to know an exact DR. Just guess. So I picked 500 miles NE. The intercept said no, not there. I tried 500 miles NW - no not there. I tried 500 miles SE - not there either. But they all said "here," so I moved my DR there, and sure enough, I knew where we were. From the last known DR position we had been blown 125-150 miles. We had overshot Bermuda! By Monday about noon I knew we had sailed south past the East Coast of Bermuda and now had to double back to the NW to get to our destination. Monday night we were in St. Georges Harbor, tied up, in good condition, undamaged, safe. Our only loss was the 150' x 5/8" three strand warp. It had unlayed and hockled in the middle, in random 10' sections, and had to be scrapped. Not much to pay for a safe trip.

 

Drogues on Monohulls

D/M-17 Monohull, Cutter

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D/M-17

Monohull, Cutter

41' x 8 Tons, Modified Fin Keel

36" Dia. Galerider Drogue

Force 11 Conditions

 

File D/M-17, obtained from Michael & Doreen Ferguson, Auckland, NZ - Vessel name St. Leger, hailing port Vancouver, monohull, G.R.P. cutter, LOA 41' x 8 Tons - Modified fin keel - Drogue: 36" Diameter Galerider on 250' x 3/4" polypropylene three strand rode, with 5/8" stainless steel swivel - Deployed in the Queen's Birthday Storm in deep water about 400 miles south of Fiji with winds of 60 knots and seas of 40 ft. and greater - Speed was reduced to about 3.5 to 4 knots during 60 hours of deployment.

St. Leger was in the same June 1994 "Queen's Birthday Storm" that claimed three lives and numerous yachts. Her Canadian owners, Michael and Doreen Ferguson, sent the following report to Skip Raymond of Hathaway, Reiser and Raymond, who then forwarded it to Victor Shane for inclusion in the database. Transcript:

We launched St. Leger in 1 May 1982. She is a 41 ft. G.R.P. cutter with modified fin keel and fully unbalanced rudder, using a "Sayes Rig" self-steering vane. We moved aboard St. Leger the day before the launching and have lived aboard since 1982. We retired in 1991, Mike was a Sargent with the Royal Canadian Mounted Police - the NCO I/C of Marine Services with commercial maritime qualifications. After a hair raising experience in severe weather in Queen Charlotte Strait in 1989, we purchased a Galerider drogue directly from Hathaway, Reiser and Raymond after seeing an advertisement in a yachting magazine.

In May of 1991 we left our home port of Vancouver, Canada, and headed for Alaska. Thus began our life as full time cruisers. In April 1993 we crossed the Pacific from Mexico, arriving in New Zealand in November of that year.

In June 1994 we departed Tauranga, New Zealand, bound for Fiji, with only Michael and I aboard. At 1600 hrs on our second day out and approximately 75 miles from the North Cape of New Zealand, we first heard of a low pressure system situated over Vanuatu, predicted to track southeast into our intended path. The weather forecast in our area predicted southeast winds 35-40 knots, not particularly severe, so we decided to continue on our course under reduced sail. Later, under bare poles and in deteriorating conditions, we ran before it in very steep, short seas, and the wind sustained at 50 knots, with higher gusts.

DM17

At about midnight on day 2 of the storm we decided to deploy the Galerider as our boat speed was now 11-12 knots in precipitous seas. We deployed the Galerider using a single line off the starboard quarter, approximately 250 feet of 3/4 inch three strand polypropylene line. We selected polyprop three strand because of its floating ability. Our plan was to slow St. Leger down, whilst still maintaining steerage using the "Sayes Rig" vane, due to shorthanded crew. Immediately upon deployment our boat speed was reduced to 3.5 to 4 knots and we felt much more comfortable.

The wind vane continued to steer beautifully, but as St. Leger slowed down in the troughs of the huge seas the tow line and Galerider tried to catch up to us, leaving a loose coil of 12 to 15 feet of tow line floating in close proximity to the vane's trim-tab steering paddle. Fearing that the slack line might tangle in the trim-tab and surely tear it off, Mike began bringing in the slack each time we were in a trough, using a primary cockpit winch, until the Galerider was approximately 80-90 feet behind the boat. The drogue was in the same wave as St. Leger, but on the other side of the crest [on the back side]. We observed the Galerider for hours! A small "half-moon" section of the drogue was visible at times, and we noted the three strand polypropylene tow line did not unwind, nor did the Galerider oscillate or rotate. And best of all, this enabled the wind vane to steer the whole time.

