PERFORMANCE
at SEA
The series
drogue has been at sea for over 20 years. No boat has ever been
damaged and every skipper has expressed satisfaction with its
performance.
Team Philips
Perhaps the most dramatic example is the story of the giant
catamaran Team Philips, a boat that was designed for "The
Race", a non-stop race around the world with essentially
no design restrictions. The boat was highly unconventional with
two 135 ft. hulls and two 135 ft. unstayed rotating wing masts,
one on each hull. A crew pod, the bottom of which was 11 ft above
still water, was attached between the hulls.
The boat,
which was built in England, was launched much later than intended.
Finally it was taken to London and ceremonially blessed by the
Queen. Problems encountered during early trials caused further
delays. To qualify for the race it was necessary to complete a
transatlantic round trip crossing. The time was Dec. 01 and the
time for further trials had run out. The skipper resigned rather
than attempt the crossing. Another skipper took over and the crew
of 6 set out in early Jan. About 800 miles out they encountered
a typical winter storm. They had no choice but to run before it.
The boat surfed down the face of the large waves at 15 to 20 knots
and plunged into the trough with a violent impact. In the middle
of the night the crew pod began to break loose from the attaching
structure.
By the greatest
good fortune, one of the shore crew had insisted that a series
drogue be carried and that it be pre-rigged so that it could be
launched from the pod simply by dropping the length of chain in
the water. Within minutes of launching, the boat slowed down to
1.5 knots and rode comfortably. They reported that they could
feel the drogue gently decelerate the boat as it rode the wave
face.
In the morning
they managed to contact a container ship. When it arrived they
retrieved the drogue, which was in good condition, and managed
to maneuver the boat alongside the container ship where all six
were able to scramble up a net and board the ship.
The next day
the epir signal stopped and an aerial search failed to find the
boat. It was presumed to have sunk.
The crews
comment: "It was a real life saver". .
Practical
Seamanship Magazine
Contest 40, 250 mi. N. W. of Bermuda. " Gusts were furious
now. The seas were 25 ft with faces at 45 degrees and breaking
crests. Deployed drogue. Slowing effect was phenomenal. Deploying
the drogue was like jumping off a 30 ft. wave with a 40 ft. yacht.
The feeling of being elastically tied to the sea itself is hard
to imagine. We slowed to 1.5 knots with the stern pointed aggressively
into the sea. It was as though we had entered a calm harbor of
refuge. With the reduction in the yachts motion our situation
seemed to be not too bad. We were exhausted and took the opportunity
to get some sleep".
Many skippers
have commented on the bungee type feel to the boats motion with
the drogue deployed. This important characteristic was developed
from model testing in the U.S. Coast Guards flow channel, which
has glass walls so the underwater motion of drogue models could
be observed. In a major storm, a yacht moves forward as it passes
over the crest and backward in the trough for a distance of 50
ft. or more. The length of the drogue and the weight at the end
is designed so that the drogue normally assumes a hook shape with
the weighted end hanging almost vertical. When the boat is passing
over the crest the drogue tends to straighten out and more of
the cones take up the load thus checking the boat. In the trough,
the weight sinks, taking up the unwanted slack in the towline.
Thus the drogue is always aligned to respond to a dangerous breaking
wave strike. The cones are attached at both ends so they cannot
turn inside out if moving backward.
Model tests
clearly show that the behavior of a parachute or cone drag device
is unacceptable. As the device is pulled forward, it forms a wake
behind it. When the towline goes slack the water in the wake continues
to move forward and turns the chute or cone inside out, often
causing it to tumble or foul the shroud lines. In the Coast Guard
full scale tests in breaking waves on the Columbia River bar,
the series drogue performed flawlessly and was retrieved with
no damage, while a cone type drogue was destroyed.
Hurricane
A Tartan 38 left Beaufort, N. C. just after Hurricane Gordon
passed over Florida and into the Gulf of Mexico. Unfortunately,
the storm reversed direction and recrossed Florida back into the
Atlantic, catching the boat a couple of hundred miles out. The
storm brought 75 knot winds and 30 ft waves. The crew deployed
the drogue at 2.00 PM and rode throughout the night in relative
comfort. The boat was undamaged.
