V8 - well , numerically , yes . However they were four separate V2 engines - and yet again you are right in that these were double action two stroke engines - that makes as many power strokes per revolution as in a gasoline V8 four stroke engine - g - however in that way any two cylinder SE steam engine was equivalent to a gasoline V8 engine , and if you think of their low rpm torque abilities there is something in that comparison that can’t be denied .
A friend of mine many years ago had developed a concept for a V6 steam motor double bogie shunting and secondary line all purpose tank engine that was to drive axles the way geared diesel locos do . The V6 engine was to be hung underneath main frame beams between bogies , it had a particularly smooth torque profile which in connection with drive shaft and bevel gear coupling of driven axles provided for high adhesion factor ( defined as limit of adhesion on rails - not to be mixed with traditional steam ‘factor of adhesion’ which was defined as quotient of given adhesion mass by cylinder tractive effort , disregarding actual adhesion conditions on rail ) The concept allowed for a steam locomotive of widely adapting versatile performance parameters with diesel competitive starting tractiv effort .
That’s starting to sound like a cross between the Shay and Heisler designs, using three cylinders per side as the Shay (though the Shay only had them on one side) with the cylinders in Vee formation as the Heisler. The torque from the V-6 would have been smoother than the torque from the Heisler’s V-2, so we would expect some improvement in adhesion. My understanding was that Shay’s generally had a higher tractive effort than early diesel switchers of equivalent weight.
I seem to recall that Doug Self’s “Loco Locomotives” website had some variations on the multiple Vee type steamers.
Just a question / comment…When I first saw this proto design several years ago I suppose I was fascinated with something so different.
Then…finally finding actual prints and photos of the arrangements of the “V” engines on the ends of each axle, It really caught my interest.
Now, I’m wondering how “slippery” that configuration might have been, especially in starting a load. Drive axles not connected…{Believe I’m correct on that}, it seems each axle would have spun easier than when all four would have been connected…Or am I remembering it wrong…
I briefly tried to find a photo of the “V” cyl. arrangement up close today, as I’ve seen in the past, but the short time I searched, I didn’t come up with any, but I know it’s out there.
Anyway…I think this was a fascinating experiment, and it was happening back 70 plus years ago…Interesting.
Well , that’s pretty much what I wrote before - it was Duplex one step further - both in smooth running and in slipperiness . It sems however they were able to tackle that problem or were just about managing it when it all came to stop because of war . Slipperiness in an engine of individually powered - non-coupled - axles is a question of (a) keeping mass on axles even and balanced at all times and (b) providing for good sanding to secure a certain minimum of adhesion factor on rails (c) keeping axle boxes well aligned and free of play and geometry of wheel tires within decent limits . With PRR T1 engines slipping preferredly their first set of drivers I wonder if it didn’t create differences in tire profiles first to second set which would have ever more encouraged premature slipping of leading engine .
Oh , yes - it was in a way a refinement of the Heisler - not so much the Shay in that the Shay had engine unit and drive shafts outsides including sliding elements . In the V6 C-C design power bogie tank engine , drive was fully derived from contemporary diesel-hydraulic engines minus torque converter minus gear speeds . The steam motor itself was also much looking like a diesel in that it was fully closed and had intake and exhaust lines much like a combustion engine - only that it’s inner secrets would have worked substantially different with a whole different valve gear , too . I don’t remember if the motor was to be reversible , though , or if change of direction was to be by reverse gear . The effect was that of a unique engine , looking from lower to upper starting much like a diesel-hydraulic C-C unit , then having side tanks full length and above them a conventional steam loco boiler , cab and rearward fuel tank . Surprisingly , it all combined in pretty agreeing ways and produced a stunning yet harmoniously looking little engine . Even if I would , I needn’t even ask , the guy would not want to see a technical drawing of his posted - the ‘Make a Flame’ picture , see ‘Chally to the Nines’ thread page nine - was about as far as I got with my encouraging .
I have a mental picture of the frame from the 1961 K-M units for the Espee and D&RGW with what I think a DB tank engine would look like. A bit different than a Pacific Coast Shay to say the least.
It wouldn’t be too difficult modifying a V type gas or diesel engine to work as the proposed steam engine, though probably not the optimal solution. The camshaft drive would need to be modified to open/close valves once per crankshaft revolution as opposed to every other crankshaft revolution, which would allow for the steam to be supplied via the intake manifold and exhausted through the exhaust manifold. I kind of doubt that the standard intake valve could hold off much steam pressure…
Hmmm, another possibility would be using a steam turbine driving through a multi-speed planetary transmission. This would be a larger scale version of what was proposed for gas turbine cars, the power turbine would be connected directly to the planetary gearset of an automatic transmission, with the turbine taking place of the torque converter.
Bah, visually another inverted bathtub. No match for a J, I-5, Daylight, or T. -or CP Royal Hudson
The bautfiul Daylight evening photo is marred by one item: The loco has a flat pilot/cowcatcher. I don’t think all SP 4-8-4’s had this type and those with more pointed ones were esthetically better in my opinion.
It wouldn’t be too difficult modifying a V type gas or diesel engine to work as the proposed steam engine <<
I’m afraid that very much depends on what you might consider >> difficult << if you mind the regular concept steam engine worked in double acting mode , i e produced power both sides of pistons going out and in while combustion engines usually only produce power on down stroke with pressure on topside of pistons - except for slow runnng very large ships diesel engines which also have piston shafts and crossheads as a steam engine .