We towed the Galerider without incident for 60 hours, with winds at 60+ knots (our "Swoffer" wind gauge was pegged at its limit). At approximately 0800 hrs on day 5 the wind had dropped to 18-20 knots. The low pressure system was east of the Kermadec Islands and moving away from us. The seas were still high, but we readily retrieved the Galerider, which was in almost new condition with no damage or excessive wear after a tough workout!

We should also mention that the New Zealand Air Force Orion aircraft searching the area [for other vessels in distress] made a low pass over us and we advised them by radio that we were OK and not in need of their assistance. Our sails were set and we spent the next week hard on the wind in light northerly winds with very lumpy, confused seas. We arrived safely in Suva, Fiji, where we exchanged tales of the "Queen's Birthday Storm" that claimed three lives and seven cruising yachts. Everyone involved was interested in what "worked" and what didn't.

Drogues on Monohulls

D/M-16 Monohull, Cutter

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TRAYLORD/M-16

Monohull, Cutter

65' x 18 Tons, Fin Keel

Series Drogue - 144 x 5" Dia. Cones

Force 9-10 Conditions

 

File D/M-16, obtained from John A. Traylor, Alta, Wyoming - Vessel name Beyond, hailing port Portland, Oregon, monohull cutter, designed by John Traylor, LOA 65' x LWL 56' x Beam 12' 8" x Draft 8' x 18 Tons - Fin keel - Drogue: Jordan series, 144 x 5" Diameter cones on 330' x 1"- 3/4"-5/8" nylon braid rode, with 24' of 3/8" chain at the end of the array - Deployed in a whole gale in deep water about 90 miles west of Point Conception, California, with winds of 40-60 knots and seas of 18-24 ft. - Vessel's stern yawed 10° - Drift was about 68 nm in 33 hours of deployment.

Before setting off on a major ocean passage John A. Traylor equipped Beyond with a number of drag devices, including a Para-Tech sea anchor and a Jordan series drogue. The series drogue was used in a gale off Point Conception. Transcript:

 The drogue took me personally about 24 man hours to construct, from a kit sold by Dave Pelissier (Ace Sailmakers). Once I had tied a few cones on the rode, construction was easy, but of course boring! The tow-rope specified for our 18-ton cutter is: first third 1" nylon braid, second third 3/4" nylon, and the last third 5/8" nylon. Total number of cones: 144. We did fabricate a bridle, each leg being about 25 feet long, leading to large port and starboard bronze cleats on the stern. The end weight was four fathoms of 3/8" chain.

It took me about thirty minutes to bring the gear up from below and lash the bag into deployment position, and rig the bridle. The most difficult task was to remove the Aries vane (one of Nick Franklin's last models, which can be quickly dismounted). This was a bit dangerous - I had to go down into our stern "sugar scoop" and unhinge the vane, all the while watching for the next wave which might sweep the scoop. Once the Aries was secured, deployment was very easy. Just drop the chain off the stern and stand clear.

There was no noticeable shock [when the drogue took hold], but I could clearly see the heavy nylon rode stretching and squeezing the water out as it absorbed the load. We had been running under bare poles. Over a period of perhaps 40 seconds our speed dropped from 8 knots to about 1 3/4" (one and three-quarters) knots. The rudder was lashed amidships with a nylon bungee. There were no signs of rudder stresses. Chafe was not a problem throughout the duration of the 44 hour gale, but would have been if we had not removed the Aries vane gear.

Our vessel is 65 feet long and has a center cockpit. We had no water shipped in the cockpit, so I cannot comment on the performance of the cockpit drains, companionway, etc. The rather large "sugar scoop" stern was frequently swept by the cresting seas, and the noise was occasionally quite loud. On several occasions large waves broke astern and completely filled the "scoop." But the series drogue kept the hull very well aligned into the seas, with at most 10 degrees of occasional yaw. Once the long narrow hull was held stern to the seas, the wild ride was much smoother. Either my wife or myself stood watch in the deckhouse, where we could look astern and watch the seascape.

