top of page

ALCO Northern 4-8-4

The ALCO Northern (4-8-4) is one of the largest 1-1/2" scale steam locomotives commercially available with some finished engines weighing as much as 2500 lbs. These engines are beautifully detailed and are recommended for the person who wants something large, different, and challenging to build. Design changes to the engine has eased the build making it more manageable by those who are not professional machinists. We suggest that anyone considering this beautiful machine try and visit one at a local track or at a club around the country to get a sense of the sheer size of the locomotives.

The original Northern, as designed between 1947 and 1951, was primarily patterned after the Union Pacific 800 class ALCO built Northerns.  However, our parts can be used as the basis for any of the larger Northerns and Hudsons used by many of the railroads around the country.  Available castings for this engine, a water-jet cut frame, 80" box-poc or spoke driver, newly designed individual journal box, newly designed swing-link lead truck-courtesy of Chuck Hackett, designed by Dennis Riches, some water jet cut and CNC machined ready to install parts, and much, much more.

The ALCO Northern is truly a unique steam locomotives and almost all of the parts have been retooled and re-patterned. The castings available today are of superior quality. Original drawings and blueprints have been scanned and are currently being digitally re-mastered.

While the castings available to build this engine are plentiful, many of the original parts were built up from bar stock. As time permits many of these parts will become available as castings to aid the builder. We welcome a question/answer session to assist in the decision to build one of these two engines.


Catalog Information


Engine Length

Tender Length


Weight (Engine Only)

Track Gauge

Bore & Stroke

Lead/Training Wheels

Drive Wheel Diameter



Minimum Turning Radius

96 inches

66 inches

21 1/2 inches

1,500 pounds (approximately)

7 1/2 inches (modification required for 7 1/4 inches)

2 3/4 x 3 1/2 inches

5/5 1/4 inch diameter

10 inches

Coal, Oil, or LPG

12 inch diameter steel

60 feet

Recommended machinery for building from rough parts:

  • 16 inch swing lathe

  • Full size milling machine

bottom of page