FINDING ANOTHER WAY : THE QUEST FOR POWER

PENNSYLVAIA RAILROAD CLASS T 1

We Have seen how an Australian Railway went about it http://butnought.blogspot.com/2020/07/conjugating.html and then how British and French Railways went about it http://butnought.blogspot.com/2020/07/the-friendship-of-giants.html, but we should not overlook that remarkable world of practice which is American Railroading in its heyday.

Just as Australian, British and French Railways experienced the demands of heavier trains and the need for greater speed, the Americans did so too, only more so in some ways.

American Railroads were of course not Government-owned. They were all companies and often direct competitors. They were blessed with historically larger loading gauges and frequently heavier built permanent ways.In many cases the density of population made possible things that could not even be dreamed of in Australia for example.

One of the outstanding Railway companies in the United States was the Pennsylvania Railroad whose famed symbol was the red Keystone which was emblazoned an all its locomotives. It had a proud tradition of extraordinarily successful locomotive design. This went back to the turn of the Century. 

The peak of development as the American Railroads came out of the early and the Civil War periods was the Atlantic type (4-4-2) Steam Locos. With their large driving wheels and ample fireboxes, they had boilers which could and did sustain very fast and relatively heavy passenger trains which grew in popularity. This growth, this success, led to the demand for more and heavier trains and thus double-heading became necessary. But this is always uneconomical given the doubling of crew sizes and it involves more complex practical arrangements. The requirement led to one of the greatest success stories of American railroading: the P.R.R. K4s Pacifics(4-6-2). It has been said that, at least at that time, steam locomotive design was more of an art than a science. Whatever the truth of that saying, the K4s were certainly masterworks! 

PENNSYLVANIA R.R. Pacific K 4  

(N.B. The red Keystone emblazoned on the Smokebox door.)

                                                                                                                                                                          No less than 425 of these splendid locomotives entered service between 1914 and 1928. They became, via the movies, the "face" of American railroading. They were still active until 1957 when steam operation on the PRR ceased. Two of them, nos.1361 and 3750 are preserved. By the time the 1930s arrived, trains had become so long and heavy that on occasions even K4s had to be double and even triple-headed. Clearly more powerful locomotives were required. The PRR was not shy about experimentation and, at the New York World's Fair in 1940 it had exhibited a streamlined duplex, 6-4-4-6 locomotive. This was, in operation, less than successful, and the T 1 design 4-4-4-4 shown at the beginning of this post was developed and brought into service. In 1942 two prototypes of these duplex locomotives were built and in 1946 the class of 50 in production began to come into service.They were remarkable locomotives generating 6,500 h.p. and a tractive effort of 64,653 lbs, and easily exceeding 100 mph. But times were a-changing and they were all withdrawn in 1952-3 and replaced by diesel locomotives in that era of cheap oil fuel. They were not without their operating problems notably slipping of the driving wheels.This has been traced to problems in balancing the springs and to lack of adequate driver training.

Passenger traffic was not the only pre-occupation of the PRR. Their freight services were also in need of greater power, and in 1944 they began taking delivery of the highly-successful Q2 Duplex  4-4-6-4 locomotives. Producing no less than 7,987 h.p. and 100,816 lbs.of tractive effort they were splendidly successful. Nevertheless, the economies of diesel operation in that low-cost fuel era, meant that all Q2s were withdrawn in 1951.

                                                    PENNSYLVANIA R.R. Q 2 Class

                                                                                                                                                                       Though both claimed a pre-eminent position in the market, the PRR had long kept a steady eye on the New York Central Railroad, which had the distinction of operating the Twentieth Century Limited which was the country's best-known train and famous throughout the world. It's distinctively streamlined locomotives by Dreyfuss were striking. it operated between Chicago and New York - a distance of 958 miles at an average speed of 60 mph. The train was so popular that, at its peak, it ran in seven divisions. Mail carried by the  train bore a distinctive stamp impression.

                                                                                                                                                                                                            The TWENTIETH CENTURY LIMITED                                                                                                                                                                                                                                                                                                                                                                                             

                                                        New York Central Hudson 4-6-4

                                                         without the above streamlining.                                                                                                                                                                                                                                                                                                                                                                                           The Hudsons employed on the Twentieth Century Limited were said to be poor performers at low speed but superbly capable at high speed. All were withdrawn in the dieselisation rush and not one was preserved. In a particularly vindictive mode, the same was done to all PRR locomotives, the two Railroads having been amalgamated and the diesel obsessed management wanting no association with steam. The famed Twentieth Century Limited had been dieselised in 1945.

