British Railways 2-10-0 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class Evening Star - Class 9 (Locobase 2129)

Data from BR Standard Class 9 2-10-0 Engine diagram. See also Gustav Reder (Michael Reynolds, trans), The world of steam locomotives (New York: Putnam, 1974); O S Nock (Railways of the World in Color, Volume VI), plate 59.

These were the last new steam engines built in Great Britain. Called by OS Nock (RWC VI, pl. 59) "the most outstanding design of all the [post-1948 nationalization] British standard range ...," they reflected World War II encounters with a War Department decapod design, which led to a decision to add a driver set to plans for a 2-8-0. These were a relatively small example of the 2-10-0 arrangement with a Belpaire boiler over the fifth driving axle, plate frame, straight boiler bolted to an extended smokebox of slightly smaller diameter, inclined outside cylinders driving the middle axle, elephant-ear smoke lifters. Glover (1967), noting the "ungainly appearance" of the sharp rake of the cylinders caused by loading gauge restrictions, adds that this placement "can hardly have been unattended by unfavourable effects due to the vertical element in the line through which power was transmitted."

All but the last engine were delivered with the KylChap double-blastpipe stack; Evening Star used a Giesl ejector. (The Giesl ejector, Reder comments, " was a surprisingly successful Austrian development which replaced the normal blast pipe nozzle and produced a remarkable increase in performance. Unfortunately it came too late to be used generally.")

They were intended for freight haulage with their 62" drivers, but the accumulated skill and experience allowed them to deputize for 4-6-0s and Pacifics in 90-mph (145 kph) express passenger service.

C. Hamilton Ellis (1968) noted that the last engine, appropriately named Evening Star (92220), was condemned for replacement by diesels in 1965, five years after her emergence from the Swindon Works (established by the Great Western). His verdict is blunter and less romantic: "This was a good, simple, straightforward yet powerful design, and one feels that it was an economic blunder that, if they were thus soon doomed, such engines should have been built at all. There were, already, enough good steam engines."

True enough, perhaps, but let Glover's valedictory stand for all those who believed steam locomotives represented more than mechanical transportation: "Nevertheless, these engines were of remarkable conception and design and few would refuse to recognize them as representing a worthy culmination of the resource and ingenuity displayed by British locomotive engineers over the century and a quarter [that followed Stephenson's first design]."

Principal Dimensions by Steve Llanso of Sweat House Media

ClassEvening Star - Class 9
Locobase ID2129
RailroadBritish Railways
CountryGreat Britain
Number in Class221
Road Numbers92000-92250
Number Built221
BuilderL&NW - Crewe
Valve GearWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)21.67 / 6.61
Engine Wheelbase (ft / m)30.17 / 9.20
Ratio of driving wheelbase to overall engine wheelbase 0.72
Overall Wheelbase (engine & tender) (ft / m)55.92 / 17.04
Axle Loading (Maximum Weight per Axle) (lbs / kg)34,720 / 15,749
Weight on Drivers (lbs / kg)173,600 / 78,744
Engine Weight (lbs / kg)194,208 / 88,091
Tender Loaded Weight (lbs / kg)117,600 / 53,343
Total Engine and Tender Weight (lbs / kg)311,808 / 141,434
Tender Water Capacity (gals / ML)6750 / 25.57
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 7.80 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)58 / 29
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60 / 1524
Boiler Pressure (psi / kPa)260 / 17.90
High Pressure Cylinders (dia x stroke) (in / mm)20" x 28" / 508x711
Tractive Effort (lbs / kg)41,253 / 18712.07
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.21
Heating Ability
Tubes (number - dia) (in / mm)138 - 2" / 51
Flues (number - dia) (in / mm)35 - 5.25" / 133
Flue/Tube length (ft / m)15.25 / 4.65
Firebox Area (sq ft / m2)179 / 16.64
Grate Area (sq ft / m2)40.20 / 3.74
Evaporative Heating Surface (sq ft / m2)2015 / 187.27
Superheating Surface (sq ft / m2)535 / 49.72
Combined Heating Surface (sq ft / m2)2550 / 236.99
Evaporative Heating Surface/Cylinder Volume197.92
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation10,452
Same as above plus superheater percentage12,647
Same as above but substitute firebox area for grate area56,313
Power L119,728
Power MT1252.67

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