Bachmann Message Board

Discussion Boards => HO => Topic started by: Steam Freak on June 27, 2007, 02:24:44 AM

Title: 3 Cylinder Steam?
Post by: Steam Freak on June 27, 2007, 02:24:44 AM
Has there been any ideas of making any 3 Cylinder Steam engines besides a Shay for Bachmann Spectrum?

Title: Re: 3 Cylinder Steam?
Post by: Jim Banner on June 27, 2007, 11:30:08 AM
With Shays, the three cylinders are all visible.  With three cylinder rod locomotives, the third cylinder is hard to impossible to see with the locomotive in motion.   The 120 degree offset between the outside cranks is too subtle an indication of a third cylinder.  So why would a model manufacturer want to go to all the trouble of a third cylinder when almost nobody would ever see it?  And who would want to pay extra for a third cylinder that you could not see?

An alternative would be models of three cylinder locomotives built with only the two outside cylinders.  But the howls from the rivet counters would be deafening.   

Title: Re: 3 Cylinder Steam?
Post by: ebtnut on June 27, 2007, 12:50:15 PM
Well, most three-cylinder locos had Gresley valve gear to drive the third cylinder.  This was normally mounted on the pilot deck, and was quite prominent.  The only mass-produced loco I am aware of that represented this was the Rivarossi Indiana Harbor Belt 0-8-0.  There have been a few brass models done of three-cylinder locos--they didn't achieve great popularity.  UP and SP had some 4-10-2's, and the UP's 4-12-2's were originally 3-cylinder locos too. 

Title: Re: 3 Cylinder Steam?
Post by: GN.2-6-8-0 on June 27, 2007, 01:46:17 PM
I do have a sound file of a U.P 9000 on my hard drive,forget where i got it but it did have a very distinctive sound ;D

Title: Re: 3 Cylinder Steam?
Post by: r.cprmier on June 27, 2007, 03:30:58 PM
The New Haven ran some three-cylinder locomotives.  two that come to mind were the 0-8-0 and the R-1 4-8-2.  These engines were beasts to maintain, and were not very popular with the service shops in Midway, and Readville.

Jim is correct to say that it would -by and large-be a fruitless endeavour, as most or all of the detail associated with this arrangement would be lost in "essential" detail.


Title: Re: 3 Cylinder Steam?
Post by: Steam Freak on July 06, 2007, 06:42:50 PM
That is true. But even if the model didn't have a 3rd crank, I would still like to see Bachmann Spectrum make a 4-10-2 or a 3rd Cylinder 0-8-0. I think a 4-12-2 would be a little too large for HO.

Title: Re: 3 Cylinder Steam?
Post by: Virginian on July 07, 2007, 04:34:18 PM
Get an articulated and have 4 cylinders - one better.

Title: Re: 3 Cylinder Steam?
Post by: r.cprmier on July 07, 2007, 05:34:18 PM
Steam Freak;
I am not telling you what to think or do, but Why not take a good look at what made up a three-cylinder locomotive?  You are correct when you say that the third crank would not be visible.   That said, how much more would be "there to see", thereby justifying a company taking that risk involved in mouldmaking, design, etc?  I would bet no one out there would give it a thought.  This is not to belittle your thoughts or dash your hopes, so please don't take me wrong.  I am just giving it some logical thought and sharing that with you.

Historically said; in this train business, two engines were real headaches:  Three-cylinder Steam units, and that opposing piston diesel design Fairbanks-Morse came up with.  They were great submarine diesels, and a very powerful and efficient railroad powerplant; but they were a major headache to do anything extensive on.

Speaking of F-M, I just bought two units and am going to do a repaint and detail, considering they are Proto 1000, and that category could surely stand superdetailing.  I also bought four A-B units FA-2s.  New Haven Pullman Green, delux gold, here we come...(yeah yeah, I know...FA-1s...  My jing, remember?)


Title: Re: 3 Cylinder Steam?
Post by: SteamGene on July 07, 2007, 06:06:05 PM
I believe that most three cylinder steam locomotives had the third cylinder removed during their life span.

Title: Re: 3 Cylinder Steam?
Post by: Atlantic Central on July 07, 2007, 06:50:31 PM
Gene is correct, most 3 cylinder rod locos where converted to two cylinder operation. Some sooner than others, but basicly it was an experiment that failed. The small amount of addional power was by no means worth the added complexity and maintenance. They where failures from the standpoint that no improvement in operation was actually realized.

And, from a modeling standpoint, they would represent the the narrow time frame in which they where built, so that lessens their appeal to modelers.

Also, back to the prototype for a minute, since steam cylinders are in a power stroke in both directions and rod driven steam locos operate at relatively low piston speeds, it was questionable physics in the first place to think any real advantage could be gained.

And, it was done largely before the development of super power boilers so steam consumptsion issues come into play. That is no doubt why switchers where the main type of 3 cylinder loco with some success. It was an idea that improved low speed torque somewhat, but smaller wheels and bigger cylinders do the same thing much cheaper.


Title: Re: 3 Cylinder Steam?
Post by: japasha on July 07, 2007, 10:39:17 PM
The SP and UP three cylinder engines went their life spans as three cylinder engines. UP did modify some to outside walshearts valve gear with two sets on one side. The Indian Harbor belty used three cylinder 0-8-0s through dieselization.

The French did have some three cylinder compounds but most were converted to four-cylinder compounds.

The biggest user of three cylinder locomotives was in England.

Three cylinders were tried in an effort to smooth the power delivery to the rails. 120 degree crank offsets made power delivery smoother. as opposed to 90 degrees on a conventional locomotive. Alco and Balwin felt that longer rigid wheelbases would be better served with three cylinders. They were correct but simple atriculateds made more sense with their shorter driver wheelbase . big, long locomotives just were not the way to go. As much as people like the Big Boy, it was an operational pain as it was limited to certain mainlines for operation, much the same as the three cylinder 4-12-2. These were not flexible engines like the New Haven or IHB locomotives.

I have an SP 4-10-2 in HO. It plain won't run well on anything less than 30 inch radius.  You don't want to know about the UP4-12-2.  Now, the flying Scotsman would be a good three cylinder model for us....