STEAM POWERPLANTS and DRIVES

[kiwimodeller]

Hi, I am completely new to the world of Paddlers and have just joined the forum in the last few days so am looking for some help to make decisions on what to build and what to buy. I do not usually jump in at the deep end - more often at the shallow end and whack my head on the bottom! My main interest is steam power but having just read Eddie's posting about the Martin Howes and Bayless it seems that the only commercially built steam plant still available is the Saito and I do not have that many spare arms and legs. I do have an early Saito inline twin engine (a T2) and also a reasonably big single cylinder engine built by a friend from Model Engineer plans. Kephre has warned me of the danger of too much weight up high in a paddler so my first question is has anybody run what was meant to be an upright engine laid over at an angle? As there is no oil in the engine and the only lubrication is what I put on with an oil can between runs I cannot see why it would not work but then what do I know? Any thoughts? If this is not practical are there any plans available for a paddler steam engine? My friend still owes me one more favour so I might be able to twist his arm to build another plant.
Second question is how essential is it to be able to slow the inner paddle wheel when turning and if it is essential has anybody developed a drive system that incorporates ratchets or clutches or some other way of disconnecting the drive to the wheels when using a steam plant?
I have had a bit of a look around the internet for boats and the one that looks most interesting is the Metcalf Mouldings P S Berry Castle hull at 58" so the third question relates to the suitability of this for steam power and also whether I could use either the Graupner wheels or the German ones mentioned elsewhere on the forum? Well that should be enough to try the minds of the experts for a night or two, look forward to your comments. Thanks, Ian.

[Eddy Matthews]

There are numerous plans for steam engines in the "Plans & Drawings" forum Ian.

One of the nicest is an Edgar T Westbury twin cylinder diagonal engine http://www.paddleducks.co.uk/forum/viewtopic.php?t=321 This is designed for a large 6 foot model, but the plans could be rescaled for something smaller... There are dozens of plans for other marine engines in the same forum, lots of which could easily be adapted depending on the model and the type of steamplant required.

The PS Berry Castle may not be the ideal choice though as it's fairly shallow draught and has a very narrow hull - Not ideal for a steam powered model paddler! A tug would be the obvious choice as you have much more beam and bouyancy to support the weight of a steamplant.

It isn't necessary to slow the inner wheel when turning as most paddlers have large barn door type rudders - They'll never turn on a dime, but they do handle pretty well in general.

The Graupner wheels are perfectly good, and they can certainly be worked on to make them look much more realistic. Take a look at what Mick (mjt60a) has done with his Graupner wheels...

[derekwarner_decoy]

Hi PD's  - Ian - the necessary lube oil to model steam engine cylinders is via a displacement lubricator - this [displacement lubricator] accepts steam [heavy water] into the lubricitator which even at the elevated but cooling temperatures, due to specific gravity sinks to the bottom of the lubricator  & hence displaces an equivalent volume of oil enroute to tye cylinders

As you have noted lubrication to outboard bearing surfaces was/is independent of engine driven lube oil pump feed

So whilst we may accept this steam engine component lubrication as simple, we must understand and remember a little of Bernouli + [Boyls & Charles combined gas equation] -   Derek

[Khephre]

Ian,

Stuart Badger installed two twin cylinder steam engines into his 1:24 scale Paddle Tug Old Trafford (later renamed Reliant). Each provided independent power to its paddle wheel by way of chain drive.

You can also see from the accompanying picture in the photo gallery (tried posting here but my PC's playing merry Hob today!) that Stuart geared the engine output down by using different sized sprockets on the engine drive shaft and paddle shaft. The model is 1:24 scale and is 53 inches LOA.

From Paddleduck's Yahoo days came this comment from Stuart:

" Old Trafford (Reliant) is fitted with a 6 channel radio, 4 channels of which are being used. The engines need one servo each for reverse/speed control. One engine is operated from the left hand throttle stick which has a ratchet. The other is operated from the right hand (elevator) spring return stick. Most modern radios have the ratchet fitted to both sticks giving the choice of spring return or graduated operation. I have ordered an extra ratchet for my radio so that BOTH vertical axis sticks will operate in 'throttle' mode.

" One channel of the radio operates the rudder (on the right hand stick) and the fourth operates the steam whistle. The electronic gas control valve is independent of the radio. "

There's no doubt that having independent paddles is great for manoeuvrability (particularly applicable to tugs) but a single shaft for both paddle is not out of place either - you simply need a bit more room to turn and a decent sized rudder.

