Milwaukee Road class F7
| Milwaukee Road class F7 | |
|---|---|
|
A class F7 being moved out of the Alco factory | |
| Type and origin | |
| Power type | Steam |
| Builder | American Locomotive Company |
| Serial number | 69064–69069 |
| Build date | August to September 1938 |
| Total produced | 6 |
| Specifications | |
| Gauge | 4 ft 8 1⁄2 in (1,435 mm) |
| Leading wheel diameter | 36 in (914 mm) |
| Driver diameter | 84 in (2,134 mm) |
| Trailing wheel diameter | 38 and 44 in (965 and 1,118 mm) |
| Wheelbase | Loco & tender: 89 ft 10 in (27.38 m) |
| Length | 100 ft 0 in (30.48 m) |
| Axle load | 72,250 lb (32.8 tonnes) |
| Weight on drivers | 216,000 lb (98.0 tonnes) |
| Locomotive weight | 415,000 lb (188.2 tonnes) |
| Locomotive and tender combined weight | 791,000 lb (358.8 tonnes) full |
| Fuel type | Coal |
| Fuel capacity | 50,000 lb (22.7 tonnes) |
| Water capacity | 20,000 US gal (75,700 l; 16,700 imp gal) |
| Boiler pressure | 300 lbf/in2 (2.07 MPa) |
| Firegrate area | 96.5 sq ft (8.97 m2) |
| Heating surface: – Total | 4,166 sq ft (387.0 m2) |
| Superheater type | Type E |
| Superheater area | 1,695 sq ft (157.5 m2) |
| Cylinders | Two, outside |
| Cylinder size | 23 1⁄2 in × 30 in (597 mm × 762 mm) |
| Performance figures | |
| Tractive effort | 50,294 lbf (223.72 kN) |
| Career | |
| Operator(s) | Milwaukee Road |
| Number(s) | 100–105 |
| Retired | November 1949 to August 1951 |
| Disposition | All scrapped. |
The Milwaukee Road's class F7 comprised six (#100–#105) high-speed, streamlined 4-6-4 "Baltic" or "Hudson" type steam locomotives built by Alco in 1937–38 to haul the Milwaukee's Hiawatha express passenger trains. Following on from the success of the road's class A 4-4-2s, the F7s allowed the road to haul heavier trains on the popular Chicago–Twin Cities routes.
The F7s are major contenders for the fastest steam locomotives ever built, as they ran at over 100 miles per hour (160 km/h) daily. One run in January 1941 recorded by a reporter for Trains magazine saw 110 mph achieved twice—in the midst of a heavy snowstorm. Baron Gérard Vuillet, a French railroading expert, once recorded a run between Chicago and Milwaukee where the locomotive reached 125 mph (201 km/h) and sustained an average 120 mph (190 km/h) for 4.5 miles (7.2 km).[1] However, the British locomotive LNER Class A4 4468 Mallard is officially accepted to be the world's fastest, with a run recorded at 125.88 mph (202.58 km/h) in 1938.
The Milwaukee F7s are accepted as the fastest steam locomotives by a different measure—scheduled speed between stations. In 1939, shortly after they were introduced into passenger service, the Twin Cities Hiawatha schedule was modified such that the engines would need to run the 78.3 mi (126.0 km) between Portage and Sparta, Wisconsin in 58 minutes—a start-to-stop average of 81 mph (130 km/h).[1]
First-built #100 was also the first withdrawn from service, on November 10, 1949; last-built #105 was the final one in service, withdrawn August 10, 1951. All were scrapped.
| Milwaukee Road No. | Alco serial No. | Built | Retired |
|---|---|---|---|
| 100 | 69064 | August 1938 | November 1949 |
| 101 | 69065 | August 1938 | April 1951 |
| 102 | 69066 | August 1938 | August 1950 |
| 103 | 69067 | August 1938 | June 1951 |
| 104 | 69068 | September 1938 | June 1951 |
| 105 | 69069 | September 1938 | August 1951 |
See also
- CNW Class E-4 - nine very similar 4-6-4 locomotives built for the Milwaukee's Chicago competitor, the Chicago and North Western Railway.
References
- ↑ 1.0 1.1 Scribbins 1970, p. 63.
- ↑ Edson 1977, p. 51.
- ↑ Scribbins 1970, pp. 226–227.
Sources
- Benn, Bryan. "Fastest Steam Locomotive". Retrieved 2010-02-05.
- Edson, William D. (Spring 1977). "Milwaukee Road Locomotives". Railroad History (The Railway and Locomotive Historical Society, Inc.) (136): pp. 28–129.
- Hollingsworth, Brian; Cook, Arthur (2001). The Great Book of Trains. Osceola, Wisconsin: MBI Publishing. ISBN 0-7603-1193-5.
- King, Ed; Scribbins, Jim (Spring 2002). Classic Trains (Kalmbach Publishing Co.). Vol. 3 (No. 1): pp. 65–73. Missing or empty
|title=(help) - Reed, Brian (1972). Loco Profile 26 – The Hiawathas. Windsor, Berkshire, UK: Profile Publications Ltd.
- Scribbins, Jim (1970). The Hiawatha Story. Milwaukee, WI: Kalmbach Publishing Company. LCCN 70107874. OCLC 91468.
- Ross, Don. "Chicago Milwaukee St. Paul & Pacific: 4-6-4s". Don's Rail Photos. Retrieved 2011-11-07.
External links
Media related to Milwaukee Road class F7 at Wikimedia Commons