Questionnaire on enhancing the manoeuvrability of canal boats via a Kitchen rudder

[Québec]

As a reseacher myself, I'd advise carefully reading your source material before adopting a defensive position.

 

The long and very informative article you sent the link to contains the following:

 

"In fairly recent time, an enterprising canal narrow-boat owner has salvaged the 'Kitchen' gear from an ex-Royal Navy 25-foot 'motor cutter' and fitted it to his newly-built boat - It will be interesting to note if there are any difficulties with it, for the drawback of the 'Kitchen' gear was that it 'fouled' easily with weeds, canals not perhaps the best of environments for such an arrangement, though at least the water is shallower for anyone having to go over the side to clear the gear."

 

ETA: Our 40' trad seems to be able to spin round on a veritable sixpence, and a sharp pull-push on the tiller can make a crucial diiference in tight situations

Edited February 26, 2014 by Québec

[Trilby Tim]

This is interesting stuff! I am the supervisor, Chris is my student, his degree is primarily mechanical engineering, so the main purpose is in developing a CFD model of the rudder and optimising various parameters of it. Another aspect of his course involves business and marketing, so he has to assess the potential size of the market and any obstacles to realisation. This is the aspect that this questionaire aims to cover. As such your responses are highly useful and I urge anyone who's not filled in his questionaire to please do so. A negative result is still a result, so please answer as you see fit, his project is to optimise the design and do the engineering behind it, we've no intention of comercialising it, so if the answer is that it's an interesting piece of engineering with no commercial future then that's fine by me.

I'm also the owner and designer of the Trilby (I'm writing this post sitting aboard her) and so am responsible for the YouTube clip that's been posted in this thread. I've open sourced everything I've done so far with this design (see the boat design forum), if Chris so wishes then his report will also be made freely available.

 

In fairly recent time, an enterprising canal narrow-boat owner has salvaged the 'Kitchen' gear from an ex-Royal Navy 25-foot 'motor cutter' and fitted it to his newly-built boat - It will be interesting to note if there are any difficulties with it, for the drawback of the 'Kitchen' gear was that it 'fouled' easily with weeds, canals not perhaps the best of environments for such an arrangement, though at least the water is shallower for anyone having to go over the side to clear the gear.

I presume the "enterprising canal narrow-boat owner" is also me as the photo in that article is clearly the back of the Trilby (I believe taken from this forum). I'm honoured to be described as enterprising but I'm baffled by the rest of that statement, I designed the rudder on the Trilby and gave the drawings to my builder (Paul Widdowson) to build, so there's nothing taken from a 25ft cutter, I have no idea where that came from, I've commented on the article to try to correct it, but the error remians. Still there's plenty of things said on the internet that are far more wrong than that!

There's a lot of questions raised over the practicality of the kitchen rudder. These are very valuable and I hope that Chris will reflect these in his report. clearly for it to be a viable proposition these concerns would need to be addressed, however I'd offer the following points based on my own experience with using it. Note: I've not clocked up enormous distances, I've not been to Birmingham or Coventry, but I've been through Rotherham and Doncaster enough times and they're not the cleanest of waterways!

-Clearing weeds/debris from prop: I have a weed cutter on the propshaft which deals with weeds and light debris just fine, no need to go near the weed hatch. I have had rope and heavy sacking (cement bag of similar) wrapped round the prop and have been able to clear it by reaching through the weed hatch with a knife. Yes, it's a ball ache, and harder than for a conventional rudder, but not impossible and certainly not a major issue.

-"Rowing" around tight corners: No need to, the turning effectiveness is higher than a conventional rudder so you don't need to.

-Sucking up debris: Actually I'm not sure about that. Surely any propellor that gives a certain amount of thrust draws the same volume of water in, so all propellors will suck debris into them, I don't see why ducting the propellor will increase that tendency.

