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Parachute Sea Anchors, Drogues, Sea anchors

In an Emergency you can use anything to stop drag
 
Buckets reduce drag on small boats.

Parachute Sea Anchors, Drogues, Sea anchors - What's the difference?

There is a difference and it is impossible for one to do the other's job. In simple terms a 9ft diameter or larger parachute sea anchor is required to hold a bow head to wind, whereas a 3ft diameter (drogue) simply does not have the power and would allow the yacht to fall backwards or be thrown by a wave. The 3ft Para-Drogue, deployed astern, is designed to slow a boat allowing directional stability downwind. The parachute sea anchor complements the Para-Drogue and vice versa. Traditional sea anchors (Admiralty cone, windsock type) are an item that time has overtaken and today should be renamed to fit into the drogue family. A drogue does not have the power and cannot develop the power to hold the bow of an ocean-going vessel head to wind in any condition.
Ideally a drogue can be used as a means of allowing the safe deployment of a Para-Anchor by substantially slowing a vessel down when it is impossible to heave to or luff up owing to sea state. In this situation the downwind speed of the vessel is substantially reduced and the Para-Anchor can be deployed over the windward side from the cockpit.

Size is important.

As with conventional anchoring the size of anchor is important. Under stress a boat will drag an undersized anchor and lay beam on to the weather. Marginally oversized is fine, as it gives an additional level of security. Substantially oversized and it is a weight penalty and a waste of money. When anchoring to a parachute sea anchor, the same arguments apply. It is therefore important to have a parachute sea anchor large enough to hold bow on in all conditions. As a guide, refer to size chart on following page.

Para-Anchor Specifications

Para-Anchors Australia manufactures parachute sea anchors to an exacting standard of quality with every stage of construction checked and acknowledged.
  • The Para-Anchor is manufactured from high density nylon, brightly coloured for safety in an air search.
  • Each radial seam is over-sewn with polyester webbing to absorb the high loads.
  • All localised stress points in the canopy are further reinforced with vinyl and webbing inserts.
  • The double braid shroud lines are secured to the Para-Anchor through stainless steel eyelets to the base of the swivel, which is unique in design offering a very compact, strong and effective unit.
  • Attached at the apex of the canopy is a small segment of stainless steel chain. This, combined with the retrieval system, allows for a very efficient and safe method of deployment.
  • The self-deploying bag is permanently attached to the back of the swivel allowing for easy deployment.

Many uses

There are many occasions when boats at sea require repairs to be carried out. Having the bows to the seas, especially if mast climbing is involved, is a major advantage. Even the amount of pitching is reduced, let alone the rolling. When laying to a Para-Anchor any rescue attempt by helicopter or rescue vessel is much safer because the boat is very predictable in its behaviour and capable of being approached from down wind. Single-handers find parachute sea anchors are worth their weight in gold. The degree of self-sufficiency is multiplied many times.

The rode

It is extremely important to use nylon for the rode (either 3 strand or braided) with a minimum of around 120 metres. On multi-hulls, bridle and rode lines should total approximately 120 metres (100 m rode and 20 m bridle arms). Typically, nylon has a stretch factor of approximately 30% when wet (50% dry), thus extending your rode to about 150m. Because of the stretchiness, about 25% of the load will be captured by the rode itself. The longer the rode, the less the strain on the boat and the parachute sea anchor. Rode diameter and length is very important to achieve the maximum comfort and safety from the Para-Anchor system. Too large a diameter and the stretch of the line is reduced. At the same time too small a diameter of line and the elasticity in the line is reduced by the fact that the rode line is stretched to its maximum too much of the time. If the diameter is too small the risk of a rode line breaking is very much a possibility. It is often said that the rode line length should be x times length of boat or y times height of waves, etc. It is an impossible task to adjust the rode length in the conditions that are applicable at the time of use. Who wants to be on the foredeck adjusting the length of the rode line at 0200 hrs, with minimal crew as backup in 50 knots. An impossible task. At some time in the past we have all towed a motor vehicle. Had we towed that car with an excessive amount of towline it would have been impossible to control the tension in the line. The towline would have spent most of its time dragging on the road with a risk of the towed car fouling the line. With a rode line that cannot develop the correct level of elasticity (shock absorption) because of incorrect diameter or length, the boat secured to the Para-Anchor will misbehave badly, surging forward, backing down and veering around.

Deployment

There is more than one way to skin a cat. There are more ways than one of deploying a parachute sea anchor, but a simple, safe and effective method is to rig the system prior to departure. Secure the rode line from the bow outside of the lifelines fastened to the toe rails or stanchion bases by plastic cable ties, and lead it to the cockpit where it is made secure to the nearest stanchion base. When the parachute sea anchor is required, shackle all lines to the appropriate parts and deploy the retrieval floats over the windward side followed by the Para-Anchor in its self-deploying bag. Allow Para-Anchor to inflate with the water. Once inflated and all lines have deployed and the boat is stable, check for security and eliminate chafe. Now set up a regular radio and anchor watch and then go below and enjoy the ride.

                                                                                                                                       

Retrieval Process

Retrieval may be achieved by use of an easy to use partial trip line. We suggest the use of a 10mm silver (polyester) floating line about 15m in length, (depending on the size of the Para-Anchor) attached to the stainless steel chain at the apex of the Para-Anchor and, and leading up to a buoy (floating fender). From this buoy, attach a second buoyant line, a 10mm x 25m with a small float (bright colour) attached to the bitter end. The second float will be carried down wind from the primary float. On retrieval the boat moves up to and retrieves this bright coloured float. With load applied to the line the parachute sea anchor collapses and is then pulled in. With the use of this system no tangle or foul-up has been recorded.

