Trix HO 25913 US Class 3900 Steam Locomotive “Challenger” Fall 2026 MHI Q3

Prototype: Union Pacific Railroad (UP) class 3900 “Challenger” heavy American steam locomotive in the rebuilt version with an oil tender. The design replicates the prototype as it looks as a museum locomotive, road number 3977, in Cody Park in North Platte, NE. Eras III and VI.

Highlights

Limited to 500 units worldwide.
A numbered certificate of authenticity is included.
Factory-installed, speed-dependent, dynamic smoke exhaust.
Heavy metal construction with many separately applied details.
Locomotive engineer and fireman figures in the engineer’s cab.
Striking smoke deflectors.
RailCom-enabled DCC/mfx digital decoder with extensive light and sound functions.
A buffer capacitor to bridge short unpowered sections of track is fitted.

Product description

Model: With digital decoder and extensive light and sound functions. Different operating sounds, such as oil and water being replenished or the sounds of opening and closing the sliding windows and the ventilation hatch on the cab, can be controlled digitally. It also has a controlled high-performance motor with a flywheel, mounted in the boiler. Six axles are powered. Traction tires are fitted. The chassis is articulated to negotiate sharp curves. The model has Boxpok wheels. The loco and tender have headlights and backup lights. The headlights will work in conventional operation and can be controlled digitally. The cab lighting and the illuminated number boards/marker lights can be controlled separately in digital operation. Maintenance-free, warm-white LEDs are used for the lighting. A buffer capacitor is fitted. The factory-installed, speed-dependent, dynamic smoke exhaust can also be controlled digitally. There is a powerful speaker in the tender. An imitation coupler in a standard pocket can be mounted on the pilot at the front of the locomotive. There is a close coupling with a guide mechanism between the loco and tender. Steam lines on the front group of driving wheels are mounted to swing out and back with the cylinders. The metal handrails are separately applied, as are many other details. Figures of a locomotive engineer and fireman for the engineer’s cab are included. The locomotive is screwed to a presentation base to protect it during transport. Length over the couplers 42.5 cm / 16-3/4".

Notes for operation: Although the locomotive can be used on curved track with a radius of 360 mm / 14-3/16" or larger, we recommend larger radius curves. Due to the overhang of the long boiler, any signals, catenary masts, bridge handrails, tunnel portals, etc. must be installed in a way that ensures sufficient clearance on curves. Due to the high weight of the locomotive, the track must be firmly secured in position. The turntable and transfer table can be traversed by the locomotive but not turned or moved. Products bearing the wording “Union Pacific” are made under trademark license from the Union Pacific Railroad Company.

A matching US heavy-weight car set is available in the Trix H0 range as item 23729. An AC version of this model is available in the Märklin H0 range as item 39913.

Spare parts for our articles can be found here in our spare parts search.

One-time series.

Digital Functions