April 16, 1929—February 10, 1012
Added to museum: 1/14/09
Jerry Brown running his 1/6 scale steam crane in 2007. —Bruce Ward photo
By Craig Libuse
Spectators, including me, at that 2005 Men, Metal and Machines Show in Visalia, CA were treated to seeing Jerry Brown’s steam crane in action. Restrictions on use of live steam indoors meant it was running on compressed air, but it was impressive to see nonetheless. The crane project was started in 1972 and first run in public in 1978 after 1700 hours work over the course of six years. By 2005 it had been hard at work for 27 years, and it had the look of a real working machine. Unlike the pristine display engines usually seen at model engineering shows, it was greasy, oily and not disguised as anything but a machine intended to do heavy work. Jerry does use it to actually dig full-size earth.
Update: February, 2014. We recently received word that Jerry passed away in February, 2012. We confirmed with the executor of his estate that the steam crane featured here is now in storage. The executor hopes one day to prepare an operator's manual for it and get it running again. Future display plans have not been confirmed.
Photos from the 2005 Men, Metal and Machines model engineering show in Visalia, CA show Jerry demonstrating the crane for a spectator. The second photo shows the crane in "operating" condition. An air line is used to power the crane, as show regulations prohibit the firing of a boiler inside the exhibit hall. (Click on either photo to view a larger image.) —Craig Libuse Photos
The photos that accompany the article Jerry wrote for Australian Model Engineering magazine were taken during construction of the project, when parts were freshly cast, machined and painted. Compare these to the photos above. This is an example of good craftsmanship put to work rather than pampered.
Following is a little about how Jerry came to work with metal, and after that is an article that Jerry submitted to Australian Model Engineering magazine in which he describes how and why the project was built. It is reproduced here with permission. Like a number of other stories of great model engineering accomplishment, he was always fascinated with the big machines and knew he would never be able to own the real thing, so he did the next best thing—he built himself a scaled-down working model. His story tells why and how.
By Jerry Brown
The hobby of building miniature functional models of full-size machines is known as model engineering. It likely originated in England as did much of the machinery modeled. Quite fittingly there is an English magazine called Model Engineer that put out its first issue in 1898.
For as long as I can remember, this has been my main hobby. I've always been fascinated by large machinery. Of special interest are engines and earthmovers such as revolving power shovels. When I was growing up in the 1930’s, large industrial engines ran at speeds so slow I could count the exhaust beats. Many were steam (external combustion) and early gasoline or diesel (internal combustion) engines with exposed moving parts, which helped in understanding how they worked. Early on, I was building crude models from fruit crates, tin cans and whatever else I could scrounge, which was easy in those days; now even the trash is locked up.
I had no idea how to build miniature engines to run these things, so they were all hand-powered. In 1945, about half way through high school, I built a lathe from scrap material. It was crude but it could cut metal. I had learned basic foundry skills in the school shop, and had set up a small non-ferrous foundry in the family garage. This enabled me to build a small steam engine. It was patterned, from memory, after a toy (Weeden) engine I had years earlier. Not much, but it ran, and proved I could do it. I was on my way. Magazine articles kept up my interest, and a few years later I built a better lathe (which is still in use.) It and a drill press from a WW2 machine shop constituted my shop. (That old drill press is also still in use, and I wouldn't trade it for any current import.)
With these I built another engine, and this one could rightly claim the title of a miniature steam engine. I was hooked. After a hiatus for Army service I made up for lost time with an intensive build-up of my shop. After acquiring a standard lathe and milling machine I was ready for a serious project. My goal was to build, from scratch, an engine big enough to do useful work. Perusing old steam engineering books, I was able to design what I wanted—a 1.25" bore x 2.25" stroke engine similar to those that powered mills and factories in the 19th and early 20th centuries. I made wood patterns to form sand molds, and poured metal castings for the major parts. After everything was assembled I tried a test run on compressed air. No problems, so next was a steam test (with borrowed steam at a club meet, since I had no boiler.) It ran fine, with no leaks, which an onlooker said was rare for a first-run on steam. I subsequently had a boiler built, and mounted it with the engine on skids for portability. After some 40 years it's still running as well as ever, powering a grain mill which grinds corn for my pancakes. Fired with scrap wood (or corn cobs) it's a big attraction at antique engine shows
Despite these accomplishments, I still hadn't fulfilled my childhood dream of building a steam-powered miniature revolving crane/excavator. These were all gone from the construction world in my time, except for some that survived into the 1970s as pile drivers because their boilers could supply steam for the hammer. I always liked watching these things. If I were a musician I'd have to be a percussionist because, like the legendary John Henry, I love to hear that cold steel ring. In 1972, working for a company that made live-steam miniature railroad equipment, I figured the time had come and I'd best not wait any longer. The crane would be a vastly more complicated project than a plain stationary engine, but I plunged in, learning as I went. It was a labor of love, culminating in1978 with the first steam-up. Thirty years later it's still going strong, digging in my garden and demonstrating at shows what steam power once did (like building the Panama Canal.) Since schools are closing out shop courses, I hope it also shows that old technology is still viable and that you don't need a lot of formal education to make use of it. The first locomotive that came here from England arrived disassembled. The story goes that a village blacksmith, one of a now nearly vanished breed that, with little theory but lots of experience and intuition could build or repair anything, was chosen to put it together. He'd never even seen a steam engine, but assembled the parts into a working locomotive.
