Wylam 0-4-0 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class Puffing Billy (Locobase 639)

Data from a Spanish-language site ([]). See also "The Centenary of Hedley's "Puffing Billy", The Locomotive, Volume 19 (15 May 1913), pp. 104-106.

One of the earliest steam locomotives. Walking beams had shafts reaching down to small cranks on the frame; these drove an intermediate gear that distributed the piston force between the two axles through a larger gear that meshed directly with those on the two axles. The engine puffed because Hedley and Blackett attached blast pipes to each cylinder.

After its initial trials, Puffing Billy's weight was spread out over the 36 lb/yard (18 kg/metre) rail on two bogies, each of which carried four wheels. A diagram shows geared wheels meshed with similarly sized gears on all four axles, all driven by the single intermediate gear through the middle drive gear.

Poor steamer because of lack of good drafting.

Withal, the engine operated until 1862 and has been preserved.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassPuffing Billy
Locobase ID639
CountryGreat Britain
Number in Class3
Road Numbers
Number Built3
Valve Gear
Locomotive Length and Weight
Driver Wheelbase (ft / m) 6.23 / 1.90
Engine Wheelbase (ft / m) 6.23 / 1.90
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m)
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)20,260 / 9190
Engine Weight (lbs / kg)20,260 / 9190
Tender Loaded Weight (lbs / kg)9110 / 4132
Total Engine and Tender Weight (lbs / kg)29,370 / 13,322
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)17 / 8.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)39 / 991
Boiler Pressure (psi / kPa)50 / 3.40
High Pressure Cylinders (dia x stroke) (in / mm)9" x 36" / 229x914
Tractive Effort (lbs / kg)3178 / 1441.52
Factor of Adhesion (Weight on Drivers/Tractive Effort) 6.38
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)
Grate Area (sq ft / m2) 5.16 / 0.48
Evaporative Heating Surface (sq ft / m2)87 / 8.09
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)87 / 8.09
Evaporative Heating Surface/Cylinder Volume32.82
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation258
Same as above plus superheater percentage258
Same as above but substitute firebox area for grate area
Power L1
Power MT

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