Compound locomotives; type 42

Experimentation with new locomotives

The Company had decided to experiment with two new types of locomotives :

• one with carrying axle at the front (type 49, called "Charente" by the CFDs, having already been described in the locomotive type Charente locomotive item),
• the other to two two-axle articulated units , called "type 42" by the company, because of the registration of the prototype, ordered from the S.A.C.M. of Belfort, in 1889, and head of series of 7 identical units. Later, this series was commonly called "compound type" by the user networks.

This model, which is the subject of this paragraph, was of the type Mallet with a compound operating system. It was characterised by the use of a front drive train preceding a fixed group of axles which were also driven. The pivot of the front drive axle was located between the cylinders of the stationary set. On each side of this pivot, vertical connecting rods connected the rear of the mobile bogie to the front of the fixed bogie. These rods balanced the weight of the cylinders, which were cantilevered at the front, and also served as a return system to return the mobile unit to its position when exiting the curves.

Description of the two-axle articulated locomotive: type 42

These machines were equipped with a boiler with 89 tubes of 0.045 metric metre diameter and 3.34 m long, giving a heating surface of 46.49 m2, roughly comparable to type 49, but for a smaller number of tubes. Composed of three ferrules, the cylindrical body bore the steam dome equipped with balance valves on the second and the sand tank on the third. This boiler, with a round smoke box door, rested on the two bogies, the fixed one carrying a pair of small cylinders (called inlet or HP.) and the mobile one a pair of large cylinders (called expansion or BP.).

In compound operation, steam acted directly in the HP cylinders and then by expansion in the BP cylinders. It was also possible to admit steam directly into the BP cylinders in single expansion operation, which allowed for increased tensile stress and therefore faster start-up.

The advantages of these machines type 42

The advantages of this type of machine were the following:

• More complete use of steam power through the use of prolonged expansion.
• significant increase in tractive effort through maximum use of the tractive weight equal to the total weight of the machine
• ease of passage in very small radius curves due to the use of two bogies, giving more flexibility to the machine.

These advantages, highly appreciated by the C.F.D., due to the significant traction economy provided on the rough lines with heavy traffic, were nevertheless diminished by a more expensive maintenance.

Their 0.900 m diameter wheels did not allow them to operate at high speeds, but their tractive effort being almost double that of type 49 gave them the ability to pull heavy convoys. During the tests, carried out on the Château-Landon and South Indre-Loire lines in 1889, the prototype machine towed a 70 t train at a speed of 34 km/h on a ramp of 20°l°°°. This speed could be maintained over a distance of 13 km, under these conditions, on 6 May 1889, between Ligueil and Loches.

The shelter, which was completely enclosed, was fitted with two rectangular portholes with a visor on the front face and a large opening on the rear face, which was subsequently closed off by means of a glass frame. The units in the two sub-series were distinguished by the different presentation of the aft face of the shelter:

• on machines 42-48, this one had a cut edge.
• on units 63-64, it was straight and the front had been shifted slightly towards the water tanks in order to maintain the same volume in the cabin.

The primitive livery was uniformly black in colour. Only the front and rear crossmembers were painted vermilion red, and the white lettering of the registration was marked with the "N" on the left and the numbers on the right of the centre stamp. In addition, two oval plates were affixed to the water boxes in the usual location, one bearing the construction details, the other the company name and engine number.

Subsequently, some units used in Seine-et-Marne, in particular No. 43, were given a two-tone livery: grey on the water boxes and the bottom of the shelter under the belt, and black for the rest of the machine.

Delivery and assignment of the locomotive with two articulated two-axle groups: type 42

Prototype No. 42 was delivered on September 28, 1888 to Egreville for tensile tests during the beet campaign. Used intensively on the section from Egreville to Souppes and at the Sucrerie Ouvréré branch at Montuffé, it towed the majority of beet convoys where it provided services comparable to those of two "Yonne" type units. In view of these excellent results, the Company decided to complete the series with two additional machines, intended to complete the fleet at the Egreville depot and thus free up two "Yonne" machines to arm the lines of the South Indre-et-Loire network. However, the C.F.D. sent the 42 to Ligueil on 30 April 1889, before carrying out this exchange, to carry out tests. These were judged to be very satisfactory, but as the traffic did not justify the use of this type of machine, it was returned to its original depot the following month.

Initially intended to equip the Haute-Loire and Ardèche lines, the rest of the series was shared between the Egreville (No. 43 and 44) and Yssingeaux (No. 45 and 48) depots. However, because of the heavy traffic forecast for the 1890 beet campaign, machine No. 45 was delivered to Egreville on 20 August 1890 and used as a reinforcement until 24 December of the same year, when it was transferred to Yssingeaux.

The two additional units, numbered 63 and 64, intended to replace machines Nos. 43 and 44 that had been distracted from their original destination, were delivered the following year to the Tournon depot. Locomotive no. 64 was, like engine no. 45 and for the same reasons, temporarily detached to the Egreville depot from 23 September to 8 December 1891, before returning to its final assignment.

The different mutations

Some units were transferred as and when needed to reinforce certain depots:

• the 43 was detached to the depot of La Voulte- sur-Rhône from 1 July 1901 to 5 December 1904 where it covered 19,244 km, then transferred to Chablis from that date to 8 August 1906 where it covered 4,703 km and finally, repatriated to Egreville.
• the 44 left Egreville on 17 August 1905 for Montmirail where it travelled 12,032 km until 2 February 1907, when it was transferred to Mortcerf. On this line it covered a distance of 4,596 km and reached Egreville on 8 September 1910.
• the 48 was transferred to Saint-Jean-d'Angély on October 15, 1907 to replace Couillet n° 11 and attached to the traction annex of Ferrière d'Aunis. During its transport, in double traction with a 130 "type G", it was the victim of a collision at KP 46.9 between Le Gué-d'Alleré and Landes-Torxé on train No. 43. After being repaired by the small workshop at Ferrière d'Aunis, it was only able to operate on the Epannes line on 9 November 1907. It covered 56,463 km until December 12, 1914, the date of its return to Le Cheylard, after an exchange with locomotive No. 62. It was requisitioned on 30 June 1943 by the TODT Organisation to be used on the Littoral des Chemins de Fer de Provence network. It was only returned to Le Cheylard in 1946, in very poor condition. Parked, waiting for R.G., it was finally not put back into service and was sold as scrap metal the following year.
• the 64 was detached to the Florac depot from February 18, 1916 to May 18, 1919 to replace machine no. 251 requisitioned for the needs of the National Defence.

source : MTVS 1989-1