I like to think there may be a little of that old blacksmith in me, and that with my miniatures I'm helping to interest young people in this kind of creativity before it all goes across the pond to China. For if that happens, we may some day wish we had it back.
By Jerry Brown
Photos by Jerry Brown and Bruce Ward
(Article published in March-April, 2008 issue of Australian Model Engineering magazine)
My interest in power shovels and cranes goes back at least as far as I can remember. While more “normal” people were watching sports, I would be happier looking at these things. Their operators seemed no less skillful than ball players, and what they were doing seemed much more useful. Revolving shovels, with their various mechanisms working in concert, have a measure of balance and coordination matched by few other machines—a symphony of motion. When run by steam, with all its characteristic sights, sounds and smells, they take on added interest, almost seeming to come alive. Ever since childhood days of building crude wood and tin-can toys, I had dreamed of building a genuine operational miniature, and since steam seemed the only practical self-contained power source that could be satisfactorily scaled down, there was no question about how it would be powered. But due to the usual interventions, those dreams were a long time materializing.
A lifetime of various metalworking skills were needed to take on a project like this. (Click photo to enlarge.)
By 1972 I had accumulated most of the equipment needed for such a project, realized I wasn’t getting any younger and that I had better get started while such things could still be done. As it turned out, that was a more timely decision than I knew. What I still lacked was know-how. I had built stationary engines, but this was obviously going to be far more complex. Port-reversing slide valves would be required as a convenience on the main engine and a necessity on the swing engine, and I hadn’t the foggiest idea how to make them. Then there would be all the gear ratios, power calculations, clearances, controls, etc. All kinds of information and parts are available for railroad models but none for this sort of thing. Faced with all that, plus the skepticism of some who learned what I had in mind (along with no small amount of my own), away I went. At this point I would like to gratefully acknowledge the help I received from fellow live steamers, without which the project may never have been completed, certainly not as successfully as it was. One fellow had a full-size Erie shovel; another was a collector who graciously loaned old parts books and drawings. That solved the valve problem plus many others.
The first decision concerned size: How big should this thing be? I guessed that a 2 inch-per-foot scale (1/6 full-size) version of a 50-ton crane might be about right. From pictures I built a wood and cardboard mockup. I had guessed right—much bigger would be a transportation problem, and much smaller wouldn’t have the weight to dig very well in full-size earth. So with that, I set to work, learning as I went. What developed was a sort of composite of Bucyrus and Northwest, the makes I had most access to. Except for chains, most plumbing fittings and spur gearing, it is all scratch built. The caterpillar track base is 25 inches square, rope size is 1/8 inch 7 x 19 galvanized steel, and the working weight with heavy clamshell is nearly 600 pounds. Its stability was demonstrated when the clam picked up a 50-pound log, nearly a 100-pound total load, with the boom at about 45 degrees and no sign of tipping. Castings are mostly of zinc alloy and bronze, poured in my shop foundry. All functions are steam operated. Boiler feed water is from three sources: injector, duplex steam pump, and a power pump run by the main engine. There are two double-cylinder engines, one powering all hoist and travel functions, and another (the swing, or slewing engine) for rotating the superstructure. I suspect the reason for a separate engine for this function, rather than a clutch system from the main engine as in more modern machines, was that it was simpler since the same engine was used for the crowding action on dipper shovels. In any case, it was an additional challenge, and adds more interest to the operation. One of the biggest thrills of the entire endeavor was the first test run of the main engine.
Going from drawings of the cored steam passages in the full-size to drilled ones on the model, I wasn’t sure I hadn’t gotten disoriented somewhere until I finally put air to it. With only one side assembled, less stuffing box packing and with the valve cam set by eyeball, I hesitantly opened the air valve. Much to my relief it ran beautifully in either direction.
