Chicago, Rock Island & Pacific 4-8-4 "Northern" Locomotives in the USA

Class R-65A, B, C/R-67 (Locobase 250)

Data from 1930 Locomotive Cyclopedia, supplemented by RI 1- 1942 and RI-9 1952 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 22 February 2013 inquiry about this class that led me to tighten up the entry.)

Schenectady delivered the first two batches in 1929, the third in 1930. Works numbers were 67670 inFebruary 1929, 68003-68004 in July, 68005-68020 in August, 68021-68023 in September, 68024-68026 in October, 68288-68291 in March 1930, 68292-68326 in April, 68327 in May.

Firebox had 150 sq ft (13.9 sq m) of thermic syphons, Coffin feedwater heaters, and Chambers front end throttle. All of the class received 74" drivers by 1944, which led to their class ID changing to R-67. The 1952 diagrams indicate that locomotives fitted with an auxiliary booster engine on the trailing truck were designated R-67-B, those without were simply R-67.

According to Drury (1993), this design's size and weight limited their operation to the Chicago-Des Moines corridor, the Chicago-Dalhart, Texas line, and the segment between Herington, Kan and El Reno, Okla. Later bridge-strengthening allowed these heavyweights to pull freights and passenger trains to Denver, Fort Worth, Tucumcari, and Minneapolis. Ten of this large stud of Northerns (the largest on a North American road) received a larger tender, roller bearings, and thicker driver tires.

Class R-67 (Locobase 251)

Data from 1947 Locomotive Cyclopedia, supplemented by RI 9 - 1952 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. (Thanks to Chris Hohl for his 22 February 2013 inquiry about this class that led Locobase to tighten up the entry.) The first ten were produced in 1944 (Order S-1920, works numbers were 719450-71948 in April 1944 and 71949-71954 in May.), the last ten in 1946 (Order S-1984, works numbers were 74366-74367 in January 1946, 74368-74369 in April, 74370-74374 in May, 74375 in June).

Firebox had four thermic syphons that totalled 155 sq ft (14.4 sq m). Piston valves measured a relatively small 12" (305 mm) in diameter.

Note that these twenty locomotives, built fifteen years after the earlier R-67-B group, had much less superheating area and older ratio of tubes to flues. Cylinder volume and driver diameter remained the same, but boiler pressure increased by 20 psi (1.38 bar). Wartime restrictions on high-temperature alloys probably had something to do with that retrograde. Another possibility is that reported difficulties in maintaining Type E superheaters may have prompted the change.

In fact, the class strongly resembles the Delaware & Hudson K-62s built at the same time by the same builder. Among more modern features these engines showed were roller bearings on all axles and Boxpok drivers.

The first ten engines were oil-fired, the last ten burned coal. The tenders for each group held the same amount of water, but the latter group's tenders carried 22 tons (20 metric tons) of coal.