More Articulated Steam Egines please!

[tomikawaTT]

First, let's hone a definition or three:

Articulated (1) - a blanket definition covering all of the more specific definitions below:

Articulated (2) - any locomotive with a frame arrangement that allows all its engines (cylinders with associated driven wheels) to assume an angle to the frame carrying the boiler.  Meyer-Kitsons and Fairlies (single as well as double) were articulated.  (The Mason Bogie of Colorado narrow gauge fame was a single Fairlie in basic design.)  The most widely used fully articulated loco was the Beyer-Garratt.

Semi-articulated - any locomotive with a frame common to its boiler and one engine, with one or two subframes (fitted with engines) that can assume an angle to the main frame.  This is what 99.44% of US built "articulated" locomotives were, although the Mallet pattern was not the only semi-articulated.  (Mark, do you happen to know how a DuBosquet was hinged?)

Flexible - any locomotive with an engine fixed to the frame carrying the boiler which has drivers (powered through geared or electric links) in subframes that can swivel in relation to the main frame.  Shays, Heislers and Climaxes were reciprocating steam examples.  Sticking to steam, but going with electric traction, the Heilmann, N&W's Jawn Henry and the C&O turbo-electrics also fit this definition.

I guess the WWI German trench engines that looked like 2-6-2s and ran like 0-10-0's could be called "semi-flexible," since the end axles were geared to the main engine and could swivel...  I rather believe this isn't the kind of articulated CudaKen had in mind (and not just because it was 600mm gauge!)

Chuck (modeling Central Japan in September, 1964)

[marknewton]

The Leader Class an articulated?  Hmm?  That's something of a moot point.  Personally I wouldn't call it an artic...

Why not? It's as much an articulated loco as a Garratt, Meyer, K-M or Fairlie.

The next is a Klose Mechanism loco which, like the Hagens below it was a flexible not an artic.

I might concede the Klose, but not the Hagens - it's articulated. The rear four drivers are in a separate swivelling frame.

The last one is a real weirdity... if you look carefully you can see that the leading truck has two complete sets of cylinders one above the other.  This is because this design had a seperate rack engine combined into the leading truck. 

Yes Dave, I'm aware of this. Two of these engines survive, and I've crawled all over and under both.

IIRC these were Abt rack engines.  IIRC there were never any artic or flexible rack engines... they could probably not have synchronised the two sets of driven gears to the rack.

Sorry, there were. These K-Ms and the contemporary CTR Esslingens were articulated rack engines. In addition to the rack engine superimposed on the front adhesion engine unit, the rear engine unit is powered on the rack pinions only. "Synchronising" the two sets of rack pinions on one engine was no different to engaging the rack with two engines double heading. I take it you've never had any footplate time on a rack and adhesion engine?

The difference between an Artic and a Flexible is that the former has more than one frame with driving wheels and each frame has a set of steam cylinders (which cylinders on the two frames the Leader doesn't have)

Your definition doesn't take into account designs in which the coupled wheels are mounted in subframes or bogies to allow for a flexible wheelbase, which is why it's not one favoured by those knowledgable about steam. And Leader had cylinders on both bogies - three on each.

If you go back far enough there were a few locos that had booster units that could be fed steam to give extra power for starting.

Not that far back. Boosters were common on modern North American locos right up until the end of steam there. Google on "Franklin booster engine", you'll find plenty of examples.

I'm pretty sure that some of the GNR 8' Singles had these tenders... they were not successful

Yes, designed by CME(?) Sturrock. There were also a few other railways in Europe that tried Sturrock's idea.

The idea of a booster was always to get extra traction.

It would be more accurate to say that boosters were designed to increase tractive effort at low speed, where the boiler was producing more steam than could be used by the locos cylinders alone. Since most locos could haul a heavier train than they could start, boosters were quite useful.

All the best,

Mark.

