by Tom Piccirillo/photos by the author except as noted
Headquartered in Philadelphia, the Pennsylvania Railroad was a 10,000-mile trunk system connecting the major cities of the Mid-Atlantic states with Chicago and the Midwest. If someone was to claim that PRR’s K4s steam locomotives are worthy of the same fame as the most popular steam locomotives of the 20th century, they’d get no argument from me. A total of 425 of these coal-fired workhorses were built by PRR’s Juniata Shops in Altoona, Pa., and by Baldwin Locomotive Works from 1914 through 1928, and were not completely replaced by diesels until 1957.
Class “K” refered to Pacifics, “4” refered to the 4-6-2 wheel arrangement, and “s” denoted it was equipped with a superheater. The combined engine and tender weight was 517,000 lbs. and, with their 80” diameter drivers, could attain a speed of 87 miles per hour and develop more than 3,200hp. Only two examples of the K4s class survive. No. 3750 is on static display outside of the Railroad Museum of Pennsylvania in Strasburg, while no. 1361 is undergoing a multi-year restoration at the Railroaders Memorial Museum in Altoona.
The Model
The first mass-produced O scale models manufactured in the 1930s were durable machines, with heavy-duty drivetrains and metal superstructures. Many were made using cast-bronze frames and sheet-brass superstructures, resulting in the so-called “Bronze Age” of O scale. With a modest amount of care and maintenance, many have survived to this day.
Such is the case with Scale-Craft’s model of the PRR K4s. Founded in 1933 by Elliott Donnelly, Scale-Craft Model Trains was based in the Chicago area and offered highly detailed scale models to an emerging hobby market. In fact, a Scale-Craft K4s pulled a model of the Broadway Limited on the layout at the 1933 Chicago World’s Fair for 150 days, 12 hours a day, without fail. The K4s model was produced through 1941, with the first versions powered by a rear-axle drive; later versions were center-driven.
This K4s model was already 39 years old when I acquired it in 1978. It had originally belonged to the Central Jersey Model Railroad Association’s O scale club in Westfield, N.J., and had been converted from outside third-rail operation to 2-rail after the club’s demise in 1977. It was a smooth runner and spent many hours over the years in passenger service during exhibitions. The many miles it clocked did nothing to diminish the ruggedness of its mechanism, although the paint and detailing showed signs of age. So, it was time for an upgrade.
After comparing the model against photographs and drawings of the prototype, I made a list of the tasks needed to upgrade the model to today’s standards for operation, detail, and finish. The motor would be replaced with a DCC-compatible one, and a sound decoder would be added. The oversized firebox side sheets would be removed, and the 32” diameter pilot wheels would be replaced with correctly sized 36” wheels. The cast-bronze details, such as the pilot, smokebox front, headlight, air pump, power reverse, tender steps and water scoop, would all be replaced with state-of-the-art brass investment (lost-wax) castings. Rivet detail would be added to the cab, firebox, and tender tank, as well as any plumbing. Finally, the tender trucks would be replaced, and the entire locomotive would be repainted, lettered, and weathered.
Getting Started
The tender shell was separated from its frame and all paint was stripped from the tank. The steps, water scoop, air tank, ladders and class lights were replaced with lost-wax detail parts. The tender shell was detailed with molding along the bunker extensions, and rivet decals were installed on the tank sides and ends. New trucks replaced the old bronze sideframe castings. A new water hatch casting was installed…
