Self-steering - Huntingford Helm Impeder

 Recently fitted  "Huntingford Helm Impeder's" (HHI) to my Fatty Knees 8 dinghy and Teria an Investigator 563 trailer sailer. 

Helm impeders hold the tiller in any position but still allow the tiller to be moved a bit until the right balance is found to let the boat self-steer for awhile. This allows the helmsman to do other things, especially useful when sailing short handed. 

With the helm impeder engaged the skipper can become the crew and do things such as raise/lower sails, drop the anchor or even pour a cup of coffee and take a break.

John Huntingford of the Dinghy cruising association (DCA) in the UK invented this helm impeder and it remains popular with DCA members. It  is featured in a great book by Roger Barnes "The Dinghy Cruising Companion" (The book although written for cruising dinghy's has allot of things that are practical for ballasted trailer sailers too). 

There's also some good u-tube videos on the HHI. Helm Impeder - Nick Crabbe and Huntingford Helm Impeder - Romantia Christiana. 

Plus an interesting blog post Huntingford Helm Impeder - The Blue flower

FK8 Huntingford helm impeder.

Started on the smallest boat first, to test the idea. Printed out the HHI diagram and studied all the info.

Found most of the parts needed more cheaply at the hardware store and also in my "boat-bits" spares box. Some other parts were from the ship-chandlers, a small open V cleat and small pulley (block). 

Once it was all set up it worked well. The tensioning line can be adjusted to get just the right amount of friction to impede the tillers' swing. It can be let loose for easy helming with tiller swing limitations and unclipped quickly to remove the rudder. 

Being a small dinghy, only 3mm braid, 4mm shock-cord and the smallest of fittings needed. 

Jai Dee's tiller with Huntingford Helm Impeder

HHI from below

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"Cam Jam" about $6 at Bunning's - an optional extra, allows the tiller cross-line to be adjusted or released to gain space quickly down aft ("Cam Jam" was found in the load tiedown devices section)

Cross-line gunwale attachment. ss snap hook and ss saddle

Aft pulley under tiller, for tensioning line.

Huntingford Helm Impeder for Teria.

The second HHI was bigger but much faster to make, as I already had some items and had learnt from the first one. Used a welded ss ring bolt at the forward end of tiller this time. Got this at the hardware store plus more ss screws, ss shackles, ss snap hooks.

The ringbolt shaft extended above the tiller, so made up a quick tiller extension as well to utilize this fitting. Another reason for ring bolt is the tiller is fairly narrow at this end and a fairlead (as in the sketch diagram) was too wide to screw on here. (some boats have ring screws instead, but I couldn't see any ss ones in this hardware, they might be better and much neater)

The after pulley needs care with placement, so it doesn't hit anything when moving tiller to full locks. So setup the rudder and tiller on the boat and marked the best spot for it to stay clear of the transom.

Used the same 3.2mm braided line from the FN8 HHI as it is very strong and wear resistant. Put thicker 6mm shock cord double looped in, but used the same size cleat and snap hook as the FK8's one.

However tried a "closed" V cleat to keep the line in place after it is released. A cleat with a small fairlead is my prefered type (open V cleat was preffered by some sailors, so its an individual choice)

HHI setup on tiller in cockpit of Teria.

The welded ss ring bolt under tiller (with experimental tiller extension above)

Update 2024: Removed the tiller extension after a few trial runs. Simpler was better. Also it was not needed as the helm impeder does the work of holding course.