Spoon rudders

Anything to do with hull shapes in general (i.e. not specific designs)
Post Reply
Posts: 1
Joined: Thu Sep 16, 2021 2:54 pm

Spoon rudders

Post by Slimtim »


This is my first post so please be kind if this question isn't up to the standard that is expected!

I race a 1955 Merlin Rocket dinghy on the Thames. The Merlin is a restricted development class and so there is a keen interest among our very enthusiastic fleet about boat tuning - you may be interested to know that on restricted waters, the older Merlins like mine have a distinct advantage over the modern versions which may seem counter-intuitive but is a fact and means you see a lot of old hulls maintained to a very high standard and fitted with the latest rigs, foils and controls.

I have been racing my boat for a couple of seasons since saving her from a Sea Scout bonfire and then spending many hours restoring her. She is super to sail and we are getting within 2% of the front of the fleet (time gap measured over an hour based on 40 races).

The boat is about to go in the shed for the winter and I have a list of ideas as to how I can evolve what I have to gain that 2%.

One of the parts of the boat that I have left untouched so far is the rudder blade. This is the classic 'spoon' shape typical of the 1950s that I rescued from another wreck. It has a number of benefits such as making the boat turn quickly, has a small frontal area, gives great feel, and won't stall at low speeds etc. However, it isn't a very sophisticated being essentially a cut out flat plank of mahogany with some limited faring along both edges.

While I'm wedded to the benefits of the spoon shape for the type of sailing I do (I've tried straight blades without much joy) I would be interest if people can suggest how I can improve the spoon blade I have. Particularly with regards to its shape (how should the cord vary from the waterline down to the tip?), its length, the degree of sweep, and also the cross section.

I'd like to give this old piece of equipment a modern makeover so it becomes the spoon rudder for the 21st century! If you can help with some informed recommendations, I'd be grateful for the support.

Post Reply