My first steam engine

[quinten1231]

My first steam engine just arrived this morning.

Its a stuart 5A with reverse linkage bought on eBay. The man I bought it from said that it has been his family's mantelpiece for the past 25 years and never used.

The first I did after receivng it was opening the cilinder cover to see how it looks like inside, and it looks great.
Turns over fairly easy with one hand and has compression, and the reverse linkage seem to be solid and not worn out or loose. The only small possible mistake I might have spotted is that the valve stem is not perectly above the eccentric rod in either direction (see photo) it is only off a little however I have no idea what the tolerences are with a 5A. But that problem could be solved by minor modification of the reverse linkage.

I bought it for 921 pounds (1403 usd), I believe it was a good buy because the engine looks great inside and out, and there appears to be no wear or play on the bearings or any other parts for that matter.
but I would like to hear the opinions of experienced steamboaters.
I have attached several photos of the engine.

I also wanted know if I can just open up the steam chest cover to look inside (not sure of its the right name, but I mean the cover with the S milled in) I wanted to ask before I mess something up. I don't think anything can happen, but better safe than sorry.

[quinten1231]

Few more

[quinten1231]

The last ones

[Lopez Mike]

Very nice engine. Can't comment on the price as I haven't bought castings in a while but I suspect you have done well. It takes more hours than you might think to build an engine. And just as many for a small one as a larger one!

I think you can feel quite safe in opening up the valve chest. That engine is very simple and easy to adjust. Take pictures, as you are. You will, at some time, have it completely apart.

I wouldn't worry about the alignment of the eccentric rod and the valve rod. See if it is the same in forward and reverse motions.

Note that the only real places to get anything out of whack would be to not have the piston have equal clearances from the cylinder heads at the bottom and the top of the stroke and to adjust the slide valve on the valve rod such that the valve timing was not symmetrical.

These engines should not have very much piston to cylinder head clearance. Depending on whether the builder followed the drawings or was creative, you may not be able to adjust the piston position without fuss. The valve adjustment is easy and obvious. Just make sure that the valve is slightly free on the valve rod. It needs to float in order to seat properly.

There is no assurance that things are correct as they are. Buy an inexpensive protractor and attach it to the crankshaft with a pointer. You can note at what angles of crank rotation the steam ports open and close. The exact angles aren't so important as that they be close to the same at each end of the stroke.

They can be fairly poorly adjusted with little change in efficiency. You will notice any serious maladjustment when listening to it run. It will be uneven.

Most small steam engines are sticky and hesitant to run at low speeds at first. Don't be hesitant about running it on air as long as there is a little bit of lubrication. Looks like there is plenty on the cylinder walls now.

If I'm explaining things that are obvious to you, please excuse me. The things I mention are those I see on units brought to me for admiration, adjustment and repairs. The most common malfunction I've seen over the years is that the valve is not seating properly due to binding on the valve stem or rough surfaces. The surfaces can be improved by running or by judicious honing with a flat plate (glass or a machine tool surface) and some very fine (500 or 600 grit) sand paper with oil. The sand paper placed grit side up on the flat surface and then hand polishing the surface with care not to let it rock and end up with a curved surface. Wash up well when done. No grit in the engine please.

Enjoy!

Mike

[quinten1231]

Mike

Thank you for the info, I don't have access to a compressor at the moment. Once i do i will let it run on air to see if there are any irregularities, and check the valves after I heard it run. i did already notice that the flywheel is not perfectly positioned on the crankshaft, maybe just badly installed or something went wrong when fixing it in the lathe, it has a slight axial wobble. But that does not concern me since i want to change to the larger flywheel with spokes in the future, looks much better and I was recommended by a machine shop that it will be better for marine use.

I also noticed that there some small metal strings (smaller than the size of arm hair, almost looks like dust strings but it is not) which could be a sign of wear from somewhere, however cannot find where they come from. Either it is scraping somewhere, or badly oiled before, or this engine truly is unused and it might be some signs of parts running-in which might have been machines with too little tolerances. They do seem to come from around the area of the crankweight and bearings (maybe the counterweights scrape the bearing, they are a very close fit)

Is this normal? I mean does it happen more often on newly build steam engines, or is this an absolute no-go. Like I said before, there is absolutely no axial or radial playnon the bearings, could this be the reason?

Will try to run it on air sometime next week to see and hear it actually operate.

Sorry for asking such minor things, but I just want to make sure I bought an engine that i can use.

Regards Quinten

[Lopez Mike]

I have no idea what those metal hairs might be from. I can't say that I've even seen anything like that from wear. I wonder of someone was polishing things with steel wool and those are just bits of that?

Sometimes the small 'marine' flywheel' is used because it doesn't stick down as far below the engine and lets one mount the engine lower in a boat. My engine has a flywheel rather more like the large 5A style and it doesn't look bad in the boat. Easier to give it a kick when reversing.

You will get good service out of that engine. Just don't expect it to push a large or heavy boat. Weight is more of a problem than many steamers realize. My little, 24' x 6', boat zips along easily on only a 3 x 4 single rated (I suspect optimistically) at 5 h.p. I think a big reason for it's decent performance is the low weight of the whole boat. People pay a great deal of attention to shape and looks and then let the pounds pile on. I haven't weighed Folly yet but will be surprised if it exceeds a ton.

I have good friends with boats having fifty percent more power but over twice the weight. It's a slippery slope. Drag increases as about the square root of the waterline length at higher speeds but increases directly with weight at all speeds.

Make your boat for this engine as narrow and long as you can (read: cargo canoe?) and keep the weight down and you will startle people with its performance.

