| Chicago Burlington & Quincy Railroad 2-10-2 Class M-1 6000 at Philadelphia, Pennsylvania on an unknown day in March 1912, photograph by Baldwin Locomotive Works, print by H. L. Broadbelt, Chuck Zeiler collection. First a note about the following information: it is excerpted from the book, Steam Locomotive Of The Burlington Route, by Bernard G. Corbin and William F. Kerka. Usually reliable, while cleaning the photo I noted the builder's construction number as 37599, March 1912. This conflicts with the numbers in the book, which show number 6000's c/n as 37592, and number 6003's number as 37599. I'm going with the photographic evidence, however, it is possible that Baldwin dressed up 6003 as 6000 for the photo. Five Class M-1 2-10-2's were built by Baldwin for the CB&Q in 1912 (road numbers 6000-6004), at the time the largest non-articulated locomotives ever built. They were intended for the southern Illinois coal fields, exerted a tractive force of 71,500 pounds with a weight-on-drivers of 301,800 pounds. Originally fitted with Barnum under-fed stokers (which forced coal by screw conveyors through four horizontal troughs in the bottom of the firebox), they were eventually refitted with conventional over-feed types. Although the rigid wheelbase was 20 feet 9 inches, they could negotiate a 21 degree curve, as considerable lateral motion was allowed in the first and fifth driving axles. To provide for this, the knuckle pins were fitted into spherical bushings of cast-hardened steel in the side-rod stubs on the second and fourth pair of drivers. An unusual feature of the M-1 locomotives was the use of additional counterweights on the main driving axle. This consisted of two cast-steel bobs placed between the frames and keyed to the axle. The mass of the reciprocating and revolving parts, and the small size (63 inch) of the driving wheels, would have made it impossible to balance the engine properly without these additional counterweights. This particular locomotive (and 6003) was retired in December 1933. |