Hull design

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Re: Hull design

Post by Mike Cole » Thu Dec 03, 2015 9:44 pm

That insulated pipe is the exhaust pipe taking the used steam from the engine down to probably a keel condenser
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Re: Hull design

Post by Ribble Rose. » Thu Dec 03, 2015 9:54 pm

Is it likely that it may have been exhausted at the stern of a boat ?
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Re: Hull design

Post by Ribble Rose. » Thu Dec 03, 2015 10:16 pm

I`m on a steep learning curve here but I`ve just read this "Steam condensing generally can take three forms on small launches:
1. "Injection Condenser", which is Direct Contact Steam Condensing. This system was used on almost all of the 19th century riverboats and excursion steamers that operated in fresh water. Exhaust steam enters a chamber (operating at vacuum conditions), about the size of the engine's steam cylinder. Cooling water ("Injection Water") from the river which is forced into the chamber by atmospheric pressure, is discharged as a spray into the exhaust steam space, condensing the steam. The condensed steam, along with the cooling water, is then pumped overboard by a large reciprocating pump. This pump, usually driven by direct connection to the main engine, also removes any air that leaks into the system, thus allowing high vacuum exhaust conditions. This system is only for operation in fresh water, and no condensate is recovered for re-use. The Injection pump is large, as it must pump both the condensate flow, plus the injection water, which is 20x to 80x the condensate flow. When the pump stops, injection water will continue, flooding the condenser, and possibly the engine cylinder, so a float valve to prohibit this is required." So if there was an exhaust pipe from the stern could this be what the hole was for ?
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Re: Hull design

Post by Edward » Fri Dec 04, 2015 1:25 pm

Dear Ribble Rose ,

It's very unlikely that it was a steam exhaust going out through the stern ; the usual practice in the UK was either to "Puff" , that is to exhaust the used steam up the funnel thereby increasing the draught through the fire , or to condense . Those were the usual practices but almost every imaginable variation has been tried and some people just exhaust the steam "over the side ." So the hole Might have been an exhaust .

You have described an injection condenser ; I've never heard of one being used on small launches in the UK but that doesn't mean that there weren't some : the commonest form of condensing was a keel condenser where the exhaust steam is passed through a pipe or set of pipes on the outside of the hull under the water before being returned into the hull and usually pumped back into the boiler.

Condensing was used either to create a partial vacuum in the exhaust thus increasing the power produced by the system or , if the boat was operated on poor quality or salt water to obviate the need to carry large amounts of fresh make up water for the boiler ; or to do both .


Regards , Edward .
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Re: Hull design

Post by Ribble Rose. » Fri Dec 04, 2015 5:37 pm

Thanks Edward for answering that question .I must admit though to me it makes perfect sense to exhaust out of the stern ,I only say this as when I fitted the Volvo MD1 I cut the exhaust hole towards the rear quarter and now when I`m under engine the exhaust quite often blows back over the helm .(not the best thing I`ve done)
I have been looking at steam engines installed in boats and on quite a few of these I can see a small tube coming from a small through hull fitting on one of pictures it had a ball valve.This looks as though it would explain the small through hull fitting I have .
Can someone please explain to me what this pipe is for? The pipe in question comes from the top left of this picture .https://i.ytimg.com/vi/J8KDyS69M3c/maxresdefault.jpg
Thanks again for your time and patience with my questions.Ian
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Re: Hull design

Post by Edward » Fri Dec 04, 2015 11:03 pm

Dear Ribble Rose ,

As this is a model it probably has little relevance to full size practice . If I'm looking at the correct pipe it comes from the black cylindrical tank at bottom right and exits the hull near the top left . I think in this case this IS the exhaust , the black cylinder is a "condenser", more accurately a condensate trap .

Models seldom run at much more than about 70 psi and compared to full size applications usually have very poor lagging and a much greater surface area in comparison to their internal workings . As a result they run on very wet steam , so this model condenser doesn't have much work to do condensing the exhaust .

Regards , Edward .
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Re: Hull design

Post by artemis » Mon Dec 07, 2015 5:24 am

Well - guess I'll have a try at this.

Based on about 70 years in and around wooden boats of all kinds in the Puget Sound area -

1. The shape of the bow and the hull generally would indicate original build as a sailboat. Probably fitted with a weighted keel.

2. As there is no evidence of any engine supports originally fitted (no markings, cuttings, etc. of original ribs) the boat was fitted with an engine later. The rather primitive and poor design for the engine bed are definitely not very professional.

3. The hole in the stern and the lagged pipe running aft indicate an engine exhaust (probably originally fitted with a two-stroke engine).

4. The hole in the side was probably an overside discharge for some sort of bilge pump or water cooled engine - but not carried aft with the enhaust.

Original sailboat, converted to motor. Will work about as well as any sailboat converted to steam.

Have fun, but I'd save my money and spend it on a hull better suited to steam and in better condition.
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Re: Hull design

Post by artemis » Mon Dec 07, 2015 5:24 am

Well - guess I'll have a try at this.

Based on about 70 years in and around wooden boats of all kinds in the Puget Sound area -

1. The shape of the bow and the hull generally would indicate original build as a sailboat. Probably fitted with a weighted keel.

2. As there is no evidence of any engine supports originally fitted (no markings, cuttings, etc. of original ribs) the boat was fitted with an engine later. The rather primitive and poor design for the engine bed are definitely not very professional.

3. The hole in the stern and the lagged pipe running aft indicate an engine exhaust (probably originally fitted with a two-stroke engine).

4. The hole in the side was probably an overside discharge for some sort of bilge pump or water cooled engine - but not carried aft with the enhaust.

Original sailboat, converted to motor. Will work about as well as any sailboat converted to steam.

Have fun, but I'd save my money and spend it on a hull better suited to steam and in better condition.
Ron Fossum
Steamboating Magazine Editor
http://www.steamboating.org
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Re: Hull design

Post by Dhutch » Wed Dec 09, 2015 6:37 pm

I cant add much, but certainly an interesting boat and topic of discussion!


Daniel
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