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19th Century Steam Launch engine Plant.

Lester Bowman

Hot Rolled
Apr 9, 2011
Modesto california USA
Here are pictures of a wonderful little steam plant which was originally found in a warehouse in Manteca California years ago. Manteca is near the San Joaquin Delta and I believe it was used here as the Porcupine boiler shows no salt encrustation when peering into the blowdown pipe.

Incredibly complete with an engine with the California bear cast into the steam chest. I haven't measured the bore and stroke yet but I would say 2" x 3" stroke. It has Stevenson's reverse gear fitted. The governor is an anomaly for a steam launch engine but has the same age as the engine.There is a bronze feed water pump bolted to the engine with the ram connected to the cross head..a stroke for every revolution. A small 6" diameter "dog leg" spoked flywheel is fitted.

The fittings are all early style as you can see. Weighted safety valve and cocks of a very early pattern. It also has a water hand pump for secondary water feed.It has an early steam cylinder lubricator fitted.

The boiler from what I can see is a "Porcupine" boiler with the tubes in a " Bottlebrush " pattern.From what I can see at this point the tubes and central header pipe appear to be in good condition. The wrapper is pretty rusty but has protected the internals all these years. Here are some pics...


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Additional Pics showing Boiler and some other details. Whatever fired the boiler is missing..perhaps some kind of kerosene burner. You can see two "mixers" entering the firebox area. The flame enters through a round tube about 12" in diameter and 5" high and would "swirl" within this tube.

Last pic shows the Porcupine tubes with my camera held in the firebox using the flash. I cannot see this through the firebox door.The top of the boiler casing is cast iron. The boiler diameter is 18" with a stack aprox 8" diameter.

Any feedback and comments welcomed. Mostly I just wanted to share with you a rusty old treasure:)

Anyone have a clue as to whom made the boiler or engine? Years ago I saw another one of these engines owned by Joe Beatty who has since passed on. I do not believe his had reverse gear.He told me it was originally used to run a large ventilation fan in a plant. It was mounted up in the rafters and drove the fan with a belt.A boy would turn on the steam and start the engine by pushing the ventilating fan with a "stick". This one also had the California Bear cast into the steam chest..at least this is what he thought the bear represented.


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I missed the California Bear...and a picture of the gas mixers or burners. I'm not quite sure what they are or how they function yet.


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Nice find. What makes you think it is a launch engine? I have seen small steam engines like the one you posted that were not launch engines, but the reason for the reversing gear escapes me at the moment.
Base of this plant indicates it was mounted in the rear of a boat or launch. You can see where it was notched to clear a rib. Marine engines almost always had a reverse. A Porcupine boiler was a very commonly used boiler for light water power because they were light.

The brass mounted flange would take the propeller drive shaft or drive to it. With the unit mounted in the boat..the angle or tapered underside of the base would allow the engine to align with the prop drive shaft.Everything points to marine use.

The "box" holding the redwood base of the plant isn't original but was made to hold the plant off the ground.The screws which held the plant in the boat are still present on the base plinth.


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You have found another interesting little time capsule. "Bottle frame" vertical engines were most usually intended for stationary or similar applications. Smaller engines of this type could be found driving ventilating or heating blowers in buildings as well as driving draft fans on boilers as well as mechanical stokers. Aboard
vessels and ships of some size, the bottle frame engines might be found driving the circulator pumps (for circulating raw water from overboard thru the steam condenser).

It was not usual to find a bottle frame engine of this type with reverse gear on it. At the same time, while the reverse gear and the shaft coupling as well as the mounting all are clues the engine was used in a launch or small steamboat, the fact it has a governor on it is not normal practice on a marine steam engine.

The overall appearance of the boiler plant- the hand feedwater pump appearing to be homemade, and the way the overall plant is kind of pieced together- would seem that someone built it as a "do it yourself" project for their own small steamboat. The porcupine type of boiler was something a person could build out of pipe, and was likely a fast steamer with making good steam for the size it occupied. On the other hand, being a quasi-watertube boiler, anytime the engine was running, the feedwater had to be kept flowing into that boiler. It meant the person running the steam plant was probably pumping that feedpump fairly steadily.