But the pinnacle of steam locomotive design on the New York Central was to be the "NIAGARA" Class of 4-8-4 locomotives Which were extraordinary in performance. They were designed to operate 6 days out of 7 without service and even then the service was carried out in the most exceptional manner in specialised facilities by men in some instances in asbestos padded suits cleaning the still hot fireboxes from the inside so that the locomotives almost never cooled off. The locomotives developed an exceptional 6,700 h.p. and a 61,568 lbs Tractive Effort. There were 27 in the Class and the last was decommissioned in 1956 - not one was preserved.

                                        NIAGARA CLASS LOCOMOTIVES 4-8-4

The same issues in locomotive design were addressed by the Norfolk & Western Railroad with particularly happy results. The company was heavily involved in the coal industry and was the last of the American railroads to succumb to the pressure to dieselise. In 1941 it introduced its streamlined J Class 4-8-4 s. These remarkable locomotives featured rather small driving wheels at 70 inches diameter (e.g. the NYC Hudsons were 79 inches and the PRR T1 was 80 inches..)

Nevertheless, they were no slouches when it came to speed and were capable of 111 mph. They were very powerful delivering 5,300 h.p. and a tractive effort of 

  84,981 lbs. There were 14 in the Class but only one is preserved, the famous 611. In their day they hauled the well-known trains in their region the "POWHATAN ARROW" and "POCAHONTAS

.                                 NORFOLK & WESTERN  J CLASS 611     4-8-4                                                                                                                                                                                                                                                                                                                                                                                SUMMARY

There is a lot to be considered in the design and construction of steam locomotives and I have tried here to give a brief sketch showing how the various issues have been addressed by some major operators. I have enjoyed doing it of course as I did in writing earlier http://butnought.blogspot.com/2017/04/horses-for-courses-even-apart-from.htmlI hope that my paltry efforts might move some folk to read further, or at least share in some passing fashion the joy I find in reflecting on the mighty achievements now past.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

THE FRATERNITY OF GIANTS

SIR NIGEL GRESLEY (1876-1941)

We are accustomed to certain concepts of British anti-French prejudice as being as reliable as if cast in steel. These ideas go back even centuries. And the more "Establishment" the British person is, the more lively the prejudice we expect.

Now in the pre-WW II era there was no mechanical engineer in England more celebrated than the great Sir Nigel Gresley. He was the Chief Mechanical Engineer of the London and North Eastern Railway (L.N.E.R.) and designer of many locomotives but of greatest note for his A4 Streamlined Pacifics especially their class member "MALLARD" at the time, the fastest steam locomotive in the world at 126mph, although Sir Nigel Gresley only accepted 125mph!

                                                   L.N.E.R. A 4  MALLARD

But the brotherhood of Mechanical Engineers exceeds the power of national prejudice. There was another, greater Mechanical Engineer in France: Andre Chapelon. Unlike Sir Nigel Gresley, this genius was relatively frustrated by his administrative superiors, and, unable to get approval to build many new locomotives according to his ideas, he had to content himself with re-building existing locomotives. This he did with remarkable brilliance, which was acknowledged by his peers around the world, but treated as an embarrassment by his superiors. Chapelon was among the earliest champions of a scientific approach to the detail of locomotive design and performance, which had up to that time, been largely pragmatic being based on trial and error -  evolution from previous practice.In 1925 Gresley was so impressed by what he read of  Chapelon's work that he went to France to visit him and consult him. When he returned to England he put in hand the experimental fitting of a Chapelon "Kylchap" exhaust system to an existing L.N.E.R. 4-4-0 "Derbyshire". In 1930 Chapelon visited England and rode the footplate of "Derbyshire". Unfortunately, Chapelon's plans had not been well followed and the system did not work as well as it ought. 

This was far from being their only collaboration. The conventional steam locomotive has a "fire tube boiler" that is, it is pierced with tubes which take the heat from the firebox through the surrounding water to the smokebox and exhaust through the chimney. The steam generated gathers atop the boiler in the steam dome and travels from there, via the valves, into the cylinders and then out through the valves to the exhaust, creating a draught which draws the heat from the firebox through the tubes. The faster the locomotive goes, the stronger the draught, the hotter the boiler and the more steam.It is a real demonstration of a virtuous circle. But in the mid-1920s Gresley began to consider the concept of a water tube boiler such as used in marine applications. This would have been the first variation from the essential principles formulated by George Stephenson in his splendid "ROCKET" in 1829. The motivation for considering this radical change was to obtain marked economies in fuel consumption which, in his latest high-speed trains was becoming a serious concern. 