During the
same storm, the Coast Guard airlifted to safety the crew of the
42 ft. ketch Seaflower.
Rough Crossing
, Ocean Navigator, No. 88
This is an interesting and instructive description. The skipper
and his wife in a 35 ft. aluminum cutter were on a passage from
Newfoundland to England in August, 97. They ran into a storm with
two successive lows reaching Force 10 (48 to 55 knots). The eye
passed directly over the boat. Waves were estimated up to 25 ft.
with numerous breaking crests. The drogue held the boat to a yaw
of less than 20 degrees and ride was reasonably comfortable. The
boat incurred no damage and the drogue was retrieved in good condition.
Since the skipper was aware that the wind would return from a
different direction, he left the drogue deployed when the boat
was in the lull. He reported considerable rolling and yawing as
the wind shifted 180 deg. The cockpit filled several times as
random waves slopped aboard.
The skipper said that he never felt endangered in the force 10
conditions. The series drogue is designed to sink straight down
when the boat has no way on - as was the case here. There have
been a number of instances where a single cone type drogue has
drifted or been driven forward and has fouled the propeller or
rudder.
Other Uses
Magazine Latitude 38, from a 35 ft. Sloop captain ...."but
the surprising thing is that you don't have to experience storm
force winds in order to get good use out of the drogue... Rita
and I were alone in near gale conditions. After fighting the weather
for two days we were both exhausted. Deploying the drogue was
quicker and easier than heaving to. Further, it allowed us to
continue on our downwind course at a speed of 1.5 knots, despite
the 35 knot winds. During the night the conditions got much worse
and I was quite happy to stay on the cabin sole and feel sorry
for myself. I remembered when Rita was building the drogue I'd
pronounced that we would "never use that thing".
New Skippers
At Sea
With the advent of fiberglass yachts and modern navigation
gear more sailors are venturing offshore, even if only for one
or two nights at sea. The drogue has proven useful in a number
of instances:
"My wife, two sons, and I recently sailed our catamaran from
Miami to Tortola, B.V.I.
We took the offshore route through Providence Channel, and stayed
north until 65 west.
Two days out and 150 miles from land we were caught in a full
gale, wind speeds to 40 knots and wave heights 16 to 20 ft. The
boat began to surf down into the troughs under bare poles. I had
pre-rigged the drogue so that all I had to do was to drop the
chain over the stern. In less than one minute the world went from
life threatening to easy motion and one knot drift.
I feel strongly that without the drogue we would have gone end
over end. We stayed on the drogue for 24 hours"..
32 ft.
trimaran competing in a feeder race to Europe 1 STAR
"A Busy Month For The U.S. Coast Guard's Vessel Rescue Net
Work"
- Port hull
forward cross member had snapped- 700 miles southeast of Nantucket-gale
force winds, 20 ft. seas- mast blown down - hulls smashing together.
- Set series
drogue and activated EPIRB - readied life raft and donned survival
suit.
- Skipper
David Dietz: "When something so out of control as this
happens there isn't much else you can do other then having a
good meal and listening to some Jimmy Buffet" which is
what he did.
- A cargo
ship was directed to him by a Coast Guard aircraft and he was
picked up about 5 hours later and taken to Norway.
- Note that
he reported no further damage to the boat after the drogue was
deployed.
Rough Trip
to Iceland
Yachting Monthly Retired couple with 3 years of experience cruising
their Victory 40 ketch. Voyage from England to Iceland in late
May. Small depression had formed South of Iceland. By morning
the wind had picked up to 45 knots and veered about 45 degrees,
which produced quite confused seas. Within an hour it had increased
to 55 knots gusting to 70, and occasional seas were breaking into
the cockpit. At last, we thought, a chance to tryout our series
drogue and see if the long hours making it had been well spent.