Mike

[quinten1231]

Mike

I was actually thinking of a 12 foot rowboat of wood (more nostalgic) or polyester hull with wooden seats and floor. Or possibly a 12ft sailing dingy hull.
Personally i am not a big fan of canoe's.
a good rowboat has been designed specifically for low drag, ofcourse it will have to carry more weight than usual rowing application, but I believe it should work out. I am planning on building it as a 2 person boat.
How heavy would a simple dry leg boiler be for a 5A? I have seen some pictures of boats with a 5A and the boiler seem HUGE in relation to the engine, especially when I compare that boiler size of lets say a tiny power twin boiler.

I want to use coal or wood as fuel.

Ofcourse there will be more weight coming onboard than just the boiler, such as fuel, hotwell, pump, propshaft propellor etc, but i believe that a well chosen rowboat will work rather well.
But then again, I could be completely wrong.

I was thinking of something like the picture below (thats a 12foot one) it wont be a spacious boat, but it could work, and it would be easy to store and trailer. unless i severely under estimate the size and weight of a complete steam plant, i would place the boiler towards the bow so that the two passengers would compensate for the weight, and the engine would be around the middle so that there is plenty of space for the prop shaft and that the angle of the prop shaft can be kept at a minimal, if necessary a chain drive incase the angle becomes too steep.
I prefer to keep it small for now and leave the bigger hulls for a larger engine.

Please tell me if my design thoughts are impossible or unsafe.

[Lopez Mike]

A row boat hull can work well. The problem is that it's not only hydrodynamics that make me harp a bit on length. The various things that will be in your boat tend to take up length more than they do width. Things tend to be less scrunched together when they can be one in front of each other rather than side by side.

Weight creeps in in many small ways that add up. The outer shell of the boiler is all too often made of heavier stock than needed. Indeed, consider aluminum since it's only task is to keep the insulation dry. I'm speaking of a water tube boiler here. If you are thinking of a fire tube unit, don't discard the idea of a wet leg boiler. What you are looking for is the best ratio of weight to steam production. A water leg pays for itself in surface area. Also, with a fire tube boiler, don't make your lagging cover of heavy wood. Cedar works fine if it is protected.

Since low center of gravity and weight are at a premium in a small boat, I would look seriously at one of the Blackstaff water tube designs covered in Steamboats and Modern Steam Launches. I'll do some research later this weekend.

I'm a fire tube devotee so perhaps some others more expert on this might chime in. I do think that a water tube unit might well be built with less weight and a lower center of gravity. For a lazy skipper (me) a fire tube is at one end of the spectrum and a monotube at the other. I have lived with monotube boilers and I just didn't care for fooling with it so much. Too quick to react to changes. I know how to fly an airplane. I want to sit back and watch the scenery glide by.

Mike

[quinten1231]

I am actually only considering a vft boiler since I love the way they look, wouldn't it be possible to make the boiler lower and slightly fatter (since a rowboat has enough beam) this would automatically give me a larger fire grate area which based on reading seems to be important with coal and especially wood fired boilers, it would also be beneficial to the center of gravity.

Regarding a water-tube boiler, i read that it builds up steam much faster but it requires more work to produce a steady supply of steam, especially at full speed.

You are right about the water-leg, I was thinking of a dry leg mainly out of laziness, but thinking about the whole time span of building a steamboat I highly doubt the time difference of dry-leg vs wet-leg will be noticeable.

What exactly do you mean with things taking up more space in the length rather than width, could you give me an example of what sort of things, because at the moment i can only think of: engine, boiler, hotwell, propshaft, wood coal storage, set of oars incase something goes wrong, and ofcourse seating area but that would be at the stern area behind or next to engine.

The engine would be failry close to the boiler and the fire door of the boiler would be diagonally for easy access, the hotwell takes up very little space and could be placed anywhere around the engine where nobody would sit, same for the feed pump. Coal/wood storage would be in front of the boiler spread over both sides of the boat.

Am i missing out on something big?

I would also like to add that this boat would be more for small trips of a few hours rather than a whole day.

[marinesteam]

I don't know if it's your style, but don't rule out the Thames Canoe such as Selway Fisher's 23'6" Brambling Electric Canoe . There are several boats of this type in the SBA directory with small steam plants. I sometimes wish I had started with one of these as my project as I would be far closer to completion.

Ken

Mike

I was actually thinking of a 12 foot rowboat of wood (more nostalgic) or polyester hull with wooden seats and floor. Or possibly a 12ft sailing dingy hull.
Personally i am not a big fan of canoe's.
a good rowboat has been designed specifically for low drag, ofcourse it will have to carry more weight than usual rowing application, but I believe it should work out. I am planning on building it as a 2 person boat.
How heavy would a simple dry leg boiler be for a 5A? I have seen some pictures of boats with a 5A and the boiler seem HUGE in relation to the engine, especially when I compare that boiler size of lets say a tiny power twin boiler.

I want to use coal or wood as fuel.

Ofcourse there will be more weight coming onboard than just the boiler, such as fuel, hotwell, pump, propshaft propellor etc, but i believe that a well chosen rowboat will work rather well.
But then again, I could be completely wrong.

I was thinking of something like the picture below (thats a 12foot one) it wont be a spacious boat, but it could work, and it would be easy to store and trailer. unless i severely under estimate the size and weight of a complete steam plant, i would place the boiler towards the bow so that the two passengers would compensate for the weight, and the engine would be around the middle so that there is plenty of space for the prop shaft and that the angle of the prop shaft can be kept at a minimal, if necessary a chain drive incase the angle becomes too steep.
I prefer to keep it small for now and leave the bigger hulls for a larger engine.

Please tell me if my design thoughts are impossible or unsafe.