Kitchen rudder

Discussion in 'Boat Design' started by duluthboats, Mar 8, 2002.

  1. steamboatmodel
    Joined: Nov 2005
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    steamboatmodel Junior Member

    Hi Walrus,
    Do you have any photos of the Kitchen Rudder on any of the Royal Navy craft?

    Regards,
    Gerald
     
  2. BCM
    Joined: Nov 2005
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    Location: Port Colborne Canada

    BCM Junior Member

    Gerald,

    I am the author of the Kitchen Rudder article in Woodenboat magazine issue #185.
    In this article, I documented Kitchen Rudder use by the Canadian Navy at Dartmouth N.S. during WW2. These were installed on open boats, probably the same 32' Cutters as used by the British Navy.
    I have since discovered that the same Cutters were used by the Australian Navy. A description and a picture of their Kitchen Rudder use can be viewed by going to www.woodenboatfestival.com.au ... then click on "newsletter" and download the Woodenboatfestival newsletter December 2004. Contained in the newsletter is an article titled "Woodenboat Profile HMAS Sydney". This article includes a description of the 32' Cutters, the Kitchen Rudder and the picture that you are seeking.

    Barry
     
  3. safewalrus
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    safewalrus Ancient Marriner

    steamboatmodel

    Sorry no 'Photo's, as a young matelot I wasn't interested in such things - especially as they were considerd at the time, commonplace! How times change! As to the comments on the forum of lack of ships names using this equipment, most large warships (carriers, cruisers etc) would have a couple. One each side as a 'seaboat' (32 foot cutter) - try Albion, Bulwark, Centaur, Tiger, Blake, Ark Royal etc. they were also used on a more modern larger workboat of some 44 -45 foot, GRP blunt nose (pram) crew of four minimum! Iknow I got in the poo! deeply for using one, for most of the afternoon on my own! Naval Officers said it couldn't be done - it could, piece of wee wee!:D
     
  4. steamboatmodel
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    steamboatmodel Junior Member

    Thank you Barry,
    This is exactly the type of thing I am looking for. I enjoyed the article in Woodenboat very much, It was your article, some plans in Model Shipwright and some old Model Boats magazine that started me on this quest. I am hopping I can find evidence of a steam powered craft that I can use a single cylinder Steam engine in.
    Regards,
    Gerald
     
  5. steamboatmodel
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    steamboatmodel Junior Member

    Thank you for your timely reply, do you remmember if an of them were steam powered?
    Regards,
    Gerald
     
  6. BCM
    Joined: Nov 2005
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    BCM Junior Member

    Gerald,

    For information about Steam powered boats including design information, look at http://www.steamlaunch.com/.

    Regards

    Barry
     
  7. SAE140

    SAE140 Guest

    So - how does it work then ?

    I only discovered this thread whilst searching for something else ...

    Ok - most stuff regarding Kitchener's Rudder has been covered already - but what I simply don't understand is how the rudder ever gets to generate reverse thrust. That it does isn't being disputed (which would be kinda daft).
    My question is HOW does it do it ? (Even the one-third of forward thrust which is mentioned).

    The diagrams I've seen show thrust as arrows originating from the aft side of the prop. But - as water is for-all-intents-and-purposes incompressible - then there will be as much 'pulling' as 'pushing', as it were.

    So - to my way of thinking - when the clams are positioned in reverse mode, there will be more-or-less equal amounts of water being moved in both fore and aft directions. So how come a net reverse thrust is being generated ?

    I'd like get some understanding of this, as I'm definitely gonna build one of these, and understanding the theory might determine how successful the outcome is.

    Ta in advance.

    Colin
     
  8. duluthboats
    Joined: Mar 2002
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    Location: Minneapolis,MN, USA

    duluthboats Senior Dreamer

    Hi Colin,

    The prop pushes the water and the rudder redirects the flow. Try it with a tea cup and a hose the water will go everywhere, but it will not stop. ;)

    Gary :D
     
  9. SAE140

    SAE140 Guest

    Hi Gary.

    Mmmmm - experimentation with a jet of water won't help this thicko too much - my difficulty is in conceptualising what's happening with a screw propellor.

    As I view the situation, the prop is screwing into the water and pulling itself forward - moving (say) 1 cu.ft. water/ min - this cu.ft. of water is pushed backwards, hits the reflector and is projected forwards. So - with my logic, the pulling should directly equal the (reflected) pushing - less any losses of course.

    That it doesn't is a helluva mystery (to me). I think one writer commented that it appeared like a 'pulling yourself up by your bootstraps' situation - yep - that's exactly where I'm stuck at.