Practise and timing

It is highly recommended that practice be undertaken before the voyage commences to familiarise yourself with this procedure. The parachute sea anchor should be deployed prior to conditions becoming unmanageable or disastrous. As in reefing (we should reef 10 minutes before we thought of it) so does this apply to parachute sea anchoring. A wise approach is to deploy in daylight.


Air Deployment unit unpacked.

The power of the parachute

During one of our sea trials, Para-Anchors Australia chartered a high powered, high speed, 100 passenger, 20-knot tourist catamaran. With Para-Anchors Australia's Force 10 unit deployed astern, the big cat's power was slowly built up to the power setting that should have produced 10 knots of boat speed. Much to the skipper/owners surprise (verbal comments not able to print) the big cat had not registered boat speed on its instruments. We estimate that at this point the boat was doing less than 1 knot and pulling 3 tons of force. It was at this point, and much to our disappointment, that the test line broke. The parachute showed no sign whatsoever of any stress.

Airborne deployment

Para-Anchors Australia have developed an airborne deployment package specifically designed to hold a vessel in distress, thus requiring minimal assistance or no further assistance after deployment of the parachute anchor. The airborne package consists of 100m of nylon webbing (equivalent to 16mm nylon 3-strand rope).

Tightly packed in a series of linked cells, Tasman 15 parachute sea anchor, float and retrieval system. The operation of this unit is simple and straightforward. Once received by the vessel in distress, the nylon rode tail is removed from under the restraining flap and clipped to a strong point on the bow of the boat. The complete package is then thrown into the ocean while at the same time tearing open the yellow velcro retaining strap. The parachute sea anchor will now deploy from the container, pull out 100 metres of line, stabilise and hold the bow of the vessel head to wind.


Air deployment in container

The Fisherman Series

This parachute sea anchor by Para-Anchors Australia is a unit specifically designed for the amateur fisherman, or charter boat operator. The main objective is to improve fish catch by controlling the behavior of the boat relative to the direction of water movement (current). The fisherman is able to the stay on the fishing ground longer, use very light tackle and less fuel because he does not need to move as often. However, should conditions deteriorate and the boat become disabled, the Fisherman Series is designed with the capacity to save both boat and crew.

Bigger catches

John Stevens OBI CHARTERS ... "The fisherman para anchor has transformed my business. since the parachute sea anchor has been in use. greatly increasing our fish catches and giving more comfort for our passengers".

Professional Fisherman Series

Professional Fisherman Setup

This unit is designed along the same lines as our Yachtsman series, with the ability to allow a trawler to hold station and fish or rest while waiting to retrieve their catch. Graham Cull, skipper on a 150 ton squid trawler, comments "While sitting to a 100ft diameter parachute sea anchor in 55 knot sloppy Bass Strait, we were moving upwind with the current and very comfortable". Graham was not fishing at the time. "We were sick of bashing into it", on the way to his homeport of Queenscliff Victoria. Longliners fishing the east coast of Australia regularly use the parachute sea anchor, not as a fishing tool, but as a means of gaining a comfortable night waiting to retrieve their catch come daylight.

Drogues -Running before it
Drogue Setup

There are many situations where conditions are poor but not really life-threatening, and you would rather continue sailing and still maintain control. If you're running before big seas, especially breaking seas, broaching can be a danger, notably if you are running dead square to the wind. Whether in the ocean or entering a harbour (perhaps over a bar) even in a narrow channel, broaching can be disastrous. This calls for a drogue. Para-Anchors Australia's Para-Drogue is based on parachute technology, but in the case of a drogue we use two parachute sea anchors. The two units are cut differently and closely coupled. They are designed to interact with each other, creating a very high drag and consequent pressure wave. The Para-Drogue will not break free of the water and maintains an even and positive drag on the stern of a vessel. The Para-Drogue has a simple adjustable vent that can be pretensioned to vary the load being applied to the boat.

Para-Droque test results.

  • BOAT SPEED DRAG
  • 5 knots 265kg
  • 7 knots 480kg
  • 9 knots 890kg
When stowed, the para drogue is able to be stored in a shoe box sized locker. Manufactured from high density nylon with all seams and panels heavily reinforced.

Emergency steering with a para drogue

Para-Anchors Australia's Para-Drogue has been approved by the Australian Yachting Federation as an Emergency Steering Device under regulation 15-12, 1995. On a multi-hull, a bridle is required to be able to vary the drag position on the after end of the boat. A similar effect can be achieved on a monohull by strapping a spinnaker pole across the transom and rigging a bridle through the end fittings back to the primary winches, allowing easy steerage.

Ice Cat Challenge

Terry Travers and Robin Chamberlin carried both the parachute sea anchor and Para-Drogue on their challenging voyage to Antarctica. Regarding the use of the Para-Drogue, Terry advises "This arrangement served us well for the three days of the gale allowing us to steer by winching in the arm of the bridle in the direction we wished to turn. After the gale passed we retrieved the Para-Drogue and inspected it, finding it like new."


Towing with the drogue

Under normal circumstances, especially with a sea running, a towed vessel can easily overrun the towing vessel or at least be directionally unstable. When the towed vessel in turn tows a Para-Drogue, towing steerage and manageability becomes a breeze.

Rode Setup

 



PAF 100 undergoing final inspection.

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