History: In 1930,
100 engines of class M-1a were developed. They were built by Juniata,
Baldwin, and Lima. They were slightly heavier than the M-1's, and had
Worthington feedwater heaters with the mixing chamber back of the stack.
Two compressors were mounted on the left side. Ten M-1a's, along with
twenty M-1's were used for passenger service.
In 1946, several M-1a locomotives were upgraded and re-classified M-1b.
Some important changes made to the locomotive included a twenty pound
increase in steam pressure to 270 pounds and installation of circulators
in fireboxes, which increased heating surface by thirty-five square feet.
These changes occurred after the locomotives were sixteen or more years
old; consequently, their final years were spent hauling the heaviest loads
of their lifetimes.
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.
27" x 30"
Firebox 79-7/8" x 125-15/16"
Steam pressure 250 lbs.
Tractive force 64,550 lbs.
Weight of engine in working order 390,000 lbs.
Weight of engine on drive wheels 271,000 lbs.
Weight of engine on front trucks 59,000 lbs.
Weight of engine on trailing trucks 60,000 lbs.
Weight of tender 378,360 lbs.
with Tender 15-1/4"
Weight 2 lbs. 10 oz.
Minimum radius 22"
Power Bowser DC-71
Color Brunswick Green
Note: To make Eight Wheel
Tender, purchase #7006 Trucks
and screw onto tender.
Assembly- Exploded View Drawings(click on
any image to enlarge)