Compound locomotives with 2 groups of 3 axles; type 400

In order to overcome the operating difficulties encountered on the new lines of the Vivarais network, in 1901, the Company had a new type of machine studied which could tow loads of 801 on ramps of 32.5°/°° combined with curves of 100 m radius and this, at a speed of 20 km/hour.

To do this, the C.F.D. engineers recommended the Mallet type with compound operation with two groups of three axles. A competition launched in France for the construction of a prototype, with an option for four additional units, in the event of success in the tests, did not meet with the expected success. Indeed, the French constructors, whose order books were well filled, were not anxious to take the risk of a study, without having the certainty of obtaining a large order.

The C.F.D. did not have any better results when they turned abroad, as only the Swiss Locomotive Building Company (S.L.M. in Winterthur) agreed to take on such a supply, taking as a basis the model it had built for the Rhaetian Railways, which was close in power and design to the machine requested.

The S.L.M. 401-408 series

Description of the S.L.M. 401-408 series

The prototype built by the S.L.M., differed from the model of the Rhaetian Railways by the adoption of 2 groups of 3 axles instead of 5 including 4 engines. On the other hand, the chassis was inside the wheels, unlike the Swiss machines. The other characteristics were comparable.

The boiler, stamped at 14 kg, consisted of 152 smooth tubes 0.045 m in diameter and 3.600 m in length providing a tubular heating surface of 77,500 m2.

The safety valves, of the balance type, were later replaced by the balance model, were later replaced by the direct-load model, and were located at the rear of the steam dome, located on the second ferrule. Compared to the type 300, the cylinders were larger and the piston stroke was increased to 0.550 m. The diameter of the wheels was 1,010 m and the wheelbase of each engine truck was 2,200 m. Despite its considerable length of 10,900 m, this machine fitted perfectly into the small radius curves.

The tractive effort of 8060 kg allowed this locomotive to tow large loads on all the lines of the Vivarais network. During the tests, the prototype provided traction for a train of 60 wagons representing a load of 1601 at a speed of 15 km/h on 30°/00 gradients. This very heavy model reached a laden weight of 45.71 evenly distributed over the 6 axles, limiting the axle load to 7.6 t, 1 t less than that of the 300 type machines.

The shelter, closed on all four sides, was pierced at the bow by two rectangular portholes and at the stern by two circular portholes framing a cut-out giving access to the fuel bunkers, projecting aft. On the sides, a wide opening had been made to provide the operating crew with a good view of the track.

The rectangular water boxes were limited to the plumb line of the sandpit fixed on the first ferrule.

The mass-produced machines subsequently built by the S.L.M. up to 408 underwent some modifications , in particular the replacement of the balance valves by loaded valves and the removal of the projecting fuel boxes at the rear and their integration into the shelter.

The original livery was black, but later the water tanks and shelter of some units were painted in light green or brown. Marking consisted of the registration number embossed on the chimney and both sides of the shelter. A rectangular plaque placed on each water crate bore the names of the network and the company. A similarly shaped construction plaque was attached to the steam dome. Later on, on some units these plaques were placed.

On the rear cross member, the company monogram and registration number on either side of the centre stamp were painted yellow on a vermilion red background.

Delivery and assignments series S.L.M. 401-408

The prototype n° 401 was delivered to La Voûte- sur-Loire on February 6, 1902, the P.L.M. having refused the passage of this type of machine on the common trunks without first having made various modifications to the interpenetration devices. As this work had not yet been completed in 1903, the following machines were also delivered to this same station and their circulation was only authorised on the three-line sections of rail at the end of 1903.

Machine 401 was therefore tested on 13 February 1902 between La Voûte-sur-Loire and Rosières. It towed a 1551 train at a speed of 35 km/hour. On a 30°/00 ramp it started a 901 train and reached a speed of 30 km/h. It was then used to pull the work trains of the second network, but was not finally put back into service until March 17, 1902. Used to run heavy mixed trains, it was very much appreciated for the ease with which it could be started and accelerated, thus reducing the delays accumulated during manoeuvres in stations. These qualities corresponded to the requirements of the Company, and the order for four additional units was confirmed in July 1902.

These machines, numbered 402 to 405, were delivered from February to May 1903 and assigned to the Yssingeaux depot while waiting for the opening of the section of the Cheylard at Saint-Julien-Boutières, allowing the junction of the three lines of the network. As soon as it was put into operation, the entire series was transferred to the Cheylard depot.

