Chicago and North Western Z Class

Class of 251 American 2-8-0 locomotives

C&NW class Z
Omaha Road class Z

C&NW 1455, the first of the class Z (Alco 46607 of 1909)

| Type and origin

Power type| Steam
Builder|

* American Locomotive Company (226)
* Baldwin Locomotive Works (25)

Serial number| see table
Build date| 1909–1913
Total produced| 251
| Specifications

Configuration:
| ​
• Whyte| 2-8-0
• UIC| 1′D n2, later 1′D h2
Gauge| 4 ft 8+1⁄2 in (1,435 mm)
Driver dia.| 61 in (1.549 m)
Wheelbase| 36 ft 5 in (11 m)
Loco weight| 235,000–243,500 pounds (106,600–110,400 kg)
Firebox:| ​
• Grate area| 52.68 sq ft (4.894 m2) (108 in × 70+1⁄4 in or 2.743 m × 1.784 m)
Boiler:
| ​
• Diameter| 81+1⁄2 in (2.070 m)
Boiler pressure| 170 lbf/in2 (1.17 MPa)
Cylinders| Two, outside
Cylinder size| 25 in × 32 in (635 mm × 813 mm)
Valve gear| Walschaerts or Baker
Valve type| 14 in (360 mm) piston valves
Valve travel| 6 in (150 mm)
| Performance figures

Tractive effort| 47,500 lbf (211.29 kN)
| Career

Operators|

* Chicago and North Western Railway
* Omaha Road

Number in class|

* CNW: 249
* CMO: 2

Numbers|

* CNW: 1455–1494, 1700–1910
* CMO: 219–220

Disposition| All scrapped

The Chicago and North Western Railway class Z (and Omaha Road class Z) was a class of 251 American 2-8-0 locomotives. They were built between 1909 and 1913, when production switched to the larger class J 2-8-2 locomotives. The class letter spawned their nickname amongst C&NW and Omaha Road crews: "Zulu".[1]

## Design

[edit]

The locomotives has boiler pressed to 170 pounds per square inch (1.2 MPa) feeding steam to two cylinders that had a 25-inch (640 mm) bore and a 32-inch (810 mm) stroke. These were connected to 61-inch (1,500 mm) driving wheels buy Walschaerts valve gear, although the last 47 were built with Baker valve gear. They had 14-inch (360 mm) piston valves with 6 inches (150 mm) travel. The firebox was of the radial-stay pattern, 108 inches (2,700 mm) deep by 70+1⁄4 inches (1,780 mm) wide. The resulting 52.68 square feet (4.894 m2) was 14 per cent larger than the class R-1.

## Construction

[edit]

Apart from a batch of 25 built by the Baldwin Locomotive Works, all the locomotives were built by the American Locomotive Company at their Schenectady plant. Baldwin classified their locomotives as 10-48-E

Table of orders and numbers[2][3] Year | Quantity | Manufacturer | Serial numbers | C&NW numbers | Notes

|
|
|
|
|

1909 | 40 | Alco | 46607–635/637/636/638–646 | 1455–1494 |
1910 | 25 | Baldwin | 34991, 35015–022/060–065/101–106/144–145/223–224 | 1700–1724 |
1910 | 26 | Alco | 47845–47870 | 1725–1750 |
1910 | 27 | Alco | 49035–49061 | 1751–1777 |
1911 | 23 | Alco | 49062–49084 | 1778–1800 |
1911 | 20 | Alco | 50494–50513 | 1801–1820 |
1912 | 45 | Alco | 50849–50893 | 1821–1865 |
1913 | 45 | Alco | 53047–53091 | 1866–1910 |
1913 | 2 | Alco | 53092–53093 | 219–220 | Omaha Road

## Service

[edit]

On the C&NW, they were used system-wide on freight trains, and were the principle freight-hauling locomotive on the railway until the arrival of the class J Mikados. The extra power over the existing freight locomotives enabled running 75-car trains; unfortunately, older wooden-framed freight cars could not stand the punishment and a large number of "bad-ordered" cars required repairs.[1] The Omaha Road used its pair, like all its 2-8-0s, in switching, transfer and helper service.[4] They had in fact been delivered a week after the Omaha Road's first class J 2-8-2 locomotives.[5]

When new all had been built as hand-fired coal-burning locomotives. The large grates were tricky to fire and several firemen resigned as a result.[1] At least 17 were fitted-up for oil-firing for use in Wyoming, where fuel oil was readily available. Twelve others received mechanical stokers during World War II.

