Paris-Lyon-Mediterrannee 4-4-2 Locomotives in France

Class 221 B (Locobase 20224)

Data from US Military Railway Service Equipment Data Book for French Locomotives supplied in April 2004 by Allen Stanley from his extensive Rail Data Exchange. See also Lord Kitchener's "Sunday Streamline #39. The Iron Mask" blog entry for 3 July 2011 at [] . last accessed 4 July 2017 and Andy Hart, "Les Trains Aerodyamiques du PLM", from SNCF Society Journal Number 128 (December 2007), archived on the web at [], last accessed 4 July 2017..

In 1935, the PLM streamlined two of the Atlantics it had removed from service in 1933 at its Oullins atelier (shops). They were fitted with 48-element superheaters. ACFI reheaters between the high-pressure and low-pressure cylinders, Bourdon mechanical lubrication, a tri-lobe variable blastpipe.

"Lord K" conferred the "Iron Mask" name on them, a suitable reaction as any of the photos of the locomotives from the front in his blog suggest. Andy Hart reported that "Down the Rhone valley at least, the locos acquired the nickname "Tarasqes", after the legendary monster which came out of the river at Tarascon to devour children and cattle (as is the wont of legendary monsters) until tamed by St Martha."

Ugly 221B carTnTe may have been, added Hart, but a January 1936 article in Locomotive claimed that "the difficulty of the steam beating down on the cab" had been "remedied in a most remarkable manner." The airstream caused the emerging exhaust to trail along the train's centerline that "did not splay out to the sides." Like many streamliner services, such locomotives trailed specially modified or built cars.

Trials showed that the rebuilds could sustain higher speeds (up to 140 kph (87 mph), probably due more to the installation of the superheater. (Hart says analysis of the streamlined locomotive and trained showed a net gain of 448 horsepower saved and a 25% improvement in coal economy. He is justifiably skeptical.)

New, more powerful brakes could slow a train at that speed to a stop in 39 seconds covering only 840 metres (2,756 ft, or slightly more than 1/2 mile).

Initially successful, the engines simply couldn't keep up with demand and were supplanted by Pacifics. Soon the engines were withdrawn (B 11 and B14) and the others relegated to light and local traffic service. The longest-lived was B16, which was scrapped in 1949.

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Class 2971 / 221 A 1 (Locobase 10009)

Data from US Military Railway Service Equipment Data Book for French Locomotives supplied in April 2004 by Allen Stanley from his extensive Rail Data Exchange. See also Lord Kitchener's "Sunday Streamline #39. The Iron Mask" blog entry for 3 July 2011 at [] . last accessed 4 July 2017.

These Atlantics were Du Bousquet De Glehn compounds with Belpaire boilers. Twenty of the locomotives were said to have substantially benefited from new blast nozzles in the smokebox in the 1920s.

In 1934, the PLM streamlined three of the Atlantics it had removed from service in 1933 at its Oullins atelier (shops). They were fitted with superheaters. ACFI reheaters between the high-pressure and low-pressure cylinders, mechanical lubrication

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Class 2991 (Locobase 12458)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Vol 23, p. 169. See also Wiki PLM at [], last accessed 9 November 2011. Works numbers were 18512-18515 in December 1900, 18526-18531 in January 1901.

These were essentially identical to the Atlantics purchased by the Etat in the same year (Locobase 6058). The Wiki PLM heating surface data reflects the difference between measuring on the water side (as shown in the specifications) and on the fire side of the tubes. Excluding the wall thicknesses from the diameter results in a drop in tube heating surface from 178.8 sq m to 162.05 sq m, about a 10% drop.

The PLM didn't much care for this class and retired it in 1914-1918.