Twin Compound

[DetroiTug]

Pat,

It's really not so much for automatic operation. Much of the piping seen is for lubrication, the bearings must be lubricated. Much of it is pumps and piping for feedwater, have to keep water going in to the boiler, much of it is for pre-heaters, can't pump cold water in to a boiler. Then for condensing systems, there are.. condensers, vacuum pumps, hotwells, more plumbing etc. that need to be ran. These are a few of the necessary items to operate the steamplant. Ideally there should be two - three ways to get water in to the boiler. To operate with only one pump is really unsafe.

I learned early on, the piping, pumps etc. is one of the hidden and often overlooked costs in terms of money and labor in putting together a steam plant.

Keep in mind, the African queen was powered by an electric motor in the movie, or so I heard. If it was steam, I'd like to find some of that 100 psi tape they were using. Some of the scenes, the Stevenson link is on the middle / full cut off, and the engine was running . I was equally shattered when I learned that the San Pablo from the classic movie "Sand Pebbles" was actually a prop - one of the largest ever built. The engine room was actually built on a stage. At least the material was technically correct.

-Ron

[SteamGuy]

I knew the guy who use to operate this Stanley powered launch on the Mississippi River, and although at the time, I did not know that much about the setup, I would say it was probably pretty minimalistic. I would guess steam in, exhaust out, and condensate out as far as engine connections. Boiler was hand pumped I am sure. No condenser to my knowledge.

I have had two boilers, neither very large, and never used a feed water preheat, so maybe I am doing something wrong. I always pumped cold water into the boiler.
Ignorance is bliss.

I used an injector, with a hand pump for backup.
The injector worked extremely well. Some have expressed a dislike for injectors, but I would never operate without one after using it, even if I do have to maintain it.
You have to maintain everything else, so maintain the injector too.

Maybe someone can address the pro's and con's of a condenser.
I would never run a condenser, but that is a view coming from someone who does not operate a steam launch. A feed water heater makes sense, but I would probably not pump it, but rely on natural convection.

Someone said there is a long history of using condensers in the UK, and most would not consider operating without one, but in the US, maybe a different attitude, I am not sure.

My main objection to a condenser is oil separating/migration back to the boiler, and possible foaming from oil. Complexity and expense is another good reason not to have a condenser. I understand that with a condenser, you can steam all day with very minimal makeup water, and as the boat size goes up, a condenser would become necessary for anything except short runs.

If I had a launch, I would probably have a small aux steam engine to drive a pump or whatever else other than the prop. Maybe a little Dake or something.

Having a boiler feed pump on the main engine is nice, since you can dial in the valves to get a good rate of flow into the boiler, and a flow which varies with the engine speed, and thus varies with water usage. I have used an engine-powered pump on a Roper repica, and it worked nicely.

Oiling a boat motor would be critical, and I would probably have a forced oil system with a small engine-mounted pump, but I would mount the pump down low. Some drip oil systems cover the entire side of the engine, with plumbing that rivals an octopus. I would also use a small pump to inject oil into the steam line, and not use a displacement lubricator. They did use injection oil systems in the old days, I have some info on one.

I guess I see it as a "less is more" situation.
Even if the operating cost would be higher without a condenser, it may pay for itself in terms of savings in maintenance and headaches in dealing with the additional systems.

Granted, I would not steam around all day long, and would not steam every day either, so simplicity would be important to me.

If I had to guess, people start out with a few basic systems, and then progress to more complex arrangements as their knowledge and operating skills increase.

[S. Weaver]

... I was equally shattered when I learned that the San Pablo from the classic movie "Sand Pebbles" was actually a prop - one of the largest ever built. The engine room was actually built on a stage. At least the material was technically correct.

Goodness! Is nothing sacred? I'm slinging babbitt even as I type ...

[DetroiTug]

I have had two boilers, neither very large, and never used a feed water preheat, so maybe I am doing something wrong. I always pumped cold water into the boiler.

Pumping cold water in to a boiler will have a detrimental effect on steam generation. On the Tug, the boiler has about 40 gallons of water, one would think with that much volume, a small amount of warmish water coming in would have little effect, it kills the whole steam generating process. It's very frustrating, firing, making steam under way, close the by pass and watch the pressure gauge start dropping. The simple addition of an economizer fixed it. Just running the feedwater through a coil in the smokehood made a huge difference.