Because of that I’d find it hard to see how even the raw motor block could be used , not to speak of valve actuation having to be desmodromic since in contrast to combustion engines highest pressure is in the intake duct system , while in combustion engines it is within cylinder space during power stroke which serves to seal valves additionally to spring load .
You could do away with the double action feature , using a single action concept and double the number of cylinders in compensation - we would be talking of a V12 steam motor then .
Mind also , mean pressure in a steam engine , or motor in this instance , was several times lower than mean pressure during ( hot ) power stroke in both a diesel or gasoline engine - which again is one reason why steam engines ( or motors ) had very low outputs per unit of piston swept volume , with the best historic loco types reaching some 12 ihp / ltr of piston swept volume while more modest designs ‘easily’ failed to reach half that figure ! This contrasts with about 35 - 50 ihp / ltr in typical 1960s gasoline V8 engines , 70 - 90 in modern diesel , 80 - 120 ihp / ltr in present day gasoline engines , to name but typical rule of thumb values . Low specific output of the steam engine demanded high piston swept volu
I think they show the concept of the V2 motors pretty well . The idea of hinging them outsides was of course to continue a good thing found in the two cylinder SE engine .
Dave ,
while you rightly remind us of topic , of which we tend to meander a bit off topic , in this engine it’s really just the steam motors interest focusses on . The streamlining was sort of standardized DR design , also - if much later - called ‘Stahlhelm’ since it was considered reminding of a WW-II soldiers steel helmet - not exactly a compliment for a streamliner and not intended to be one by the sharp tongued critics . As for me I believe it’s well known I prefer steam in plain and honest ‘work cloths’ , i e with streamlining kept decent and functional , advancing actual engine lines by smoothness and elegance , not too much of fancy shrowding it in non-functional voluptuous or pretentious sheet metal applications . I will apply these criteria to some engines - you may apply them to others as you prefer , no problem .
Wow…Madog added a nice group of those photos I have been scanning for recently. I had some of them several years ago, but they escaped me this go around. Thanks.
Beautiful shots of the mechanical prototype arrangement to power this engine. I think it’s really sad it was distroyed here in the States back in '52. What a museum piece it would be if it was here now.
As for the design of the sheet metal, all that I’ve read seem to indicate the main thrust of that design was intended to allow the speed they were trying to accomplish. Seems to have worked as they did do “speed” with it on tests.
Bathtub or not…it seemed to enable it to cut thru the atmosphere. I too think there were many more “beautiful” machines in this catigory, but for what this one was intended for, perhaps the “design” was successful.
Still all aspects of it has been a major interest to me in reading, learning of the unusual engineering direction it was using. I have no facts, but the design had no rotating heavy side rods to work out the balance for…Pounding of the track, etc…[2c]
This is a great point that many of you are forgetting about the N&W J Class. It also applies to the N&W A for that matter. Was the J a very good design? Yes, without a doubt. Was it the best 4-8-4 for the N&W? Perhaps, as that question really can not be answered with out a extensive test of every 4-8-4 design out there. Even if one assumes that the J design was the absolute best for the N&W’s operating profile, does that mean by default that it was the best 4-8-4 design for every railroad? Absolutely not. A design that was operationally and economically good for the N&W, very well may have been an operational and economic disaster for another railroad with vastly different operating conditions.
There were many very good steam designs out there, but there was never one “best” design that would work equally well for all railroads.
That’s pretty much what I was intending - the only internal combustion engines suitable for conversion to double acting steam would be double acting diesel engines. Also note that I didn’t think such a conversion would be optimal, as per your comments on mean equivalent pressure.
There would be a “simple” modification to make the intake poppet valve work. The valve seat would be on the outside of the cylinder head, with the valve opening away from the piston. Assuming pushrods and rocker arms, the pivot point for the rocker arm placed on the far side of the valve from the pushrod - so the valve goes up instead of down when the pushrod goes up.
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As for using a steam turbine , that would change the whole picture s
Per GP-40’s comment about there not being a “one size fits all” 4-8-4, well certainly not. A NYC “Niagara” intended for the “Water Level Route” probably wouldn’t have worked at all for the PRR, neither would a 4-8-4 used by the RF&P on its fairly level track profile aand short run from Richmond to Washington. HOWEVER, a 4-8-4 designed to handle mountains and the concurrant up-and-down track profile like the Class “J” of the N&W, or an FEF-3 used by the UP which was also intended for pulling power up hills would probably served very well indeed. In fact, the UP didn’t find out how good the FEF-3 really was until they were downgraded from passenger to freight service and performed outstandingly.
At any rate it doesn’t matter, diesels were coming and nothing was going to stop them. I suspect most of the roads that held onto steam for as long as they did did so for reasons that made sense at the time. Steam servicing facilities were already built and were long since paid for, if the road hauled coal it usually burned it as well and was probably getting a deep discount for it.
But then it didn’t have full gear capability. Many modern steam locos were designed with limited cut-off.
Juniatha,
As for the “no full gear starting with this engine”. Even with its somewhat lower figure on the “adhesion” scale, the J, unlike the T1, has never been regarded as a slippery engine. Also, discussions on other forums and other threads have tried to dispell this rumor about the T1 (Feltonhill being one champion of this campaign).
Considering that you have never operated the J or T1, that is a statement that I feel you are unqualified to make. Still, all of this is beyond the scope of this thread and should be “chiseled” out somewhere else.
Hey Big Jim, just 'cause Juniatha’s never operated a “J” or a T-1 doesn’t mean she’s not qualified to comment on 'em. Look, you don’t have to get pregnant to qualify as an obstetrician, do you?
And can you believe this thread’s gone on to 22 pages? “Shovel in the coal boys, let her roll…”
