4000 Big Boy UP | Gauge H0 - Article No. 37993

Steam Locomotive with Tender.

Prototype: Union Pacific Railroad (UP) class 4000 "Big Boy" heavy freight locomotive. The locomotive looks as it did with road no. 4006.

Steam Locomotive with Tender.
Article No.37993
Design type1:87
KindSteam Locomotives
Article not produced anymore.

Product description

Model: The locomotive comes with an mfx digital decoder and a sound generator. It also has controlled high-efficiency propulsion, a powerful motor with a bell-shaped armature and a fly-wheel, mounted in the boiler. 8 axles powered. Traction tires. The locomotive has an articulated frame enabling it to negotiate sharp curves. It also has Boxpok driving wheels. The middle driving axles are spring-loaded. The headlights, backup light on the tender, and the number board lights are maintenance-free, warm white LEDs. 2 smoke generators (7226) can be installed in the locomotive. The headlight, backup light on the tender, the number board lights, and the engineer's cab lighting will work in conventional operation and can be controlled digitally. There is a powerful speaker in the tender and the volume can be adjusted. Coupler hooks can be inserted in the pilot on the front of the locomotive. There is a close coupling between the locomotive and tender. Steam lines are mounted to swing out and back with the cylinders. The locomotive has separately applied metal grab irons. There are many separately applied details. Figures of a locomotive engineer and fireman for the engineer's cab are included. Length over the couplers 46.5 cm / 18-5/16". The locomotive comes in a wooden case.

One-time series.


Notes for operating the locomotive: The locomotive can be used on curved track with a radius of 360 mm / 14-3/16" or more, however we recommend larger radii. Signals, catenary masts, bridge railings, tunnel portals, etc. must have installed for sufficient clearance on curves. The track must be well mounted due to the heavy weight of the locomotive. The locomotive can only be run through a turntable or transfer table. Products bearing "Union Pacific" are made under trademark license from the Union Pacific Railraod Company.


- New items brochure 2009 - Product programme 2009/2010

Prototype information

Class 4000 – The Big Boy in America. The double-heading of locomotives or the use of locomotives in pusher service was cost intensive and used a lot of crews. From the Forties on, the Union Pacific Railroad (UP) needed an extremely powerful freight locomotive especially for use on the grades of the Rocky Mountains in order to reduce to a minimum or even avoid using locomotives in situations as mentioned above. The new locomotives had to be capable of relatively high speeds so that long routes could be covered without changing locomotives. Otto Jabelmann, an experienced designer at American Locomotive Company (ALCO), developed a gigantic, articulated locomotive that entered the annals of railroad history as the "Big Boy" and that more than earned its nickname. Twenty-five units of this 40,500 mm / 132 foot 10-7/16 inch, 350.2 ton, 4,560 kilowatt / 6,115 horsepower, and 112 km/h / 70 mph fast 4-cylinder locomotive steamed through the wide expanses of the USA between 1941 and 1957. The Big Boys had a 4-8-8-4 wheel arrangement and the equally massive looking tender carried 24.5 tons of coal and 94.6 cubic meters / 24,991 gallons of water. The Big Boy show its strengths on the notorious grades in the Wastach Mountains or on Sherman Hill (1.14% and 1.55% maximum grade), and the locomotive fulfilled all of the expectations set for it. Six thousand ton freight trains were not rare in everyday operation and an experiment on level terrain showed that "Big Boy" was capable of pulling a 25,000 ton train on its own. Even on Sherman Hill this immense locomotive could still haul 3,600 tons on its own over this difficult route. With a full load the coal consumption was naturally also gigantic. A stoker automatically fed enough coal from the tender to the 14 square meter / 150.70 square foot grate in the firebox. No fireman would have been in a position to master this with pure muscle power. By the mid-Fifties, powerful diesel locomotives were gradually replacing the class 4000 steam locomotives, which has already become legendary in their "life times", so that it's not surprising that a total of 8 "Big Boys" , unfortunately not operational, have been preserved in museums to remind people of the great past for steam motive power in the USA.


(Metal frame and mostly locomotive body.
cDigital locomotives with high-efficiency propulsion. Maximum speed and acceleration / delay are adjustable. Special motor with electronically enhanced load compensation or a compact bellshaped armature. Can be operated with Märklin transformers, in the Märklin Delta system or in the Märklin Digital system. One controllable auxiliary function (function), when the locomotive is being run in the Digital system.
eDigital decoder with up to 32 digitally controlled functions. The quantity depends on the controller being used.
hBuilt-in sound effects circuit.
BSingle headlights that change over with the direction of travel.
kBuilt-in interior lighting.
UMärklin close couplers in standard pocket with guide mechanism.
3Era 3


ATTENTION: not for children under 3 years
Control UnitMobile StationMobile Station 2Central Station 1/2Central Station 3/2
Headlight(s) XXXXX
Smoke generator contact XXXXX
Steam locomotive op. sounds XXXXX
Locomotive whistle XXXXX
Direct control XXXXX
Engineer’s cab lighting XXXX
Warning Sound XXXX
Sound of squealing brakes off XXXX
Air Pump XXX
Injectors XXX
Auxiliary Blower XXX
Sound of Couplers Engaging XXX
Rail Joints XXX
Operating Sounds 2 XXX
Cab Radio XXX