[cacole]

If you want some really impressive articulated engines, check a G-scale live steam Big Boy or Garratt -- $7,000+

[Dave-the-Train]

My oath! The more articulateds the merrier!

Crandell, your recollection is correct about the Beyer Garratts, it is indeed

http://eurekamodels.com.au/Garratt.html

I nominate the following articulated locos for consideration:

The Leader Class an articulated?  Hmm?  That's something of a moot point.  Personally I wouldn't call it an artic.  On the other hand i wouldn't call it a Flexible Wheeelbase either...

The next is a Klose Mechanism loco which, like the Hagens below it was a flexible not an artic.

[http://www.dself.dsl.pipex.com/MUSEUM/LOCOLOCO/klose/kl2a.jpg[/img]

[img]http://www.dself.dsl.pipex.com/MUSEUM/LOCOLOCO/hagans/hg1a.jpg" border="0" />

Then you have three proper artics...

 

and somrthing really articulated...

The last one is a real weirdity... if you look carefully you can see that the leading truck has two complete sets of cylinders one above the other.  This is because this design had a seperate rack engine combined into the leading truck.  IIRC these were Abt rack engines.  IIRC there were never any artic or flexible rack engines... they could probably not have synchronised the two sets of driven gears to the rack. 

Cheers,

Mark

 

Has anyone got a link to a Golwe?

The difference between an Artic and a Flexible is that the former has more than one frame with driving wheels and each frame has a set of steam cylinders (which cylinders on the two frames the Leader doesn't have) OR (as in a Shay) two or more distinct trucks the wheels on which are driven indirectly from a steam engine on the mainframe.  A Flexible only has one set of cylinders and has one or two frames with driving wheels.  Where there are two frames there is a mainframe and a sub frame.

If you go back far enough there were a few locos that had booster units that could be fed steam to give extra power for starting.  I'm pretty sure that some of the GNR 8' Singles had these tenders... they were not successful.  IIRC there were one or two (probably French) tank engines with boosters... again IIRC they were used in Parisian commuter service.  The idea of a booster was always to get extra traction... sort of a steam variant of a Slug or Road Slug.

As mentioned in a different thread recently the ATSF experimented with some articulated boiler locos.  These were definitely not a succes and were cannibalised to make locos that did work.

The principle problem was always maintaining steam tight joints.

[marknewton]

My oath! The more articulateds the merrier!

Crandell, your recollection is correct about the Beyer Garratts, it is indeed

http://eurekamodels.com.au/Garratt.html

I nominate the following articulated locos for consideration:















Cheers,

Mark

[selector]

Try a Rivarossi H-8, Ken.  It is the C&O 2-6-6-6.  A monster.  Otherwise, the Mantua tankers availably cheaply from trainworld.com.  Not DCC, but they can be made so, and they are apparently nice engines.

Otherwise, big bucks in brass.  Try Uncle Dave's Brass and see what he has in the way of big brutes.  Also, don't overlook the Beyer-Garratts.  Mark Newton has a handle on someone who makes them...I recall something like eurekamodels...something like that.  Also a bit pricey.

[Vail and Southwestern RR]

Dear Ken,

You are an insane nut!  But you like cool locomotives!

 

[wgnrr]

MTH announced a Erie Triplex, which is like an articulated on steroids, if you are interiested.

Phil

[cudaken]

 I have sort of mastered the Big Boy (after it comes back from BLI to fix the lights) and the PCM Y6b kicks butt. It got off to a flakey start with the cannon plug not staying in the engine and some odd crude on the tender wheels. But two calls to Bob at BLI she is draging 40 coal cars like there is nothing behinde her. Flicker fire in the fire box was a sweet touch I will add.

 So what is next in the way of Articulated steam engines?

 I know about the Challenger, but besides it what else is out there? I read something about a Yellow Stone, what does it look like?

 Is a Y-3 all most the same engine as my Y6b?

 Pic and Links, it will be a while before I buy anything with my Daughter getting married but I need to know what to look for.

           Cuda Ken