Data from "Southern Railway: New 4-4-0 Type Engines", Locomotive Magazine, Volume 32 (14 April 1926), p. 106; and "New 4-4-0 Locomotive, Southern Railway: ", Railway Engineer, Volume 47, No 5 (May 1926), p. 186 . See also "SR L1 class" in Wikipedia at [], last accessed 14 July 2024; and "SR Maunsell L1 Class 4-4-0" on the SR Email Group website at [
], last accessed 14 July 2024..
These are almost certainly a continuation of the SE&CR L class locomotives of 1914 described in Locobase 5797 and like the SE&CR engines, these had Belpaire fireboxes. Even so, Chief Mechanical Officer Richard Maunsell of the newly grouped Southern Railway considerably updated the design.
Their construction addressed a need for express passenger power, paritularly the ex-SECR London to Dover, Ramsgate, and Hastings boat trains. Although the Lord Nelson 4-6-0s (Locobase 2513) had already begun emerging from the shops, Maunsell made us of "found money" in a previous order for L class cengines to address the need.
His new boiler allowed a boiler pressure increase of 20 psi from 160 to 180 and adopted Maunsell's own variant of the MLS superheater. The prospective tractive effort dropped when he reduced cylinder bore by 1" (25.4 mm). This new set were fed through long-travel (5 3/8"/137 mm) piston valves of 9" (229 mm) diameter. Locomotive Magazine's report noted the roomier cab designed to put all salient controls at easy reach. The smokebox, too, gained from development of the Lord Nelsons.
They would be known as the "Glasshouses", presumably because of the added cab window area, but no one was throwing stones. At numbered in the A series, they soon bore new number that simply replaced the A with a 1 (e.e 1753); BR renumbering simply prefixed 1753 etc. with a 3 (31753). The L1s proved a sound upgrade of Wainwright's already good design and served the Southern and British Railways into the early 1960s.
See also "Maunsell V "Schools" class 4-4-0" on the Southern E-Group's website at [], last accessed 5 April 2017. 900-909 produced in 1930, 910-929 in 1932-1934, and 930-939 in 1934-1935.
Designed by R E L Maunsell, these big 4-4-0s were only slightly smaller than the King Arthur 4-6-0s. Southern built a total of 40, naming each after a British public school. The Southern E-Group account says that the Schools class resulted from an intermediate-power requirement for hauling expresses on weight-restricted lines such asTonbridge to Hastings and Chatham to Ramsgate lines. Maunsell chose to "use a shortened King Arthur pattern boiler but retaining the full late series N15/S15 (4-6-0) firebox."
According to Hollingsworth (1982), the design "was a great success from the start, and very few changes were needed over the years." The E-Group says: "The end result more than exceeded expectations since the design proved to be extremely free steaming even with poor grades of coal and with remarkably low internal friction contributing to a tractive effort of 25120 lb - only 200 lb less than a King Arthur."
One performance of note was run from Waterloo Station to Southampton with a 510-ton train at an average speed of 61 mph. OS Nock (RWC V, pl 79) calls the Schools "the finest 4-4-0 ever to run in Great Britain."
Retirements came in 1961-1962.
Principal Dimensions by Steve Llanso of Middle Run Media | ||
---|---|---|
Class | L1 | V Schools |
Locobase ID | 3158 | 1060 |
Railroad | Southern | Southern |
Country | Great Britain | Great Britain |
Whyte | 4-4-0 | 4-4-0 |
Number in Class | 15 | 40 |
Road Numbers | A753-A 759, A782-A789/ see comments | 900-939 |
Gauge | Std | Std |
Number Built | 15 | 40 |
Builder | North British | Eastleigh |
Year | 1926 | 1929 |
Valve Gear | Stephenson | Walschaert |
Locomotive Length and Weight | ||
Driver Wheelbase (ft / m) | 10 / 3.05 | 10 / 3.05 |
Engine Wheelbase (ft / m) | 24.29 / 7.40 | 25.50 / 7.77 |
Ratio of driving wheelbase to overall engine wheelbase | 0.41 | 0.39 |
Overall Wheelbase (engine & tender) (ft / m) | 48.23 / 14.70 | 48.50 / 14.78 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 43,680 / 19,813 | 47,000 / 21,319 |
Weight on Drivers (lbs / kg) | 85,120 / 38,610 | 94,087 / 42,677 |
Engine Weight (lbs / kg) | 131,040 / 59,439 | 150,315 / 68,182 |
Tender Loaded Weight (lbs / kg) | 90,720 / 41,150 | 94,976 / 43,080 |
Total Engine and Tender Weight (lbs / kg) | 221,760 / 100,589 | 245,291 / 111,262 |
Tender Water Capacity (gals / ML) | 4200 / 15.91 | 4800 / 18.18 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5.50 / 5 | 5.50 / 5 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 71 / 35.50 | 78 / 39 |
Geometry Relating to Tractive Effort | ||
Driver Diameter (in / mm) | 80 / 2032 | 79 / 2007 |
Boiler Pressure (psi / kPa) | 180 / 1240 | 220 / 1520 |
High Pressure Cylinders (dia x stroke) (in / mm) | 19.5" x 26" / 495x660 | 16.5" x 26" / 419x660 (3) |
Tractive Effort (lbs / kg) | 18,908 / 8576.53 | 25,133 / 11400.15 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.50 | 3.74 |
Heating Ability | ||
Tubes (number - dia) (in / mm) | 169 - 1.75" / 44 | 216 - 1.75" / 44 |
Flues (number - dia) (in / mm) | 21 - 5.25" / 133 | 24 - 5.25" / 133 |
Flue/Tube length (ft / m) | 11.79 / 3.59 | 12.28 / 3.74 |
Firebox Area (sq ft / m2) | 154.50 / 14.35 | 162 / 15.05 |
Grate Area (sq ft / m2) | 22.50 / 2.09 | 28.30 / 2.63 |
Evaporative Heating Surface (sq ft / m2) | 1407 / 130.71 | 1766 / 164.07 |
Superheating Surface (sq ft / m2) | 235 / 21.83 | 283 / 26.29 |
Combined Heating Surface (sq ft / m2) | 1642 / 152.54 | 2049 / 190.36 |
Evaporative Heating Surface/Cylinder Volume | 156.56 | 182.97 |
Computations Relating to Power Output (More Information) | ||
Robert LeMassena's Power Computation | 4050 | 6226 |
Same as above plus superheater percentage | 4617 | 7098 |
Same as above but substitute firebox area for grate area | 31,703 | 40,630 |
Power L1 | 11,468 | 15,375 |
Power MT | 594.05 | 720.53 |