Great Central 2-8-0 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class 8K/O4 (Locobase 16004)

Data from "New Locomotives, Great Central Railway", The Locomotive, Volume 16 (15 November 1910), p. 237; and Volume 17 (15 December 1911), p. 256.

Fitted from the start with a superheater and, like most British engines of the time, fitted with a Belpaire firebox, these Consolidations used many of the same components as did the earlier 0-8-0s. The boiler was essentially identical to the Atlantic boiler.


Class 8M/O5 (Locobase 2347)

Data from Richard Marsden, "The Robinson O4 (ROD) and O5 (GCR 8K and 8M) 2-8-0s", on the LNER Encyclopedia website at [link], last accessed 19 July 2019; and Ahrons (1927).

JG Robinson two-cylinder (outside) Consolidation for freight slogging. According to Marsden, "[T]he GCR 8K would become one of the most successful British steam locomotive designs of the 20th Century. Robinson is also on record with the opinion that the 8K was his best design."

Robinson took his Q4 0-8-0 design, added cylinder volume by increasing cylinder diameter from 19" to 21", fitting a superheated boiler and Belpaire firebox, and replacing the slide valves inside 10" (254 mm) piston valves.

So successful was the design design that it became the model for the Ministry of War's Railroad Operating Department (ROD) Consolidations; see the full account at Locobase 2742.

This 8M (the LNER designation O5 was assigned upon the 1923 Grouping) is the later design with a slightly larger higher-pressure boiler.


Class 8M/O5 - 42 elements (Locobase 16005)

JG Robinson two-cylinder (outside) Consolidation for freight slogging. See Ahrons (1927) for data. Thus was such a successful design that it became the model for the Ministry of War's Railroad Operating Department (ROD) Consolidations; see the full account at Locobase 2742.

This 8M (the LNER designation O5 was assigned upon the 1923 Grouping) is the later design with a slightly larger higher-pressure boiler.

Principal Dimensions by Steve Llanso of Middle Run Media
Class8K/O48M/O58M/O5 - 42 elements
Locobase ID16004 2347 16005
RailroadGreat CentralGreat CentralGreat Central
CountryGreat BritainGreat BritainGreat Britain
Whyte2-8-02-8-02-8-0
Number in Class12919
Road Numbers412-415
GaugeStdStdStd
Number Built12919
BuilderGorton
Year191119181923
Valve GearStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)17.08 / 5.2117.09 / 5.2117.09 / 5.21
Engine Wheelbase (ft / m)25.33 / 7.7225.42 / 7.7525.42 / 7.75
Ratio of driving wheelbase to overall engine wheelbase 0.67 0.67 0.67
Overall Wheelbase (engine & tender) (ft / m)50.75 / 15.47
Axle Loading (Maximum Weight per Axle) (lbs / kg)36,960 / 16,765
Weight on Drivers (lbs / kg)147,840 / 67,059152,096 / 68,990152,096 / 68,990
Engine Weight (lbs / kg)162,400 / 73,663168,448 / 76,407168,448 / 76,407
Tender Loaded Weight (lbs / kg)103,376 / 46,891
Total Engine and Tender Weight (lbs / kg)265,776 / 120,554
Tender Water Capacity (gals / ML)4800 / 18.18
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 5.50 / 5
Minimum weight of rail (calculated) (lb/yd / kg/m)62 / 3163 / 31.5063 / 31.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)56 / 142256 / 142256 / 1422
Boiler Pressure (psi / kPa)180 / 1240180 / 1240180 / 1240
High Pressure Cylinders (dia x stroke) (in / mm)21" x 26" / 533x66021" x 26" / 533x66021" x 26" / 533x660
Tractive Effort (lbs / kg)31,327 / 14209.7131,327 / 14209.7131,327 / 14209.71
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.72 4.86 4.86
Heating Ability
Tubes (number - dia) (in / mm)144 - 2" / 51116 - 2.25" / 5767 - 2.25" / 57
Flues (number - dia) (in / mm)18 - 5.25" / 13328 - 5.25" / 13398 - 3" / 76
Flue/Tube length (ft / m)15 / 4.5715.36 / 4.6817.25 / 5.26
Firebox Area (sq ft / m2)153 / 14.21174 / 16.16174.50 / 16.21
Grate Area (sq ft / m2)25 / 2.3226 / 2.4226.24 / 2.44
Evaporative Heating Surface (sq ft / m2)1691 / 157.101815 / 168.621767 / 164.16
Superheating Surface (sq ft / m2)198 / 28.61308 / 28.61570 / 52.95
Combined Heating Surface (sq ft / m2)1889 / 185.712123 / 197.232337 / 217.11
Evaporative Heating Surface/Cylinder Volume162.24174.14169.53
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation450046804723
Same as above plus superheater percentage495053825857
Same as above but substitute firebox area for grate area30,29436,01838,948
Power L16831879612,523
Power MT407.46509.99726.08

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