The tracks are independently driven through jaw clutches for steering. The two hoist drum clutches are external band worked by steam rams. The brake bands are direct mechanical with over center toggles. Both are operated by a complex system of links, bell-cranks and springs from the control station levers, a departure from full-size practice due to the operator being some six times too large to fit inside to use foot pedals. (The pedals ARE functional, though; they lock the levers in clutch position for powering down loads, useful in crane work.) The boom hoist is a separate drum, worm-driven (and self-locking) from the main hoist gear. The boom is of riveted aluminum angle, 100-inch basic length with 20-inch optional section. Not really a “shovel” (I haven’t gotten around to building that attachment yet), it is a crane with heavy and light clamshells and a dragline bucket. Capacity is about 2 scale cubic yards (just under 2 gallons.)
To check bucket geometry and operation, cardboard mockups were tested in sawdust. After finishing the clamshell I had to see what 45 pounds of bucket would do in real soil, so hauled it out into the garden and hastily reeved it with some old sash cord. What it did (you guessed it!) was break the cord, but not before a quite respectable bite had been taken.
A test under live steam power without the cab outer shell in place. (Click photo to enlarge.)
On to steam! The boiler is a conventional vertical fire-tube type, originally steel but now, due to corrosion and maintenance problems, copper. It’s big enough to make all the steam needed and is a good counterweight. I first tried firing with wood, but soon found it was a nearly full-time job. My first oil-firing attempt was with used engine oil. It was free and burned hot, but only after raising steam with a wood fire like the big ones did in the old days. That problem was eliminated by changing to diesel fuel. I use a small spray-gun type atomizer, and when I get the feed pump at the right rate the boiler pretty much takes care of itself. In 1978 at the Fall Meet of the Los Angeles Live Steamers after six years and some 1700 hours of effort, most of it enjoyable, some of it challenging, and all of it interesting, the rig was fully operational. I bravely decided to test myself and the machinery by attempting to pick up an aluminum can with the clam. Considering the vagaries of the control system, distractions from the usual crowd of observers and my inexperience as a runner, I was sure the can would be crunched into a shapeless blob. To my surprise and relief it wasn’t; it hardly suffered a dent. I’ve never worked up enough nerve to try it again, being content not to drop a load in the middle of a swing! Allowing for the physics of reduced size, it operates much like the full-size rigs, and it’s big enough to get into the same kind of trouble if the runner goofs. Fortunately, the troubles are easier to correct. The size choice has proved to be ideal, and the non-standard control system, though inconvenient when raising suspended loads, has worked very well. (Never having run a full-size machine, I had nothing to unlearn.)
Running the clam was no big deal, but the first time I tried the dragline I acquired an instant respect for the runners of the big ones. Why did I build it? Why does one swim the Channel or build a Brooklyn Bridge from toothpicks? In this case, as I say, it was a lifetime ambition. I’ve always liked to watch the wheels go ‘round, especially when they’re steam powered. And maybe because this machinery is kind of a reminder of a time long-gone when some of our present problems hadn’t even been thought of. In any event, I’m glad I did it when I did. One thing I’ve learned is that if you want to do something, do it as soon as you can because you never know when it will be too late. Watching the clam pull itself into the ground as the closing line snakes through all those sheaves to the sound of the engine and smell of steam and hot oil made it all worthwhile. Not to mention the amazement of spectators, most of whom never saw the big ones at work. And the small boy, growing up in the plastic, throw-away age asking sort of awe-struck, “Is that made out of metal?” Steam machinery buffs will understand.
The 1/6 size model digs full-size earth. (Click on photo to enlarge.)
Chip Bassett sent in links to some video of Jerry operating the crane at a Los Angeles steam function. See the following YouTube links:
|• Description: Steam Locomotive (self-propelled) Crane, Caterpillar Mounted Main engine, 1-1/4 x 1-1/2" double port-reversing slide valve type|
|• Max. rpm: 500, Indicated HP: 0.7 @ 80 psi|
|• Estimated torque: 51 inch-pounds|
|• Swing/Crowd Engine: .75 x 1" double port-reversing type|
|• Hoist gear ratio: 7.38|
|• Scale pull on main line: 116 lb (25000/216)|
|• Main drum: 3" diameter x 3.5" long, Capacity: 17.25' per layer of 1/8" rope|
|• Auxiliary drum: 3-12 x 2-1/4", 12' per layer|
|• For clamshell work, both drums 3-1/2" dia. X 2.81", 16.5' per layer|
|• Drumshaft speed: 40 rpm|
|• Swing rpm: 4, Total gear ratio 86.4|
|• Boom hoist ratio (from crankshaft): 15.3|
|• Drum: 1-1/4 x 1-1/2" long|
|• Line speed: 8.3 fpm average|
|• Track base: 25 x 25", Loading (at 600 lb total weight): 2.4 psi|
|• Maximum travel speed: 10 fpm|
|• Gear ratio bull wheel to crankshaft: 87|
|• Travel/rev. of bull wheel: 21-1/4"|
|• Weight with 100" boom, 3 gallons of water, 1 gallon of fuel oil and steel boiler: 634 lb (less bucket) (determined by teeter-board/spring-balance method.)|
|• 1/6 scale cubic yard = 216 cu. In. or 0.94 gallon|
The following images were part of the article in Australian Model Engineering magazine as are most of the captions. (Click on any photo to view a larger image.)
