PLM.Algerien Beyer-Garratt Locomotives in Algeria

Class 231-132.AT (Locobase 514)

Data from M Ducluzeau, "Locomotive Articulee Garratt", Revue General des Chemins de Fer, Volume 55, 1st half, No 6 (June 1936), pp. 397-416. See also Railway Age of 20 January 1934 and "Beyer-Garratt Express Locomotive PLM Railway (Algeria)", Locomotive Magazine (15 August 1932), pp. 268--269.

Unusual Beyer-Garratt design in that it was designed to run at 70 mph on the Algerian System (Algiers-Oran) of the Paris- Lyon- and Mediterranean (PLM). According to Railway Age, the engine attained 81.5 mph (131 kph) on a slightly descending grade in Algeria during tests. RA added "At these high speeds the locomotive rode steadily and smoothly"

Locomotive Magazine's report discussed in detail the proposition that the Beyer-Garratt sytem of articulation was "especially well-adapted for high speed; and indeed, there is no theoretical consideration why such engines should not equal any non-articulated machine in this respect ..."

Calculated cylinder horsepower for 31-minute period pulling 600 tons was 2-250 and she reached a max of 2-660 hp. In tests against a double-headed train of two 4-6-0 compounds, each pulling 595-ton trains, the Garratt ascended an 8-mile grade (most at 2%) in 24 1/2 minutes with a minimum speed of 14 mph. The double-header took 1 3/4 minutes longer and slumped to 11 mph as a minimum. Moreover, the double-headed compounds were worked very hard (with almost no cutoff), while the Garratt operated a 40% cutoff.

(NB: Measured from the fire side and using the internal diameter of 44 mm for the small tubes and 125 mm for large tubes, tube heating surface area was 236.25 sq m/2,543 sq ft.)

Class 231-132.BT (Locobase 515)

Data from M Ducluzeau, "Locomotive Articulee Garratt", Revue General des Chemins de Fer, Volume 55, 1st half, No 6 (June 1936), pp. 397-416. See also Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005). See also Robert Tufnell, The Illustrated Encyclopedia of Railway Locomotives (London: Quarto Publishing Ltd, 1986).

These were the production examples of the 231-132.AT prototype that appeared on the PLM in Algeria four years earlier. They featured cam-operated piston valves driven by Cossart valve gear, which resembles Walschaerts but allows earlier cutoffs and was electrically operated. Note the very high BDF, which in this short-tubed, high-superheat Garratt boiler is probably quite acceptable.

Like the prototype, these were fast articulateds--Tufnell calls them "racing Garratts"--the first of the batch hitting 82 mph in tests. In service, they pulled 460-long ton trains.

After this group of 12, three more tranches were delivered over the next few years:

BT13-BT16 -- 1937

BT17-BT22 -- 1939

BT23-BT29 -- 1940.

They were out of service by 1950 because the electronic valve gear didn't hold up well.

Class 241-142.YAT (Locobase 5802)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), p 100 . Works numbers were 2673-2676 in 1931.

A Double Mountain Garratt that was about the same size as the Kenya-Uganda Class 60, but had smaller drivers. Its Belpaire firebox had a curved lower section up to the straight-side upper section. Both rear bunker and long leading water tank segments featured stylish rounded corners all around and side-by-side air tanks on the top of the rear bunker. Havng noted the "fat" single chimney in the original configurration, Durrant observed that the double chimney later installed placed the two shimneys side-by-side (almost never done). He speculated that a tight loading gauge had kept the smokebox shorer than usual.

The quartet headed trains between Guelma-Djelfa. By 1934, the PLM claimed the Garratts had consumed 17% less coal than previous engines while hauling 300 ton trains up grades as steep and 1 in 40 (2 1/2%).