Parachute sea anchor

[KellysEye]

>Another factor to be considered is sea room, or indeed room to significant sea features.

With drogues the boat will be going downwind at 3 to 4 knots. With a para anchor there is a slow drift back but as I said only boats with the rudder attached to the keel should use a para anchor. A fishing boat using a para anchor off Australia actualy went upwind due to strong current.

One thing to get right for any drag system is the bridle. It should have rope tails spliced to chain which is coverd by water hose. The chain should pass ththrough the fairleads. If the weather looks like you might need a para anchor a rope should then be attached to the bridle and led back to the cockpit. The last place you want to be in a storm is deploying from the bow.

 

[serini]

Thanks

Well Gentlemen we seem to have come a long way since I made my original post and I thank you all for your comments – please may I do this collectively? I started trying to thank each poster who increased my understanding about this subject but the participants have multiplied to the level that I will get it wrong if I try to do that, so thank you all.

I qualified my earlier posts by saying that my experience – so far – had been to run off, without a drag. I have been in the top end of a 9 but, mercifully, never in a 10 and whilst I have seen gusts up to 68kn these were just that and not sustained.

I asked in the original post for experience in deploying sea anchors as the Pardeys describe. From the exchanges and my reading my understanding now is very much as VO5 has summarised. There are circumstances where you cannot run off and use of a sea anchor and trying to achieve minimum leeway are demanded. If you have hazards under your lee then this is what you have to do. You cannot choose to run-off and then wreck yourself on the beach. Where I differ, with respect to VO5’s experience, is that if the blow is likely to be extended then I would not hesitate to rest my crew (and myself!) by heaving to perhaps with the use of a sea anchor to keep the boat within its leeward slick and then choosing to dump the sea anchor as conditions worsened and I had to run off. I cannot imagine that in deteriorating conditions I would try to recover a parachute and I would not rig a trip line for that very reason.

So, IMHO, it depends on the type of vessel you have and you should accept a progression of techniques it is just that the sea anchor from the bow is an ‘earlier in the progression’ technique rather than later and certainly not a panacea.

I don’t know if quoting is allowed here so forgive me if I am breaking the rules but I would like to quote Hiscock’s consideration of Moitessier’s great storm. I have placed ……. where I have shortened the quote:

“In 1966 something happened to shake the long-accepted theory of small craft management in heavy weather. Bernard Moitessier and his wife sailed their 12 metre ketch Joshua non-stop from Moorea to Alicante. ………he was overtaken by a great gale and ran before it with 5 warps weighted with iron pigs towing astern. These apparently had little effect on the yacht’s speed but they did prevent her answering her helm correctly. One great breaker caught Joshua on the quarter instead of dead aft as Moitessier had intended and this gave him the idea for an unusual technique which he then adopted. In a letter to a friend he wrote:

“”…It was this alone which saved the masts, otherwise the boat would have plunged forward and downward……..In a flash I grasped the technique of Vito Dumas – to keep moving at about 5 knots running dead before with as little canvas as possible and just before the arrival of each roller to give a touch of helm and luff to take the roller at an angle of 15 to 20 degrees. This trick made the boat skid so that as she planed she heeled on to her beam ends, as the sea was taken somewhat on the quarter. Directly I realised this I cut away my hawsers and Joshua was no longer in danger.”” “

Thanks again to you all for the discussion, it has been a pleasure.

 

[VO5]

Well Gentlemen we seem to have come a long way since I made my original post and I thank you all for your comments – please may I do this collectively? I started trying to thank each poster who increased my understanding about this subject but the participants have multiplied to the level that I will get it wrong if I try to do that, so thank you all.

I qualified my earlier posts by saying that my experience – so far – had been to run off, without a drag. I have been in the top end of a 9 but, mercifully, never in a 10 and whilst I have seen gusts up to 68kn these were just that and not sustained.

I asked in the original post for experience in deploying sea anchors as the Pardeys describe. From the exchanges and my reading my understanding now is very much as VO5 has summarised. There are circumstances where you cannot run off and use of a sea anchor and trying to achieve minimum leeway are demanded. If you have hazards under your lee then this is what you have to do. You cannot choose to run-off and then wreck yourself on the beach. Where I differ, with respect to VO5’s experience, is that if the blow is likely to be extended then I would not hesitate to rest my crew (and myself!) by heaving to perhaps with the use of a sea anchor to keep the boat within its leeward slick and then choosing to dump the sea anchor as conditions worsened and I had to run off. I cannot imagine that in deteriorating conditions I would try to recover a parachute and I would not rig a trip line for that very reason.So, IMHO, it depends on the type of vessel you have and you should accept a progression of techniques it is just that the sea anchor from the bow is an ‘earlier in the progression’ technique rather than later and certainly not a panacea.