The effect
was immediate: from hurtling full tilt down the face of the huge
waves, we slowed down and the waves passed under us. The motion
on deck became comfortable and safe. A sight I shall never forget
was the drogue warp, stretched bar taut, disappearing into the
cliff of water as the next wave approached.
Lessons learned:
Series drogues do work. Once deployed, the motion of the boat
became safe and we were no longer surfing down the waves with
little control. During the seven hours it was trailed we drifted
5 miles through the water, 10.5 miles over the ground according
to the G.P.S.
35ft.
Cheoy Lee Lion
My wife and I were on a passage from Block Island, R.I. to the
Azores. -approaching Georges Bank with a falling barometer. Running
off under bare poles, sustained winds near 60 knots, taking a
lot of breaking waves causing some minor damage. We decided to
launch the series drogue. Used a primary winch to ease it out
slowly and keep it under control.
After deployment
our boat speed dropped to 2 to 4 knots and the drogue created
a slick behind the boat that split the breaking waves. The waves
would roar past on either side, but no more water came on the
boat. Relative peace, it was great. The boat felt like it was
tethered to a huge rubber band, always being pulled back if the
speed increased too much. Sixteen hours later we winched the drogue
back aboard and resumed our journey, with confidence level greatly
increased.
This is the
only report I have where the skipper controlled the drogue during
the launching process. The normal procedure is to stow the drogue
properly in a bag and then just drop the weight over the stem.
There have been no problems with this system. Controlling the
drogue might be difficult since significant loads could develop
if the drogue were restrained.
Rhode 41, 70 degrees south in the Atlantic
"I heard this one wave approaching like a steam train, [it] threw the boat over and [I] felt the shocking sensation of huge amounts of water over me; at the same time the noise of breaking glass and all kinds of stuff flying on top of me. The wave threw So Long sideways onto the water; the mast-top was below the surface (toplight was ripped off) and maybe 2,000 liters of seawater entered through the only partly closed companionway. After the knockdown on Friday morning we steered downwind bare-poled, without any sails, and the Aries self-steering kept the boat on course at about 5-6 knots speed. By noon Friday the still increasing wind made the situation critical with still building seas and huge breaking waves. It was not safe anymore to keep the boat unsupported at this speed. For the first time we deployed our new sea-anchor over the stern, a system of 120 little parachutes attached to 200 meters of rope [Jordan Series drogue]. The boat then settled at about two knots of speed and took the breaking seas in a very safe angle over the stern. We could feel the gentle pull of the drogue to keep the boat at a secure angle to the sea... Between Thursday evening and Friday noon the barometer had dropped 18 hp to 992hp, wind north Force 9-10. For the next 41 hours, all day Saturday, until Sunday morning we were drifting with the sea anchor with the wind at storm force and shifting from north to southwest."
A Tense Moment in Drogue History
National TV news showed a picture of a dismasted yacht located in the western approach to Cape Horn. The picture was taken from a Chilean patrol aircraft. The sea was relatively calm, and trailing from the stem was clearly seen a series drogue.The emails poured in. How did a 44 ft steel yacht manage to capsize with the drogue deployed.
After a day or so a fishing boat managed to rescue the solo skipper. He was in good shape and sent back the following message to Dave, who had sold him the drogue.
"The drogue was set after rollover. I was still moving at less than hull speed with the staysail and did not feel the need to take defensive measures yet. I was making good time and wanted to get around the Horn to avoid the next storm that was coming.
Boy was I wrong. Wouldn't go to sea without one.”...
Trawler Yachts 3-06
More diesel powered trawler yachts are making ocean voyages these days. Some of them are carrying the drogue.
Several were built in China and had the drogue aboard for the delivery trip to the U.S. I have no reports of the performance of trawlers with the drogue deployed. The drogue should provide a comfortable and safe ride through a storm.
However, I believe there is one situation, which should be checked. Unlike sailing yachts which, when lying ahull, have the wind force tending to blow the bow down because of the mast and rigging, a trawler has no mast and often has a house in the stern. Thus, the windage tends to blow the stern down.