-Susceptibility to damage: It's possible to design a kitchen rudder set up that fits entirely under the counter, nothing sticking out. Admittedly, the set up on Trilby does protrude slightly out the back, but that's because when I had her built I wanted to leave the option open to fit a conventional rudder if the kitchen didn't work. The principle is that the rudder doesn't need to to protrude beyond the back of the craft, so is protected from bumps from lockgates, coping stones etc. In terms of hitting underwater items then the rudder only goes around the prop, it doesn't go deeper or further. So if I hit something under the water with my rudder then you'd have hit it with your prop. A propellor is fairly thin brass at the tips, the rudder is 6mm steel, I know which I would prefer to take underwater impacts. You could argue the kitchen rudder protects your prop.

-"The tiller's at a funny angle in the video": That's the reverse postition, in the ahead postion it's where you'd expect a tiller to be.

-"Not been done before" Robbo answered that in #31, I couldn't put it any better.

It's clear from the responses to the questionaire that strength and reliability are the most major concerns. This is useful to know, but that's fundamentally just an engineering problem, the answer is just built is strong enough to cope!

So thanks for all your responses, keep them coming, but don't shoot Chis, he's just my messenger!

[RLWP]

Welcome to the forum Tim

 

Its good to see an engineering student using the forum for research for his project, we usually get design students!*

 

Richard

 

*flower arrangers, as they were known in one of my previous jobs

[Trilby Tim]

Cheers Richard, although I'm not new to the forum, just been away for a while, there's a build blog for the Trilby on here somewhere.

[RLWP]

Ahh, 162 posts

 

Richard

[ditchcrawler]

Ahh, 162 posts

 

Richard

I wanted to point that out, spoil sport

[Québec]

Welcome to the forum Tim

Its good to see an engineering student using the forum for research for his project, we usually get design students!*

Richard

*flower arrangers, as they were known in one of my previous jobs

I'm a trained 'flower arranger' and proud!

 

ETA

 

..and as a serious ''flower arranger', one might usefully ask how the kitchen rudder matches up to the principles of good product design.

 

Is it innovative?

Does it enhance the user's experience e.g. is it easy, pleasurable to use?

Is it logical e.g. does form follow function?

Is there an aesthetic quality to it?

Is it honest e.g. does it do what it claims to do?

Is it sustainable e.g. Is repair/replacement relatively straightforward?

Is it enduring e.g is it sturdy/built to last?

Is it thought through/consistent down to the last details e.g. the weed hatch problem?

Is it minimal design e.g. As simple as possible but as complex as necessary.

Edited March 1, 2014 by Québec

[PhilR]

A narrowboat with a properly designed traditional rudder can be steered when the engine is in neutral if there is a bit of momentum. I assume that isn't true for the Schilling rudder.

 

Also, the traditional rudder can be used as a paddle to maintain the direction of the boat when hanging around waiting for a lock etc.

[Dalslandia]

I have designed and fitted a schilling rudder on my 72X13 boat. it made a big difference in turning performance, compeered to the flat plate that it replaced.

a schilling rudder is said to be 30% or more efficient then a NACA 0015 rudder.

how much better then a plate? maybe 50%

My schilling beeing 10% smaller then original.

 

the best with schilling rudder it steer with angles up to 70 degree each way, with peak efficiency at 40deg. it can even go back ward with 65-70 degree.

it goes straight as an Arrow, it steers slightly in neutral gear.

Edit, thinking on this over night, well I didn't, it would be crazy. the most efficient single rudder is the flap rudder, but with more mowing parts it is more sensitive for Canal use, the schilling is simple as any rudder, when it is constucted, it is more expensive to make then a flat plate though.

 

Many Dutch and German big Canal/river barges have double rudders that is very efficient.

 

My boat have a rudder size K factor of 2,5% that is simple, rudder area / the water line length X draft mid ships

tug boats and Pilot wessels can be up to 4%, faster Ferrys < 1%.

 

double rudder can be made to turn individualy, also turn around so they form a thrust reverse and stop the ship faster then if propeller is in reverse.