I don’t know if quoting is allowed here so forgive me if I am breaking the rules but I would like to quote Hiscock’s consideration of Moitessier’s great storm. I have placed ……. where I have shortened the quote:

“In 1966 something happened to shake the long-accepted theory of small craft management in heavy weather. Bernard Moitessier and his wife sailed their 12 metre ketch Joshua non-stop from Moorea to Alicante. ………he was overtaken by a great gale and ran before it with 5 warps weighted with iron pigs towing astern. These apparently had little effect on the yacht’s speed but they did prevent her answering her helm correctly. One great breaker caught Joshua on the quarter instead of dead aft as Moitessier had intended and this gave him the idea for an unusual technique which he then adopted. In a letter to a friend he wrote:

“”…It was this alone which saved the masts, otherwise the boat would have plunged forward and downward……..In a flash I grasped the technique of Vito Dumas – to keep moving at about 5 knots running dead before with as little canvas as possible and just before the arrival of each roller to give a touch of helm and luff to take the roller at an angle of 15 to 20 degrees. This trick made the boat skid so that as she planed she heeled on to her beam ends, as the sea was taken somewhat on the quarter. Directly I realised this I cut away my hawsers and Joshua was no longer in danger.”” “

Thanks again to you all for the discussion, it has been a pleasure.

I wasn't going to add any further comment to this thread but reading this paragraph I must.

There seems to be a lot of confusion with regard to what a drogue is and what a sea anchor or parachute is.

The former is for towing to slow a boat down and the latter is for stopping the boat in the open sea. I don't grasp why the names of these two distinct types of kit keep being switched round. It makes for confusion.

My reasononing is that I prefer not to stream anything from the bow at all, ever. This is because if conditions worsen it has to be brought in or cut.

My preference is for streaming a drogue from the stern for the dual purpose of it acting as a sea anchor in a flat sea and then if the weather escalates for it to serve the puropse for which it was intended, that is, for it to keep the stern square to the sea, for it to provide directional stability and for it to slow it down.

My experiences in handling heavy weather are Ocean going, not coastal.
Heavy weather off the coast and in shallow water deserves a thread of its own. But I would not mess around in that event and head straight for the nearest port.

My boat is 13 1/2 ton. LOA 38'6" Sloop rig, therefore for Ocean sailing I have to be prepared for bad weather.

Out of sight of land and in deep water in bad weather I prefer to run.

I was caught in the tail end of a Hurricane off Cape Hatteras. The Hurrican had meandered ashore in Yucatan and therefore had lost its ability to worsen. But the wind and the seas were horrendous.

 

[webcraft]

Heavy weather off the coast and in shallow water deserves a thread of its own. But I would not mess around in that event and head straight for the nearest port.

I would have to say - although it is not the topic of this thread - that the above is potentially dangerous advice. The nearest port may be very dangerous if not lethal to enter in the prevailing conditions. Even when coastal sailing heading offshore for more searoom and sitting it out may be the best option.

- W

 

[VO5]

I have to post in phases otherwise I get cut off...

I hads my Seabrake deployed and a handkerchief foresail set. This severe gale 9 lasted two nights and two days. There was no moon. The sea was whipped to a frenzy with the spray going across like bullets making loud cracking sounds if it hit anything, and if it hit you in the face it hurt. The luminescence in the water caused the froth and spray to glow in the pitch dark. The waves were the size greater than the height of double decker buses with long, menacing overhanging crests. Were were making about 6 1/2 knots. The wind speed was 50 knots plus and the gusts went into high 60s and once a recorded 74 and then the needle went off the dial.

The Seabrake drogue performed magnificently.

The boat began to settle in the troughs so we were able to sit in the cockpit (centre cockpit sloop) with the wheel lashed to enjoy the proceedings.

The towing rig was constructed as follows:~

 

[VO5]

The Y brace is 1 1/4 dia terelene hawser. The eyes that fit round the cleats on the quarter are just big enough to slide over them and have a snug fit. They are wormed, parcelled and bound with burlap, meticulously stitched in place. the splices have 12 tucks each and are married at the ends.

The main splice, at which one legs of the Y brace meet is a splice carrying 15 tucks, and oversecured with strong seizings.

The tail of the brace has a stainless thimble secured by a back splice with 15 tucks and set hard.

The crutch of the Y brace cannot foul the rudder as its vertical scope is less than the drop of the rudder. You can read by now that this is serious kit.