With the boat lying ahull when the drogue is deployed, the drogue must provide enough drag to pull the stern into the wind and sea. Once the stern is into the wind the water forces are such that the drogue will firmly maintain this position even in a dangerous breaking wave strike. I have added extra cones to the trawler drogue to handle this condition.
However, it would be prudent for a trawler skipper to deploy the drogue in a brisk breeze and with the boat lying ahull, to check whether the stern is pulled into the wind and sea.
A Good Ride
The drogue has been at sea for over 20 years. The performance has been flawless. Every skipper has reported favorably.
However, a number of skippers, after riding out a very severe storm, have offered some comments, which puzzled me: "As soon as the drogue took up the load the situation changed dramatically. It was like sailing into a harbor of refuge, there seemed to be less wind and the noise of the storm actually diminished. The surface of the sea was less disturbed and the drogue seemed to create a "slick" around the boat." etc.
Of course, the drogue can do none of these things. I attributed these comments to the psychological sense of relief that the skipper felt when the boat was no longer rolling, yawing, and charging down the face of the steep waves.
However, some skippers I knew were not prone to loose statements and I now think I understand how such impressions can actually be experienced.
In a severe storm with large waves, the boat is carried forward as the wave lifts it up the face. Then the crest passes under the boat and the boat descends into the trough. As the severity of the storm increases, the waves become steeper and often have whitecaps with some moving water at the crest. It becomes increasingly difficult for the boat to make it over the top and the boat spends a longer time on the face.
Finally, as was the case with the Winston Churchill, a wave may break with enough moving water at the crest to drive the boat down the forward face of the wave, a very dangerous event.
With the drogue deployed the boat is quickly pulled over the crest of each wave and does not linger on the forward face, the boat spends a much longer time in the trough. Where the wind is less and the surface of the sea is less disturbed. Even the noise or the storm would be reduced when the boat is in the Iee of a 15 to 25 ft. wave. Thus the average wind and noise would be less with the drogue deployed, the sea would appear calmer and a more benign ambience is actually experienced.
An Epochal
Change In Storm Tactics
I chose the incidents described above as being representative
of different boats and circumstances. Actually I am aware of at
least 50 occasions of storm encounters and drogue deployments
reported to me by the sailors involved or described in marine
publications. In all cases the stories are remarkably similar.
The effect of the drogue is dramatic. The situation changes from
frightening to relaxing, and the crew often sleeps through the
remainder of the storm in relative comfort.
Conventional
storm survival lore and literature is no longer necessary or pertinent.
Whenever the situation deteriorates to the point where further
progress is no longer possible or even when it becomes unpleasant,
the logical choice is to ride to the drogue until conditions improve.
This also applies in the event of crew fatigue, illness, or the
need for a stable platform to permit rigging repair.
Although the
drogue was developed using sophisticated engineering tools and
procedures, the device itself is very low tech. There are no special
materials, no moving parts or controls, no special hydrodynamic
shapes. The only material subjected to high loads is the double
braided nylon rope. It is poignant to realize that every sailing
vessel which went to sea from the time of the Romans had on board
all the materials and skills needed to build a drogue which would
have been capable of bringing the ship safely through a survival
storm. They had strong hawsers used for anchoring, spare sail
cloth for sail repair, and a sailmaker with the skill to fabricate
the cones.
With the help
of the drogue; St Paul on his biblical voyage across the Great
Sea could have safely made passage to Rome instead of being shipwrecked
in the wilderness, and the spread of Christianity would have taken
a different course. The settlement of the American continents
might have been advanced by 400 years if the Vikings had the drogue.
Their vessels, although ideal for fast coastwise voyaging, were
hopelessly unsafe on the open sea under storm conditions. Since
they were undecked, they could not lie ahull without swamping,
and if they tried to run off they would surf and plunge into the
next wave. The Viking ships had no structural bulkheads and would
have split open like a pea pod on impact with the green water
in the preceding trough.
With the help
of the drogue, the Vikings might have been able to support their
colonies in the New World.
So much for
conjecture!