|This wood and cardboard mock-up shown at the Los Angeles Live Steamers event in July, 1972 was used for confirming the decision on size.|
|Wood patterns for the caterpillar travel base castings|
|The transporter, shown with mock-up of travel base frame, has 12 equalized ball bearing wheels.|
|Sixty-two zinc alloy castings for the travel base. Note swing bull gear in eight sections.|
|Jerry drills the hinge pin holes in the track pads. Since all the holes in 58 castings had to be parallel, this was the most elaborate piece of tooling for the entire project.|
|The cast bull wheels and associated parts|
|This underside view of the lower propel shaft shows the jaw clutches for steering.|
|A chain hoist is now needed to lift the unpainted travel base while it is set onto the tracks for testing.|
|The shop hoist aids in fitting the tracks.|
|The primer coat of paint is applied|
|The completed travel base showing a hand crank on the vertical shaft for demonstrating the action|
|Castings for the revolving frame|
|Drilling the boom foot casting for the hinge pins|
|A bottom view of the welded frame|
|A bottom view of the frame shows the four conical rollers, side extensions and the rear crossmember|
|The primered revolving frame is fitted to the travel base|
|The right-hand engine frame and cylinder|
|Piston and rod parts. The original pistons shown here were made from cast iron. The engine is now fitted with brass pistons with Teflon rings.|
|By May, 1975 the main engine and gearing were complete and could propel the machine using compressed air.|
|The hoist drum, showing the actuating mechanism for the clutch band|
|The clutch and brake drums with laggings for hoist cables. The dragline lagging is mounted--the symmetrical set is for clamshell work. (All laggings have since been grooved.)|
|The cross shafts for brake and clutch control. Mounting these under the frame was one of the toughest jobs because there was already much in the area where they had to go.|
|Frictions (bands) with their leather linings|
|The brass castings for the steam cylinders (rams) that operate the drum clutches. They are somewhat similar to the power reverse gear on a locomotive.|
|The machined parts. Surprisingly, with all the guesswork involved, they worked, giving a useful mechanical advantage.|
|Parts of the worm driven boom hoist|
|The boom hoist, assembled|
|Jerry runs an operational test using 35 psi of air pressure to the engine to pick up a 35 pound load. The tipping point was 5 feet from the center post with no counterweight, an encouraging result.|
|The original boiler parts ready for welding. As mentioned in the article, the rust-prone steel boiler was later replaced with a copper one.|
|The slewing engine departs from full-size practice by using a 2-piece design to simplify foundry and machining procedures.|
|The swing engine gear train|
|The completed boom sections primed for painting. The total length when assembled is 10 feet, which corresponds to 60 feet on the full-size version.|
|Most of the 100 pieces that make up the clamshell bucket|
|When assembled, a piece of old sash cord was hastily reeved to see what 45 pounds of bucket could do. What it did was break the cord, but not before its digging ability was proved. The seeming paradox of an upward pull making these things dig into the ground is explained by the multiple parts of the closing line which greatly reduces this force, plus the counterweight and the weight of the bucket itself. Assisted by the rather fierce looking teeth, even this miniature bucket can dig quite respectably in any reasonable soil.|
|(Left and below) The completed machine in use while still looking relatively new. (Compare this to the photos in the introduction to this article which were taken many years and many holes later in 2005.)|
|Jerry Brown puts the crane to work at the LA Live Steamers steam club meet Memorial Day weekend in 2007.—Bruce Ward Photos|
|This photo was taken at the 2005 Men, Metal and Machines show held in Visalia, CA. Jerry was there operating his steam shovel, and can be seen working on it while a spectator looks on. —Craig Libuse Photo|
More photos of the crane shortly after completion
|Photos shot during the first steam-up!|
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