There's a common view that paddle steamers were not permitted to use independently operating paddle wheels while carrying passengers following an alleged accident in which a paddler had apparently capsized by putting one wheel ahead and the other astern. Which vessel? Where? We don't seem to know this.

Another version of this story goes that the drive shafts were locked otherwise one wheel could go deep and become very hard to turn whilst the other would  come out of the water and turn freely, allowing the engine to overspeed and damage itself.The solution in this version was to lock them together at sea and release them for manoeuvring.

A quote from Kemp's Oxford Companion to Ships & the Sea: ".....as paddle tugs carry no passengers, they are permitted by law to be able to disconnect the shaft and to work each wheel independently of the other."

So Ian you can have a bob either way!

cheers for now
Tony

[kiwimodeller]

Thanks for all the input so far. Derek, I am well used to using lubricators to feed oil to the cylinders and valve gears of my engines and I realise they will work no matter what angle the cylinders are at. I was refering to the lubrication for the crank bearings etc which is usually just done with the oil can. However it does sound like the engines I have at present are not suitable for a side wheeler and that the Berry Castle would probably not be the best choice of hull to start with for steam power. Can anybody comment therefore on the possibility of putting a conventional steam plant in to a stern wheeler, perhaps the Dumas Creole Queen or something similar? I am not totally averse to building a proper engine and will drag out all my old "Model Ships and Powerboats", "Model Engineer" etc., but I would like to build boats for my existing engines first so if they are not suitable for paddlers I guess I will go back to plan"A" and put off the paddler idea for a while. Thanks, Ian.

[kiwimodeller]

Tony, having read your reply and now having looked at the photo I think that I would go for a single wheel axle and locked wheels at least to begin with. The boiler in the photo is similar to what I have and I could easily get my engine in the space shown and turn it sideways with a reduction to the wheel axle. The reduction in the photo does not seem to be a very low ratio so obviously they are not high revving engines. I could run a gearbox if necessary, I already have a reversing gearbox on one of the engines although it is 1:1 but that would not be hard to change. Can you tell me anything about the hull or suggest something similar that I might start with? I would be more keen on starting with a kit or semi - kit to begin with rather than building from scratch. Thanks, Ian.

[Eddy Matthews]

You can use almost any engine for a paddler Ian - A simple single cylinder oscillating engine can be turned sideways and then use a belt or chain drive to the paddleshaft on a sidewheeler. A similar setup could be used on a sternwheeler...

So it's not really a problem that your current engines aren't suitable - You just need to choose the correct boat and think through how your going to make the drive work etc.

The Creole Queen is actually a diesel/electric powered vessel, but there's absolutely no reason why you couldn't make a steam powered version, lets face it, how many members of the general public would actually know it wasn't correct?

The PS Berry Castle could be made to work, but with such a narrow beam and shallow draft it's certainly going to be a challenge! I know from bitter personal experience that it's easy to choose the wrong model and end up with something that tries to roll over and sink with every movement of the rudder! Hence my suggestion to look for something different with a larger beam for stability - The sternwheelers are generally much easier to make
into working models, at least as far as stability is concerned..

[derekwarner_decoy]

Sorry Ian - I misunderstood - your older twin Saito engine laid over to the horizontal plane would be fine as Tony & Eddie have noted & possibly a chain drive reduction to the paddle axis etc

The only additional requirement for this cylinder axis would be to  reposition the as fitted cylinder blow down valves to ensure they are lower than the lowest point of the cylinders

It may be worth the time to talk to some steam train model people as naturally the model train cylinder axis is in the horizontal plane - Derek

[kiwimodeller]

Thanks all. It seems like the consensus is about 100rpm for the paddlewheels (give or take a few) so I will have to find out what revs the engines do. I have info on my little Saito V4 which says no load speed is 6000 rpm but I am sure that the revs with a prop of the reccomended size are nothing like this. I do not have data on the Saito twin or my single but would suspect that they do not rev anywhere near that high so I am going to guess at 2,000 to 3,00 rpm and work out that appropriate gearing would be around 25 to 1 but the gearing in the photos Tony posted does not appear to be anywhere near that low. In view of Eddie's comment that most engines can be made to work I will begin again on the hunt for a hull kit. I would prefer something around the 48 to 56" size as I have several boats around that size and find they are roomy enough but still fit in our little station wagon. Any suggestions welcome. I am hoping to meet Tony (if he is not off overseas) and a couple of others with paddlers at our sailing day this weekend so I will get a better idea of what is needed. Thanks, Ian.

