FRENCH COMPOUND LOCOMOTIVES' HOMEPAGE

Technical data page 2

Second series of 4 8 0(240 P 1 to 240 P 25)

Evolution of his first 480, those were in fact deeply redesigned (not only aesthetically) to incorporate the latest work of Chapelon on thermodynamics and using his full mathematical engine modelling method. They also used "refinements" unusual here such as mechanical firing, even roller bearings on driving axles, driving and coupling cranks on some units (Union Pacific type coupling rods).
 

• Boiler: Identical to the ones used on 4701-4721. Click here for a quick jump to it. Mechanical firing, Stoker, HT1 type.
• 
   
• Cylinders:
• • High pressure (H.P.): Two external, 420 mm (16.53'') bore, 650 mm (25.6'') stroke, driving the second pair of wheels;
  • Low pressure (L.P.): Two internal, 640 mm (25.1'') bore, 690 mm (27.16'') stroke, driving the first pair of wheels;
  • As always, high volume steam chests.
  • 
     

     

    Note the increase in L.P. cylinders capacity, reveals the refinement of some Chapelon's modelling equations since the building of his first PACIFICS.
     

• Valve gear: As on PACIFICS again. Two independent (i.e. 1 for H.P. group, 1 for L.P. group) classical Walschaerts mechanisms with separately-driven reversing screws, driving oscillating camshafts actuating dual seat valves. Again, if you haven't read it yet, short note about separate valve gears.Valves diameters:
• • H.P. cylinders inlet valves diameter: 7.87'' (200mm.).
  • H.P. cylinders exhaust valves diameter: 8.26'' (210mm.).
  • L.P. cylinders inlet valves diameter: 10.43'' (265mm).
  • L.P. cylinders exhaust valves diameter: 10.82'' (275mm).
  • 
     

     

    Same remark as for the L.P. cylinders capacity...
     

• Steam circuit: Identical to P.O. 3701-3721 but regulator flow section increased to 275 cm² (42.62 sq. in.), also incorporating steam flow directing fins in piping and casts tracts.
• 
   
• Chassis: 32mm. (1.35") thick steel frames assembled by cast iron horizontal and vertical spacers, and by L.P. cylinders unit.
• 
   

• Wheels diameters:
• • Truck: 0.96 m (3.14 ft.).
  • Driving: 6.06 ft (1.85 meter).
  • 
     
• Weights:
• • Working order: 111.22 tons.
  • 
     
• Overall dimensions:
• • Length: 42.65 ft..
  • Height: 13.9 ft.
  • 
     
• Performances:
• • Power output: 4700 HP
  • Consumption:
  • • Coal: 1.05 kg. (2.3 lbs.) per H.P. per hour
    • Water:
  • Tractive effort: 57409 lbs. ("Starting" mode, semi-single expansion mode specific to Du Bousquet - De Glehn architecture), 45771 lbs. in normal compound mode.
  • Test trains reports: To come...
  • 
     
• Other details:

The 160 A 1, 6 cylinders 2 12 0 prototype
 

• General info.: The design goal fixed with the 160 A 1 was to obtain huge steam expansion at low speed in the best economical condition, as it was intended for heavy freight trains hauling on the mountainous roads operated by the P.O. railroad in the massif central where impressive hill climbs can be found. Chapelon thus decided to use a dual superheating system, using Houlet units for H.P. steam superheating and a 4 elements type A Schmidt unit piped in a 2 serial / parallel configuration instead of being in the usual 4 in series config. in order to improve steam flowing for L.P. steam (re)superheating .
• 
   

   

  In order to minimize losses due to cold wall effect, all the 6 cylinders are fitted with steam envelopes traverse by inlet steam before entering the cylinders.

  Again, as the goal was to obtain maximum efficiency and economy at low speed, the dimensions to give to L.P. cylinders imposed their break-down into four units (apparently only, as Chapelon later found it was not an absolute necessity with lessons gained by tests of 160 A 1 and 242 A 1, resulting in a suggested ideal four cylinders, triple expansion configuration where 1 H.P., 1 M.P. and 2 L.P. would be used fed by a 40 kg. per sq. cm. or 572 P.S.I. combustion chamber fitted Franco-Crosti boiler. Entropy diagrams of such an engine applied to the grate and other general dimensions of Chapelon's 242 A 1 showed a 40% increase in power output and a gain of 55% of overall efficiency, the 242 A 1 surpassing in these conditions the power to weight ratio of any ACTUAL electric engine!! Using a shared barrel boiler as the one designed for 160 A 1, the power gain would be the same, but efficiency gain reduced to 45% - not so bad -. Will develop in another chapter. But, as Chapelon added ironically himself "... the worse should be to find a backward enough railroad to try it!"). Built as a unique prototype, and to try to give an idea of French craftsmen's skill, the 1 piece 4 L.P. cyl. unit was not a cast but a welded item (visible on a picture of the building of this engine).

