Making a bridle

[Tintin]

I want to make up a bridle for a seris drogue, but am unsure how best to do it.

Should I make 2 seperate legs each with either a soft or hard eye so I can use a shackle to join them to the drogue lead, or make one twice the length of each leg and use a figure of eight knot in the middle to attach to the drogue (which finishes with a soft eye).

Thoughts?

 

[prv]

I can't see a problem with either.

Pete

 

[William_H]

Bridle

I would imagine that you need rope large enough to make handling easy when retrieving which means strength is not a great concern. Hence either will be fine. good luck olewill

 

[barnaclephill]

Should I make 2 seperate legs each with either a soft or hard eye so I can use a shackle to join them to the drogue lead, or make one twice the length of each leg and use a figure of eight knot in the middle to attach to the drogue (which finishes with a soft eye).

No hard eye to chafe or cause a pressure spot, under the loads when used. 2 separate legs with eye splices in each. Thus has been what was supplied when bought, and is visible in the pics from this page: http://www.seriesdrogue.com/workshop/

And IIRC, the length of the bridle was 2 1/2 times the width of the distance b/n cleats.
Yes, just confirmed by the pics on Bryan's site above. He also has a link or the whole of the designer's notes/Coast Guard report.


PS the eye splice b/n the bridle & leader is on the 'buy' page

 

[Tintin]

Thanks all.

 

[maby]

I can't see a problem with either.

Pete

But neither actually does what the bridle is there for - the drogue needs to be able to slide along the bridle in order to distibute the load between the two cleats, not be attached hard dead centre.

 

[Fascadale]

I made the bridle in two parts, with a hard eyes at both ends of each part.

Hard eyes at the boat ends to shackle onto the (as yet unmade) strong points on the hull, and hard eyes at the bridle end to shackle onto the drogue warp.

I would not want the drogue warp sliding up and down the bridle. I think that is inviting the possibility of chaffing.

Equally I would not be worried about distributing the load between the legs of the bridle.

Here is a long thread in which some drogue practicalities are discussed

 

[whipper_snapper]

But neither actually does what the bridle is there for - the drogue needs to be able to slide along the bridle in order to distibute the load between the two cleats, not be attached hard dead centre.

THat is not my understanding and I have never seen a bridle, for a drogue or anything else, that does that.

 

[G12]

But neither actually does what the bridle is there for - the drogue needs to be able to slide along the bridle in order to distibute the load between the two cleats, not be attached hard dead centre.

Is that correct? That would enable it to apply load off centre......

I know she's a very small boat but Roger Taylor's Ming Ming has special plates made for attaching his drogue, one on each quarter. This would seem like a very good idea......

 

[oldvarnish]

But neither actually does what the bridle is there for - the drogue needs to be able to slide along the bridle in order to distibute the load between the two cleats, not be attached hard dead centre.

I'm sure that can't be right. You need the load equally distributed between the two cleats and the pull directly along the centre line of the boat. I can imagine all kinds of instability if the drogue were able to move from side to side - plus the chafe which can be a major factor with all drag devices.

 

[Tradewinds]

A lot of forces involved

Jean Socrates in the Southern Ocean on Nereida deployed her series drogue the other day - didn't last long

Journal entry here

She doesn't seem to have much luck with them - she needs to carry a couple of spares!

Perhaps Spectra is the wrong stuff for a bridle - no give.

 

[paul.norton]

Retrieval line

Interestingly, she mentions a floating retrieval rope. Where is this attached to the serial drogue? If attached to the chain end, I can imagine some almighty snarl-ups

I assume the retrieval line would be to the mid-point of the bridal - am I correct?

 

[timbartlett]

Personally, I would go for nylon -- strong, nice to handle, easy to splice and nice and stretchy -- nothing fancy, and definitely nothing like Spectra.
Any knot/bend/hitch will weaken the rope a lot more than a well-made splice.
Assuming you are thinking of using the drogue as a drogue (i.e. towed astern to keep the boat stern-to sea) then I can see no merit in having the drogue line sliding around on the bridle. Quite apart from the chafe problem, consider:
- (sliding arrangement) the boat yaws to starboard = the drogue line will naturally slide to starboard = most of the load will be on the starboard quarter cleat = the initial yaw will be exacerbated
or
- (fixed arrangement) the boat yaws to starboard = the starboard leg of the bridle goes slack = most of the pull is on the port quarter cleat = the boat is forced to yaw back to port.

 

[oldvarnish]

Interestingly, she mentions a floating retrieval rope. Where is this attached to the serial drogue? If attached to the chain end, I can imagine some almighty snarl-ups

I assume the retrieval line would be to the mid-point of the bridal - am I correct?

I've read a recent post somewhere in which they described attaching a line to the mid point of the bridle and using that to winch in the drogue. Presumably, once you've got the drogue line into the cockpit, you can take it to a winch.

 

[JayBee]

Our Seabrake drogue was supplied with a polyester main warp terminating in a small soft eye, through which the middle of a one-piece polyester bridle is cow hitched.

We don't have any experience of using this gear, but the method of bridle attachment looks OK to me. The warp seems unlikely to slip from the mid point of the bridle , but we'll see. The attachment is tight, with one or both legs of the bridle under tension. No movement equals no chafe.

It is common practice to use cow hitches for similar purposes in commercial towing operations. It has the virtue of simplicity - only one splice involved at the boat end and no shackle pins to worry about.

 

[oldbilbo]

I note this from jean Socrates' blog:

The spectra line had obviously seen too much sunlight and must have degraded as a result

And I recall that Richard Woods had considerable trouble when the 'UV-degraded netting' on his catamaran failed/burst and he couldn't work on the bow-beam to set his para-anchor adequately, AIR.

There's a message here, which is ages-old.

 

[Tintin]

I'm sure that can't be right. You need the load equally distributed between the two cleats and the pull directly along the centre line of the boat. I can imagine all kinds of instability if the drogue were able to move from side to side - plus the chafe which can be a major factor with all drag devices.

,

Agree. and the bridle legs are 2.5 times stern width, so there wouldn't be much scope for a slide from side to side anyway. All the various sites show it fixed.