241P 17

241P 17 was the locomotive most people traveling on 'Le Mistral' had come for. Having returned to service in 2006 this was the first foreign charter the locomotive had been booked for - quite a coup for Mike Hedderly. The tour would take the loco to parts of France synonymous with the class but which none had visited for a very long time. No.17 is the only one of its class in working order and the first to run since the early 1970s. Being the last express passenger locomotive type built for SNCF they are something special.

241P 17 at Le Creusot, being prepared for 'Le Mistral'.

The history of the class is embroiled in politics and what would appear to be professional jealousy. The truth, as I see it, is that the class should never have been built. The SNCF already had something better available - the Chapelon 240P, a 4 cylinder compound 4-8-0. This type held a number of performance records which still stand to this day. André Chapelon, the world renowned locomotive engineer of the Paris Orleans Railway (PO), had started his career on the Paris Lyon Mediterranean Railway (PLM) but left in disgust. The engineers in charge refused to listen to his scientifically based arguments and proposals to significantly improve the power and efficiency of their steam locomotives. It would appear to have been a case of those at the top of tree not wishing to be shown up by the young upstart. Chapelon made no secret of his feelings to the PLM people, perhaps his biggest mistake?

Chapelon moved from the PLM to the PO, a railway much more receptive to his ideas. This is not the place to give a biography of him or his work but his success was so great that he was initially disbelieved but then feted as people began to understand what he had achieved and how simple to achieve it was. Pacifics across France were rebuilt with his guidance, perhaps most notably on the Nord Railway. On the PO in addition to the improved Pacifics some were rebuilt as 4-8-0s. The 240.700 type, whilst mechanically under-engineered, were able to sustain over 3030dbhp. These locomotives, perhaps more than any others, really got peoples' attention. Their success lead directly to the rebuilding of further Pacifics as 4-8-0s, but of an improved type. Learning from the weaknesses of the first batch Chapelon and his team designed the 240P type for the SNCF - the railways of France having been "nationalised" around this time. The 240Ps were primarily operated on the hilly section of the PLM mainline in the Laroche and Dijon areas. On test they were able to sustain 3600dbhp, just the sort of output required on the long gradients and hefty trains. The 240Ps out-performed the PLM 4-8-2s with ease.

Post WWII the SNCF were looking for new express passenger locomotives, mainly for the former PLM mainline, but also for other sectors of the network. The requirement was for a locomotive to be able to sustain 2500dbhp and haul 800 ton trains on the level at 120kph (75mph). Given the performance of the 240Ps - which were able to take such trains up 1 in 125 gradients at close to 120kph - common sense would have suggested they build a new batch to meet the requirements from the existing design and with guaranteed results. But no! Former PLM engineers were in the ascendancy at SNCF. They used this power to promote an enhanced version of a former PLM type, the 241C - a machine less powerful and efficient than the smaller Chapelon 231E Pacifics...... The engineers in charge did not want any involvement from Chapelon in the new design! Thus the 241P came into being. However, fortunately for SNCF, Schneider of Le Creusot, contracted to design and build the machines, were in touch with Chapelon so he was able to rescue the design, within reason, from being an embarrassment.

241P 17 at Valence, heading north.

Construction of the 241P fleet began in May 1946 with the first locomotive entering traffic in 1948. 241P 17 is recorded as having entered traffic on 10 May 1950 allocated to Lyon Mouche depot. It was withdrawn on 14 May 1971 from Le Mans depot. In its career No.17 became the highest mileage member of the fleet covering 1.741,865km (1,082,395 miles).

The 241P type is a 4 cylinder compound. The high pressure cylinders are mounted between the frames, but unusually, are set back being situated between the first and second driving wheels. The crank axle is the third driven axle. The steam feed from the superheater header in the smokebox back to the cylinders can be seen on either side of the front portion of the boiler. The exhaust steam from these cylinders is fed in a large pipe between the frames to the steam chests for the low pressure cylinders mounted on the outside of the frames. From these the steam is exhausted to atmosphere via a double PLM type exhaust of the same type used on 241C1. The nozzle tip area was 203cm².

The large boiler incorporates a combustion chamber and round top firebox with the combustion arch sitting on arch tubes. It is rated at the normal French pressure of 294psi (20bar). The French had long realised that higher pressure and thus higher steam temperatures had a thermodynamic (efficiency) benefit. Coupled to the correct water treatment regime and good thermo-mechanical boiler design these pressures did not mean notably higher boiler maintenance costs. In addition to high steam pressure generous superheating was provided, again for reasons of efficiency. Elements of the Houlet type were used. The gauge frames, two fitted, were of the reflex type.

Following on from the 240Ps, 141Rs, 141Ps, 150Ps and the various De Caso 4-6-4s the 241Ps were fitted with a mechanical stoker of the HT1 type. The stoker motor was fitted to the tender. Naturally a rocking grate was fitted with the firebars being the Hulson type.

The ashpan was split into three parts - one between the frames and one part either side of the frames. All sections of the ashpan were of the hopper type.

As would be expected of top-link French motive power the ACFI type of open feedwater heating system was fitted along with the associated cold and hot water pumps, another system with proven efficiency benefits. When the locomotive was not powering the boiler could be filled with a non-lifting injector of the U1 type.

When built the 241Ps were fitted with a screw reverser. However, in the early 1960s power reverser's from withdrawn 141Rs were fitted to the fleet, probably a very popular move with drivers. Being based in a PLM type the 241Ps adopted the Von Borries approach to compounding with one throttle valve and one reverser for both the high and low pressure engines linked in a fixed ratio. The Chapelon system incorporated two throttles and two independent reversers - something of an over complication!

Under Chapelon's direction the steam circuit was considerably enlarged with special attention being paid to port openings in the cylinders to ensure minimal pressure drop. More than anything it was this work which "saved" the 241Ps.

Mechanically the design was improved over the 241C with more substantial bearings and frames. However traffic experience showed, as with the 240.700 type, that the mechanics were not quite up to the job with hot axleboxes occurring on a semi-regular basis.

The air brake pump was of the cross-compound type, then standard for French steam locomotives. For lighting a 24V, 500W turbo generator was fitted on the fireman's side running plate.

Unfortunately little effort was made to conceal the many items of kit attached to the class so, to British eyes, the locos have a somewhat messy appearance not helped by the height variations in the running board, but make no mistake the locos are very impressive and imposing machines.

In service the 241Ps were able to sustain in the region of 2900dbhp and produce a peak cylinder power of about 4000hp.

After withdrawal from service 241P 17 was moved to Le Creusot where, for many years, it was stored out of public view. Restoration began in 1993 and was completed in 2006. Following some test running the locomotive returned to service in September 2006.

241P 17 is looked after by Chemin de Fer du Creusot, based in Le Creusot. The official website for the locomotive is http://www.241p17.com

What does 241P 17 sound like? In truth at most times it is virtually silent. But occasionally there is some noise. These audio files, taken from video recorded on 'Le Mistral' will give some impression. All recordings are in MP3 format.

The following books are recommended as further reading on the 241Ps and the story around these machines. The final two are in French:

'La Locomotive à Vapeur' by André Chapelon	'Compound Locomotives' by J.T. van Riemsdijk	'Chapelon - Genius of French Steam' by Col. H.C.B. Rogers	'Les Locomotives à Vapeur Unifiées 241P, 240P, 150P' by Bernard Collardey & André Rasserie	'La Locomotive à Vapeur 241 P 16' by Phillippe Mirville & Jean-Marc Combe

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