Developed as part of the range of twelve Standard engine designs that entered British Railway service in the 1950s. RA Riddles used the Class 2 Mogul's (Locobase 2369) boiler and cylinders for this Prairie tank. The first 20 were built at Crewe and went to work on the London Midland Region (a renamed portion of the LMS). The later 10 were delivered from Darlington and ran on the Southern Region.
Because all of the 2Ts were scrapped, the Bluebell undertook a project to rebuild the very similar Class 2 Mogul as a 2T replica.
Data from "BR Standard Class 3. 2-6-2 Tank Engine" diagram; and [] for a history of this class. See also [
] . Developed as part of the range of twelve Standard engine designs that entered British Railway service in the 1950s. As the 82045 history notes, Chief Mechanical Engineer RA Riddles determined that unlike the other standard designs, this design's requirements didn't match up to an existing LMS boiler. So development drew on an earlier Great Western 2-6-2 design that was shortened slightly.
According to the admittedly partisan 82045 site (which chronicles the construction of the "next" Class 3), the result was neat and well-proportioned. (They fell about in the middle of the pack in size and power among the 2-6-2Ts that served standard-gauge railways.)
The class has frequently been described as mediocre, but, says 82045.org, "...this is not borne out at all by many of the men who worked on them ...what is particularly telling is that the hard-bitten GWR crews of Machynlleth after initial hostility came to accept them as worthy replacments for the ...Small Prairies they had driven." They were "...fast, free-running engines with excellent powers of acceleration."
Sent all over England and Wales after their introduction in 1952, Class 3Ts were used on "...just about every conceivable duty ...and could turn in some sparkling performances." Only express passenger workings were off-limits, a run for which their 63" drivers would have disqualified them in any case.
They were in service for only about 10-15 years and all were scrapped. The 82045.org group began building a new Class 3T from scratch in the 21st Century. As of 2021, work continued.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | Class 2T | Class 3T |
Locobase ID | 4376 | 3107 |
Railroad | British Railways | British Railways |
Country | Great Britain | Great Britain |
Whyte | 2-6-2T | 2-6-2T |
Number in Class | 30 | 45 |
Road Numbers | 84000-84029 | 82000-82044 |
Gauge | Std | Std |
Number Built | 30 | 45 |
Builder | several | Swindon |
Year | 1953 | 1952 |
Valve Gear | Walschaert | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 13.75 / 4.19 | 15.17 / 4.62 |
Engine Wheelbase (ft / m) | 30.25 / 9.22 | 32.58 / 9.93 |
Ratio of driving wheelbase to overall engine wheelbase | 0.45 | 0.47 |
Overall Wheelbase (engine & tender) (ft / m) | 30.25 / 9.22 | 32.58 / 9.93 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 31,360 / 14,225 | 36,512 / 16,562 |
Weight on Drivers (lbs / kg) | 92,400 / 41,912 | 110,880 / 50,294 |
Engine Weight (lbs / kg) | 148,400 / 67,313 | 168,000 / 76,204 |
Tender Loaded Weight (lbs / kg) | ||
Total Engine and Tender Weight (lbs / kg) | ||
Tender Water Capacity (gals / ML) | 1620 / 11.36 | 1800 / 6.82 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 3.40 / 4 | 3.40 / 3.10 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 51 / 25.50 | 62 / 31 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 60 / 1524 | 63 / 1600 |
Boiler Pressure (psi / kPa) | 200 / 1380 | 200 / 1380 |
High Pressure Cylinders (dia x stroke) (in / mm) | 16.5" x 24" / 419x610 | 17.5" x 26" / 445x660 |
Tractive Effort (lbs / kg) | 18,513 / 8397.37 | 21,486 / 9745.90 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.99 | 5.16 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 162 - 1.625" / 41 | 143 - 1.625" / 41 |
Flues (number - dia) (in / mm) | 12 - 5.125" / 130 | 18 - 5.125" / 130 |
Flue/Tube length (ft / m) | 10.85 / 3.31 | 10.85 / 3.31 |
Firebox Area (sq ft / m2) | 101 / 9.39 | 118.42 / 11 |
Grate Area (sq ft / m2) | 17.50 / 1.63 | 20.35 / 1.89 |
Evaporative Heating Surface (sq ft / m2) | 1025 / 95.26 | 1042 / 96.81 |
Superheating Surface (sq ft / m2) | 124 / 11.52 | 185 / 17.19 |
Combined Heating Surface (sq ft / m2) | 1149 / 106.78 | 1227 / 114 |
Evaporative Heating Surface/Cylinder Volume | 172.57 | 143.96 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 3500 | 4070 |
Same as above plus superheater percentage | 3885 | 4681 |
Same as above but substitute firebox area for grate area | 22,422 | 27,237 |
Power L1 | 8910 | 9572 |
Power MT | 637.77 | 570.96 |