André Chapelon, always under heavy , updated march 13, 2021
 

André Chapelon. October 26th, 1892 - july (22nd?), 1978.  He was nicknamed "Le petit" - "Shorty" - by colleagues and friends.

J.T. Van Riemsdijk & K. Brown, "The pictorial history of steam power", "Steam on the railways" chapter, Octopus Books, London 1980 and Gallery Press, 1984. Retranslated from a french edition.
 

PLEASE NOTE: Every paragraph will become a link to a specific page in a (more or less) close future... These are only short introductions. More hours per day, please! Come back from time to time, I sometimes add a few details here.

Biography:

• Born October 26th, 1892 in Saint-Paul en Cornillon, Loire. He was the great-grand son of a man named James JACKSON from Sheffield, Great Britain, one of the numerous English "forge masters" that came in France from the 17th. century to teach new steel production methods. James Jackson arrived in France in 1812 (precision given by a member of the Chapelon family).

His first creation: The KYLCHAP exhaust system, one of the first examples of high efficiency "fluid engine"
 

What was exactly his contribution and theories to compound locomotives design: Mainly the to relegate of rule-of-thumb and voodoo-inspired theories and design rules to the "cul de basse-fosse", deep holes were thrown and forgotten alive persons in ultimo punishment some centuries ago, in favour of the real scientific knowledge of his time and by a systematic checking of theories by the use of extensive tests of engines in real conditions and with the help of correctly used modern metering equipment such as, for example, high speed stroboscopic cameras he used to study steam flowing. Details and more by clicking HERE someday may be

His compound locomotives:

• 4 6 2  P.O.'s 3566 transmutation (1929).

Three series of PACIFICS resulting of the 3566 prototype (1929-35).

The 4 6 2 P.O.'s 4521 turned into the 4 8 0 P.O.'s 4701,  most powerful locomotive of any kind (electric, diesel, ...) in europe at that time (1931) with 4 200 H.P..

Two series of 4 8 0 resulting from the prototype, first in 1932, second in 1940, the latest being quite modernized with an improved power output of 4 700 H.P..

2 12 0 prototype, 6 cylinders compound (2 H.P., 4 L.P.) with re-superheating between H.P. and L.P. cylinders, steam envelopes (around cylinders, forgive this precision if you know a bit about physics, mechanic of fluids or 100 000 H.P. boats' steam engines) and other features unusual in the world of locomotives. The most innovative steam locomotive based on the classical Stephenson's concept (no turbine, no super high boiler pressure or other gimmick inapplicable to a locomotive).Once completed, extensive test started in the beginning of 1946. Those tests were acknowledged by railroad's international community as the most extensive and complete ever done on a locomotive, and allowed the discovery of absolutely virgins fields of experiments. Lessons gained here opened a really new and refreshing track that nobody has used yet. Measured normal tractive effort: 83700 lbs. Chapelon had computed that if applied to the 4 4 6 4 Q 2 of the Pennsylvania R.R., efficiency figures obtained with the solutions used on 160 A 1 would raise the power output of the P.R.R. engine up to 18.000 H.P.and give an equivalent (in percent) increase of tractive effort.

His last normal gauge locomotive: The 4 8 4 A 1, 3 cylinders prototype, pre-WWII project also completed in 1946, again the most powerful european locomotive at that time (50's), 5,300 H.P., mean tractive effort of 46,255 lbs..

Very innovative work on single expansion engines too:
 

• The 141 E 113 MIKADO of 1945, Chapelon's brilliant answer (hardly snatched to his hierarchy) to the insult made to his talent and over 20 years of constant successes by the order of 1,300 all purpose MIKADOS, named here "141 R",  issued by newly created, government-managed railroad company S.N.C.F. to ALCO, BALDWIN and LIMA (lend lease I believe), an engine incredibly hidden by S.N.C.F. management.

 
• Improvements to the 141 R American MIKADOS.

 
• The 2 8 0 140 J 153 transformation, or how a not so good type of 35 years old single expansion engine can be turned for a very few money into something as reliable, as powerful, faster, 40% lighter and burning 30% less coal (data collected after years of service) than the brand news American MIKADOS mentioned above, and staying a S.E. engine. His last work for the S.N.C.F., sad "Bye bye, stupids!" from a real genius to the fully sclerosed technocrats managing our brand new financial abyss, the S.N.C.F.. Having read what was on hand in France and on the web about Whardale's "Red Devil", I think I can write that the Chapelonized Consolidation J 153 is her biological mother.

 

• 2-8-4 with a load of 9.84 tons per driving axle
• 4-8-4 with a load of  12.8 tons per driving axle

• 2 10 4 for freight trains
• High speed (125 mph) 4 6 4
• Very high speed (155 mph) 4 6 0
• 2 8 4
• 4 8 4
• 4 6 4 tank engine for fast suburbs and short distance services, designed to be driven by a single man (oil fired).

• 141 P serie, all purpose 4 cylinders compound Mikados
• 241 P serie, 4 cylinders compound for express passenger and fast freight trains 4 8 2

An invention curiously unrecognized made by an assistant of Chapelon: The Willoteaux's piston valve, used on the 242 A 1, 141 E 113, and a on a great number of machines designed by other french engineers. Its major advantages if it is compared to a Trick piston valve are that it twices flow sections for bot inlet and exhaust, another being its lightness. If you know application of those in other countries, please send me some infos.

Il y en a d'autres!

Applications of Chapelon's theories and creations to other french railroad companies' locomotives:

International opinions about the work of André Chapelon, some texts also containing interrogations and RIGHT answers about the evident negation of this work made by nationalized railroads management against unanimous technical staff opinion leading to premature withdraw of most then to the total destruction of Chapelon's highly subversive engines. Straight hooliganism
 

I think only some engineers and scientists around the world can figure out to how much non scientific or technical but administrative, hierarchical and thus human difficulties Chapelon was faced to all along his career. It's not only my opinion, it's shared here and elsewhere by everyone knowing the topic and seems thus reach the status of Historical truth. Unfortunately, it seems to be a constant of the life of engineers and researchers in France still today (3000 engineers left France for foreign countries in 1996, an official figure in constant and regular increase)

Bibliographie:

• La locomotive à vapeur, by A. Chapelon, Baillère editor Paris, 1938 and 1952 editions. LE livre
  
  
• La locomotive compound: Son état actuel, son avenir, par A. Chapelon, publié par le magazine Science et industrie d'aout 1933 à janvier 1934

• La machine locomotive Mobilitate viget viresque acquirit eundo, par E. Sauvage et A. Chapelon, Librairie polytechnique Ch. Béranger, 1947
  
  
• Les locomotives à vapeur françaises à grande vitesse et à grande puissance du type PACIFIC, by L.M. Vilain (a rare enthusiastic and competent author on the topic as well as an excellent photograph, this man spent most of his life standing along railroad tracks just to give us wonderful pics.), preface by André Chapelon, VIGOT FRERES editor, 1959
  
  
• Les PACIFICS du P.O.- MIDI et l'oeuvre d'André Chapelon au réseau d'Orléans, by M. Maillet, EDITIONS DU CABRI editor 1980
  
  
• L'oeuvre d'André Chapelon à la S.N.C.F. et son influence mondiale, même auteur et editeur
  
  
• Divers numéros du défunt "Rail Magazine"

MANY MORE bibliography to come! I.S.B.N. codes available (when it exists!) on request.