# Steam boat question OT



## lincoln pin (Feb 24, 2009)

On a full size steamboat is water supplied to the boiler directly from the body of water the craft is floating on? Is there some sort of holding tank on board? What about ocean going steamers, do they boil sea (salt) water to create steam? Just wondering. 
Thanks, 
Mike Anderson


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## xo18thfa (Jan 2, 2008)

Posted By lincoln pin on 19 Jul 2010 06:10 PM 
On a full size steamboat is water supplied to the boiler directly from the body of water the craft is floating on? Is there some sort of holding tank on board? What about ocean going steamers, do they boil sea (salt) water to create steam? Just wondering. 
Thanks, 
Mike Anderson


Hi Mike: Now-a-days they can probably scoop up sea water and run it thru a reverse osmosis process to clean it up. Deisel powered ships we used to deploy on in the Army could produce huge amounts of fresh water with on-board equipment. Our little LST's could produce 100,000 gallons of drinking water a day. I think in the old days they carried water with them. Marine power plants had extensive condensers to recover exhaust and oil-water seperators to clean it up.


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## rwjenkins (Jan 2, 2008)

Full-size steamboats use a condenser to turn the exhaust steam back into water. This serves a couple of purposes: One, it conserves fresh water, allowing it to be cycled back into the boiler; and two, it creates a partial vacuum on the exhaust side of the engine that increases the efficiency of the engine. A steamboat condenser uses water from outside to cool the exhaust steam as it runs through a set of tubes inside the condenser. Of course, steam locomotives don't have the luxury of a ready supply of cooling water to operate a condenser, but a few (notably the South African Railways 25c class 4-8-4's) were equipped with air-cooled condensers to extend their water supply in a desert environment. In a steam locomotive, the exhaust steam is used to provide draft for the fire, but on a steamboat, tall smokestacks provide a natural draft, helped if necessary by forced-draft fans. 

Of course, even in a closed system as on a steamboat, there will always be some loss of water that needs to be replaced. Additional boiler feedwater can be drawn from outside, and desalinated and purified as necessary. Great Lakes freighters (some of which are still steam powered) replenish their boiler feedwater tanks while steaming across Lake Superior or certain parts of Lake Huron where the water is exceptionally pure, and very little if any water treatment is necessary. Steamships operating on salt water have desalination equipment, as salt water would quickly corrode the boiler otherwise.


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## Andre Anderson (Jan 3, 2008)

I have built several models of western river steam boats and they did not use any evaporators. The western riverboat very early in their history went to a high pressure system. The advantage of evaporators efficiency didnot meet the need for a simple and easy to maintain system. These boats did not have the advantage of the machine shops of the eastern rivers so they were kept as simple as possible. One other thing to remember is that the life of a western rives boat was only 6 to 7 years, they were built light so they would run in as little water as possible. Between being run hard and the hazards of the rivers these boats did not last long and the cost and complexity of using an evaporator just could not be justified. The water was pulled from the river through a sea chest, from there it went to the cold well from there the water went to a feedwater heater and from there it went to the boiler through the what was called the mud drum. This was a drum that ran under the boilers and was hoped that the mud would settle out before the water got into the boiler. The one thing that you must remember that the boiler on a western river boat was 5 or 7 boilers side by side, these were all tied together on the bottom with the mud drum and on the top with the steam drum. The steam for the engines came out of the steam drum went to the throttle, from there to the engines and from them to the vent pipes that went straight up and out. The exhaust steam was not used to improve the draft in the boilers, it was used to heat the feed water. None of the plans or books I have seen or read ever mention the use of a evaporator to reuse the condensed steam for feed water. The use of evaporators only came into use till after 1900. If you need more information let me know and I will get you more. 

Andre Anderson


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## SCSteamer (Jul 24, 2009)

Steam locomotives used local "fresh" water, and in the later years, there were chemical additives to mitigate the problems, such as scaling, which reduces heat transfer. Even tap water has too much chloride for a modern high pressure steam boiler. Typical maximums allowed are less than 15 ppm - otherwise chloride stress corrosion will cause leaks / ruptures in a very short time. 

Look at the Clyde Puffer link - http://www.savethepuffer.co.uk/ They got their name due to the one pass piston engine sound as they plyed the waterways around Scotland. Originally, they used sea water directly, but that caused significant maintence issues, and eventually went to condensing engines and fresh water in holding tanks.


