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Strange Swedish Locomotive

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Posted by Erik_Mag on Monday, October 4, 2021 10:24 PM

I spent a couple of weeks in Oxelösund  (the "O" in TGOJ) back in 1986 well after the TGOJ was electrified. Didn't realize at the time that the TGOJ was the home of the Swedish steam turbine locomotives covered by an article in the July 1967 issue of Trains. IIRC, the locomotives were in service for about 20 years.

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Posted by 7j43k on Monday, October 4, 2021 10:10 AM

Paul Milenkovic

I am not sure how the Swedish turbine locomotive solves the angularity problem between the jackshaft on its rod connection to a crankpin on a driver. 

 

I think the same way they solved the angularity problem between the multiple drivers:

with a multi-piece, flexible side-rod system.  It has been used on steam locomotives for over a century.

When one of the drivers goes up on a bump, and the others don't, it is dealt with.  In this case, we have a "driver" that doesn't go up on bumps.

 

Ed

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Posted by Paul Milenkovic on Monday, October 4, 2021 9:39 AM

BEAUSABRE

Dave, Yes direct turbine drive, like a PRR S2, although I think the turbine is on the pilot dek. And of course, you don't hear "chuff-chuff" but "swooosh"

 

Ah, yes, the S2.

As anyone who has struggled with an out-of-quarter model steam locomotive can tell you, the drivers, rods, and axle boxes have to all be lined up just right that the fine thing doesn't bind.  It is not just the quartering of the driver crank pins, it is also getting the axle-box guides in parallel alignment.  A lot of effort has gone, at least with the prototype, into optical or other means of finding that alignment and into axle-box shims or wedges to correct any misalignment.

That said, a jackshaft drive has long been of interest for a turbine locomotive such as this one along with early electric locomotives, diesels and even geared piston steam.  Jackshaft drive is where the engine or electric motor rotates a shaft attached to the frame, the jackshaft, which is in turn coupled to the wheels by siderods.

The problem with jackshaft drive, on the authority of Wikipedia along with ALCo's Alfred Bruce in his book on steam locomotives, is the potential for binding between the jackshaft that is fixed to the frame and the crankpin on a driver, where the driver is allowed to go up and down against its spring connection to the frame.  This is not a problem with a direct rod drive from a crosshead because the driver crank going up and down will only cause small changes to the piston position in its stroke.  This should only be a problem if the cylinder clearance volume were much less than used in steam locomotive applications.

There are a variety of imperfect remedies, which include using as long a driveshaft as possible to minimize this effect, some complicated linkages to allow the driver axle to change height with respect to the jackshaft with reduced binding or simply using loose bearing clearances and restricting the locomotive to low-speed service.

The S2 and the British Turbomotive, however, used quill drive in place of jackshaft drive.  This arrangement is described on another thread, and yet another thread has pictures of the gearing connecting the turbine on the S2 to the quill.  The quill, by the way, is a hollow tube that surrounds the axle.  That hollow tube that is gear driven is fixed in relation to either the locomotive frame or the truck frame, and the sprung axle is allowed go move up and down relative to that tube.  The mechanical connection between the quill -- the hollow tube surrounding the axle -- and the axle itself is either through cups and springs as on the GG1 or through some linkage arrangement that I have never been able to figure out from the few pictures on the Web on modern European electric locomotives and maybe some express passenger train diesels.

I am not sure how the Swedish turbine locomotive solves the angularity problem between the jackshaft on its rod connection to a crankpin on a driver.  I think what the designers did is that the turbine somehow rests on the pilot truck?  You would think that ordinary siderods introduce the angularity problem if there are bumps or sags on the rails that raise one driver relative to another.  I think what is happening is that his relative displacement of one wheel in relation to another is slight compared to the amount the locomotive can bounce or sway on top of its springs, especially in high-speed operation.  If the turbine rides on the pilot axle but floats in relation to the locomotive frame, maybe this reduces the jackshaft angularity problem?  If this is the case, having the turbine getting the unsprung jolts of the rail might be only a solution for a low-speed locomotive as this Swedish locomotive used in hauling ore?  For high-speed operation as with the S2 and the Turbomotive, quill drive to one or more axles (even though it has siderods, the S2 had quill drive to the inner two axles) is preferred?

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by BEAUSABRE on Monday, October 4, 2021 5:23 AM

Dave, Yes direct turbine drive, like a PRR S2, although I think the turbine is on the pilot deck. And of course, you don't hear "chuff-chuff" but "swooosh"

"In 1932, in conjunction with the Nydqvist and Holm company, Fredrik Ljungstrom developed a very successful 2-8-0 steam turbine locomotive, based on an existing conventional design, for freight traffic on the Grangesberg-Oxelsund Railway. (The TGOJ) The main purpose of the TGOJ was the transportation of iron ore from mines around and at Grangesberg to the Baltic port of Oxelosund, a distance of 159 miles (255 km). The first turbine locomotive proved to be more efficient than its conventional sisters; it could pull 1830 tons up a 1 in 100 gradient, and was reckoned to save 10% on fuel. All the engines were non-condensing, with a forward-mounted turbine and jackshaft drive. It was visited by Dr. Guy and William Stanier, and became the inspiration for the LMS Turbomotive.

Two further locomotives of the same class (M3t) were subsequently built. All were in operation until the mid 1950s when the line on which they operated was electrified. Two of the class are preserved in the Railway Museum at Grangesberg, Sweden.

The mines were worked out, and ore transport finally stopped, in 1990."

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Posted by daveklepper on Monday, October 4, 2021 4:36 AM

1. Direct turbine drive?

2. Turbine under thecab, behind the drivers?

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Strange Swedish Locomotive
Posted by BEAUSABRE on Monday, October 4, 2021 2:49 AM

Can you see what is strange about this loco?

https://youtu.be/ZsrzUjcHeAs

 

 

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