Very satisfactory machines

Thanks to their qualities, these excellent machines were immediately used to the maximum , which did not fail to worry the Management of the Company who, on May 28, 1904, requested the acquisition of a batch of three identical machines "in order to be able to cope with the possible repairs which could not fail to occur, in view of the current service they provide" (Report of the Director of the C.F.D.). This additional order was placed in Winterthur and the three units Nos. 406 to 408 were delivered in 1906. At that time, machine 401 was assigned to the Yssingeaux depot, 402 to the Dunières traction annex and 404 and 405 to the Saint Agrève depot, 403 being placed in the reserve at Le Cheylard. The three new units were attached to the Cheylard depot. The arrival of these machines made it possible to group together the Mallet series 42 at Le Cheylard to pull freight trains on the Tour- non and Voulte-sur-Rhône lines, the I.G. type locomotives being reserved for passenger trains and the shunting service.

These locomotives were used until the closure of the system, except for the 402, which was parked in January 1943 and overhauled in 1953.

Machine no. 408 was detached to the Florac depot from September 12, 1909 to February 3, 1911.

Machine no. 406 was to be transferred to the Chemins de Fer de Provence network on January 17, 1944, but its shipment was cancelled the same day it was sent to La Voulte-sur-Rhône for transfer.

Two units have survived and are used for the tourist line from Tournon to Lamastre: they are n° 403 and 404.

The 409-414 series of the M.C.A.S.

As traffic became more and more important, the number of powerful locomotives became insufficient and the C.F.D. had to reinforce the fleet of 400 machines by means of two successive orders in 1927 and 1931. As the French manufacturers were less congested, the Company obtained several proposals for the supply of these machines from them. The S.A.C.M., the company's usual supplier and at the origin of the introduction of Mallet compound on its lines, offered its type 172 and was chosen because of its numerous references.

Description of the 409-414 series M.S.A.C.S.

The first delivery concerned the 409 and 410 machines, directly inspired by the Swiss series, from which it took the main characteristics. However, the heating surface was slightly smaller and the empty weight was 1 t lower than the previous series. The general appearance was more modern with the adoption of water boxes with a forward sloping end and a more enveloping passenger compartment ending in a cut-out section.

The second delivery with machines Nos. 411 to 414 differed from the first by the shape of the shelter and the transfer to the rear of the fuel bunker, thus recalling the silhouette of the type 120 or 4001 locomotives.

The livery of these machines was black and the marking was made by means of rectangular plates placed:

• on the water crates for the company's registration and initials,
• on the smoke box door for registration.
• And oval builder's plates attached:
• on the cab between the access door and the rear of the machine for the 409-410 series.
• on the lower front part of the shelter for the 411-414 series.
• In addition, the rear cross member was marked with the same markings as the 401-408 series.

Delivery and assignments of the 409-414 series of the M.C.A.S.

Machines 409 and 410 were delivered on May 20, 1927 at La Voulte-sur-Rhône and made their test run between Le Cheylard and Saint-Agrève, then assigned to the Le Cheylard depot. As soon as machines 411-414 arrived, they were transferred to the Florac depot where they were incorporated on :

• on July 6, 1932 for the 409
• on September 12, 1932 for the 410.

They did not reach their original home base until 1 July 1942 for the 409 and 5 July 1945 for the 410.

The 409 was parked in February 1948 and the 410 in November 1950, their fireplaces being worn out. Made available by the closure of the section of La Voûte-sur-Loire in Raucoules-Brossettes, they waited for a possible buyer until 1964, when they were decommissioned.

Machines 411 and 414 were received at La Voulte-sur-Rhône in April 1932 and sent to Le Cheylard for tune-up. They were tested on the Le Cheylard section at Saint-Agrève on May 11 and 18, 1932. Attached to the Le Cheylard depot, they were used regularly until 1947.

At that time the 411 was parked for hearth wear and was reformed in 1953.

The 412 was parked in April 1951. It became available in 1949, following the closure of the La Voûte-sur-Loire line, and was not refurbished until 1964.

The 413 and 414 were also parked respectively in 1952 and 1949 in good condition, then used sporadically until 1953. At that time, they were sent to Raucoules-Brossettes station to await depreciation. Happier than their sisters, they were recovered by the Chemin de Fer Touristique du Vivarais and restored to working order. They still run on this line today.

source : MTVS 1989-1