History: The Union
Pacific 4-8-8-4 "Big Boy" are considered to be the longest and
heaviest locomotives built by Alco. They were designed in 1941 and 1944
to conquer the grade between Ogden and Evanston through the Wasatch Mountains.
This design utilized lateral motion devices, and were able to run as fast
as 80 miles per hour, but their best horsepower was at 30 miles per hour.
The engines had 23 3/4" x 32" cylinders, 68" drivers, used
300 pounds of boiler pressure and weighed 772,000 pounds. Twenty engines
were originally ordered in 1941. These were engine numbers 4000 to 4019.
Five more engines were eventually ordered in 1944. These were numbered
4020 to 4024.
Around September 10, 1941 the 4000 was tested on the grade that it had
been built to beat. It was hauling a 3800 ton train and made the 65 mile
plus trip into Wahsatch and on to Evanston ahead of the photographer.
Fittings were added, including twin stacks hidden behind a sheet-metal
fence and equipped with side-folding smoke hoods. Feedwater was heated
with an Elesco exhaust injector combined with a centrifugal pump. The
engines were used as coal-burners. Big Boys first used air cooling piping
supported lengthwise on each side of the pilot deck and later used Wilson
after-cooled radiators as on the Challenger series.
The Big Boys were the King of steam for eighteen years, but they might
not have ever been built, for while the 4000 series were in the design
stage, deisels were being tested experimentally throughtout the nation.
A word of advice - this
loco kit is not a beginner's kit. After all, this is a hobby.
In order to enjoy building kits, we suggest that you build at least 2
other Bowser kits before you try the Big Boy. In addition to complexity,
we make the body by cutting two Challenger boilers and soldering them
together. As a result, this kit requires patience and some assembly
experience to build it, and a lot of filling to smooth the joining seam.
Complete Kit and Accessories: The locomotive
and tender complete kit has all of the parts to build a working model. You may
wish to add your own details or purchase our "Super Detail Kit" if available.
Some models have an optional painted engineer and fireman, smoke unit kit and
other assemblies available as optional equipment to compliment your kit-building
Kit Components and Replacement Parts:
The following parts are listed in order to identify parts in your kit or to
replace parts that have been lost, damaged or simply worn out. This is
not a complete list of all of the individual parts available for this model
- please call Bowser with your specific requirements
if you cannot find the parts you need. You may also use our on-line
catalog to find parts by description. Please note that part numbers
with a price of "Call Us" may be part of an assembly and may not be available
as a separate purchase item.