Data from "Locomotive History of the London, Chatham & Dover Ry," The Locomotive Magazine, Vol VIII (3 Jan 1903), p. 4. Works numbers were 1741-1746.
William Martley turned to a solid outside frame and a straight, domeless boiler for these relatively small suburban and metropolitan engine. An unusual feature of this well tank was the considerable distance between the rear coupled axle (which was also the driven axle) and the single trailing axle under the bunker.
The author also records the sad fact that these were the last locomotives to be designed by Martley, who died in the following year.
Data from "Locomotive History of the London, Chatham & Dover Ry," The Locomotive Magazine, Vol VII (June 1902), p. 96.
Originally intended for the Glasgow & South Western, this pair wound up the LC & DR. he other was named Corsair.
Data from "Radial Locomotives", The Engineer, Volume 22 (30 November 1866), p. 425. See also W B Paley, "Engines of the London, Chatham and Dover Railway", Railway World, Volume VI[6], No 2 (February 1897), p. 37.
William Martley figured that William Adams' radial axle design would be the answer to the tight curves The trailing truck's axle hornplates tracked an arc that had a 7 ft 3 in (2.21 m) radius.Engineer's report commented that the designs ran "with remarkable absence of frictional resistance round exceedingly sharp curves. It is impossible, indeed, to watch their performance without recognizing the value of the radial axle box."
Indeed, Engineer reported that the engines were "exceedingly well got up and carefully balanced. They have been run at fifty miles per hour [81 kph] with remarkable freedom from oscillation."
The journal found a significant defect, however, in the distance between the rear set of drivers and the drawbar. When the engine entered a sharp curve, the linkage tended to "pull the next carriage off the line." The resulting "jerking and grinding motion" was "very apparent to a passenger in the next compartment." Strains on the carriage's flanges and on both sets of drivers added to the unwelcome effect of this awkward geometry. Engineer recommended extending the drawbar forward. Later reports agreed that the radial axle was a design that peformed best under a trailing axle and when run tank-end first, oscillated greatly.
Data from "Locomotive History of the London, Chatham & Dover Ry," The Locomotive Magazine, Vol VII (September 1902), p. 152. "Tank Locomotive Fitted with Adams' Patent Radial Axle Boxes", Engineer, Volume 22 (30 November 1866), 425-426. Boiler pressure is an estimate. Works numbers were 1188-1196 in May 1866; 1197-1198, 1200-1201, 1209 in July
These were suburban tank engines designed by the LC & DR's William Martley were supplied by the Glasgow builder in very nearly a single batch. Their duty was hauling the traffic between Herne Hill and the Great Northern's station at Hatfield, Herne Hill and King's Cross station in London, and the High Level Crystal Palace line.
Engineer commented on the exceptionally long spacing between the second driven axle, which lay in front of the firebox, and the trailing axle, which supported the water tank and bunker. He added:"To force an ordinary six-wheeled locomotive of such length round the curves which these engines traverse daily would be impossible."
Ah, but" All difficulties are obviated, however, by fitting the trailing wheels with Mr W R Adams' patent radiating axle boxes." The design left the axle box "perfectly free to shift right or left, through a distance of about 2" [50.8 mm] each way, representing a total traverse of rather over 4" (102 mm)." As a result, the engines rounded sharp curves with little evidence of binding. "It is impossible, indeed, to watch their performance without recognizing the value of the radial axle box."
Less satisfactory was the coal bunker's height which, when running backwards (as they did about half the time), made it "simply impossible to keep a look out from the foot plate, as the coal piled up ...is considerably above the driver's head." And the workaround chilled the writer (and this reader): "The stoker is therefore compelled to take a very perilous and absolutely unsheltered position on the side plate which runs round the tanks, holding onto the handle of his brake the best he can."