 

I kitchen rudder, I Think it can be improved on, combined with the benefit of a shroud or kort nossle to improve thrust at slow speeds.

 

the kitchen rudder look like 2 half buckets, and no toughts of improvments

it will not be simple to manufacture a improved version, so question is if it will pay off on smaller boats, on bigger ships, well they use kort nossles or azimut propellers.

 

even if you come to the conclution they will not pay of for the boat owner, the ship yard, or industry to manufacture, you have don the job stating what is and what is not.

Edited March 3, 2014 by Dalslandia

[Dharl]

From my point of view I would suggest that the Kitchen Rudder adds additional moving parts and expense to something that is not required on the canal system. The Kitchen Rudder would be of more benefit fitted to vessels working in deeper water but where good manoeuvrability is required, mainly I suspect in the commercial world rather than leisure. An example would be Short Sea Coastal Trading vessels, tugs etc. however then the Kitchen Rudder then is in competition with Becker High Lift Rudders and Twin Schilling rudders working with Controllable Pitch Propellers (CPP)

[springy]

<snip> However, without a gearbox you would be forced to stop the engine before taking the weed-hatch cover off

<snip>

 

Wouldnt dream of going down a weed hatch with the engine running !

 

springy

[Roadsteam]

 

Unfortunately, bizarre objects which can & do get caught in a propeller and require a trip down the weedhatch, can end up in any canal, even well maintained ones. Granted that there seems to be more in some canals than others, eg BCN has a particularly poor reputation for debris in the canal.

How about 10ft length of 6ft high chain link fencing wrapped around the prop of a tug, if the dredger had been unable to lift the stern high enough out of the water to get and cut the wire off it would have been a drydock job. The operator of the tug was not amused.

[larryjc]

Just spotted this thread and there is one major flaw with KRs that hasn't been mentioned. When I joined the RN a million years ago we had to do boat tests on all the types of boats that Dartmouth college owned before the end of the first year. The one boat everyone hated was the Kitchen Rudder motor boat. They were also by an order of magnitude the most crashed. The reason is simple, you start to come alongside and need to stop so you wind the handle like mad to reverse the clam shells and suddenly the bloody tiller is working in the opposite sense. Eg coming in starboard side to, as you approach the jetty you push the tiller to starboard to bring the bow to port then crank the handle when suddenly the bow starts to swing back because the thrust is now pulling the stern to port - and you crash into the jetty again!! Yes you know you should have reversed the tiller as you wound the handle but it only takes a second and as you can't see the clamshells and you were concentrating on where the boat was going you forgot. Hateful bloody things. Oh, and you also have the problem that if you get the paddles in the wrong position you have no steering at all. Yes once you have the knack they are incredibly manoeuvrable but how much damage will you do before you acquire it?

[nb Innisfree]

A steerable pod would be the DBs on a canal boat, fairly straightforward to fit, probably hydraulic powered prop. Shame somebody doesn't make a practical sized one.

[DHutch]

A Schilling, a more aero foil shaped rudder.

As per the one I designed and fitted to Emilyanne.

 

I am also a recent graduate mech eng'er myself, and would fill in the questionnaire, but it appear to no longer be online?

 

 

Daniel

[dbeierl]

And why is the tiller at such a strange angle?

He has the tiller lifted up so as to close the rudder clamshells together, redirecting propeller thrust to go astern. For going ahead the tiller will be in the normal position (and for "neutral" somewhere in between).

[George94]

Thanks for the replies. I'll try and answer some of the points raised.

 

My project supervisor has a canal boat with a kitchen rudder fitted to it and has not had any problems with weed fouling or things getting stuck in it. So I think the problem may be a bit over exaggerated particularly on well maintained waterways. Also the bottom of the clamshells is not lower than the keel of the boat so anything big would hit that first and a mattress or similiar would be to big to get sucked into it.

If something did get caught in it you could still have a "weed hatch", and close the rudder to gain better access to to propeller.

