Great eastern 4-4-0 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class 11A/ D6 (Locobase 7475)

Data from [], the 4-4-0 entries in Richard Marsden's online LNER Encyclopedia, last accessed on 1 March 2006.GCR Rolling Trust website -- [], accessed 31 May 2007 -- for weights and wheelbases.

See Locobase 8971 for the original, saturated-boiler 11A. When the class began refitting with superheated boilers in 1912, a 15-element superheater was fitted. This was replaced over time by the 18-element version shown in the specs, but not all 11s were so fitted. The Smith-design piston valves that originally fed steam proved troublesome and several replacements proved unsatisfactory until a Robinson piston valve first installed in 1912 became standard.

Marsden describes the 11's work on the newspaper trains that ran from London to Manchester to supplant the unpopular Manchester Guardian (which opposed the Boer War then in progress). In 1899, one train covered the 206 miles in 220 minutes including stops, a brisk 56-mph average.

As Cheshire-based locomotives (from about 1910 on), Marsden says, the class "...acquired a strong reputaton as a reliable locomotive that could maintain punctual timings. On a number of occasions, bookings had minutes trimmed off or extra stops inserted. It is telling that the D6s [as the LNER would classify them] were capable of maintaining these tight timings on a regular basis."

Although withdrawals began in 1930, nine of the class served into the World War II years. The last retired on the last day of 1947.

Principal Dimensions by Steve Llanso of Sweat House Media

Class11A/ D6
Locobase ID7475
RailroadGreat eastern
CountryGreat Britain
Number in Class33
Road Numbers268-70, 852-881
Number Built
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)9 / 2.74
Engine Wheelbase (ft / m)23.42 / 7.14
Ratio of driving wheelbase to overall engine wheelbase 0.38
Overall Wheelbase (engine & tender) (ft / m)44.67 / 13.62
Axle Loading (Maximum Weight per Axle) (lbs / kg)38,080 / 17,273
Weight on Drivers (lbs / kg)74,256 / 33,682
Engine Weight (lbs / kg)109,536 / 49,685
Tender Loaded Weight (lbs / kg)96,992 / 43,995
Total Engine and Tender Weight (lbs / kg)206,528 / 93,680
Tender Water Capacity (gals / ML)4400 / 16.67
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)62 / 31
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)84 / 2134
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)18.5" x 26" / 470x660
Tractive Effort (lbs / kg)14,407 / 6534.91
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.15
Heating Ability
Tubes (number - dia) (in / mm)90 - 1.93" / 49
Flues (number - dia) (in / mm)18 - 5.25" / 133
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)108 / 10.04
Grate Area (sq ft / m2)19.59 / 1.82
Evaporative Heating Surface (sq ft / m2)893 / 82.99
Superheating Surface (sq ft / m2)138 / 12.83
Combined Heating Surface (sq ft / m2)1031 / 95.82
Evaporative Heating Surface/Cylinder Volume110.40
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation3134
Same as above plus superheater percentage3542
Same as above but substitute firebox area for grate area19,526
Power L17408
Power MT439.88

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