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[Underpressure]

This is my 'Big Tug' which I have just finished converting from electric to steam. This is the boat that sprung several leaks when I ballasted her recently. All those are now repaired and she is ready to sail.

I claim no credit for the build, as I rescued the model from a local model shop a few years ago, she was a little battered, but all there.

She has counter rotating twin props and only one engine, so I have shown my experimental arrangement, that may get changed to a belt drive if it fails to perform.

The plant is a Cheddar P4: Pegasus V4 oscillator engine and Proteus Mk1 boiler with a condenser is of my own manufacture (as are all the condensers in my boats). The gas tank is mounted on a slight upward angle and is strapped to copper plates which are bolted to the boiler mounting plate, so it should receive some warming effect.

Neil

[SteamboatPhil]

Nice job, my only thought is , will the second shaft start slipping because of the rubber drive when on load.

[gondolier88]

Same thoughts occured to me- try these guys if you do find you have problems- www.motionco.co.uk.

On a positive- that boat looks fantastic- my one and only gripe is your use of bright red under the waterline in my opinion (which counts for nowt I know!) a satin 'red oxide' colour looks more fitting. Love the funnel though- so who's initials are they then...?

The steam plant is great too- you've kept it simple and compact which is key to a succesful steam boat.

Have you done steam consumtion tests on this setup yet- I have a feeling you may need to add an engine driven feedpump.

Well done!

Greg

[Underpressure]

I have to say I have my own doubts about the drive system, but I am able to turn the engine over by rotating the indirectly driven prop, so we'll have to see.

I have done some consumption test on the bench and I think I will easily see 40 minutes on a full boiler. Again, only time on the water will tell. I already have the correct water pump, which came with the engine and there is plenty of room in the boat for a water tank, so not a difficult job if I do need more water.

Regarding colours, not my choice, but at least it has had several coats of matt varnish, as it was nice and shiny when I got it. I did consider red oxide, but it was too rusty looking and not orange enough, still, there is always next winters repaint, I usually give my boats a spruce up before the sailing season begins. As to the CS on the funnel, which is also on the front of the bridge, I could be a smart a r s e and say it stands for Cheddar Steam. In reality I have no idea and cannot find a real tug operator with that layout.

KISS: I am a great believer in nice simple straightforward layouts. Too many pipes and valves and I just get confused  Each to their own, but simple to build makes it simple(r) to fix.

Sea trials this week, weather permitting, so several questions should be answered.

Oh and for those who don't know the tug, she is 1200mm (47 inches in old money) long, so you can imagine how much she displaces when ballasted down to the water line!

Neil

[MONAHAN STEAM MODELS]

Those Cheddar Pegasus engines are beautiful! They run great too! I was lucky enough to see one in the flesh a few years ago.

[Underpressure]

I'm happy to be corrected, but I seem to recall John telling me that they only ever made one batch of 50 engines. Mine was one of the last ones sold in summer 2003, I think John said he had five left, a few minutes later he only had four 

I have bench run the engine for about an hour and done a 20 minute test in the tug, also on the bench, it is a very smooth running engine and I can't wait to get the tug on the water.

Neil

[Bernhard]

Hi  it looks great,,,,nice engine to,,,,,,will you not use the super heater?,,,

Regards Bernhard

[Underpressure]

Hi  it looks great,,,,nice engine to,,,,,,will you not use the super heater?,,,

Regards Bernhard

I'm not sure if there is any advantage in using super heated steam in an oscillator engine, although I do have one for that boiler.

Any comments, from our more learned members?

Neil

[gondolier88]

Superheaters at this size are no more a superheater than a steam 'drier'. Hence I wouldn't worry too much, but as Mr Tesco says when he gets into bed with Mrs Tesco, 'every little helps'.

You could always try it superheated later and see if there's a noticeable difference.

Greg

[Underpressure]

Superheaters at this size are no more a superheater than a steam 'drier'. Hence I wouldn't worry too much, but as Mr Tesco says when he gets into bed with Mrs Tesco, 'every little helps'.

You could always try it superheated later and see if there's a noticeable difference.

Greg

Greg, can you go a little deeper into this. What is the advantage of 'drying' the steam? Less condensate obviously, but I don't really know enough about steam engines to appreciate why that is a good thing, having only ever bugge...um, messed about with small oscillator engines.

Neil

[HS93 (RIP)]

It may help warm the engine up as its got four cylinders there is a chance of it spluttering a bit on wet steam till it gets warm, but I may be wrong i have found engines warm up quicker with one so run smoother quicker if that makes sense but I am open to be corrected.

peter

[kno3]

Nice tugboat and interesting steam plant set-up. I was surprised by the engine mounted to the side, but it's an effective (even if unusual) solution for driving 2 propellers.

About super-heating: I use it in 2 of my steam plants and my impression is that it helps them perform better. Especially because the engine warms up faster and there's less water condensing in it.
In your case, with 4 cylinders, using superheat should significantly reduce condensation in the engine.

However, you shouldn't exaggerate. I had the surprise, when I first experimented, that superheated steam from a double coil in the central flue of my alcohol burning Wilesco could melt soft solder easily. I have since switched to a higher temperature solder and also reduced the superheater to a single coil.

[Underpressure]

Kno3, I was originally going to mount the engine centrally and drive both prop shafts with belts of some sort. I then considered that it was all going to get very messy and complicated and then there was always the risk of the boat being stranded if a vital belt broke, so what you see was my 'alternative' method. The addition of a little ballast on the opposite side to the engine ensures the boat does not list.

Thanks for all the input on super heating. I have the correct heater for the boiler and will consider fitting it, once I have a couple of test runs done. There are one or two other concerns I want to overcome / alleviate before I start to change things, but I will give it a try and see what difference it makes.

Waiting for the weather now, as it has turned very cold over night and we all know what effect that has on steam boats....and their operators.

Neil