Showing the Development of the Huge American Locomotives
THE “BIG BULL-
ONE of the most remarkable features of railway operation during recent years has been the development of the mammoth locomotive. The era may be said to have commenced in France, but it is the Americans who have brought this movement to its highest pitch of perfection.
The issue was forced upon the United States and Canadian railways. The necessity to haul immense loads, such as coal, ores, grain, etc., over long distances without breaking bulk, often struggling against heavy grades, presented peculiar difficulties. The eight, ten, or twelve-
Under such circumstances the futility of the small wagon may be appreciated. But there was another factor which influenced the situation very vitally. With the small wagon the proportion of “live” or paying tonnage in a train is small in comparison with the “dead” or nonpaying train tonnage, while more train-
Once this development started it went ahead rapidly. The vehicles were increased in capacity, until to-
But the augmentation of the load per train precipitated another problem. The hauling power of a locomotive became over-
THE GIGANTIC MALLET COMPOUND BUILT FOR THE ATCHISON, TOPEKA AND SANTA FE RAILWAY. The engine weighs 308 tons, and the tender 117 tons, a total of 425 tons. Its length over all is 120 feet 7½ inches.
The locomotive engineers were urged to evolve larger and more powerful engines to dispense with “double-
In this search for greater locomotive power many striking and interesting types of engines were evolved, some of which are foreign to British working. Among these were such huge creations as the “Consolidation”, the “Mastodon”, and the “Mikado”, with eight large drivers, the distinction between the types being attributable to the arrangement and number of the leading, trailing and driving wheels.
Here it may be as well to describe how locomotive types are classified. The colloquial descriptions such as “Atlantic”, “Pacific”, “Baltic”, “Consolidation”, and so on are somewhat confusing, inasmuch as they convey no idea of the arrange-
It was conceded generally that the ten driving wheel locomotive represented the limitations of design with a rigid wheel base. While engineers were racking their brains as to how to obtain greater power there appeared an invention which changed completely the whole problem of locomotive design. This was the articulated engine, as evolved by M. Anatole Mallet, of Paris. Its appearance on the French railways created a sensation. American engineers, realising its advantages, and the fact that therewith it was possible to obtain that increase in power which was demanded so urgently, embraced the idea forthwith.
The outstanding feature of the Mallet locomotive is the division of the frame into two parts, which are connected together by a hinged joint. Each section of the frame carries a set of driving wheels and a pair of cylinders. In this way it is possible to obtain an engine having as many as twenty driving wheels -
THE SANTA FE COMPOUND MALLET LOCOMOTIVES of the “3000” class are the largest and most powerful in the world. They measure 120 feet 7¾ inches in length. The high-
These monster engines for the most part are utilised for three distinct services -
This articulated Mallet engine, built by the Baldwin Locomotive Works at Philadelphia, has proved highly successful in the heaviest class of mountain service.
The Pennsylvania Company also have designed a very powerful locomotive, classified by the company as the The H-
An interesting experiment was carried out with this engine in order to ascertain the precise freight-
A PENNSYLVANIA RAILWAY GIANT’S RECORD. The train consisted of 120 steel cars laden with coal, of a total weight of 8,850 tons, and measuring 4,888 feet in length. This engine hauled its load a distance of 127 miles in 9 hours 36 minutes.
Engine No. 1221 of the H-
Despite the huge load the one engine, having a tractive power of 42,661 pounds, hauled the train over the distance of 127 miles unaided, occupying 9 hours 36 minutes on the journey, giving an average speed of 13 miles an hour. As, however, this time included delays aggregating some three hours, the actual running speed averaged 19 miles an hour. In making the trip the engine consumed over 13 tons of coal.
A unique feature of the train was a telephone connection between the brakesman in the rear van and the driver of the locomotive, the wires being carried along the sides of the vehicles.
While the Pennsylvania Railway Company has no intention of operating such trains regularly, yet from time to time it embarks upon such tests to determine the capacity of its freight locomotives over the improved lines, where grades have been removed and curves compensated.
Recently some very powerful “Mikados”, among the largest and most powerful of the 2-
A POWERFUL BALDWIN “MIKADO” (2-
The boiler, 86⅛ inches in diameter, has a total heating surface of 4,592.8 square feet, and works at a pressure of 180 pounds per square inch. The fire-
These engines, with a maximum tractive power of 57,000 pounds, are superseding Consolidation locomotives, having cylinders of 26 inches diameter by 30 inches stroke, and a theoretical maximum tractive power of 51,400 pounds, in the slow freight traffic, while in the express goods service they are replacing Mogul -
Among the most impressive, and largest, as well as the most powerful engines yet constructed, the Mallet compounds built by the Atchison, Topeka, and Santa Fe Railway, forming what are known as the “3000” class in the railway’s service, stand pre-
The high and low pressure cylinders respectively are of 28 and 38 inches diameter, with a common stroke of 32 inches. The fire-
The driving wheels have a diameter of 57 inches, while that of the truck wheels is 34¼ inches. The tender is carried on twelve wheels, and has capacity for 12,000 gallons of water and 4,000 gallons of oil, liquid fuel being used, while the working pressure of the steam is 225 pounds per square inch.
This huge locomotive has a maximum drawbar pull of 111,600 pounds, and in an experimental run to ascertain its hauling capacity one of its class drew a train of 100 loaded freight cars, representing a live weight of 4,341 tons, from Emporia to Argentine, a distance of 111.5 miles, where the maximum grade is 21 feet per mile, in 6 hours 20 minutes. It has hauled a load of 1,911 tons at a speed of 12 miles per hour over a grade rising 79.2 feet per mile. At a speed of 10 miles per hour the engine develops some 3,000 horse power. At present these engines are being utilised for the most part in territory served by the Atchison, Topeka and Santa Fe Railway, where the ruling grade is 90 feet per mile, the train-
DELAWARE, LACKAWANNA AND WESTERN RAILROAD MAMMOTH. Its weight in working order, with loaded tender, is 235.85 tons.
* The American ton of 2,000 pounds, and gallon equivalent to .8 Imperial pints are used in the references to USA loco-
[From Part 2 of Railway Wonders of the World by Frederick A. Talbot]
You can read more on “Mammoths of American Railroads” in Wonders of World Engineering