[Eddy Matthews]

I'm glad we haven't put you off with the few misunderstandings Ian! :-)

I prefer a paddle speed of 140-150RPM (no load speed), which probably gives 100 RPM under load.

Metcalf Mouldings also do a nice hull for the "Waverley" which has the paddleboxes and sponsons moulded in, therefore saving a lot of work. I believe it's about 53" in length if my memory is correct.

Just remember when choosing a paddler that the sponsons make them look very wide and stable - But the hull will only be 1/3 or less of the complete width, so they aren't as stable as they first appear!

Keep an eye on the weight of things as you build the model, particularly outboard of the hull (paddleboxes, sponsons, paddlewheels etc) and above deck level. Keep everything as light as possible to maintain stability, and place the boiler and engine as low as you can get them in the hull.

To get an idea of the problems you need to think about, get a normal screw propelled vessel with a hull that's similar in length and beam to the model you intend building, then temporarily put a wooden beam across the deck and add 5 or 6 ounces of lead onto each end about 2-3 inches outboard of the hull - Try sailing it then and see what happens, especially when turning, just be careful it doesn't roll over and sink particularly if it's someone elses boat!

That isn't intended to put you off, but to give you an idea of the problems you'll encounter when modelling a paddler. Saving an ounce of weight here and there can make the difference between a model that works and one that doesn't - Put a BIG notice up in your workshop "BUILD LIGHT, AND THEN BUILD IT LIGHTER!"

[kiwimodeller]

All great input thanks and I am getting a much better idea of what I need to do and look out for. So far I am thinking that I would like a side wheeler of the older style such as Reliant/Trafford with not too much superstructure.. I had seen the Waverly hull at Metcalfs but thought it had too much top hamper for what I wanted. In the middle of the night (yes I often lie awake thinking about boats - weird really!) I wondered how much difference there is between hulls and sponsons of different era's and whether I could buy the Waverly hull which is about the size I want and build an earlier superstructure on to it. Would this look out of place? Thanks, Ian.

[PJ]

I wondered how much difference there is between hulls and sponsons of different era's and whether I could buy the Waverly hull which is about the size I want and build an earlier superstructure on to it. Would this look out of place? Thanks, Ian.

Ian:

Probably not a good idea to take "Waverley's" hull and put an earlier superstructure on it. That particular "Waverley" (last of a line of ships of the same name) has a rather modern hull profile with her raked bow and stern.  In fact if you study paddlers you wil see distinct design trends from era to era and from country to country. You'll find it helpful to spend a couple of evenings familiarizing yourself with UK paddler images and a good start would be Tom Lee's excellent website.  
http://freespace.virgin.net/tom.lee/

When you're ready for more, just holler and we'll give you more web sites.

Just a note to remember that "Waverley" is a sea going excursion paddler whereas "Old Trafford/Reliant" was a tug, so their profiles are very different.  The tug option would be much easier since, as you've noted, there is far less superstructure to contend with.  Additionally, 1:48 scale tugs are more compact and easier to transport.  A 54" excursion paddler model is no small thing to cart around and lift in and out of the water!
I believe either Metcalfe or Kingston Mouldings offer a GRP "Reliant" hull.
If you're really ambitious you might use that hull and research another paddle tug of that era as there were dozens in operation during that period.  A good candidate might be "Eppleton Hall" currently owned by the US Parks Department and on permanent display in California.

Good luck and keep us posted.

PJ
Victoria, BC Canada

[AlistairD]

If you are looking for a side-wheeler  without too much superstructure, her a re a couple of photos of Argentinean  train ferries EXEQUIEL RAMOS MEJIA and ROQUE SAENZ PENA, which are now preserved  at Posadas on the Parana River on the border with Paraguay. Both were built by A  & J Inglis on the Clyde, builders of WAVERLEY, in 1913
 Â 
 Alistair
 

 

 
All great input thanks and I am getting a much better    idea of what I need to do and look out for. So far I am thinking that I would    like a side wheeler of the older style such as Reliant/Trafford with not too    much superstructure.. I had seen the Waverly hull at Metcalfs but thought it    had too much top hamper for what I wanted. In the middle of the night (yes I    often lie awake thinking about boats - weird really!) I wondered how much    difference there is between hulls and sponsons of different era's and whether    I could buy the Waverly hull which is about the size I want and build an    earlier superstructure on to it. Would this look out of place? Thanks,    Ian.



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