The brace can additionally be used for steering by running a line fron either eye back to ta winch.

The tow line is 3 1/2 ships lengths. the breaking strain is 8 tons. (bear in mind that the boat pulls the drogue and not the drogue pulling the boat) There is a stainless eye at each end. There is a swivel at the drogue end.
In total there are four shackles connecting the assembly to the drogue.
Between the drogue and the tow line I have 10 feet of 5/16 chain.

 

[VO5]

The whole kit is very easy to deploy and recover according to a set of pre thought out drills.

Deployment:~ ( I have described recovery in a previous post on this thread).

First the eyes are dropped on the aft cleats, clear of everything aft.
The whole assembly is kept on deck. The first half of the tow line is lightly bound with knitting woll just to keep it tidy and the second half the same.
The first binding is removed and a bight let out. The fore sail is then eased completely to take way off.

The second half, which includes the remainder of the towing warp, swivel, chain and drogue are then thrown overboard and seconds later the drogue bites.

Once the drogue has bitten and the tow line goes taut, the fore sail is sheeted in tight using both sheets to set it fore and aft.

Once this is done, the wheel is lashed midships and the rudder post and quadrant below are also secured.

And that...is what I do, as it works perfectly for me, as it guarantees directional stability and curbing of speed.

As the Seabrake is constructed to adjust to the pull exerted on it The vessel does not carreer out of control but slides down the faces of waves and settles in the troughs. The following seas lift her and pass under the keel.

The secret is that in these conditions you have to keep the stern down.
If the stern is not kept down, and to my knowledge there is no other drogue rig that can do this, very real risk of broaching can occur.

That is why Moitissier had difficulty with his warps,, because the ropes and the weights did not keep the stern down. Simple.

 

[VO5]

I would have to say - although it is not the topic of this thread - that the above is potentially dangerous advice. The nearest port may be very dangerous if not lethal to enter in the prevailing conditions. Even when coastal sailing heading offshore for more searoom and sitting it out may be the best option.

- W

Yes Webby, agreed.

But any practitioner of prudent seamanship will take action EARLY and not later.

Therefore the option of heading back to port in expectation of conditions getting worse...and done in good time...cannot be ignored....and should be acted upon immediately.

 

[Deleted member 36384]

VO5 the point about the Y Brace crutch length is a good one and not readily apparent. I would have sized the Y Brace to clear the Aries Self Steering as the primary consideration. I'll check mine now.

The point about locking the rudder at the quadrant; is this just done with say, wooden chocks between the quadrant and stops or do you have some locking device?

Thanks,

Blowing Old Boots

 

[Phoenix of Hamble]

Yes, both good points that i'd be very interested in too

 

[doris]

The point about locking the rudder at the quadrant; is this just done with say, wooden chocks between the quadrant and stops or do you have some locking device?

Blowing Old Boots

For what it's worth I have a relay to my Raymarine ram that locks the rudder when using the Hydrovane. Power consumption is irrelvent, can't see why it would not work here as well. Raymarine were quite happy about this not invalidating any warranty.
Takes care of things when the Hyro is working and the rudder can get well loaded up .

 

[Boo2]

The bow wanders if a Jordan is deployed, since the Jordan causes drag, but does not offer directional stability like the Seabrake does.

Some new physics here ? Or just more nonsense from VO5 ?

The boat will experience exactly the same forces from any drogue excerting the same rearwards force, whether a JSD, warp + weight or any favoured patent device. The boat is attached by a bridle at the stern to a device which exerts its force via a single line to the part in the water.

Newtons laws apply, not magical marketing puff, and because of this the boat will track the same whether a Seabrake, JSD or parachute is used.

Boo2

 

[Boo2]

The Seabrake drogue performed magnificently.

What happened when it got thrown forward by a following breaking wave ?

Boo2

 

[VO5]

VO5 the point about the Y Brace crutch length is a good one and not readily apparent. I would have sized the Y Brace to clear the Aries Self Steering as the primary consideration. I'll check mine now.

The point about locking the rudder at the quadrant; is this just done with say, wooden chocks between the quadrant and stops or do you have some locking device?

Thanks,

Blowing Old Boots

The point about the crutch of the Y brace being calculated is that if the Seabrake is streamed from the stern to act as a sea anchor we don't want it clearing the rudder underneath and causing mischief with the prop and the keel and whathaveyou. Therefore the Y brace crutch if the drogue hangs vertically from the stern will rest about 6" above the bottom of the rudder.

A reason for having this crutch constructed with such an acute (relatively) angle between the arms is that it can be used to steer the boat in case of need or choice. This is done by heaving in on one of the arms and the vessel will turn and head in a new direction with the rudder still locked midships.