The weighted lever safety valve is not unusual on ancient marine boilers. For many years, it was in widespread use on marine and stationary boilers. I am guessing that sometime around WWI, the use of weighted lever safety valves was prohibited by various codes and statutes in the USA. For someone building a small boiler like this one, even many years ago, finding a pop type safety valve small enough might have been a problem or too expensive. Making a weighted lever safety valve was something a person could do with relatively simple shopwork. A standard set of questions on oldtime examinations for marine and stationary engineers used to be based on weighted lever safety valves- things like calculating seat area and mechanical advantage of the lever and determining weight needed for a given working pressure, or other problems along those lines.

The reverse gear also looks more on the home-made side. A "factory" reverse gear would have had a heavier Stephenson's link and been a bit more substantial in how its parts were made. The relatively thin Stephenson's link could have been hand filed from a scrap of steel plate by someone in a home shop or as a "government job" while working in a place where they had access to simple tools and a vise.

The fittings on the boiler and engine point to it having been built at a time when steam fittings and lubricators for small engines were commonly available. As for the burners, it is another guess, but given the era the steam plant was built, it is possible those were some sort of "blowtorch" style burners. Not so long ago, it was possible to buy kerosene burners that were very similar to the old gasoline fueled blowtorches. These usually consisted of a fuel tank which was pressurized with compressed air, often from a built-in hand pump. The pressurized fuel passed through a "vaporizer"- often a tightly wound coil of tubing that the burner flame heated- before passing thru the nozzle orifice. Flame size was regulated by a needle valve. Lighting this type of blowtorch was a sometimes hazardous proposition as raw fuel first came out of the orifice and was ignited, making a sloppy and very rich flame and often dripping burning fuel. Once the vaporizer heated up, the blowtorch came into its own. As small as the porcupine boiler is, some sort of "blowtorch" style burners would have been likely. Fuel could have been gasoline, naptha, or kerosene.

The bottle frame steam engine design was used by many engine builders. Some put their names upon the steam chest cover or elsewhere on the engine, and many remained anonymous. The raised bear cast on the steam chest cover is an interesting touch, given the California state flag. Some 41 years ago, I worked with a fellow who was a graduate of the California state maritime academy. He had been a licensed chief engineer for steam vessels, horsepower unlimited. He told me a little bit about the California maritime academy, and he mentioned that the training ship was "The Golden Bear".

It looks like you found a home made marine steam plant, and a time capsule at that. I think getting your vertical firetube boiler into operating condition to raise steam with it may prove simpler than dealing with this porcupine type of boiler. The little steam plant ran non condensing from what I see in your photos. Scaling inside those water tubes and pitting inside the tubes may be a problem, but, this type boiler looks like it could be duplicated from scratch. In the era the boiler in your photos was built, the builder had no choice but to go with threaded connections. Drilling and running a pipe tap into the vertical center "drum" of the boiler was the only way to build it. With today's availability of things like GTAW (TIG) welding, the building of this type of boiler might be able to be done a bit easier and with a sounder job. All those threaded porcupine tubes in your photo look like they have some external wastage (loss of material). Maybe flame impingement from the blowtorch type burners, maybe soot left on the tubes held moisture and resulted in rusting and pitting. The threads on each tube scream "stress riser" at me, and visions of the inside of that center "barrel" with a bunch of threaded pipe ends sticking inside the wall of it also come to mind. A boiler relies on circulation to make steam, and with all those threaded pipe ends sticking into the interior of the center barrel, the restrictions and turbulence could not have been good for circulation. With modern methods, I think a new boiler of this type could be built and be better in terms of construction as well as performance. Interesting project that I could get my teeth into if you choose to go in that direction.
I always have space on my kitchen table and time to do engineering on projects for friends. Some blank paper, a calculator, and the quiet of our home (at the edge of some woods, away from traffic noise), and one or both of our cats "reviewing the calculations" is how I often relax. Doodling, sketching, running numbers on all sorts of projects- some of which happen and many more that don't- is a way in which I pass time when I am "at a loose end".

I am a selective but extremely voracious reader. The result is that if we go to town and visit the library, I bring home a few books and devour them cover-to-cover in a matter of a few hours apiece. It does not pay to buy paperback books. I only read stuff that is either non-fiction, or if fiction, must be "technically correct" and the writer must have "lived what he wrote about". The result is most of the time, for relaxation, if I am not doing some physical work such as shopwork or work on our property, I tend to occupy my mind with "engineering puzzles". My wife knows there are jobs I call "work" and then jobs that are hardly worthy of being called "jobs". These latter are either something new and interesting, or something done to help another person out, or done for friends. These have the best reward for me, and my wife knows that I tend to take on plenty of this sort of thing and it is what I need to function at a variety of levels. Any time you want to sketch up as-built details of the porcupine boiler and send them along to me, I am happy to start the engineering review and run the numbers.

