Unspecified 0-4-2 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class Tagus/Darwin (Locobase 4875)

Data from Kerr, Stuart & Company's own web page at [link] . This was one of the standard designs for industrial locomotives suitable for light rail (18-25 lb per yard) and for any gauge between 2' and standard.. Tagus was the saddle-tank variant while Darwin had side tanks. Each was rated at 51 hp.

See Wren for full description.


Class Tattoo/Thames (Locobase 4874)

Data from Kerr, Stuart & Company's own web page at [link] (no longer available) and "Kerr Stuart & Co. Tattoo Class" on Locomotive Fandom at [link], last accessed 1 September 2024.

This was one of the standard designs for industrial locomotives suitable for light rail (18-25 lb per yard/9-12.5 kg/metre) and for any gauge between 2' (610 mm)and standard. The identical Thames model had side tanks instead of the Tattoo's saddle tank. See Wren for full description.

Locomotive fandom's Wikipedia mirror notes two different valve gear setups as "Stephenson from 1904 and modified Hackworth from 1917".


Class unknown (Locobase 20729)

Data from "Tank Locomotive", Engineering, Volume 39 (19 June 1885), pp. 667, 672.

This little industrial tank was displayed at the International Inventions Exhibition in 1885. Although small, it used a large tapered stack with spark arrester and a full canopy over the footplate. Possibly to fit the gear into the very small space, the Morton gear featured several different links in its train, all of which is minutely described in the Engineering report.

Principal Dimensions by Steve Llanso of Middle Run Media
ClassTagus/DarwinTattoo/Thamesunknown
Locobase ID4875 4874 20729
Railroad
CountryGreat BritainGreat BritainGreat Britain
Whyte0-4-2ST0-4-2ST0-4-2T
Number in Class1
Road Numbers
GaugeStdStd2'6"
Number Built801
BuilderKerr, Stuart & CoKerr, Stuart & CoDick, Kerr & Company
Year1885
Valve GearvariousMorton
Locomotive Length and Weight
Driver Wheelbase (ft / m)3 / 0.914 / 1.22
Engine Wheelbase (ft / m) 7.92 / 2.417 / 2.13
Ratio of driving wheelbase to overall engine wheelbase 0.38
Overall Wheelbase (engine & tender) (ft / m) 7.9211.75 / 3.58
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)19,040 / 8636
Engine Weight (lbs / kg)24,528 / 11,12619,040 / 8636
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)
Tender Water Capacity (gals / ML)288 / 1.09168 / 0.64126 / 0.48
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 0.30
Minimum weight of rail (calculated) (lb/yd / kg/m)16 / 8
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)27 / 68624 / 61027 / 686
Boiler Pressure (psi / kPa)160 / 1100160 / 1100120 / 830
High Pressure Cylinders (dia x stroke) (in / mm)8" x 12" / 203x3057" x 12" / 178x3057" x 12" / 178x305
Tractive Effort (lbs / kg)3868 / 1754.503332 / 1511.372221 / 1007.43
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.71
Heating Ability
Tubes (number - dia) (in / mm)51 - 1.75" / 4436 - 1.75" / 4440 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 6.25 / 1.90
Firebox Area (sq ft / m2)25 / 2.3219.50 / 1.8121 / 1.95
Grate Area (sq ft / m2)5 / 0.464 / 0.37 3.50 / 0.33
Evaporative Heating Surface (sq ft / m2)132 / 12.27109 / 10.13134 / 12.45
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)132 / 12.27109 / 10.13134 / 12.45
Evaporative Heating Surface/Cylinder Volume189.08203.93250.70
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation800640420
Same as above plus superheater percentage800640420
Same as above but substitute firebox area for grate area400031202520
Power L1265124732415
Power MT572.69

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