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BigBoy Information Center: Tender


     BigBoy had a centipede type tender, developed by the Union Pacific Railroad and used with all BigBoys. It had 14 wheels (4 leading and 10 trailing). The tender was 39' 1 3/4" long, 9' 7" high and 10' 10" wide. Fully loaded, it weighed in at 82 tons (164,000lbs). It had a capacity of 28 tons of semi-bituminous coal and 25,000 gallons of water.

Tender Coal Capacity: 28 ton (2000lbs/ton)
Tender Capacity: 25,000 gallons

  BigBoy's Tender

A picture from above of BigBoy's Tender
The 3 manhole covers are for water

     In order to feed BigBoy's voracious appetite for coal, a large Stoker was used. This was like a cork screw, or auger, that pulled coal from the tender, broke it up, churned it through a large diameter pipe leading from the tender to the FireBox and shot it into the fire. A fireman could never shovel fast enough to feed the engine. BigBoy ate an average of 122,500lbs of water (12,500 gallons) and 22 tons (44,000lbs) of semi-bituminous coal per hour!

Stoker Schematic

Here is a schematic of a typical Stoker with auger

Auger in Tender

A picture of the Auger from inside the tender of BigBoy 4017

Stoker under Tender

Here is the piping between the locomotive and the tender
The Stoker is that large black pipe leading right (tender) to left (firebox) in the background

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