Figuring a "porcupine" type of boiler should prove an interesting exercise, and evaluating it and suggesting design modifications is all right up my alley. If you choose to get this little steam plant operational, I will be happy to help with the boiler engineering.

Joe Michaels
Lester's marine power plant find

For Lester or for whoever's lap this piece of machinery falls into, Joe's offer:

"...Figuring a "porcupine" type of boiler should prove an interesting exercise, and evaluating it and suggesting design modifications is all right up my alley. If you choose to get this little steam plant operational, I will be happy to help with the boiler engineering.
Joe Michaels"

is a golden opportunity that it would be a serious mistake, in my view, to ignore.

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Heck this is clearly an historic piece of hardware!

Nobody here's seen The African Queen?


It even has the tape on the fittings.

funny you mention the "African Queen". The actual steam launch went through a series of powerplant changes and iterations. I do not know the complete history, but I do know that when the "African Queen" was filmed, it had an open-column steam launch engine and vertical firetube boiler. At some point, after the movie filming, the launch passed into some other owner's hands. They may have pulled the steam plant out and put in a gasoline engine. After that change, the launch was converted back to steam power. In this incarnation, the engine was an Orr and Sembower (Pennsylvania) "bottle frame" engine- a larger version of the engine Lester has found and what this thread is about. The O & S engine that was used to repower the "African Queen" was coupled to the tailshaft (the shaft the "screw" or propellor is on) with vee belts as I recall.

The bottle frame engine is a lot heavier for the power produced than an "open column" launch engine. Open column steam engines were commonly used on small launches where weight might be more of an issue.

The present owner of the "African Queen" contacted me some years back to get information about a Penberthy Injector for the boiler. He was restoring the "African Queen" to approximately what she had been in the movie. To do this, the present owner had obtained a British built open column launch engine, and a British vertical firetube boiler. The intention was to use the "African Queen" to take out tourists and guests at a hotel in Key Largo, Florida. Since the vessel would be taking out passengers (more than 7 passengers at a time) as a paying proposition, and possibly due to hull length, the vessel was classified as an "Inspected Vessel" by the US Coast Guard. This threw the British made boiler off the table, as USCG required a boiler built to ASME Code and needed proper documentation on materials used, welding, etc. I believe the owner of the "African Queen" wound up having another boiler made by a US shop that was National Board Certified.

The "African Queen" was (and may still be) working out of the hotel dock in Key Largo. During the 50th anniversary of the evacuation of troops from Dunkirk, the owner of the African Queen got the idea to have the launch shipped to England to participate in a re-enactment as one of the "small ships". Whether the "African Queen" had been a participating vessel in the actual evacuation of the troops from the beaches at Dunkirk is something I do not know. What I do know is the "African Queen" got out in the Channel and found heavy enough seas to get into trouble off Goodwin Sands. I believe the Goodwin Sands Lifeboat had to respond and tow the "African Queen" into port. The end result was the owner had the "African Queen" loaded on a semi trailer and hauled on a cross-channel ferry, then put in the water on the French side of the Channel. It sounded like quite a boondoggle, and probably cost more than most of us would have as "mad money" for pastimes or our old iron addictions.

In the movie, the "African Queen" is fired on wood- the fuel at hand on the banks of the river. Down in her present home in Key Largo, I believe she is fueled on propane.

One of my favorite lines from the movie is when Charlie Olnott (sp ?) tells Katherine Hepburn: "A machinist can make anything" as he devises a couple of torpedoes from oxygen cylinders and uses rifle cartridges and nails to build a contact detonator. I suspect in her present incarnation, the "African Queen" is in finer fettle than she ever was in any of her past lives. Oldtime machinists like myself who might cut a shim from a welding rod can, or might make a part out of a chunk of a busted axle shaft or leaf spring probably do not get near that vessel. I imagine some fuss is made over who works on the African Queen, acting like anyone who can adjust clearances in a bearing or handle a steam plant is some kind of exotic specie. I am of the Charlie Olnott school, and I think the unknown person in the murky past who built this little steam plant in this thread was of that same school. He may have made heels for his shoes from worn rubber steam pump valve discs (something old steam plant men did), may have saved bacon drippings for lard oil to use for tapping and thread cutting, and probably made shims from anything handy- advertising cards, sardine tins, or whatever miked up to what was needed. It's a nice window into the past to see this little home made steam plant, adapted from a stationary engine for marine use, and to know someone else had the same idea on the "African Queen".
This threw the British made boiler off the table, as USCG required a boiler built to ASME Code and needed proper documentation on materials used, welding, etc. I believe the owner of the "African Queen" wound up having another boiler made by a US shop that was National Board Certified.

