Available Items


G Gauge RailKing One Gauge 4-8-8-4 Big Boy Steam Engine (Oil Burner) With Proto-Sound 3.0
  • Union Pacific


G Gauge RailKing One Gauge 4-8-8-4 Big Boy Steam Engine With Proto-Sound 3.0
  • Union Pacific

Uncataloged Limited Edition G Gauge Union Pacific Big Boy Steam Locomotives Announced

January 15, 2021 - M.T.H. Electric Trains has announced special limited-edition releases of the RailKing One Gauge G Scale Union Pacific 4-8-8-4 Big Boy Steam Locomotive. These unique releases are part of a series of products representing the last M.T.H. production runs as the company concludes its 40 year history this Spring.

Each of these locomotives can be ordered from your local M.T.H. Authorized Retailer.

Click on any of the item numbers to the left to learn more about each locomotive.



Each locomotive will include a signed Certificate of Authenticity by M.T.H. President Mike Wolf and are available in two different versions - No. 4014 Oil Burner in current Union Pacific gloss Restoration livery and No. 4014 Original Coal Burner. Models outfitted with the Restoration livery include the "Big Boy" chalk lettering on the boiler front, tender water level markings and a sound set celebrating the excursion runs of 2019.

Writer Henry Comstock beautifully described the Big Boy's place at the apex of steam engine history: "A Union Pacific 'Big Boy' was 604 tons and 19,000 cubic feet of steel and coal and water, poised upon 36 wheels spaced no wider apart than those of an automobile. That it could thunder safely over undulating and curved track at speeds in excess of 70 miles an hour was due in large measure to the efforts of two long-forgotten pioneers. As early as 1836, the basic system that held its wheels in equalized contact with the rails was patented by a Philadelphian named Joseph Harrison; and a French technical writer, Anatole Mallet, first thought to couple two driving units heel to toe below one boiler in 1874."


This enduring symbol of American railroading returns to the rails for the last time from M.T.H. Electric Trains in 2021, complete with quillable, variable intensity steaming whistle. Blow the whistle from your DCS handheld controller, smartphone or tablet, and watch the whistle steam output vary as you “play” the whistle like a prototype engineer.

All models include a powerful motor for pulling power and speed that rival the original Big Boy, as well as authentic articulated chuffing sounds simulating the two drive trains drifting in and out of synch.

Product Features

  • Polycarbonate Boiler and Tender Body
  • Die-Cast Metal Chassis
  • Authentic Paint Scheme
  • Handpainted Engineer and Fireman Figures
  • Painted Cab Backhead Gauges
  • Legible Builders Plates
  • Metal Handrails, Whiste and Bell
  • Tender Truck Chains
  • Sprung Drivers
  • Remote-Controlled Proto-Coupler
  • Hook & Chain Coupler Assembly
  • G Scale Kadee-Compatible Coupler Mounting Pads
  • Prototypical Rule 17 Lighting
  • Constant Voltage LED Headlight
  • Operating LED Firebox Glow
  • Operating LED Marker Lights
  • Operating LED Numberboard Lights
  • Lighted LED Cab Interior
  • Operating Tender LED Back-up Light
  • (2) Powerful 5-Pole Precision Flywheel-Equipped Skew-Wound Motor
  • Synchronized Puffing ProtoSmoke System
  • Steaming Quillable Whistle
  • Locomotive Speed Control In Scale MPH Increments
  • Wireless Drawbar
  • 1:32 Scale Dimensions
  • Onboard DCC/DCS Decoder
  • Proto-Sound 3.0 With The Digital Command System Featuring Quillable Whistle With Passenger Station (Oil Burner) or Freight Yard (Coal Burner) Proto-Effects
  • Unit Measures:
  • Operates On R3 Curves

    Steam DCC Features


  • F0 Head/Tail light
  • F1 Bell
  • F2 Horn
  • F3 Start-up/Shut-down
  • F4 PFA
  • F5 Lights (except head/tail)
  • F6 Master Volume
  • F7 Steaming Whistle
  • F8 Rear Coupler
  • F9 Forward Signal
  • F10 Reverse Signal
  • F11 Grade Crossing
  • F12 Smoke On/Off
  • F13 Smoke Volume
  • F14 Idle Sequence 3
  • F15 Idle Sequence 2
  • F16 Idle Sequence 1
  • F17 Extended Start-up
  • F18 Extended Shut-down
  • F19 Labor Chuff
  • F20 Drift Chuff
  • F21 One Shot Doppler
  • F22 Coupler Slack
  • F23 Coupler Close
  • F24 Single Horn Blast
  • F25 Engine Sounds
  • F26 Brake Sounds
  • F27 Cab Chatter
  • F28 Feature Reset