Chicago & North Western 4-8-4 "Northern" Locomotives in the USA

Class H (Locobase 252)

Data from tables in 1930 Locomotive Cyclopedia. (Thanks to Chris Hohl for his 21 June 2024 email supplying information on the roller bearings in both engines and tenders as well as reporting the 1940-1944 boiler pressure ncrease.) See also DeGolyer, Volume 81, pp. 433+; and George Drury, Guide to North American Steam Locomotives (1993, rev ed. 2015), p. 121; and "Supplement to Locomotives of the.Chicago & North Western Railay", January 1, 1938 and July 1, 1948 supplied in August 2013 by Allen Stanley from his extensive Railroad Data Exchange collection. Works numbers were 61013-61017, 61060-61072, 61091-61101 in September 1929 and 61123-61127 in November.

As built in 1929, these dual-service engines had an outside-cradle frame (also known as a banjo frame) holding the four-wheel trailing truck. While needed to clear the large ashpan, wrote Drury, this frame was a weak point.

The first five were delivered with Baker valve gear; the rest had Walschaert's constant-lead gear. Other features included 14"(356 mm) diameter piston valves; a firebox fitted with combustion chamber (116 sq ft/10.8 sq m), thermic syphons (129 sq ft/12 sq m) and firebrick tubes (21 sq ft1.95 sq m). Two of the thermic syphons were placed in the firebox, the third "centrally located' in the combustion chamber. Boiler served by Worthington Type S feedwater heater and Standard Type B (modified) stoker. As built, these engines had a Franklin booster that added 11,300 lb to starting tractive effort. These were huge engines that initially were restricted to the Chicago-Omaha main line.

At thte time of delivery, cost per engine came to $120,000.

Drury noted two rebuilds. 1940 introduced roller bearings on all axles, lighter Boxpok drivers, and lighter main and side rods. Chris Hohl's 2024 email noted that Timken roller bearings appeared on all axles. Tenders received roller bearings as well, Hohl reported. 3001-3025 used those from American Steel Foundries while the last ten were prepared to receive them as well.

3001, 2004-3005 exchanged their Baker gear for Walschaert constant-lead gear in 1946.

From 1941-1947, the shops raised the boiler pressure setting to 275 psi (19 bar) in seventeen locomotives identified in the 1948 accounting as class H-R 3001-3003, 3006, 3011-3012, 3015-3017, 3021, 3024-3027, 3029-3031

Of these, 3011, 3016, 3026-3027, 3029, 3031 underwent the much more extensive reconstruction wrought on 24 locomotives beginning in 1946. See Locobase 3582.

Class H-1 (Locobase 8382)

Data from C&NW 10 - 1952 Locomotive Diagrams; and George Drury, Guide to North American Steam Locomotives (1993, rev ed. 2015), p. 121.(Thanks to Chris Hohl for noting the change in tender roller bearings,booster truck tractive effort increase, and the list of retirements shown below.).

As noted in Locobase 252, the H-class 4-8-4 went through two major rebuilds during their careers. In addition to the numbers shown in Locobase's road number accounting, the shops also rebuilt 3026-3029 and 3031-3035 as H-1s.

The first, in 1940, is described in Locobase 252. In 1946, 3004's refit went substantially farther with a new boiler mated to a new firebox and mounted on a cast nickel-steel frame with integral cylinders, air reservoirs, and pilot beam. Tube and flue diameters both increased, (from 2" and 3 1/2", respectively), but their number decreased and total evaporative heating surface declined by a total of more than 1,300 sq ft (120.77 sq m). The shops swapped out the tenders' ASF roller bearing for SKF units.

Essentially, these were new locomotives. George Drury commented that the rebuild "...was a much better engine than it had been in 1929, and it had been an excellent engine then."

24 were modernized by C&NW in 1946-1949 before dieselization stopped the program. They left service beginning in 1950, the last departing in 1956. Chris Hohl compiled the detailed listing:

1950: #3023 / 1952: #3006, 3015, 3017, 3021, 3024-3025, & 3030 / 1953: #3004-3005, 3008, 3010, 3014, 3018-3019, 3028, & 3033-3035 / 1954: #3011, 3016 & 3029 / 1955: #3007, 3022, 3026-3027, & 3031 / 1956: #3009, 3013, 3020, & 3032