  Other remarkable construction practice are for example the dynamic balancing (respect to connecting rods) rods of a very unusual shape used to drive the "combination lever" of the classical Walschaerts gear, a system used on one other type of locomotive in France, I give an example of this first application known here in the picture gallery (2 8 2 tank engines for fast suburbs work designed in 1932), don't know for others countries. Please, feed me back with infos if you know other applications of this trick.
   

• Boiler: Of a simple but unusual design.
• 
  Belpaire firebox. Grid surface 4.4 sq. meters or 47.3 sq. ft..
  Length between plates: 5.70 meters or 18 ft. 8.26''.
  Barrel shared in two parts by an intermediate tubes plate. The front one is smallest, with a length of 2 meters or 6 ft. 6.7'' and is set up as a pre-heater compartment in which is injected the water supplied as usual on "modern" French engines and already described for other engines or: 1 A.C.F.I. feedwater heater and pump used when the temperature of water in the tender is too high to allow injector priming, 1 main injector feeding the A.C.F.I. unit, 1 aux. injector supplying "cold" water.
   
  • Heating surface: 250.54 sq. m. or 2693 sq. ft..
  • Superheating (H.P. steam): 72.10 sq. m. or 775 sq. ft..
  • Resuperheating (L.P. steam): 110.61 sq. m. or1189 sq. ft..
  • 
     
• Cylinders:
• • High pressure (H.P.): Two internal, 520 mm (20.47'') bore, 540 mm (21.25'') stroke, driving the fourth pair of wheels;
  • Low pressure (L.P.): Two internal of 520 mm (20.47'') bore and 540 mm (21.25'') stroke, driving the second axle and two external, 640 mm (25.1'') bore, 650 mm (25.59'') stroke driving the third pair of wheels.
  • As always, high volume steam chests.
  • 
     
• Valve gear: Two independent (i.e. 1 for H.P. group, 1 for L.P. group but here, movement of the external L.P. cylinders camshafts are derived to drive internal L.P. camshafts) classical Walschaerts mechanisms with separately-driven reversing screws, driving oscillating camshafts actuating dual seat valves. Valves diameters:
• • H.P. cylinders inlet valves diameter: '' (mm.). Sorry! Figures to come.
  • H.P. cylinders exhaust valves diameter: '' (mm.).
  • L.P. cylinders inlet valves diameter: '' (mm). Infos about Chapelon's engines
  • L.P. cylinders exhaust valves diameter: '' (mm). very scattered even here!
  • 
     
• Engine timing: Angle between H.P. cylinders cranks is 90°, the R.H one forming a 131° with the external (L.P.) crank located on the same side of the engine. Internal L.P. group cranks are opposed (180° angle) and their corresponding external ones at 120°, arrangement giving 6 regularly spaced torque pulses per driving wheel turn.
• Steam circuit:
• Chassis: Again of typical "old continent fashion" type, 60mm. (2.36") thick steel frames assembled by cast iron horizontal and vertical spacers, and by L.P. cylinders unit.
• 
   
• Wheels diameters:
• • Bissel: 2.81 ft. or 0.86 meter.
  • Driving: 4.59 ft. or 1.40 meter.
  • 
     

  Weights:

  • Working order: 134.93 tons.
  • 
     
• Overall dimensions:
• • Length:
  • Height:
  • 
     
• Performances:
  
  • Power output: 2,750 H.P.
    
  • Measured normal tractive effort: 83700 lbs. in compound mode.
    
  • Consumption:
    
    • Coal: 0.850kg (1.87 pound) per H.P. per hour.
    • Water: 8.5 kg (18.72 pounds) per H.P. per hour.
      
      Average values gained at end of the test period of 6 years.
       
