Kitchen rudder

Hi all,
New guy here. I did a search of the archives and found no mention of the Kitchen rudder. So is there anyone out there with information on this rudder? I have the Boatbuilder article by Gerr. And a few other bits and pieces. I'm looking for stuff on linkage, sizing, even pictures. I have been around the web with this one so anything will help. A fellow on Woodenboat's forum said it was a good bunch here. If your into wood they also have a good bunch of guys and gals.
http://media5.hypernet.com/cgi-bin/UBB/ultimatebb.cgi
I have interests in CAD, CAM, CNC, along with building small boats.
Gary

 

Hi Gary.

I'm not familliar with the term "kitchen rudder." Do I scramble eggs with it? Please describe.

Thanks.

 

Hi Stephen,
LOL!! Your not the first to tell me that. This is a rudder that was developed by Admiral Kitchen (British Navy) and patented in 1916. It's for power boats. It consisted of two half circles, somwhat conically shaped, that surround the prop in a ring. With the ring open it acts as a nozzel. When it's closed, you have reverse. A few advantages are improved prop efficiency, it eliminates prop walk at low speeds, and you have an instant reverse without a gear box. I know if it was so great, where did they go. Well someday one of my boats will have one. Never was one to follow the herd. I'm always looking more info. on them. One of these days I'll get around to ordering a copy of the original patent. U.S. Patent No. 1,186,210
Gary

 

First, welcome to the forums Gary!

Since Stephen didn't know the reference I don't have to be embarrassed that I didn't know either and was about to ask you the same thing

There are two recent patents which make reference to 1186210, one of which appears to be a direct descendent of the same concept:

"Manoeuvring device for boats", Dalsbo, 1990, #4,895,093:
The invention is a manoeuvring device for boats, comprised of a pair of pivotal tube plates (17, 18) mounted outside a propeller 14 and, under normal operation, forming a tube (19) around the propeller. These plates can be swung to one side relative to a medial position to enable sideways steering of the vessel, and be brought together astern of the propeller to form a blade when reversing. The tube plates (17, 18) extend down beneath the propeller (beside 19B). A tube wing (20), extending in a longitudinal direction, is mounted immediately beneath the propeller (14) and is arched upwards towards the propeller wings. Under normal operation, a tube that is sickle-shaped in cross section is delimited between the tube wing and the lower portion of the tube plates. The pivot axis of the tube plates (17, 18) is preferably located close to the propeller wing plane.



Here is the original patent also:
http://patimg1.uspto.gov/.piw?Docid...ageNum=&Rtype=&SectionNum=&idkey=CC86F79C5C48
This is from either http://www.uspto.gov/patft/ or http://www.surfip.gov.sg/sip_home.htm -> After you search click the blue button for Images.

 

The efficiency of the fixed nozzel makes sense in many cases, but I was under the impression that using a baffle to redirect propelled water forward to provide reverse was not so efficient. Isn’t this one of the common drawbacks to jetboats which use a similar (in function if not design) redirecting-baffle for reverse and have a more difficult time docking and such?

 

Jeff,
Your amazing, last time I did the patent search they didn't go that far back, on the web. The newer one is interesting as well. The only current application that I know of is on RC boats. You could be right about the reverse. In the Gerr article, he says that the British Navy was very impressed with it's performance. The big problem they had was with the complex mechanical linkage. I would think that electric or hydraulic actuators would simplify the control.
Well it's fun to think about anyway. Not much else to do with a blizzard roaring outside.
Thank you for the reply and the links.
Gary

 

Very interesting, Gary. I might contemplate using something like that on the design below instead of the jet drive if I could do it in combination with a partial tunnel. Here's one company I think could manufacture it if there was demand:

http://www.machineworksatessex.com/

 

My take on the Kitchen rudder is that it would only be useful on slow speed craft. It has a lot of area to generate drag at higher speed. When not steering it looks a lot like the Kort nozzle which is only good at low speed.

Yes, no?

 

Hi Tom,
I think your right as far as the use for displacement boats. It is for that use , that I intend. I would like to see it on something similar to Atkin's Big Surprise.

Stephen
When I get it worked out I'll build it myself. I'm a very good machinist and have access to a large shop.
Nice boat. but I don't know if this is the right rudder for it.

Gary Schollmeier

 

Perhaps, but let's stay on that point a moment. My boat is actually intended for semi-displacement speeds - too slow for the jet drive really. I'm probably going to move the console to the center and put the engine under it to get the weight forward. My reasons for the jet drive are:

1. Maneuverability.
2. Susceptibility to damage and tangling in mooring lines, especially when operating as a harbor launch.
3. Safety when someone is in the water.

If those concerns can be addressed with this drive, it might well be more efficient than the jet at the 12-15 knot speeds I wish to optimize for.

If this reasoning sounds right to you, I 'd be interested in your drive, perhaps in combination with a Cummins 4BT-3.9M. I don't have prop calcs yet, but the launch is 25' long incl. fenders, I hope to keep the dry weight around 3500 lbs, and I expect it to be about 5000 lbs with full fuel and several passengers. What I'm looking to do is to sell a kit of pre-cut panels for assembly anywhere in the world, along with equipment specs, so what I'm asking is if you'd be interested in being one of suppliers of equipment for the kit. If successful, I hope eventually to do larger versions of this hullform.

 

Stephen,
I think the Kitchen rudder would be ideal for the use that you have described.
1. It will increase the maneuverability.
2. It will protect the prop from damage from striking something. Line tangles will still be a worry.
3. It should be somewhat safer then an exposed prop.
As for being a supplier of these systems, no I don’t think so. If I have this worked out by the time you need it I would be happy to give you my drawings. Or to anyone else that is interested. I think this is a good idea that was lost for some reason and I would like to see it in use.
Now, I’ll lay this out here in the hopes that we can get a good discussion on the merits of my idea. I would also use a small diesel. For the boat above I think 25-40 hp would do the job. For reduction and engagement I would use a variable speed clutch/pulley set up. This would be light weight, easy to maintain, and dependable. The reverse could be engaged by a simple hand lever. It’s low cost and simple, maybe, maybe not. LOL!
Now Stephen, about those panels for your kits, did I tell you that I’m building a 4’X8’ 3 axis CNC gantry router in my garage? Good for wood and plastic.

Gary

 

Hey look what I found. One more tidbit to add to my collection.

http://www.pcez.com/~artemis/SLAkitchen.gif

Gary

 

Greetings:

I would like to know if anyone following this thread knows a source of good used Cummins 4B, 4BT, or 4BTA diesel engines in the uppermidwest region of the USA.

I live in bush Alaska and would like to source these engines before my trip outside this summer for possible purchase.

Please respond here or to my e-mail, diesels@mail.com.

Thanks - Tiasto

 

What would be the max speed that the kitchen rudder would be okay with before the drag became a problem.

I'm building a Bolger Wyoming and am interested in this setup. I've always been a bit on the "try anything once" side, hence the 50' Wyoming. It's a flat bottom sharpie designed for up to 150 HP. I'm thinking of running a 130 HP 4 cylinder. Max speed will be around 22 knots but cruising will be about 9 or 10 knots.

jeff@goldencoast.com

 

Kitchener rudder

The Kitchener rudder was used on many Royal Navy and Commonwealth Navy small craft such as the 32 foot motor cutters up to about 1975. Its advantage was good steering in sheltered waters, no need for the gearbox to reverse and excellent control when comming alongside. The coxswains got very good at controling the combined tiller and acme thread engaged wheel that controlled the "bucket " You will find it described in older editions of the RN Manual of Seamanship. I do not know if the US Navy used it. Boden B.P.