    If a prop didn't pull, and only pushed, I wouldn't have this mental block.

    Cheers

    Colin
     
  10. SAE140

    SAE140 Guest

    Have just found the following quote on the Ocean Navigator site:

    "In the late 1910s or early 1920s the U.S. Navy performed trials on a 38-foot launch fitted with a Kitchen rudder. They reported that from 12 mph it could be stopped in just one boat-length. Incredibly, they also reported that the Kitchen rudder enabled this launch to be turned around on center in other words, in place! You can t do better than that for low-speed, close-quarters maneuvering."

    Astonishing.

    Colin
     
  11. duluthboats
    Joined: Mar 2002
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    duluthboats Senior Dreamer

    If the boat is tied to the dock and the prop is turning it is acting only as a pump, it is this slippage that allows the boat to reverse with the prop turning forward.

    The quote you site and others like it are what have fascinated me about this rudder.

    Gary
     
  12. SAE140

    SAE140 Guest

    Hi Gary

    thanks for trying (!) - I've given up trying to sus it - it obviously works (and works well), so I'll give my brain a rest and just get on with it !!

    I see it was even fitted to an outboard prop (US Patent 2,155,112), so it's a flexible design !

    I'm not sure why there were so many complaints about the force required to operate the clam-shells - it seems to me that all that's required is to extend the clams forward a few inches to create a pair of 'balanced' clam-shells, which presumably should work just like a balanced rudder does ?

    I'm looking forward to playing with this idea - a scale model first, of course.

    Colin
     
  13. safewalrus
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    safewalrus Ancient Marriner

    Sae 140 I wouldn't worry to much about why, i drove the damn things and I can't figure it! It just does - wonderfully so! the problem is replicating it!
     
  14. SAE140

    SAE140 Guest

    So I'm not alone in being puzzled then ?? That's a relief !

    Looking at patents 1,186,210 (Kitchen's original), 2,155,112 (Anderson's outboard engine add-on which uses Kitchen's clam-shells to effect neutral/reverse), and 4,895,093 (Dalsbo's improved 'Kitchen Rudder' which is shaped to create a rear-facing jet-like orifice), it seems to me that there are several variables involved - none of which are discussed in the patents or elsewhere (to my knowledge).

    For example, there is the fore and aft distance from the propellor to the shells.
    Kitchen shows a prop just inside the leading edge of the clam-shells but forward of the pivot point, whereas Dalsbo locates his prop to more-or-less coincide with the pivot point. Anderson's is located well in front of the shells with a substantial gap between prop and clam-shells.

    Not difficult to see why this is so - Kitchen is relying on the gap between prop and shell 'opening up' as water begins to be deflected backwards. In contrast Dalsbo is re-directing water backwards via a 'duct' below the prop so the gap stays the same. And Anderson's ? Well, I think this placement is just a necessary consequence of this kind of retro-fit modification, and is probably less effective than the other two ?

    Then there is the gap itself betwen prop and clamshell. Just how critical is the size of this gap ? Is there an accepted rule of thumb when working with Kort nozzles and other similar devices ?

    And with Kitchen's patent there is the interaction between the two - as the cross-sectional size of the 'reversing orifice' *and* prop to wall gap both grow larger as more reverse is applied. Here there are two streams of water moving in opposite directions, but which are in contact with each other. Gotta be loads of eddying there. Perhaps for this reason alone Dalsbo's may be easier to replicate ... ?

    "the problem is replicating it!"

    Agreed ! What appears at first sight to be a seductively simple idea will undoubtedly require some careful experimentation if the best performance is to be achieved.

    Well done John Kitchen !!

    Colin
     

  15. BCM
    Joined: Nov 2005
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    Location: Port Colborne Canada

    BCM Junior Member

    The Kitchen Rudder controls the direction of the propeller slip stream. When the clams shells are closed, the stream is reversed, when part open, some is reversed, some not, so the vessel does not move, when closed and turned the action is as a stern thruster. Quick closing puts the brakes on. Part closing slows the vessel.

    I use a Kitchen Rudder. An article about it was published in Woodenboat issue 185.

    I am attaching some images to this post. Each image is numbered to facilitate discussion. To suggest a scale, propeller is 12 inches diameter

    When I built the device, I first prepared a complete set of detailed engineering drawings These can be made available if anyone wishes to manufacture a copy.

    I will be exhibiting this Kitchen Rudder at the ACBS show at Gravenhurst Ontario on July 8. Gravenhurst is about150 km north of Toronto .. a bit far for those living on UK.

    Barry
     

    Attached Files:

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