Caledonian 4-6-2 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class 191 - Oban bogies (Locobase 2358)

For data see E C Poultney, "Recent Locomotive Practice on the Caledonian Railway - Part II", Engineer, Volume 132 (11 November 1921), pp. 499-500. See also Ahrons; "New 4-6-2 Type Tank Locomotives: Caledonian Railway", Locomotive Magazine, Volume XXIII [23], No 300 (15 August 1917), p. "4-6-2 Superheater Tank Locomotives, Caledonian Railway," Locomotive Magazine, Volume XXIV [24], No 306 (15 February 1918), pp. 21-22; and Wikipedia at [], last accessed 25 October 2017.. Works numbers were 21480-21491 in 1917.

William Pickersgill's inside-valve, outside-cylinder local passenger tanks. Although their power dimensions were similar to those of the 60-class 4-6-0 tender locomotives shown in Locobase 2331, these had slightly less tube and flue areas and only about half the superheater area.

Demands of war called the class to serving heavy munitions trains in the Glasgow District. With the 1918 Armistice, they were put on the Inverclyde line, which connects Glasgow with Wemyss Bay on the Firth of Clyde. Wikipedia notes that the drivers called them "Wemyss Bay Pugs", a mysterious moniker whose meaning becomes clearer when one reads another Wikipedia entry noting that "pug" was often used to describe small shunters and occasionally tank engines. (Locobase guesses that the original nickname derived from the snub-nosed, short-legged dog breed whose owners dote on the pet's amiable disposition.)

After being displaced later in their careers by larger engines, the 944s were assigned as bankers (helpers) on the notorious Beattock Bank. All but two survived long enough to be nationalized in 1948. British Railways retired those engines in 1948-1953.

Principal Dimensions by Steve Llanso of Sweat House Media

Class191 - Oban bogies
Locobase ID2358
CountryGreat Britain
Number in Class12
Road Numbers944-955/15350-15361/55350-55355, 55358-55361
Number Built12
BuilderNorth British
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.25 / 4.04
Engine Wheelbase (ft / m)33.08 / 10.08
Ratio of driving wheelbase to overall engine wheelbase 0.40
Overall Wheelbase (engine & tender) (ft / m)33.08 / 10.08
Axle Loading (Maximum Weight per Axle) (lbs / kg)41,328 / 18,746
Weight on Drivers (lbs / kg)123,312 / 55,933
Engine Weight (lbs / kg)205,296 / 93,121
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)205,296 / 93,121
Tender Water Capacity (gals / ML)2160 / 8.18
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.30 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)69 / 34.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)69 / 1753
Boiler Pressure (psi / kPa)170 / 11.70
High Pressure Cylinders (dia x stroke) (in / mm)19.5" x 26" / 495x660
Tractive Effort (lbs / kg)20,704 / 9391.19
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.96
Heating Ability
Tubes (number - dia) (in / mm)159 - 1.75" / 44
Flues (number - dia) (in / mm)18 - 5" / 127
Flue/Tube length (ft / m)14.58 / 4.44
Firebox Area (sq ft / m2)121 / 11.24
Grate Area (sq ft / m2)21.50 / 2
Evaporative Heating Surface (sq ft / m2)1516 / 140.84
Superheating Surface (sq ft / m2)200 / 18.58
Combined Heating Surface (sq ft / m2)1716 / 159.42
Evaporative Heating Surface/Cylinder Volume168.69
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3655
Same as above plus superheater percentage4094
Same as above but substitute firebox area for grate area23,038
Power L18530
Power MT457.51

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Wes Barris