Rudder Modifications

Page published: 22 November 2011

Go to TopIntroduction

The bottom of the standard rudder is designed to sit level with the bottom of the main keel, as seen on the profile taken from the 1970 brochure. In theory, this should mean that there is minimal risk of causing damage to the rudder as the main keel will hit the bottom first.

SeaHawk Profile showing Rudder

However, a number of owners have modified the rudder on their boat. This page shows two examples and indicates reasons why others might want to make similar alterations.

Go to TopFar Cry

Lifting Rudder

Ducan Curtis part-owner, with his brother, of Far Cry, made a lifting rudder, to replace the standard fixed version.

For most owners, the main purpose of this change is to make sailing off a shore or from a shallow slipway easier. However, One owner, sailing in Poole Harbour, had a different reason. Reporting a cruise with four adults and three children on board, he said he found that when the centre plate was up, the rudder was touching the bottom before the main keel. (Hardly a surprise with that load!)

Duncan first prepared a model, in card, of his proposed design. The new blade itself was fashioned from the original 1" thick mahogany, to which additional strips of 1" mahogany were added at the top and front.

The new side panels were created from 12mm marine ply and to these are fitted 50mm wide pintle and gudgeon. Large handles are also fitted that help when the rudder is to be lifted off the boat.

The rudder can be held up by a line secured by a clam cleat, mounted on top of the rudder, and is held down by a downhaul, just visible in the photograph, attached at the bottom to the gudgeon on the swivelling blade. This cord then travels up through a U-section channel that forms a tube to emerge just beneath the tiller, where it passes over a pulley to the tiller.

A Duncan has supplied a JPEG file (669Kb) showing details of the Far Cry Lifting Rudder including the photograph above and those of his card model plus some of his working sketches. He reported on the rudder a while later saying:

I am happy to report that the sea trials for it have gone very well! It has had only one minor modification, to enable it to lift even higher.

We have been aground once so far ( early days!) and the rudder lifted automatically! (Our stern swung into the stony bank while we were trying to free a stuck centreboard.) The cam cleat on the uphaul was easy to secure, so as to keep it raised until we were out of trouble.

There is also one additional advantage I didn't anticipate at the time. Lifting the rudder avoids having the rudder conflict with the prop of the outboard, which could normally happen when doing tricky moves under power!

It has good leverage when under sail, so it seems to do the trick under water. There is a bit of buoyancy in the rudder itself, which means you need to give the downhaul rope a bit of a tug to get it lowered, once it has been raised. I might advise adding a bit of lead to it.

All in all we are very pleased.

Go to TopFeckless

For Phil Brown the modification to the rudder was to improve general sailing performance. When a query was raised about his longer rudder he responded:

I don’t find there is much chance on Windermere of grounding so the few extra inches are not a worry.
...a pivoting blade would save the rudder in the event of striking a rogue rock, but the way I have done it is more stable and if I did hit a rock the pintle brackets would break before the rudder or transom damaged. I consider that a reasonable risk. I’ve only graunched over a rock once in 8 years here.

Old and New Rudders - Feckless

Continuing his description, he said:

The new blade was one I made and fitted to a Prelude for a few weeks, which explains the lighter patch at the top.

Line 1 is the vertical and Line 2 the pintle pivot line. There is no science involved. I tried it on the Line 1 first and it worked a treat so I haven’t even bothered trying it on Line 2. I would imagine it would be more balanced (but I have next to no weather-helm anyway) but I think it would give a poor entry to the leading edge when the tiller is put over as the boat is heeled.

Phil used to have a site on which he said of this first video:

This was part of an experiment to replace my rudder with something a bit more efficient on my Seahawk 17. It tended to lose grip and stall when hard-pressed. This video was taken using the old rudder in winds gusting to 19 knots.

About the companion second video, he says:

This was taken whilst testing a new, and deeper, rudder blade. Previously the boat would not sail "hands-off" at all and would round-up on it's own in even the lightest of breezes. In this video I can sail using just the mainsheet to steer. The wind was less than in the earlier test but got up to 14 knots towards the end of this clip.

For those interested, Phil has a channel, foleybrown, on YouTube that has quite a number of videos shot from "Feckless" on Windermere.

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