Chicago and North Western D class

The Chicago and North Western Railway D Class was a class of 92 American 4-4-2 "Atlantic" locomotives. They were built by Schenectady Locomotive Works and by its corporate successor the American Locomotive Company between 1900 and 1908. In addition, the Chicago, St. Paul, Minneapolis and Omaha Railway bought seven, classifying them as '''class G-3'''

Design

The locomotives had a boiler pressurized to providing steam to two cylinders with a bore and a stroke. They were connected to driving wheels by a variety of valve gear: most had Stephenson valve gear and piston valves; No. 1026 was fitted up with Youngs rotary valves and valve gear in 1903, but later reverted to Stephensons valve gear. The 1908 batch had Walschaerts valve gear, the first five locomotives having piston valves and the last ten were delivered with Young rotary valves; these were replaced with piston valves when the locomotives were fitted with superheaters.

Construction

All 92 locomotives were built by Schenectady Locomotive Works and by the same works under its corporate successor, the American Locomotive Company.
In September 1904, ALCO announced their introduction to steam locomotives with superheated boilers, following some successful test runs by a European locomotive at a St. Louis exhibition. The C&NW subsequently asked ALCO to construct one D class 4-4-2 and one R-1 class 4-6-0 with superheated boilers. The railroad became unsatisfied with the performance of Nos. 1300 and 76, and no further D's or R-1's were built new with superheaters.

Year	Quantity	Manufacturer	Serial numbers	C&NW numbers	Notes
1900	6	Schenectady	5613–5618	1015–1020
1901	4	Schenectady	5840–5843	1021–1024
1901	6	Schenectady	6138–6142/44	1025–1030
1902	6	Alco	25411–25416	1080–1085
1902	6	Alco	26524–26529	1086–1091
1903	10	Alco	27571–27580	1092–1101
1904	12	Alco	29705–29716	113, 152, 464, 475, 482, 493, 895, 1303–1307
1905	6	Alco	30294–30298	1297–1302
1905	4	Alco	38509–38512	367–370	Omaha Road
1906	10	Alco	39247–39256	1308–1317
1906	3	Alco	39410–39412	364–366	Omaha Road
1907	10	Alco	42200–42209	1443–1452
1908	15	Alco	45697–45711	125–128, 158, 390–399

Service

At the time of their introduction, wooden cars were the norm. The class D locomotives were quite capable of pulling a 10-car, 400-ton train on the 138-mile Chicago to Clinton route in 3 hours 25 minutes inclusive of eleven stops.
Unfortunately, steel cars came into use soon after, and the locomotives became outclassed. They were then downgraded to commuter service and locals.
On the Omaha Road, one of the later uses of their class G-3 was powering the Minneapolis to Ashland train The Namakagon substituting for the regular gas-electric car when it was in the shops or the load exceeded its two-car capacity.
Retirements started in 1931, and continued until the end of steam in 1956 when the last two were retired from Chicago commuter service.

Year	Quantity in service at start of year	Quantity scrapped	Numbers	Notes
1931	91	1	1087
1936	90	3	1306, 1314, 1443
1937	87	1	1302
1938	86	9	1018/90/91, 1100, 1300/05/09, 1448/52
1939	77	6	1019/21/84, 1101, 1447/49
1940	71	24	125/27, 390/92/93/96/98, 464, 895, 1024/27/30/82/85/89/92/93/99, 1303/04/10, 1444/46/51
1941	47	5	1025/28/81/94, 1445
1942	42	3	1026/86, 1313
1943	39	6	128, 391, 475, 1029/80/88
1944	33	4	152, 1095, 1301, 1315
1945	29	4	1308, 1311, 1312, 1317
1947	25	4	493, 1015, 1083, 1450

Year	Quantity in service at start of year	Quantity scrapped	Numbers	Notes
1945	7	3	366, 368, 370
1946	4	1	369
1949	3	1	367
1950	2	1	365
1952	1	0	364

One locomotive has been preserved: CNW 1015, the first locomotive built. It is on display at the National Museum of Transportation at Kirkwood, Missouri.