Miscellaneous Articulated Steam Locomotives

Click here for the introduction to Articulated Steam Locomotives of the World.

This page consists of several parts:

Temporarily Articulated Locomotives or Locomotives with Auxiliary Engines

1. Booster Engines

Utilisation of the tender's weight for propulsion

1. No Engine to the Tender eg modified Engerths, Stütz tender locomotives

2. Steam Tenders

Temporarily Articulated Locomotives or Locomotives with Auxiliary Engines

Booster Engines - of all the (relatively) few types considered by Wiener, the use of a booster engine was the only one of real practical significance. One of the major failings of a steam locomotive is its inability to deliver its full power output when starting up or accelerating from slow speeds - any attempt to do so will result in a slip. A booster engine mounted in either a forward or a trailing truck or even the tender can be 'switched in' temporarily to apply extra power - see http://en.wikipedia.org/wiki/Booster_engine. The downside was that their use introduced an additional complication in both maintenance and operation and they were only of intermittent use. The idea never really caught on although some railways in the USA and Australasia made attempts to make the concept work. This is a Franklin Booster, taken from this page http://en.wikipedia.org/wiki/File:Franklin-Booster.jpg which indicates that it is in the public domain (at least in the USA) as it appeared in the the 1922 'Locomotive Cyclopedia of American Practice'.

 

For a further picture of a British booster fitted locomotive see http://mikes.railhistory.railfan.net/r095.html. 

Utilisation of the tender's weight for propulsion

1. No engine to the tender eg modiffied Engerths, Stütz tender locomotives

The true Engerths (http://en.wikipedia.org/wiki/Engerth_locomotive) were a variety of unsuccessful designs involving (internal) gearing transmitting the drive and the transfer of some of the weight between tender and locomotive - see elsewhere in this section under geared locomotives although quite where in these page the locomotive illustrated belongs is another matter! A modified version of the former feature was developed by Orenstein and Koppel in the Luttermöller locomotive. Stütz developed the latter feature, but it was not widely adopted. Stütz tenders (Wiener's book uses 'Stutz') are seen on some of the locomotives at Sudhono sugar mill in East Java, Indonesia. It is therefore a moot point as to whether these are best described as 0-6-0 tender locomotives or 0-6-4 tank locomotives although they more closely resemble the former from a distance:

The Austrian narrow gauge 399 class are often called 'Engerths' but used the same system (as confirmed by the designation 'D2st' in my copy of the Krauss builders list where st = Stütztenderlokomotive) . They were originally supplied to what is now known as the Mariazellerbahn and which later worked for many years on the lines out of Gmund, This picture comes from http://en.wikipedia.org/wiki/File:Austria_narrow_gauge_mh6.jpg and may not be reproduced except under the conditions stated on that page; It shows one of the locomotives returned to its first home - since electrified, the current location of each of the six locomotives is given in the first link at the top of this section.

2. Steam Tenders

Wiener divides steam tenders into those used permanently and temporarily. They were never very fashionable, apart from the technical problems arising from using articulation, fitting them to locomotives with standard boilers led to them being short of steam.

In the UK, River Esk was designed by Henry Greenly as a 2-8-2 tender engine, and built by Davey, Paxman Ltd. in 1923 for the Ranvenglass and Eskdale 15" gauge railway in what is now Cumbria. The original valve gear was fitted in Colchester by the builders, with their Lentz poppet vales, however, these gave problems, but these were sorted by the addition of Walschaerts valve gear in 1928, by the Yorkshire Engine Co. They also fitted a 0-8-0 steam chassis under the tender, with their Poultney system, and this was supposed to supply extra power on the granite trains, but was unneeded and removed in 1931. This picture originally appeared on this forum - http://s9.zetaboards.com/MRW_Forums/topic/7099776/1/ (Link dead by May 2023) apparently it is a scan of an old Ravenglass and Eskdale postcard:

A picture of 'River Mite' with another steam tender on the same railway (as 4-6-0 + 0-6-4) appears at the end of the Binns Bradford Barton book which has technical details.

Those in the 'temporary' class by and large worked in the same way as 'booster engines' - see above - a feature that was (almost) entirely restricted the the USA according to Wiener.