Class M (Locobase 15890)

Data from NYC&HR 9-1905 Locomotive Diagrams Including Subsidiaries. Works numbers were 37751-37753 in July 1905.

Locobase 12630 shows the other eight heavy switchers supplied to the Lake Shore & Michigan Southern at the same time. A comparison of the works numbers shows that this trio immediately followed the LS&MS engines. The extensive commentary in 12630 describes all of them as they were delivered.

The three Ms operated on the New York Central for over a decade during which they were renumbered in 1912. Delivered with 25" (635 mm) cylinders, the Ms were rebored to 24". In 1917, they joined their sisters on the Lake Shore and took the next three road numbers.

Class M-1 (Locobase 15044)

Data from Roy V Wright (Ed.) 1912 Locomotive Cyclopedia of American Practice, Sixth Edition (New York: Simmons-Boardman Publishing Company, 1912), p. 164. Works numbers were 44049-44050 in November 1907.

Locobase explains in Locobase 12629 that he doesn't usually write about all-adhesion switchers in Locobase for lack of resources and time. But a request from Gareth Edwards prompts this entry as well as the Michigan Central entry in which he was particularly interested. See Locobase 12630 for a longer discussion on the rationale behind these big engines.

This pair was produced for the CI&S, a "tributary" of the Lake Shore & Michigan Southern, in November 1907 and had slightly less firebox area than the LS&MS engines shown in Locobase 12632.

See Locobase 12631 for the superheated modification.

Class M-1/M-1a (Locobase 12630)

Data from MC 1 - 1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Ten-Wheel Switcher for the Lake Shore," Railway Master Mechanic, Volume 29 (August 1905), pp. 278-279; and the "The World's Largest Switching Engine", Railroad Men, Volume 19, No 1 (October 1905), p. 17. (Thanks to Chris Hohl for his 6 March 2018 email pointing out the original driver diameter. and the shorter engine-tender wheelbase.) Works numbers were 37746-37750 in June 1905 and and 40965-40967 in July 1907. Locobase 12629 shows the three Canada Southern locomotives that followed the LS&MS design.

Locobase explains in Locobase 12629 that he doesn't usually write about all-adhesion switchers in Locobase for lack of resources and time. But requests from Chris Hohl and Gareth Edwards prompted this entry as well as the Michigan Central entry (Locobase 12630) in which Edwards was particularly interested.

The RMM report on the LS&MS class gives a detailed justification for the design of these engines and can be quoted at length:

"The hump or gravity yard will be the scene of operations of these engines, and is responsible for their immense proportions. The modern system of receiving yards and classification tracks in which the gravity section is centrally located, necessitates the use of a high powered machine, since the approach to the hump, from which the cars descend by gravity to their assigned tracks, is usually on a rise of one per cent in each direction, while the classification tracks are practically level. The fact that all switching is done over the hump explains the need for a heavy engine, one that is able to take an incoming train without breaking a coupling, and make the proper distribution of the cars composing it. In fact such an engine requires more power to negotiate the one percent grade than the engine that delivered the train, especially on such a level road as the Lake Shore."

All of the drivers were flanged (because curvatures in the yard would be so gradual) and all of the axles were equalized both longitudinally and laterally, through a cross-equalizer at the front. When delivered, the engines had 52" (1.321 mm) drivers, but later in their careers their driver diameter was reduced by 1" (25.4 mm). Perhaps the railroad used thinner tires. Twelve-inch (305 mm) piston valves seem a bit small for these large engines. For some reason, the tenders on this class were shorter than those on the NYC engines shown below,.

(Note that all of the above applies to the three New York Central locomotives shown in Locobase 15890. These joined the LS&MS engines in 1917.)

According to George Drury (1993), each of these was to replace two 0-6-0s. If big was good, then, bigger was better. As often happened with such large switchers or helpers, however, their very bulk proved an inconvenience. They were heavy, stiff, cumbersome (to borrow George Drury's word).

Many were superheated, but except for the three ex-Michigan Central engines shown in the Canadian Southern entry (Locobase 12629), all were retired before World War II.

Class M-1/M-1a/M-1f (Locobase 12632)

Data from NYC 8 - 1917 and NYC 1 - 1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange collection.

Locobase 12630 has the saturated version of the largest single class that made up the predecessors to this superheated upgrade. In addition to the new tube and flue counts in the boiler, the cylinder volume increased with cylinders increasing in diameter by an inch and a half (38 mm). Piston valve diameter was still 12" (305 mm).

The three NYC/LS&MS locomotives shown in Locobase 15890 received the same superheated boilers, but retained the 24" (610 mm) cylinders and developed an initial tractive effort of 56,448 lb (25,604 kg).

Class M-1b - superheated (Locobase 12631)

Data from NYC 1 - 1930 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase explains in Locobase 12631 that a request from Gareth Edwards prompts the preparation of the CI&S pair shown in Locobase 15044.

Not long after they entered service, the pair was superheated. The shops added two fewer flues to the firebox than in the LS&MS conversions, which resulted in less heating surface area.

The pair was retired in 1934.

Class M-1c (Locobase 12633)

Data from CCC&StL 3 - 1914 Locomotive Diagrams dated 1 March 1914 and supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also "Ten-wheel Switching Locomotive for the Big Four," The Railway Age, Vol XLV, No 8 (21 February 1908), pp. 244-245. Works numbers were 44051-44052 in November 1907.

Locobase explains in Locobase 12629 that he doesn't usually write about all-adhesion switchers in Locobase for lack of resources and time. But a request from Gareth Edwards prompts this entry as well as the Michigan Central entry in which he was particularly interested. See Locobase 12630 for an extended contemporary explanation of the reasoning underlying this design.

The differences between the details shown for the Cleveland, Cincinnati, Chicago & St Louis pair in this entry and the others are probably attributable to differences in measurement, which is in itself an interesting exploration to undertake. RA's report tells us that the engines would be operated with cut-off at full stroke "nearly all of the time", which accounts, they remark, for the "unusually large" ratio of 314 sq ft (29.17 sq m) of heating surface for every cubic foot of cylinder.

Railway Age's 1908 report (and a similar report from American Engineer and Railroad Journal from the same year noted by Chris Hohl in a 20 January 2018 email) gives the tender's water capacity as 7,500 US gallons (28,388 litres). But the Big Four diagrams show 7,700 gallons, which Locobase kept because it apparently was based on operational use. Similar reasoning determined use of 1914 data for engine and tender loaded weights.

This pair was not renumbered according to a revised New York Central sequence as they were sold for scrap in April 1933.