Attainable Adventure Cruising—What's New

Heavy Weather Gear and Strategies #10—Jordan Drogue Launch System

posted by John & Phyllis Web Site

OK, enough blather about why we selected the Jordan Series Drogue and why you need a complete system for dealing with a drogue or sea anchor; on to the nuts and bolts of our deployment system.

Attachment Points
When setting up to use our new Jordan Series Drogue, the first issue we examined was attachment points for the bridle. Although we have massive stern cleats and fairleads that would theoretically be able to stand up to Jordan’s projected maximum load of 30,000 lb (13,600 kg) for Morgan’s Cloud, we opted to fabricate and build two dedicated chainplates for the following reasons:

• Any rope that passes over a fairlead is potentially vulnerable to chafe no matter how well rounded that fairlead is. (It is amazing how often we have read accounts of heavy weather deployment of sea anchors and drogues that end with a broken warp due to chafe.)
  
  
• We don’t want to be messing around with chafe gear and be trying to “refresh the nip” by adjusting bridles under heavy load in storm conditions.
  
  
• We want to be able to set up our Jordan Drogue system before we go to sea and leave it that way without having to remove it to free a cleat for something else.
  
  
• We want to get the bridle legs as far out on the corners of the boat as possible, which should make her yaw less. Also, this positioning has the added benefit of keeping the bridle legs away from the self steering gear.
  

Before we leave the subject of chafe and loads, it is worth noting that most of the examples on Jordan’s web site discuss quite small boats. In our opinion, the owners of boats displacing 30,000 lb (13,600 kg) and up (MC displaces 52,000 lb (23,500 kg) fully loaded) need to spend a lot more time and effort in this area. For example, when we test deployed our Jordan Drogue on a flat calm day while motoring at just 1200 rpm the load was in excess of 3000 lb (1360 kg) (estimated in relationship to known loads on our primary winches). Think about that and then envision Morgan’s Cloud on the top of a 50’ (15 m) breaking wave and starting down the front—now there is a terrifying picture. It is not at all inconceivable to us that, as the drogue takes the strain of stopping the boat from surfing, the load would go to ten times that of our test.

After some calculation, we ended up having two stainless steel chainplates 27” (68 cm) long by 2.75” (7 cm) wide fabricated from ½” (130 mm) stock. We fastened the chainplates to our toe rails with seven 7/16” stainless steel bolts. We can only get away with this positioning, even though these toe rails are massive and welded to the hull, because there is a substantial existing chainplate (originally designed to take the load of the spinnaker sheets) in the way of three of the bolts. For most boats, to get adequate strength it will be necessary to bolt through the hull and a substantial backer plate. In the case of fiberglass boats it may be necessary to build up the laminate thickness in the way of the plate.


Set Up
Before going to sea, we will shackle the bridle legs to the chainplates with two ¾” Crosby 209a alloy galvanized shackles with a safe working load of 14,000 lb (6350 kg) and a deform point of twice that, and then wire the shackles closed. Interestingly, the weakest point (every system has one) in all of this is the hole in the chainplate, which will fail at about 26,000 lb (11,800 kg). Since it is unlikely that more than 70% of the peak load will come on one bridle leg, this is well within acceptable limits.

We will then carefully lead the bridles clear of the self steering gear, back to the the aft deck and flake (never coil) them, together with the series drogue, into a sail bag with the bitter end and 12’ of chain, to act as a sinker, going in last. We will tie the chain end to the mouth of the bag so it does not get lost and keep things tidy by using plastic wire ties to lash the bridle to the stern rails. Finally, we will lash the bag down securely on the aft deck.

Deployment
To deploy, we just have to cut the wire ties, flip the port bridle outside the self steering gear, open the bag and chuck the chain over the side via the same route as the bridles come inboard—a far cry from this scenario.

While different boats will require different deployment systems we think they should all be:

• Completely chafe free.
  
  
• Strong enough to withstand Donald Jordan’s design loads. As can be seen by the steps we had to go through, on larger boats this is not a trivial challenge.
  
  
• Completely pre-rigged before going to sea.
  
  
• Preferably deployable without opening a locker hatch and so opening the boat to the sea. Difficult or impossible on some boats, I know.
  
  
• Easily deployed by a seasick, scared and tired sailor in the black dark. (We even have the steps written down, complete with pictures, in the boat’s manual, since I know that in such conditions I’m capable of making some deeply stupid blunders.)
  

Those of you with sharp eyes will note that there is an extra line in the photograph. All will be revealed in our next post on retrieval.

Earlier Posts in the Series
#1 Goals
#2 Heaving-To
#3 When Heaving-to is Dangerous
#4 Options When Heaving-to is Not Working
#5 Stopping Wave Strikes While Heaved-To
#6 Survival Storms
#7 Our Old Backup System
#8 Our New Backup System
#9 You Need a System

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Labels: Seamanship

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