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## Dan Rowe (Mar 8, 2009)

Posted By lincoln pin on 19 Jul 2010 06:10 PM 
On a full size steamboat is water supplied to the boiler directly from the body of water the craft is floating on? Is there some sort of holding tank on board? What about ocean going steamers, do they boil sea (salt) water to create steam? Just wondering. 


Small freshwater steam boats often use open cycle to reduce wieght and simplify the machinery. 

The answer for ocean going vessels depends on when in history. Efficeint evaproators are a modern invention they were devoloped after WW2. Very early salt water ships used sea water in the boilers. All of the early ironclads used raw water in the boilers fresh or salt. This of course reduced the service life of a boiler but the pressures were low. As the pressures rise sometime around 1890 the practice of using salt water on ocean going ships is abandoned. Now fresh water has to be hauled for the crew and the boilers this can be a very extensive amount on a passenger ship.

I sailed on the C-4 Mariner Class of merchant ship as a cadet and an engineer. These were built in 1945 and they only had shell and tube evaps. This is a simple steam coil in a shell these things are only usefull for making boiler water from shore water. Any attempt to distill salt water will salt the dang thing up in a day or so so more time is spent on maintanence then running.

I have been down below on the SS Badger which has a Skiner uniflow engine and it is a car ferry on Lake Mich. I did not see modern evaps and as the Badger was built in the 1950's I am almost positive they use lake water and a shell and tube evap. to make boiler water. The Badger was originally owned by the C&O RR and when I was below I spotted Westinghouse cross compound air compressor on the bulkhead. Well I just pointed and started laughing. The engineer who was showing me around was impressed as most marine engineers had to ask what it was. C&O was not going to use some fancy marine compressor when they had a bunch of perfictly good compressores in the warehouse.

Dan


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## hookpilot (Jul 22, 2010)

I'm building a 1:24 scale model of the US Army Corps of Engineer snag boat W.T. Preston and have a set of plans from the original boat. Steam was not condensed and reused. All feedwater was stored aboard the boat in two 4000 gallon tanks. The danger of using river water was drawing up silt and mud that could collect in the boiler and create hot spots. My model will be a live steamer. Preston and many western river paddle wheel boats were quite a bit different from the Missisippi riverboats. My model's engine will be scale with a bore of 5/8" and stroke of 3" x 2. I'm currently trying to find plans for the steam donkey 3-drum winch up forward. Preston was used to pull stumps and logs from rivers and Puget Sound. The W.T. Preston is now sitting in a museum in Anacortes Washington State on display. I was fortunate enough to see her in operation in the early 70s. The model will also have a small vertical steam engine directly driving a Stuart dynamo to operate all the lights on board. Give me a shout if any of you railroad logging folks have seen drawings or plans for a 3-drum steam donkey or winch. The model will be a bit large, over 81-inches long and 17 1/2 at the beam and stand 27 inches from keel to masthead. 

As others here have said, you could probably get away with pulling fresh water out of a pond or lake as long as it was clean. Still, I'd flush the boiler out once in a while to be on the safe side. 

Mike in Honolulu


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## Andre Anderson (Jan 3, 2008)

Posted By lincoln pin on 19 Jul 2010 06:10 PM 
On a full size steamboat is water supplied to the boiler directly from the body of water the craft is floating on? Is there some sort of holding tank on board? What about ocean going steamers, do they boil sea (salt) water to create steam? Just wondering. 
Thanks, 
Mike Anderson

Mike,

Why the questions?

Andre


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## lincoln pin (Feb 24, 2009)

@ Andre,
Just curious, no plans to build a steam ship yet!


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## Andre Anderson (Jan 3, 2008)

Mike,

I hate to admit this but I have pulled all of my steam engines and boilers out of my boats, I had this epiphany one day at the pond, from the back of my head comes this voice "Fool what are you doing lighting a fire in a wood boat that you spent 3000 hours building". I was using alcohol and if any got spilled you would never see the fire until it was to late, it was no fun anymore after that little thought worrying about the boat burning up so I switched to batteries and have not looked back. 


Now that I have a live steam American that uses butane this may all change, I am thinking about building a new boat that will use butane rather than alcohol.

Andre


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## RimfireJim (Mar 25, 2009)

The 1960's vintage US Navy ship I was on used 7-stage flash evaporators to desalinate sea water for boiler make-up feedwater and potable water. Condensers to recover as much used steam as possible. One would not normally think of a Fast Combat Support Ship as a "steamboat", but it was certainly an ocean going steamer, with a 600 psi superheated main steam system to supply the turbines. About 100,000 shaft horsepower total for the two engine rooms. That was power, man! All scrap now :-(


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