In 1942, several locomotives were leased out to other operators; by war's end, these had either been purchased or returned. Sales included five to American Smelting and Refining Company (ASRCo), five to the Seaboard Air Line Railroad (SAL), two to the St. Louis Southwestern Railway (Cotton Belt or SSW), 25 to the Ferrocarriles Nacionales de México (NdeM) directly, and another seven via a dealer. They also later acquired ASRCo's five.

The first retirement was in 1936; fifty were still in service in mid-1948. The Omaha Road retired both of its Zulus in June 1956.[3]

Table of pre-1948 scrappings[2][6] Year | Quantity in
service at
start of year | Quantity
scrapped | Numbers | Notes

|
|
|
|

1936 | 251 | 1 | 1750 |
1937 | 250 | 5 | 1719/30/51/86, 1827 |
1938 | 245 | 4 | 1488, 1721, 1893, 1908 |
1939 | 241 | 2 | 1481, 1720 |
1940 | 239 | 42 | 1462/74/76/82,
1704/08/09/11/14/22/23/26–28/32/40/54/55/65/66/70/72/74/83/91/95,
1808–10/15/21/30/33/47/56/62/65/67/91/92/94,
1903 |
1941 | 197 | 34 | 1455/59/60/64/65/70/73,
1700/10/31/36/42/60/63/96/98,
1807/12/17/18/24/29/34/40/44/45/54/61/68/71/78/82/86
1900 |
1942 | 163 | 3 | 1467/94, 1793 | scrapped
1942 |  | [5] | 1717/24/85, 1837/58 | to ASRCo 4000–4004; to NdeM 1582–1586
1942 |  | [7] | 1466/68/69/86, 1790, 1848/97 | to NdeM 1550/51/55/52/53/54/56 via dealer
1942 |  | [2] | 1477, 1725 | to Cotton Belt 540–540 (SSW class K-1)
1942 |  | [18] | 1458/61/87
1702/84/89/99
1820/31/53/60/66/72/74/81/83/88/98 | to NdeM 1558–61/69–81/57 (class GR-43)
1943 | 128 | [5] | 1744/87, 1806/43/59 | to SAL 933–937 (class H-2)
1943 |  | [7] | 1729/46/59/64/77/81/82 | to NdeM 1562–1568
1944 | 116 | 15 | 1463/72/75/78,
1718/37/43/56/67/97,
1816/25/36/38/84 |
1945 | 101 | 22 | 1457/71/85/91/92,
1701/34/38/45/53/68/69/73/92
1835/42/57/63/76
1901/04/05 |
1946 | 79 | 12 | 1480, 1713/33/47/52/62, 1804/05/77/89/90, 1907 |
1947 | 67 | 17 | 1456, 1706/12/41/49/57/58/80, 1819/50/51/64/85/96/99, 906/10 | 1899 became stationary boiler at Chase Roundhouse, Milwaukee
1948 | 50 | 0 |  | first half-year only

No locomotives of this class have been preserved.

## References

[edit]

1. ^ a b c Mailer (2004), p. 139.
2. ^ a b Cole (1938), pp. 60–61.
3. ^ a b Mailer (2004), p. 302.
4. ^ Mailer (2004), p. 144.
5. ^ Mailer (2004), p. 145.
6. ^ Chicago and North Western Railway (1948), pp. 8, 10–12.

* Cole, F.A. (1938). Locomotives of the Chicago & North Western Railway. Boston: The Railway & Locomotive Historical Society.
* Chicago and North Western Railway (1948). Locomotives of the Chicago & North Western Railway, supplement. The Railway & Locomotive Historical Society.
* Drury, George H. (1985). The Historical Guide to North American Railroads. Milwaukee, Wisconsin: Kalmbach Publishing Company. ISBN 0-89024-072-8. LCCN 85080107.
* Mailer, Stan (2004). The Omaha Road: Chicago, St. Paul, Minneapolis & Omaha. Mukilteo, Washington: Hundman Publishing. ISBN 0-945434-04-9. OL 8448884M.
* Barrie, Wes. "Chicago & North Western / Chicago, St Paul, Minneapolis & Omaha 2-8-0 "Consolidation" Locomotives in the USA". steamlocomotive.com. Retrieved 2020-05-01.

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Chicago and North Western Railway steam locomotives

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