Maybe someone can address the pro's and con's of a condenser.
I would never run a condenser, but that is a view coming from someone who does not operate a steam launch. A feed water heater makes sense, but I would probably not pump it, but rely on natural convection.

It's to control the feedwater. Running in saltwater, condensing is the only way to go, otherwise one would have to carry a large volume of make up water. It's also advisable, to even use one in fresh water, because pulling directly from the river, the water is not good for the boiler, contaminants and oxygen issues. Lime and scale build up - rusting. I don't condense and I understand that my boiler is going to have to be watched even more closely for rust etc. As I read what someone wrote the other day, as much as our boats get used, probably not that big of an issue. But I plan on using TSP this year in the strainer. Yep, oil in the feedwater on a condensing system is an issue, however there are many clever designs for separators and simple techniques I have ran across to remedy the problem. Condensing systems also benefit from the increased vacuum on the exhaust. Non-condensing benefit by exhausting up the stack for increased firebox draft.

If I had to guess, people start out with a few basic systems, and then progress to more complex arrangements as their knowledge and operating skills increase.

That is true, but much of the progression is required. A boat engine is under a continual load, unlike a car or similar. If the boat steamplant, can't keep up i.e. make hull speed, changes have to be made, and if enough changes are made, the engine gets difficult to find sometimes. It's cheaper to add an economizer than increase the boiler size.

-Ron

[DetroiTug]

Pat,

Looking at your pic.

The long jacket on the exhaust is a feedwater heater.

Notice too, that some of the steam piping is insulated.

He was working on it to get the efficiency up.

-Ron

[DetroiTug]

... I was equally shattered when I learned that the San Pablo from the classic movie "Sand Pebbles" was actually a prop - one of the largest ever built. The engine room was actually built on a stage. At least the material was technically correct.

Goodness! Is nothing sacred? I'm slinging babbitt even as I type ...

When I read the rivets were glued on, it reminded me of when I learned there was no Santa Claus. Devastated. Oh well it was a real boat anyway. It did some service later on in the Philippines I understand with her Diesel engines. At $250K in the early 60's it was the most expensive prop ever built. Nowadays, it would be computer generated and stereoscopic 3D.

-Ron

[fredrosse]

Very nice twin design you have going there.

As far as condensing goes, the Margaret S. has a planned condenser, but I like the sound of the exhaust so much I am not anxious to install the consender. The wet vacuum pump is already fitted (for now it does duty as a bilge pump or a lake water suction to fill the water tanks while underway. The boat has two 15 gallon water tanks, and this is enough for several hours cruising when in salt/brackish waters. When on the lower Delaware River (salt water), I have always been able to stop at any marina dock and fill the tanks with fresh water if needed.

The boat is propane fired, and there are two advantages, one is ease of control, the other is a complete lack of soot on the boiler surfaces. With the turbulators in the firetubes, cleaning any soot would be a problem. We have tried to throw some firewood down the stack, to get a little smoke and wood burning smell, but the turbulators take so much temperature out of the flue gas that the wood doesn't even start smoldering.

[87gn@tahoe]

I really like your compound design. Cast back columns, turned front columns at a slight angle... PERFECT

On condensers; One has much greater control over what enters your boiler as it is a closed system... One could even run bottled or distilled water, with treatment added, and keep those nasty solids at bay. Having a hotwell and keeping it hot will drive off the destructive oxygen.

Oil in the system certainly is a HUGE issue.. Baffles and filtering material in the hotwell help quite a bit. Then there are people that run no superheat and allow the wet steam to lubricate, or those who use colloidal graphite for internal lubrication which is supposedly even beneficial to boiler internals.

Colloidal graphite is what I'm going to be using in my boat in the near future, pumped in with a miniature manzel oiler from a 1-1/2" gauge live steamer.

The ubiquitous, omnipresent "THEM" suggest one mixes the graphite into de-ionized water and pumping it in that way, I'm assuming that is to prevent clumping of the graphite...