| Chicago Burlington & Quincy Railroad 2-10-4 Class M-4 6325 presumed at Philadelphia, Pennsylvania in April 1929, photograph by Baldwin Locomotive Works, print by H. L. Broadbelt, Chuck Zeiler collection. Number 6325 was built by Baldwin in April 1929 ( c/n 60770 ) as Class M-4, rebuilt in September 1935 to Class M-4-A by application of 28X32 cylinders ( it was built with 31X32 cylinders ), roller bearings and cross counter-balanced ( main wheels only ), sold for scrap in May 1961. The following is from the Burlington Route Historical Society's Bulletin 21, 'The Q's Colorado Types', by Hol Wagner: The ( 1927 ) M-4's quickly proved their superior abilities, and in 1929 six additional locomotives of the class were purchased - engines 6322-6327. They were identical to the first group except for a few small details. They had more modern sloping-front cabs, while the original group had vertical-front rectangular cabs, and the new engines had traditional steam whistles mounted on the large outside steam pipe on the left side of the boiler, just ahead of the forward sand dome ( however, in this photo, the whistle is just ahead of the rear sand dome ). The air horns of the earlier M-4's were soon replaced with steam whistles too. Finally, all six of the new locomotives were equipped with Worthington BL feedwater heaters. |