The rudder post has two hefty arms that act against stops to prevent it over turning. The steering is Whitlock rod. Then what I do is that I have specially prepared blocks of wood that fit exactly in the gaps between the arms and the stops in the steering compartment, thus imprisoning the rudder stock, and hence the rudder, firmly in the midships position whether the wheel in the cockpit is lashed or not.

 

[Boo2]

The secret is that in these conditions you have to keep the stern down.
If the stern is not kept down, and to my knowledge there is no other drogue rig that can do this, very real risk of broaching can occur.

What utter c0ck ! Any drogue, without exception, however constructed will have the same downforce on the stern provided it makes the same drag force, and that the line(s) to the stern make the same angle to the boat.

You really are a b*ll****ter of the first order !

Boo2

 

[VO5]

Some new physics here ? Or just more nonsense from VO5 ?

The boat will experience exactly the same forces from any drogue whether a JSD, warp + weight or any favoured patent device. The boat is attached by a bridle at the stern to a device which exerts its force via a single line to the part in the water.

Newtons laws apply, not magical marketing puff, and because of this the boat will track the same whether a Seabrake, JSD or parachute is used.

Boo2

No it won't and you know very well it won't.

The Jordan is trailed behind like an undulating snake. It helps to slow down the boat. BUT it does not provide directional stability for two reasons:~

The first is that it is a snake and not a taut line.

The second is that With the seabrake this taut line is adjusted in tension as the double bucket arrangement of the Seabrake expands when under great tension and returns to its normal shape when not.

The greatest pull occurs when the vessel is sliding down the face of a following wave.
The least pull is when it is on the crest or advancing to the next one.
And so it expands and contracts keeping the heading steady, not just slowing down the boat, and additionally KEEPING THE STERN DOWN.

Keeping the stern down is crucial to not being pooped by a following sea.

Pooping occurs when the following sea gets under the boat at a point of disequilibrium and tilts it to one dise and the next wave to come along is the one that overwhelms.

This is as a consequence of not having PROPER DIRECTIONAL STABILITY and the STERN NOT BEING HELD DOWN.

 

[VO5]

What happened when it got thrown forward by a following breaking wave ?

Boo2

It does not.
I have explained to you the principle of Directional Stability and the consequence of the inability to hold the stern down.
PLUS...when the vessel slides down the face of a wave the Seabrake swells up, holding it back until it reaches the trough and the swelling relaxes.

This is because the buckets adjust themselves, in contradistinction to other designs that do not effectively do this. In consequence they only serve to slow down the vessel and NOTHING ELSE, or are you deaf as well ?

 

[VO5]

What utter c0ck ! Any drogue, without exception, however constructed will have the same downforce on the stern provided it makes the same drag force, and that the line(s) to the stern make the same angle to the boat.

You really are a b*ll****ter of the first order !

Boo2

No it does not, AGAIN, and you know it does not.

I have explained the reasons why it does not in very clear language.
If you do not understand clear language I will do my best to explain it again in even clearer language until you finally understand.

And no expletives please. It is not gentlemanly conduct.

I have no commercial interest whatsoever. I am relaying to you all my experience, that's all.

 

[Boo2]

The Jordan is trailed behind like an undulating snake. It helps to slow down the boat. BUT it does not provide directional stability for two reasons:~

The first is that it is a snake and not a taut line.

How can you talk such nonsense without being ashamed ?

The shape of the drogue / lines in the water makes no difference whatsoever to the direction of the force on the boat. The force on the boat is determined entirely by the direction of pull of the single line at the point where it attaches to the bridle.

If the forces in the line are the same then the boat will behave in precisely the same way whatever you tow.

As for the JSD "snaking" around then I would like to see a more reputable source for such a proposition than yourself, quite frankly.

Boo2

 

[Boo2]

And so it expands and contracts keeping the heading steady, not just slowing down the boat, and additionally KEEPING THE STERN DOWN.

As I have already explained to you, there is nothing that the drogue can do to keep the stern down except by providing a force in the attachment line with a vertical component. For any given drag force the vertical component of force may come about in exactly one way : the rope has to be angled downwards. Any drogue which hangs down at the same angle and generates the same force on its connection line exerts the same downforce on the stern of the boat. Expansion and contraction non fingo.

This is as a consequence of not having PROPER DIRECTIONAL STABILITY and the STERN NOT BEING HELD DOWN.

I suppose that having seen you use every other form of incorrect logic I should not be surprised to finally see ARGUMENT BY CAPITAL LETTERS make an appearance


Boo2