 

A good thing about the kitchen rudder is that while maintaining a constant engine speed you can adjust the rudder to move forwards and backwards at a speed slower than the idle speed of the engine. Also the clamshells can be turned whilest closed for sharper turning. In theory you could turn the kitchen rudder and then open and close it to "row" around tight bends although I would not have thought that you would need to.

 

The document below in the link contains more information about the Kitchen rudder and its inventor. It is a common misconception that it was Admiral Kitchener and not John Kitchen that invented it.

http://www.scribd.com/doc/22985018/Kitchen-Rudders-Their-Inventor-and-Some-Applications

 

 

So it's a Kitchen rudder, not a kitchen rudder.

Edited December 3, 2014 by George94

[bargemast]

Just spotted this thread and there is one major flaw with KRs that hasn't been mentioned. When I joined the RN a million years ago we had to do boat tests on all the types of boats that Dartmouth college owned before the end of the first year. The one boat everyone hated was the Kitchen Rudder motor boat. They were also by an order of magnitude the most crashed. The reason is simple, you start to come alongside and need to stop so you wind the handle like mad to reverse the clam shells and suddenly the bloody tiller is working in the opposite sense. Eg coming in starboard side to, as you approach the jetty you push the tiller to starboard to bring the bow to port then crank the handle when suddenly the bow starts to swing back because the thrust is now pulling the stern to port - and you crash into the jetty again!! Yes you know you should have reversed the tiller as you wound the handle but it only takes a second and as you can't see the clamshells and you were concentrating on where the boat was going you forgot. Hateful bloody things. Oh, and you also have the problem that if you get the paddles in the wrong position you have no steering at all. Yes once you have the knack they are incredibly manoeuvrable but how much damage will you do before you acquire it?

 

The reactions of the Kitchen-rudder are about the same as a jet driven boat or an outboard engined,and Z-drive.

 

I've had some difficulties getting the hang of an aluminium jet-driven passengerboat, while normally on much bigger working barges and passenger boats with ordinary rudders, it was pretty hard to get used to, and even worse when the water inlet to the turbine got blocked with waterplants (about 10 times on every trip) when there was no steerage anymore, no forward, and no reverse until the water inlet filtering screen was cleaned, of course this always happened at the worst moments.

 

Peter.

Edited December 9, 2014 by bargemast

[Laurence Hogg]

The Kitchener (or Kitchen) rudder was extensively trialled on commercial narrow boats many years ago, it was found then to be un unsuccessful method of steering and was never used. Harland & Wolff designed a "balanced" rudder for use on the Grand Union motor boats, this had tapering weights at either side opposed positioned and was a success, it self centred and reduced prop walk yet no one today replicates this?

[Dalslandia]

The Kitchener (or Kitchen) rudder was extensively trialled on commercial narrow boats many years ago, it was found then to be un unsuccessful method of steering and was never used. Harland & Wolff designed a "balanced" rudder for use on the Grand Union motor boats, this had tapering weights at either side opposed positioned and was a success, it self centred and reduced prop walk yet no one today replicates this?

Sounds like an interesting thing, can you explain it more picturaly? so I understand if possible. :-)

[colmac]

I used Kitchener gear on whalers in the Navy years ago and, once I got used to it, I thought it was really very good particularly when you wanted to come to a halt. Once you wound the buckets round and gave her some throttle she would stop on a sixpence ( or 2.5 pee to be PC )

[Nightwatch]

I used Kitchener gear on whalers in the Navy years ago and, once I got used to it, I thought it was really very good particularly when you wanted to come to a halt. Once you wound the buckets round and gave her some throttle she would stop on a sixpence ( or 2.5 pee to be PC )

i had a go at Kitchener on a whaler when I was in training at Raleigh in Torpoint. As you say once you understand how much effort you have to put in it was effective.

 

Martyn

[Idunhoe]

I found KR steering to be particularly heavy when operated at other than 'full ahead' or 'full astern'. I agree that once you have mastered the technique it makes for a very manoeuvrable boat.