Drogue attachment - no chain plate

Tintin

Tintin

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Ideally one would fit dedicated chain plates for attaching a drogue (jordan) but that would mean a fairly large job on my boat.

A thought is to use the slotted aluminium toe rail which seems quite substantial, and is bolted every 3 inches or so. My thought is to attacg a large shackle through one of the slots and use the shackle as the attachment point.

Boat is a benny first 325.

Thoughts?
 
If you have the time and opportunity to fit proper chainplates & backing pads I'd think that the way to go, as knobbling the toerail - so maybe hull / deck join ? - might be a worry in the serious weather it's intended for...
 
Comrade Red said:
Ideally one would fit dedicated chain plates for attaching a drogue (jordan) but that would mean a fairly large job on my boat.

A thought is to use the slotted aluminium toe rail which seems quite substantial, and is bolted every 3 inches or so. My thought is to attacg a large shackle through one of the slots and use the shackle as the attachment point.

Boat is a benny first 325.

Thoughts?
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I would have thought it best to use a bridle from the primary winches and lead it as directly as possible over the stern. On most boats I imagine they have the most resistance to lateral forces - I don't think the aluminium toe rail will take the same level of force.
 
Comrade Red said:
Ideally one would fit dedicated chain plates for attaching a drogue (jordan) but that would mean a fairly large job on my boat.

A thought is to use the slotted aluminium toe rail which seems quite substantial, and is bolted every 3 inches or so. My thought is to attacg a large shackle through one of the slots and use the shackle as the attachment point.

Boat is a benny first 325.

Thoughts?
Click to expand...

Are you sure the toerail is actually bolted? Many modern boats have it held on by (biggish) self-tappers. I'd have thought the mooring cleats on the quarters, beefed up if necessary (probably necessary) would be a better place to run a bridle from. You could back that up with lines winched forward if need be to spread the load.
 
Quote from Bedouin "I would have thought it best to use a bridle from the primary winches and lead it as directly as possible over the stern. On most boats I imagine they have the most resistance to lateral forces - I don't think the aluminium toe rail will take the same level of force"


Agree with this idea. The one time I had to be towed, we made a bridle of lines from the cockpit coaming winches forward to the bow cleats and then a single line from forward of the stemhead to the towing vessel. No problems and spread the load well over several strong points.
 
pcatterall said:
I can see value in having a stretchy line or snubber attached to another point to absorb shock.
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I think 'shock' loading is less of an issue with the Jordan. The cleverness of it is that it gives a steady pull. Chafe is more of an issue than shock loading.
 
I have a Jordan and in my case, the aft cleats are very manly and can carry the loads.

I have placed heavy leather patches at every possible chafe point. This suggestion came from a boat owner who spent 48 hours in a hurricane... all survived with no damage anywhere.. except chafe.

GL
 
Don Jordon spent a long time working out the loads and then testing so why not read the insructions?

Drogue Design Load
The design load for each drogue configuration is adjusted for the displacement of the yacht.
The design load is the ultimate, once in a lifetime, peak transient load that would be imposed on the drogue in a “worst case” breaking wave strike. The working load during a severe storm is about 10 % of this value.

http://www.jordanseriesdrogue.com/D_5.htm
 
bedouin said:
I would have thought it best to use a bridle from the primary winches and lead it as directly as possible over the stern. On most boats I imagine they have the most resistance to lateral forces - I don't think the aluminium toe rail will take the same level of force.
Click to expand...

If I remember correctly Jordan discounted using winches in his writings due to the leverage of the winch increasing the load on its mounting. If going this route carefully look at the fastenings for your winch, probably 5 or 6 M8 machine screws, and ask yourself if they are realy up to the job.

I fitted two very heavy duty cleats, bolted through the rubbing strakes and internal backing plates, one on each quarter close to the transom so no chafe points. The bolts go through the fibreglass reinforcing over the hull deck joint. They have not been used with the drogue but prove very useful for winter mooring lines as no chafe points.
 
srm said:
If I remember correctly Jordan discounted using winches in his writings due to the leverage of the winch increasing the load on its mounting. If going this route carefully look at the fastenings for your winch, probably 5 or 6 M8 machine screws, and ask yourself if they are realy up to the job.

I fitted two very heavy duty cleats, bolted through the rubbing strakes and internal backing plates, one on each quarter close to the transom so no chafe points. The bolts go through the fibreglass reinforcing over the hull deck joint. They have not been used with the drogue but prove very useful for winter mooring lines as no chafe points.
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Indeed - each winch has 6 or 8 M8 machine screws - but that is more than any cleat I've ever seen - certainly the cleats on my boat have only 2 screws and those may only be M6.

My winches have a mechanical advantage of 40, so assuming I apply 50kg to the winch handle they are regularly under 2000kg and the direction of pull is very similar to that required for a drogue - I suppose that aspect must depend on the geometry of each individual boat.

That said I also have turning blocks for the genoa sheets bolted to the toe rail with 2 bolts that must be under more load than the winches - but i don't think I would trust those under snatch loads
 
bedouin said:
Indeed - each winch has 6 or 8 M8 machine screws - but that is more than any cleat I've ever seen - certainly the cleats on my boat have only 2 screws and those may only be M6.

My winches have a mechanical advantage of 40, so assuming I apply 50kg to the winch handle they are regularly under 2000kg and the direction of pull is very similar to that required for a drogue - I suppose that aspect must depend on the geometry of each individual boat.

That said I also have turning blocks for the genoa sheets bolted to the toe rail with 2 bolts that must be under more load than the winches - but i don't think I would trust those under snatch loads
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Your turning block will be taking up to double the sheet load, depending on the angle the sheet makes at the block.

Your cleats sound a bit light. My main deck cleats are secured by 4 x 10 mm bolts and the quarter cleats for the drogue with two 18mm studs. If I ever have to use the drogue the quarter cleats will be backed up to the deck cleats. On the other hand I have seen a cleat and backing plate pulled through a fibreglass deck, all be it a lightwight boat and a shock load.
 
Graham_Wright said:
What's a Jordan?
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Is this a reference to my typo? Sorry should be "Jordon"?

If not it is a series drogue, invented by Don Jordon and tested by US Coastguard, using lots of small drogues attached along a long rope. The idea being there is no single drogue to tangle, fail, or get carried forward by a breaking crest. The drag is applied steadily along the length of the rope to maintain efficiency. There is lots of info on the www; available commercialy or info to specify and build your own - a winter's project.
 
I had planned to use two webbing towing strops from stern cleat to the primary winch. The webbing strop is about 4mx75mm x 8-10mm cant remember the breaking strain listed but IMHO designed for snatch loads, also could be better with regards to chafe. One around the winches the other looped through the stern cleats both taking the strain evenly. I watched a video of a Jordan being deployed and it ended up 'taking over' so load is on shortly after initial cones are deployed
I hope to never test it though!
What are the expert thoughts?
 
LadyInBed said:
Toerail is no place to attach anything that takes snatch loads, in fact I wouldn't attach fenders to an aluminium toerail!
A bridle off stern cleats, reinforced to sheet winches is my setup.
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The JSD is designed not to produce shock loads. That's not to say the loads won't be high though.
 
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