Paris-Orleans 0-10-0 Locomotives in France

Class 5.501/050-501/ (Locobase 15600)

Data from "050T nñ 5 501 a 5 525 du PO" on the WikiPO website at [], last accessed 9 January 2022. Builders were Berliner Maschinenbau A.G. (Schwartzkopff) for 5501 a 5505 (), SociTtT Alsacienne de Constructions MTcaniques 5506 a 5515, and SociTtT Fives-Lille 5516 a 5525.

Two different southeastern French railways adopted Robert Garbe's T16 design, which had

Unlike the Midi 050s described in Locobase 8942, this class used smooth tubes. Otherwise they repeated the simple-expansion, piston valve, superheated design.

NB: The heating surface areas given in the PO's specifications used the inside (fire side) diameter, calculating the tube heating surface area as 127 sq m (1,367 sq ft), which together with the firebox heating surface area came to 140.65 sq m (1,514 sq ft). Locobase used the tubes' exterior diameter (water side) shown in the specs and used by Anglo-American railways and builders.

Class Fourquenot (Locobase 8461)

Data from "Locomotive Engines at the Paris Exhibition", The Artizan (Vol II, 4th Series, #2), p. 25 and from "Sir David Campbell on Railway Apparatus", Reports on the Paris Universal Exhibition 1867, Volume IV (London: George E. Eyre and William Spottiswoode, 1868), pp. 492-493.

According to the Artizan account, this locomotive was built for branch-line service by Forquenot. He was striving for the most adhesion possible on a line that had a ruling grade of 1 in 29 (3.45%). Campbell specifies that it was for theAurillac and Murat section that had gradients of 1 in 33 (3%) and curves of 15 chains (990 ft)

To accommodate the widest possible grate, Forquenot appended short outside frame members to hold the horn plates of the last two axles, which had outside bearings to keep them away "...from the heat of the furnace."

Another concession to the unusual layout was the use of three journal bearings on the third, driving axle. That axle was driven by inside connecting rods, other rods on the inside bearings coupled to the first two axles, and outside rods turned the rear two axles. All the axles were equalized. The 2nd and 4th had 5/16" lateral play while the end axles enjoyed 11/16" play.

"The valve gear," reported the Artizan, "which is of the stationary link class, is entirely outside, and is worked from overhung cranks on the outer ends of the driving crank pin."