• Other details: The usual compound starting devices are absent on this engine as it was easily started using only the large capacity 4 cylinders L.P. group functioning in S.E. mode for a few turns of wheels. For example, it easily picked off a 1,629 tons train in a 0.8% hill (tractive effort corresponding to the maximum load allowed on coupling links in France).

To load a 2580 X 780 version of  this drawing, click on it. (.gif file, 84K)

242 A 1, three cylinders 4 8 4

• Boiler: 

  The firebox uses a rectangular grate overhanging chassis frames, and is fitted with a combustion chamber and two Nicholson's siphons.

  Grate surface (HULSON type): 5 sq. meters or 53.75 sq. ft.. Details (sketches & photos) about Hulson grates here

  Barrel diameter: 1.92 meters or 6 ft. 3.54''.

  Length between tubes plates: 5.37 meters or 17 ft. 7.28''.

  • Total heating surfaces: 252.7 sq. meters or 2716 sq. ft..
    
  • Superheater surface (Houlet type): 120.22 sq. meters or 1292 sq. ft..
    
  • Unique application of a triple KylChap 1K/1C type exhaust system.
    
  • Pressure: 20 kg/cm² or 286 P.S.I..
    
  • Mechanical firing, Stoker.
    
  • A.C.F.I. feedwater heater & pump + injectors system already described as the French modern standard water supply system.
    
     
• Cylinders:
  
  • 1 H.P. internal, 600mm. or 23.62'' bore x 720mm. or 28.35'' stroke.
  • 2 L.P. external, 680mm. or 26.77'' bore x 760mm. or 29.92'' stroke.
    
     
• Valve gear: If you've read the previous descriptions, you won't be surprised by the fact that here again, two independent, 1 for H.P. group & 1 for L.P. group almost classical Walschaerts mechanisms using separately-driven reversing screws are used. Chapelon used a second counter-crank fitted on the coupling rod crank of the third L.H. driving wheel to drive the H.P. (internal) otherwise classical Walschaerts' gear (clearly visible on pics). Again, if you haven't read it yet, short note about separate valve gears. But as Chapelon was asked by S.N.C.F. management to avoid the use of oscillating camshafts and dual seat valves each time it was possible without too much sacrifice to efficiency, this because most of the maintenance people of the formerly private companies which were united under the S.N.C.F. banner (P.O., Etat and Nord excepted) were not trained to repair and adjust them (it was absolutely not due to the cost of the system. On the contrary, those proven to be far more reliable and economical on use than classical cylindrical slide valves) and as the very efficient Willoteaux' slide valve was born, ...:
  
   
  • H.P.: Two 7.87" x 7.48" Trick's slide valves (no mistake, 1 cylinder, 2 piston valves).
  • L.P.: One 15" x 5.90" Willoteaux' slide valve per cylinder.
    
     
• Engine timing is: 90° angle between L.P. cranks; H.P. 135°, thus located on the extension of the bissectrix of the 90° angle between L.P. cranks.
  
   
• Other details: Here again, usual Du Bousquet - De Glehn starting devices are absent. An original system was used, where the machine could be run in different modes as follow:
  
  • Opening the L.P. regulator both let flow superheated steam to the intermediate receiver - "réservoir intermédiaire, thanks " (steam pressure in it is limited to 14 kg per sq. cm. or 200 P.S.I at this moment) and actuates a pressure reducer which admits steam to the H.P. cylinder at a pressure linked to the one applied to the L.P. cylinders (i.e. always higher in the H.P.). This way, the engine starts as a single expansion machine formed by the two L.P. cylinders helped and partially fed by the H.P. cylinder functioning under the difference (fixed by the pressure reducer) of pressure between its steam chest and the one in the intermediate receiver. At a speed of about 15 mph, the L.P. regulator is closed, the H.P. (see note about it in the paragraph below) regulator being fully opened and the engine enters naturally full compound mode.
    
  • Opening only the H.P. regulator - which is also the only one used when any French compound hauls a train (and Chapelon would add :"To be fully opened or fully closed, any other position leads to high efficiency losses.", I think people with minimum knowledge in physics can understand this very important remark), remember, these L.P. regulators are only parts of the starting system - actuates again another pressure reducer which lets superheated steam reach the intermediate receiver at a pressure always a fixed fraction - half or quarter - of the pressure in the H.P. steam chest; Again at about 15 mph, this pressure reducer closes automatically and the engine become compound. Intended at first as a simplifying device to move the machine alone, it proven to be so efficient that it was used in most cases, even with good loads. It was only when great starting efforts where required (trains of 1000 tons and more) that the "normal" starting system of the first paragraph was used.
    