                                                  Andre Chapelon (1892-1978)

Completed at the end of 1929, No.10000, as it was designated, was a 4-6-4 with a water tube boiler operating at 450 lbs psi. It had 6'8" driving wheels. Its unusual appearance gained it the nickname "the galloping sausage" from the engine crews. After running 70,000 miles it was brought into the workshops for a major overhaul. It seems that not a great deal could be said in its favour. Gresley consulted Chapelon whose reputation for improving locomotives was legendary. Chapelon was interested in the challenge. He recommended some highly technical changes related to superheating All of Chapelon's recommendations were followed, but No.10000 never did live up to expectations. In 1937 No.10000 was fitted with a conventional boiler and streamlined in the manner of the A4s.  George Stephenson RULES!

Judging by the photograph - and there are few of them on Google Images - M.Chapelon was not the sort of person to suffer fools gladly. Perhaps this offers a clue as to why his superiors were so determined to frustrate his brilliance.

                                                              S.N.C.F. No. 242. A. 1.

The finest example of Chapelon's genius is shown in the magnificent  SNCF (Societe Nationale Chemin de Fer - the French nationalised Railways) 4-8-4  No. 242.A.1 completed in 1946.It has been described as " the most outstanding steam locomotive that ever ran upon rails".(Col. H.C.B. Rogers O.B.E. in Express Steam Locomotive Development in Great Britain and France p 105) It produced 4,000 h.p. continually at the Tender drawbar at speeds from 50 to 75 mph.Even at low cut-offs it produced 3,800 h.p.

Books aplenty have been written about the achievements of these great locomotives and their designers. How different from our own times, those in the not so distant past, have become.

CONJUGATING

NSW D 57 Class Steam Loco -The Conjugating Gear for the centre valves may be seen below the Smokebox door.

"Conjugated" is not a word that we hear often. This is doubly so in these times, in this post-classical world, because it is a word heavy with Latin association. Literally," it means " joined together with". So, how does it relate to the massive, brooding, almost brutish image above? The clue is right in front of us, right at the front of the locomotive itself. Right there under the "chin" of the smokebox is  "Gresley's conjugating valve gear".

The locomotive shown above is one of the D57 Class freight locomotives of the New South Wales Government Railways. When they were introduced in 1927 they were the only three-cylinder steam locomotives on the N.S.W. Railways. They retained that exclusive status until 1957 when the nearly identical, but strangely less successful D 58 Class came into service. 

Three-cylinder steam locomotives were developed where the outside cylinders and valve gear on either side were complemented by a central third cylinder between the frames and driving a cranked axle, this was most commonly made practical using Gresley's conjugating valve gear. This valve gear drew its action from the outer valve gear via a rod moving on a pivot under the front of the smokebox.

Three-cylinder steam locomotives were already common in British railway practice and had been so for several decades. They were the result of the restrictions of the British loading gauges and the need for greater power to draw heavier and heavier trains at greater and greater speeds.This arose from the intense competition between the various railway companies prior to the disastrous railway nationalisation undertaken by the Socialist Labor government in 1948.

In New South Wales the need for additional power had historically been met by increasing the size of the locomotive - principally its boiler.This process can readily be traced through the development of the C32, C34, C35, C36 classes of passenger locomotives culminating in the C38 Class. In the C38 Class, we see the absolute limit in many respects, of what was possible. The locomotive and its tender filled the limits of the loading gauge much as a bodybuilder might cause his shirt to bulge and strain. They were as long as the principal turntables in place could handle. Freight locomotives were a different set of requirements, and the D57 Class was also built to the limits of the loading gauge. Moreover, its weight, especially the load on the driving axles, restricted its employment to certain main lines only.If extra power was to be gained, the third cylinder was the way to go.  It is interesting to note that in the USA there were very few three-cylinder locomotives. The reason was simple, the American loading gauges were so large that it was possible to easily envisage and build larger locomotives.

Three-cylinder locomotives had, by and large, been avoided in N,S,W, practice due to the desire to keep mechanical servicing simple since servicing facilities were relatively few and far between in N.S.W. as they are throughout Australia.

The D57 Class locomotives were colloquially known to railway staff as "the big engines".

This classic photo by the great Leon Oberg shows the Gresley conjugating valve gear

Anyone who has heard the triple-beat of the exhaust of a D57 or D58 Class locomotive, and felt the trembling of the earth as they passed at the head of a heavy freight train, will never forget the experience.