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Baltic Tank 4-6-4 Locomotive

 

At the start of this time of self-isolation, I made a foray down to our garage, where some of our locomotives and rolling stock are housed, along with a variety of other bits and bobs. I was just contemplating one of my father’s miniature steam plants that he must have built way back in the late fifties, and just as I was trying to place where the piece of lino that was on its mounting board was from, my other half pointed out a puce green locomotive.

At first glance, to my untrained eye, she looked rather ungainly a long lanky tank engine with quite small wheels, to make it worse it had a funny sort of Tender truck behind it that I later found out was not a natural pairing for this locomotive. “Odd” I thought, but being no oil painting myself I kept quiet, as hubby launched into an explanation of what this 5” gauge locomotive was and why she was special.

Firstly, her size is unusual as this model is a 5” gauge reproduction of a prototype 5’ 6” broad gauge locomotive so a scaling factor of 1:13.2 has been employed to build this model. Normally for models of standard gauge (4’ 8½” ) a scaling factor of 1:12 or (actually 1: 11.3) for the purist using 1 1/16” to represent 1 foot is employed.

I was informed of this before he told me that she was a model of a Baltic tank 4-6-4 locomotive. She is a 3-cylinder tank engine built originally to service The Buenos Aires and Pacific Railway that was in service between 1886 to 1948. These 4-6-4 tank locomotives were designed and built by Robert Stephenson and Co. and this particular type of locomotive was built between 1928 and 1930. This model Baltic tank engine’s number is 2367 and as it worked on an Argentinean Railway you can see that the number plate is reproduced in the Spanish language Ferro Carril De Buenos Aires Al Pacifico.

Apparently, the name of this “Baltic” locomotive tank engine comes from the very first 4-6-4 tender locomotive, a 4-cylinder compound locomotive designed by Gaston du Bousquet for the Chemin de Fer du Nard in France in 1911. The 4-6-4 was designed and built for the Paris to Saint Petersburg express and so was named after the Baltic sea. This model Baltic tank engine is a copy of one designed and built by Robert Stephenson and Company Ltd, Darlington, engineers, as mentioned above. It was awarded a Highly Commended certificate at the 50th Model Engineer Exhibition, also at a Midlands Model Engineering Exhibition sometime later, and bears a plaque attesting to this on the front just below the smokebox.

I was looking at the 4-6-4 wheel arrangement on hubby’s model Baltic tank locomotive which according to my mentor is a fairly good wheel arrangement for passenger tank locomotives. However, more commonly a 4-6-2 arrangement is often employed. The beauty of a tank engine with carrying wheels at each end of the locomotive is that it can run equally well forwards as backwards and hence does not need to be turned on a turntable. The 4-6-4 is well suited to high speed running across flat terrain because this type of engine has fewer driving wheels than carrying wheels, hence a smaller percentage of the engines weight contributes to traction compared to other engines with more numerous driving wheels. The 4-6-4 is therefore more suited to higher speed passenger travel rather than hauling heavy freight or slogging up sustained grades and inclines.

The 4-6-4T, is essentially the tank locomotive equivalent of the 4-6-0 tender Locomotive, but they have water tanks and coal bunker supported by four smaller wheels trailing behind the engine instead of a tender.

Hubby’s model has three cylinders. The external (outside) cylinders valve gears are Walchaert’s, but the internal (inside) valve gear is Stephenson’s link. The inside cylinder drives an internal crank on the middle axle, as do the outside cylinders so they all drive on the same axle. The middle cylinder sits over the front bogie. This front bogie even has a swing-link system, so it is in effect a self-banking bogie. The turbo generator which can be seen on the images is capable of running the front or rear head lamp depending which way the locomotive is heading on the train. Powerful headlamps were necessary on the routes served by these locomotives, owing to the fact that many parts of this railway were unfenced, and obstacles and wildlife had to be detected early on the route.

The model has a non-prototypical four-wheel coal and water tender which when the removable part of the cab and imitation bunker coal is removed, makes driving much more convenient while adding to the distance that can be covered without stopping. All in all, a lovely model acquired from Robin West of View Models on the understanding that some refurbishment is required to bring it back to its former prize-winning condition.