The gale abated rather quickly in the early hours of 27 October. The seas were quite lumpy and with no wind to steady the ship, the strain on the rigging was a concern. We decided to attempt to retrieve the drogue immediately, rather than wait for the light of dawn. With a rolling hitch on the bridle, and line led to our largest coaming winches, we found we could retrieve the drogue, albeit slowly, without damaging the cones. We were about 15 minutes into this process (and had retrieved about ¼ of the total) when my wife noticed a tanker to the northwest, already well over the horizon and with leading lights lined up directly on us. After two attempts to raise him on VHF with no response, we could now see the foam under his bow from the bright moon overhead. I had my wife standby with a knife, ready to cut away the drogue if necessary. But much to our relief we were able to "rouse the watch" on the ship by playing our 600,000 candlepower spotlight on our mast and finally, I must admit, on the bridge of the ship, perhaps a mile away! We soon heard a voice (Greek?) in unmistakably angry tones on the VHF. After a short explanation, he bore away and wished us "Bon Voyage!"

All in all, we were most pleased with the performance of the drogue. My main concern with our particular installation is the necessity to remove the Aries vane gear. This exposes the crew to some definite risk of injury. If the gear is left in place, it will eventually be destroyed and the series drogue will probably be lost as well. One would hope to foresee the onset of serious weather and make preparations in advance, but as our experience with the rapid (and poorly forecast) onset of this gale shows, this is not always possible.

Drogues on Monohulls

D/M-15 Monohull, Contest 40

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D/M-15

Monohull, Contest 40

40' x 8 Tons, Fin Keel

Series Drogue - 120 x 5" Dia. Cones 

Force 9-10 Conditions

LOCKHED2
A Jordan Series Drogue consists of dozens of small cones spliced into a long rode

 

File D/M-15, obtained from Robert J. Burns, Townsville, Australia - Vessel name Peter Sanne, hailing port Detroit, MI, monohull, Contest 40, center cockpit ketch designed by Conyplex, LOA 39' 9" x LWL 29' x Beam 12'6" x Draft 6' x 8 Tons - Fin keel - Drogue: Jordan series, 120 x 5" diameter cones on 300' x 3/4" nylon double braid rode, with bridle arms of 15' each and 35 lb. anchor at the end of the array - Deployed in a whole gale in the Gulf Stream with winds of 45-55 knots and seas of 20 ft. - Vessel's stern yawed 20° - Drift was about 12-15 nm during 6 hours of deployment, with a 3-4 knot current running.

 

Robert Burns made up his series drogue with the help of Professor Noël Dilly (previous file). En route to Newport from Bermuda he ran into a whole gale in the Gulf Stream and deployed it. Six hours later he lost the series drogue due to chafe. He then deployed a 2-ft. diameter conical parachute type drogue. This is an important file which provides an immediate comparison between the two different drogue concepts. The following are excerpts from Burns's article entitled Streaming A Drogue, appearing in the December 1993 edition of Yachting Monthly (reproduced by permission):

I've run before rising gales, but never with such menacing seas. There were three distinct inter-active wave patterns that combined to form massive pyramids which collapsed periodically in an immense surge of white water. As long as I could avoid the breaking portion of the waves there was little danger of sustaining damage from the mass of breaking seas colliding with the yacht.... We were truly surfing now, down wave faces that would break behind us, catching us as we increased speed, then engulfing the yacht in white water. Steering required intense concentration to keep the stern pointing in the direction of the breaking sea and present the minimum surface area, reducing risk of broaching. I was conscious of the forces of the rudder. The last thing we needed was to lose steerage.... If the storm was going to build for another four hours, it was time to try another tactic before it got too dark to see what we were doing.... The series drogue consisted of a 300ft length of 3/4" double braid nylon that had 120 5-inch diameter cones spliced onto the line through their axes. The drogue had an anchor attached to the outboard end for a weight and was attached to the stern with a bridle. The gusts were furious now. The seas were 25-30 feet with faces at 45 degrees and 50 degrees and breaking frequently. The shrieking of the wind in the rigging and the whip-like crackling of the ensign was making me most anxious. It was time to stop. We were above hull speed most of the time now, and it was hard to control the vessel. I sent Curley astern to kick the anchor over the side that would commence the deployment of the drogue.

The drogue had been rigged at the stern with anchor attached. As soon as the weight was released the drogue line paid itself out of its storage box. The tow line streaked out with dramatic speed and force. After less than a minute the drogue was deployed and the cones began to exert their resistive force on the bridle. The slowing effect was phenomenal. Deploying the drogue was like bungee jumping off a 30ft wave with a 40ft. yacht. The feeling of being elastically attached to the sea itself is hard to imagine. After a minute or so we had slowed from 8 knots to 1.5 knots. The stern was pointed aggressively into the wind and sea. It was as if we had entered a calm harbor of refuge. The yacht held her position near the top of the waves' crests. When a wave approached and threatened to break on board, the drogue would pull us up and over the top of the breaking waves. There was no possibility of a breaking wave hitting us broadside, as we were always above the majority of the white water.

