| 新聞內容: |
美國東西橫貫鐵路火車總重量500噸以上這部火車叫大男孩 Big Boy。
PROTOTYPE SPECIFICATIONS:
Builder Alco
Tractive Force 135,375 pounds
Drivers 68"
Total Engine Weight 772,000 pounds
Total Engine wheel base 72' 5-1/2"
Steam Pressure 300 pounds
Height 16' 2-1/2"
Length 85' 9-1/2"
ENGINE OVERHANG
(From inside of Outside Rail)
18"Radius Curve 1.688"
20"Radius Curve 1.437"
22"Radius Curve 1.375"
24"Radius Curve 1.250"
US Standard Units International System Units
Total length: 132 ft. 9-7/8 in. 40.51 m.
Tender length: 45 ft. 6 in. 13.90 m.
Locomotive's service
weight: 762,000 lb. 346 t.
Tender's service weight: 427,500 lb. 194 t.
Total weight: 1,189,500 lb. 540 t.
Power: 7,000 hp 5,884 kW
Tractive effort: 135,375 lb.
Wheel arrangement: 4-8-8-4 2´ D, D 2´
Driving axle load: 67,500 lb. 30.6 t.
Driving wheel dia.: 68 in. 1.73 m.
Truck wheel dia.: 42 in. 1.07 m.
Boiler pressure: 300 psi 20.67 bar
Grate area: 150.3 sq. ft. 13.96 sq. m.
Coal: 28 tons 25.4 t
Water: 25,000 gal. 94,750 l.
Maximum speed: 70 mph 112 km/h
Normal speed: 40 mph 64 km/h
The Big Boys were built for power. They did the work of three smaller engines, pulling 120-car, 3800 ton freight trains at forty miles per hour in the mountains of Utah and Wyoming.
With power though, comes weight -- larger cylinders, pistons, drive rods, boiler, firebox. Steam locomotive manufacturers added more wheels, both powered drive wheels and unpowered idlers.
The extra wheels added length. Long engines had difficulty squeezing through the sharp corners in mountains. A French designer named Anatole Mallet added a hinge to the middle of a locomotive to allow it to bend. Two pairs of cylinders supplied power to the two sets of drive wheels.
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The Big Boys were built in Schenectady, New York by the American Locomotive Company -- ALCo -- to the Union Pacific's design. ALCo delivered the first batch of 20 -- including the 4012 in the Steamtown NHS collection -- in 1941 and the remaining 5 in 1944.
Big Boys had over one mile of tubes and flues inside the boiler. Their firebox grate measured 150 square feet. The Big Boys had sixteen drive wheels, each measuring 68 inches. From coupler to coupler they measured 132 feet 9 inches. The tender held 24,000 gallons of water and 28 tons of coal and the engine and tender weighed 1,189,500 pounds in working order. The engines well deserved the name 'Big Boy' which was written on one of the drive rods by an unknown worker at ALCo.
The 25 Big Boys were built to pull long fast freight trains over the Wasatch Mountains of Utah and Sherman Hill in Wyoming. They served there until 1959 when the new diesel-electric locomotives took over. The Big Boys were not the most powerful engines, though they were the heaviest. But no engine ever came close to matching Big Boy's combination of speed, power and agility.
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