     
• Chassis: Always the old continent fashionned old thing.
   

• Wheels diameters:
  
  • Front truck: 3.18 ft. (.97 meter)
  • Rear truck, delta type: front 3.18 ft., rear 3.6 ft..
  • Driving wheels: 1.95 m (6.40 ft);
    
     

  Weights:

  • Driving axles load: 20.66 tons per axle.
  • Working order: 145.6 tons.
    
     
• Overall dimensions:
  
  • Length: 17.79 meters or 58.32 ft.
  • Height:
    
     
• Performances:
  
  • Power output: 5,300 H.P..
  • Measured normal tractive effort: 46,255 lbs.
  • Consumption:
    
    • Coal: 0.850kg (1.87 pound) per H.P. per hour.
      
    • Water:
      
      • 8.90 litres or 18.81 U.S. pints per HP per hour at 1,500 H.P..
      • 6.45 litres or 13.63 U.S. pints per HP per hour at 3,000 H.P..

To load a 1800 X 2329 version of  this drawing, click on it. (.gif file, 135K)

2196 X 880 version of  this drawing of a Willoteaux' slide valve. (.gif file, 44K)

141 E 113 MIKADO, first two cylinders single expansion Chapelon engine. Many diagrams used here are extracts of: "La Revue Générale des Chemins de Fer" also called R.G.C.F., november 1949.

Iindicator diagrams of the original machine Chapelon used as a basis and those of E113, I think they are significant. Also included on the graph is the "ideal diagram" of the engine. Full english legend on the large version!- I didn't mentionned before that EVERY locomotive Chapelon has been "allowed" to build used wheels and chassis parts scrapped from other engines, the only exceptions to this rule being 35 new PACIFICS (there were not enough "scrap" to satisfy orders!!) build for "La compagnie du Nord" and the narrow gauge locomotives for South America.
 

• Boiler: Belpaire firebox, trapezoidal grate: 3.87sq. meter or 41,38 sq. ft.; 

  Internal boiler diameter: 1.685 m. or 5.52 ft.
  Length between tubes plates:  5.8 m. or 19 ft.
  Total heating & superheating surfaces: 271.35 sq. m. or 2916 sq. ft.

  • Firebox: 15.1 sq. m.;
  • Smoketubes: 192.25 sq. m.; Decreased of 9% on E 113 due to the modifications to superheater.
  • Superheater: Schmidt 24 elements, 64 sq. m. on original; Houlet 28 elements 83 sq. m. on Chapelon's E 113.
  • Pressure 14 kg/cm²; or 200 P.S.I. (unchanged)
  • KylChap exhaust, single 1K/1C type;
    
     
• Steam circuit: Here is a table detailing the modifications and their effects on flowing sections.

Diagram of ports opening - Original vs. Chapelon

As usual, click on the thing for a large version.

Power curves measured on the dyno of Vitry sur Seine for various gears.

Compared coal and water consumptions: Standard 141 C serie engine Vs. Chapelon's 141 E 113

• Cylinders: Two 24.409'' (620 mm) bore, 27.55'' (700 mm) stroke.
  
• Valve gear: Standard Walschaert, but using a device increasing Willoteaux slides travel called "amplifying lever", mandatory to take full advantage of the wide ports used, device designed for this Mikado by Mr. Gautret, chief of "Equipement and Hauling" (in french: Matériel et Traction, or M.T.) service in the Ouest area.  This increased valve travel of 75% and ports opening and closing speed of about 50%. Sketch of it below:

• Valve gear continued: Despite being larger than the pistons valves used on standard 141 C, the Wiloteaux units weight 147.5 lbs. (67 kg.)  only instead of the 255.5 lbs. (116 kg.) displayed by the normal item, thanks to its smart design. This lowered efforts on the driving mechanism (otherwise increased by the "amplifying lever"). Ports were of trapezoidal shape to achieve progressive opening and avoid pieces of coal to be picked off the surface of fire by heavy suction from the blasting (exhaust?) device.
• Sketch of ports: 

To be continued...

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