Union Pacific Big Boy

Union Pacific Big Boy

Union Pacific Big Boy

Power type: Steam
Builder: American Locomotive Company
Build date:1941 (20), 1944 (5)
Total produced: 25
Configuration: 4-8-8-4
UIC classification: (2'D)D2' h4
Gauge: 4 ft 8 1/2 in (1,435 mm)
Leading wheel diameter: 36 in (914 mm)
Driver diameter: 68 in (1,727 mm)
Trailing wheel diameter:42 in (1,067 mm)
Wheelbase: 72 ft 5.5 in (22.09 m)
Length Locomotive: 85 ft 3.4 in (25.99 m)
Overall: 132 ft 9 1/4 in (40.47 m)
Width: 11 ft (3.4 m)
Height: 16 ft 2 1/2 in (4.94 m)
Weight on drivers: 540,000 lb (244,939.9 kilograms)
Locomotive weight: 762,000 lb (345,637.4 kilograms)
Tender weight: 342,200 lb (155,219.3 kilograms) (2/3 load)
Locomotive & tender combined weight: 1,250,000 lb (566,990.5 kilograms)
Fuel type: Coal
Fuel capacity: 28 short tons (25.4 t; 25.0 long tons)
Water capacity: 25,000 US gal (95,000 l; 21,000 imp gal)
Boiler: 95 in (2,400 mm)
Boiler pressure: 300 lbf/in² (2.1 MPa)
Firegrate area: 150 sq ft (14 m2)
Heating surface: Tubes and flues 5,035 sq ft (468 m2)
Heating surface: Firebox 720 sq ft (67 m2)
Heating surface: Total 5,735 sq ft (533 m2)
Superheater type: Type A
Superheater area: 2,043 sq ft (190 m2)
Cylinders: Four
Cylinder size: 23.75 in × 32 in (603 mm × 813 mm)
Top speed: 80 mph (130 km/h)
Tractive effort: 135,375 lbf (602.18 kN)
Factor of adhesion: 4.11
Career: Union Pacific Railroad
4000–4019: 4884-1
4020–4024: 4884-2
Last run: July 21, 1959
Preserved: 4004, 4005, 4006, 4012, 4014, 4017, 4018, 4023
Disposition: Eight preserved, remainder scrapped.

Sound Projects

There is 1 Sound Project for this Locomotive
UPbigboy 8 bit project by John McMasters, added on May 9, 2013

This project takes the baseline from the EM-1 to create a Coal burning version of the articulated sounds where cylinder 2 is in voice 2 and cylinder 1 plays in voice 1.
This makes it possible for the two cylinder sounds to fall out of sync and sound more real.
The locomotive sounds were created from vague impressions from an old UP production movie. The UP sounds were only used to get the pattern and timbre for the chuffs, whistle and other sounds.

Please see project description for full description and list of features.

SoundLoader Software

Using your PR3 programmer and SoundLoader Software, it’s quick and easy to download sound project files into your Digitrax FX decoders.

Format Information

With Digitrax Sound FX decoders and downloadable sound project files (.spj), you can download your choice of sound schemes into any Sound FX equipped locomotive. You can use spj’s that are available for free, you can modify those schemes or you can create your own!

Sound Decoders

Digitrax offers a wide variety of Sound FX decoders to fit many different locomotives. You’ll need to have a Digitrax SFX decoder installed to take advantage of using .spj files.

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