We furled the remaining portion of the jib, tied off the helm, checked to make sure everything on deck was secured, and then went below. Inside the main cabin the noise of the gale was much less. With the reduction in the yacht's motion, our situation seemed not too bad. We were all exhausted and took the opportunity to try to get some sleep. The time was 2130. I got up several times to check the situation. Despite the roar of breaking seas as we were pulled over the tops of breaking waves, I slept surprisingly well....

At about 0230 the sound of waves falling on deck seemed to increase and the motion of the yacht changed. Gone was the elastic "bungee effect." I was about to climb out of my bunk and put on harness to inspect the rig, when the boat heeled sharply to port under the force of a wave striking the starboard quarter. The sound of flowing water was everywhere. In the next instant the companionway doors shattered, and an angry stream of water rushed into the saloon.... I reached for the nearest overhead light... it came on to reveal the main saloon with 2-3ft of seawater sloshing above the cabin sole. Debris of the splintered hatch floated with charts, books, wet blankets and sleeping bags. The cockpit was full to the top of the coamings with frothing sea water. The night was dark, but I could still make out the towering peaks of white water around and above us. I glanced at the wind instruments; we were lying with the wind just aft of the beam, we had no headway. "So," I thought, "this is what it is like to lie a-hull." The priorities were to clear the boat of water, and try to repair the shattered companionway in case we were boarded by another sea. And to check what had happened to the drogue. The crew were in favor of launching the life raft. I recalled previous conversations about abandoning a damaged yacht. In the 1979 Fastnet Race it had been a major contributor to loss of life. We were still very much afloat. The thought of taking to a life raft was not at all appealing to me.... My priority was to reset the drogue.

I found the bridle dangling over the transom, severed on both sides. The 3/4" nylon bridle had been abraded by the self-steering mounting brackets. There was damage to the stern pulpit and deck fittings, evidence of the forces and motion exerted on the hull by the drogue before it parted the bridle. It was imperative to get the stern facing the seas again. I pulled several lengths of anchor rode and mooring lines out of the aft lazarette, tied them together, and streamed them over the transom. This had little effect as the line was mostly polypropylene and skipped along the surface. Every moment we continued to lie a-hull we were at risk of being struck by another breaking monster. I recalled that I also had a small hand-made parachute-type sea anchor stowed below. My wife had constructed it some years ago for our coastal cruising around Tasmania and it had never been used.

The parachute sea anchor was a 2ft diameter cone made of synthetic canvas with ¼" polypropylene lines braided together to form the shrouds. It looked frail in comparison to what it had to stand up against. I tied the parachute to the longest length of line and let it slip over the side. Nothing happened at first. When all 300ft of line was out and the chute was subject to some forward motion the line came taut. There was no bridle now, so the tow line was only attached to the starboard stern cleat. The yacht yawed to port, aligning the stern almost into the wind and sea. Our forward velocity was about 2 knots. Big waves would cause us to surge forward and down the waves faces, as the chute didn't have sufficient surface area to slow us down against the push of big seas. We were much better off now. If the chute held we would be safe.

Gone was the feeling of "bungee jumping" [associated with the series drogue]. The forces exerted by the chute were sharper [jerkier] and nowhere near as powerful. However, the strategy of lying stern-to was still the most comfortable and safe. The little chute did well. We had no serious broadside wave strikes, even though there were still a lot of breaking seas around us. The chute was not able to pull us up and over the breaking waves, so the occasional wave dumped on the stern. As the yacht had a center cockpit, there was less danger of it being filled.... Dawn came slowly. The fury was fading from the wind and it seemed like the little chute would see us through the gale.... We cranked out a tiny bit of jib from the furling gear. The yacht pointed directly downwind, similar to riding with the series drogue. I wondered why I had not thought of using a bit of jib earlier.... By noon 6 June we had crossed the Gulf Stream axis into the cold water of the US continental shelf.

Robert Burns constructed another series drogue for his next boat, the 50-ft. aluminum Holman & Pye ketch, Eclipse, which he and his wife Kathryn sailed to Australia.

 

Sea Anchors on Trimarans

S/T-3 Trimaran, Cross

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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.