I saw the Key Largo African Queen in 2010. Then he was open for hire (parties preferred) and the Brit Boiler had been relegated to the lobby of the associated Motel/Restaurant.

IIRC, there was a gas engine in the Movie African Queen. Katherine Hepburn wrote on this in her reminiscence of the movie "The Making of the African Queen" as "A 30 foot metal launch with a huge boiler and a fake steam pump" (She may be referring to the engine.) This which is a book heavy in the personal interactions of the actors, the physical challenge of Mid-Africa access and filming , and only secondarily on the props, both the actual African Queen and its "stand-ins" used. Notably a movable African Queen "mock-up" on a raft - convenient for river shooting. And an African Queen mock-up used in the "tank" located in London.

Raft below.


Note the "river" (real) African Queen to the right (with canopy) and the simulated African Queen boiler between the two outriggers more to left.

Joe in NH
I do apologize for hijacking the thread - but I seem to recall that Hepburn's pallor in many of the shots was for real, many of the
cast and crew were suffering from dysentary or somethink like that. Evidently Bogard did not, as he mostly consumed ethanol.

One of my favorite questions which I am obligated to ask:

Suppose the _African_Queen_ is being re-made. Who do you cast in place of Hepburn and Bogart?
I'm no expert on steam launches, but the setscrew coupling further suggests either a home-built plant, or use for something other than a launch engine. Going in reverse, the propeller thrust would pull the shaft out of the coupling. A separate thrust bearing could have been used, but would not be common in small boats.
I appreciate all this information very much.Thank you all. After working on things a bit..freeing up stubborn unions and fittings I was finally able to remove the engine saving all these precious early pipe fittings. Try to find these old style beaded fittings and you'll see why I call them precious.I will post some better pics of the engine hopefully later today.

Changing my initial perspective a bit I now tend to think this is a small bottle frame steam engine adapted to propulsion of a small boat.It has all the primary constituents for a boat power plant albeit a very small boat.However the secondary "hand" operated water pump with the neatly forged lever appears to be made from a bilge pump.The air expansion chamber chamber on the engine driven water pump is made up from period pipe fittings.

So all things as Joe suggested point toward a mish mash of parts put together for a small marine power plant. It is a unique extraordinary time capsule capturing one engine,one boiler and one boat from a time long ago.The boat we can only imagine but the engine remains showing a man knew quite well what he was doing and did it well.There is absolutely no question in my mind this came out of a small boat.The base proves this beyond a shadow of a doubt.

Take it for what it is worth but I have seen thousands of steam engines and boilers spending the last 45 years of my life studying them whenever they appeared.I have read everything I could ever find on them and in my early years started out with steam then moved into hit and miss engines then scale models doing my own research,making castings and finishing the engines.

I'm telling you guys..old engines have kept me broke over the years :) I don't have a lot of them and lately have made it a point to move the bigger ones and acquire smaller units I can handle. My back is shot and I have physical issues impacting my obsession with early steam and gas engines.

But I have a pretty good understanding of old engines and applications.I also know fully well there are many others who know much more than I do and surprisingly many are right here on this Forum. So I feel it takes all of us as a group to be able to..as much as possible..put these old steam plants into a proper perspective.

Joe Michaels..another wonderfully generous offer to help with another "unknown" Porcupine boiler project. Thank you so much for this offer. Without you the little unknown Fire Tube boiler would have never been put back into service. Now that boiler is absolutely perfect and a very beautiful piece by the way..running steam engines quite happily and so easy to operate.

So Joe..I spent yesterday heating and cooling..heating and cooling various fittings on the Porcupine so I can remove the stack and outer wrapper. There are various appendages which screw through the outer wrapper which must be removed before we can access the tube arrangement.I am trying my best using various oils and heat to remove parts in one piece..I do not break parts anymore because I am patient even on old pipe fittings.

