Wednesday, 5 October 2011

Threading the Downhaul

Watching some people thread their downhaul rope is painful, but not as painful as they find it pulling on the downhaul. If its hard to pull on then you are doing something wrong. There are 2 different types of downhaul threading, one is very simple and intuitive where the mast base pulleys and the sail tack pulleys are parallel. This first type requires no explanation to thread only make sure you do not cross the rope and keep it parallel.
The other is a lot less intuitive but spreads the load on each individual pulley a lot more efficiently than the parallel types. Once you get this one right you will know exactly what I mean, all of the rope lines up perfectly through the pulleys, and its quite quick to do.


(The unmentioned third type of threading is the XT type which can be extremely weird depending on the sail tack pulley!)


At this point the sail is usually quite far away from the mast extension and a sharp pull on the end of the downhaul will reduce this by about half, giving you more rope to use for the next two pulleys.



Give the rope another sharp pull, this should bring it even closer to its final resting place, you have a much better purchase now due to the 3 pulleys helping. Remember here to thread the rope UP through the extension pulley not down, this is the key to getting them parallel.



Now simply thread it through the cleat, make sure it grips while you hunt around for the downhaul tool! 

A few words on the choice of downhaul tool. You can spend money on them, and you can do it just as easily for free with a bar. Conveniently you have a bar that you use for your harness. I personally do not use my hook as this can damage it. 

If you just wrap the rope around a bar then as you pull the rope will naturally try to unravel and the bar will turn. If you wrap the rope back on itself like in the picture above then it just tightens on itself. Any normal dyneema will only need one wrap around, but if you use formuline which is very slippery give it a few more wraps around the bar to make sure it doesn't slip. 

When doing the final 'pull' I find it best to sit down, have my arms stretched out with a bent leg and the heel of my foot on the base of the extension. (After doing it several times in leather soled shoes I would recommend you use something with a bit more grip or you may regret it!). Use your leg power and do it quickly, overdownhaul the sail and then let it off to tune it. Pulling on the last bit of downhaul is hard and it is a lot easier when you have momentum .

Other options are to use a rig winch, or the North XT. When I started I used a North XT and they are great, you just need to replace worn out parts which are quite cheap. I stopped using it until recently as I favoured the strength of the Chinook (I had a sail that required 42cm extension or a 490 mast....the North went to 42 but the chinook went to 48). Last month I got a sail that needed only 2cm of extension and the Chinook minimum is 4cm. It is quite a tunable sail as well so I opted for a newer North XTi, which has a lot of threading options and the longer handle for race sails. It allows me to learn the characrteristics of the sail quicker with fine tuning while out on the water.

2 comments:

  1. From Boetker on the Boards Forum - first three steps: 3rd pulley on sail, 2nd pulley on extension, 1 st pulley on sail. The last three steps: The 1st pulley on the extension, 2nd pulley on the sail, 3rd is into the cleat..
    Good little way of remembering. All you need to do with this is use your uncommon sense and thread either up or down through the extension.....a few practice runs when the wind is quiet and you are dying for a session is well worth it.
    Thank Boetker

    ReplyDelete
  2. A fantasic article Lea, I like to think I might have been the source of the inspiration behind it. How about some tips on pulling Super Models? Laters, Brave Sir.

    ReplyDelete

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