We'll look that over Joe when I Get the wrapper off. If possible I WOULD like to save the boiler. Later I may or may not set it up like it was originally. I know for sure I would plumb things differently. Anyway I'll be starting with some close up pics of the engine later today and we'll go from there :)

Thanks to all who replied and yes..I am convinced it is NOT a commercially made steam plant but rather someones idea of what a steam plant should be and subsequently installed in a small boat.


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So all things as Joe suggested point toward a mish mash of parts put together for a small marine power plant.

No Thorneycroft for sure.


But it beat rowing.

I was always surprised by the relative small size of a launch engine required for "ordinary" service.

My launch engine has cast into the side of the cylinder "Wm. Blake" - and may be a side production of the Blake Steam Pump company. Mine is 3"x4" and has Stephenson reverse. Roughly 3 horsepower, it could possibly power a launch up to nearly the 23' Elliot Bay launches (http://www.steamlaunch.com/) but may be better suited to the 20' "Rose" hull offered by Beckman (http://www.steamboating.net/page63.html)


Ah, to have a cottage on a New England lake - and a small machine shop out back to support the launch.

Joe in NH
The subject of this thread- a small home-made marine steam plant, for a small launch, and the comment: "beats rowing" brings to mind a little story. I am sure most everyone has heard of Evinrude outboard motors. The story of the Evinrude and the outboard motor goes back to the turn of the 20th Century. Ole Evinrude, a Norwegian immigrant (possibly working as a toolmaker at that point in time), took his wife to a lake on a very hot summer Sunday afternoon for an outing. Ole rented a rowboat and rowed his wife and himself to either an island or some other part of the lake such as a grove of trees on shore where there was some shade. Ole's wife said she was quite overheated, and Ole said he'd fetch her some ice cream. Ole set off in the rowboat, rowed a distance to where he could purchase ice cream for his wife. He hustled back into the rowboat, and rowed his fastest to get the ice cream to his wife. By the time he arrived back with the ice cream, it had totally melted. That lit a fire in Ole Evinrude's mind, thinking of a simple and low cost way to put a motor on a boat to "beat rowing". At that time, the alternative to rowing were either a steam launch, a launch with an early inboard gasoline or naptha engine, or a sailboat. None of these seemed like a good solution to Ole, who was thinking in terms of a workingman with limited money going out for a day off of fishing or going to a picnic grove on a lake. The result was the first Evinrude outboard motor.

Ole and his wife soon were in business making outboard motors, and sales ramped up. As the rest of the story of those early days in Milwaukee goes, Ole Evinrude was successful in developing and building a carburetor for his outboard motor. In that same Milwaukee neighborhood, Harley and the Davidsons (one Harley, a pack of Davidsons) were building their first motorcycle. The carburetor had them stumped, despite their best efforts. They reportedly asked their neighbor, Ole Evinrude for some help with a carburetor. Ole helped them out but asked the H-D boys to promise they would never apply their engines to outboard motors. With a handshake, this was done. Indian- a competitor to H-D- had no problems in developing an marketing an air cooled outboard motor for a few years.

Ole Evinrude went on to head a variety of companies building outboard motors, and saw the businesses grow to huge size. The rest of the story is that Ole's love and devotion to his wife was unwavering. His wife was said to have been a somewhat frail woman, and she died quite young. When that happened, Ole was said to have given up on living, and died within that same year.

It's a nice story, and gives some insight into the old days in Milwaukee, when heavy industries, fine engineering, and entrepeneurship all flourished. It was a time when an immigrant with little or no formal education could realize the American dream, and speaks of a story-book love of a man for his wife.

One can look at Lester's little marine steam plant and wonder whether some fellow who worked at a machine shop or place with a steam plant like a hospital powerplant, brewery, ice plant, or any number of other places built that little steam plant. I like to think the fellow who built that steam plant did not have a lot of money, and used what came to hand and what he could work with. I'd imagine the fellow who built this little steam plant knew steam plant work well, as the way the plant was built speaks of a man who, while not having a lot of money to spend on it, built it in accordance with steam plant practice. This was the kind of fellow who repaired everything and anything at home, worked hard all week, and looked forward to a simple weekend, perhaps as Ole Evinrude once did. Maybe taking his wife for a nice run out on a lake in a little launch he'd built in the backyard. It's a window back to another era, when people did not go to malls for recreation, and when people built what they could not afford to buy, and when a man would burn up the oarlocks making flank speed to bring ice cream to his wife.