The first seven names referred to islands in the British Isles, the last seven to rivers:
81 Iona
82 Bute
83 Jura
84 Arran
85 Islay
86 Staffa
87 Ulva
88 Clyde
89 Kilvin
90 Spey
91 Annan
92 Tay
93 Nith
94 Esk
Because all of the place names were in Scotland, the class came to be known to the crews as the "Little Scotchmen".
According to a letter in the English Mechanic and World of Science Journal (No. 765, 21 November 1879, p. 266) from "GLP", only four of the fourteen were delivered with 16 1/2" cylinders. The writer uses the Clyde (#88) as the source for his areas and counts which are quite a bit smaller and more in line with the rebuilds mentioned below. Thus it may be that the Clyde was rebuilt well before the rest of the class.
Operating in the tunnels of Metropolitan Railway between Ludgate Hill and Moorgate Street meant being fitted with exhaust condensing equipment. A photo shows heavy outside framing, outside springs, outside coupling rod, and inside everything else including the cylinders.
The entire class was rebuilt by William Kirtley beginning in 1886; see Locobase 10460.
Data from "Locomotive History of the London, Chatham & Dover Ry," The Locomotive Magazine, Vol X (15 August 1904), p. 140. Boiler pressure is an estimate.
Originally put in service as the Tay class in 1866 (Locobase 10237), this class of Little Scotchmen was taken in hand by William Kirtley 20 years later and reconditioned with a new, smaller boiler and slightly more cylinder volume. This program may have been anticipated several years earlier because data given for the Clyde (#88) in an 1879 letter (see Locobase 10237) are virtually identical.
The significant change in boiler dimensions may have been due to a change in duties from the Metropolitan service.
Principal Dimensions by Steve Llanso of Middle Run Media | |||||
---|---|---|---|---|---|
Class | Albion | Brigand | Scotchmen | Tay | Tay - rebuilt |
Locobase ID | 10251 | 10230 | 20497 | 10237 | 10460 |
Railroad | London, Chatham & Dover | London, Chatham & Dover | London, Chatham & Dover | London, Chatham & Dover | London, Chatham & Dover |
Country | Great Britain | Great Britain | Great Britain | Great Britain | Great Britain |
Whyte | 0-4-2T | 0-4-2 | 0-4-2T | 0-4-2WT | 0-4-2WT |
Number in Class | 6 | 2 | 14 | 14 | 14 |
Road Numbers | 460 | 81-94 | 81-94 | ||
Gauge | Std | Std | Std | Std | Std |
Number Built | 6 | 2 | 14 | 14 | |
Builder | Neilson & Co | Sharp, Stewart | Neilson & Co | Neilson & Co | Neilson & Co |
Year | 1873 | 1861 | 1866 | 1866 | 1886 |
Valve Gear | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson |
Locomotive Length and Weight | |||||
Driver Wheelbase (ft / m) | 7.25 / 2.21 | 7.17 / 2.19 | 7.50 / 2.29 | 7.50 / 2.29 | 7.50 / 2.29 |
Engine Wheelbase (ft / m) | 20.25 / 6.17 | 14 / 4.27 | 19.25 / 5.87 | 19.25 / 5.87 | 11.75 / 3.58 |
Ratio of driving wheelbase to overall engine wheelbase | 0.36 | 0.51 | 0.39 | 0.39 | 0.64 |
Overall Wheelbase (engine & tender) (ft / m) | 20.25 / 6.17 | 19.25 / 5.87 | 19.25 / 5.87 | ||
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 34,720 / 15,749 | 31,584 / 14,326 | |||
Weight on Drivers (lbs / kg) | 58,464 / 26,519 | 48,832 / 22,150 | 60,704 / 27,535 | 60,704 / 27,535 | |
Engine Weight (lbs / kg) | 93,184 / 42,268 | 60,704 / 27,535 | 93,184 / 42,268 | 92,624 / 42,014 | |
Tender Loaded Weight (lbs / kg) | |||||
Total Engine and Tender Weight (lbs / kg) | |||||
Tender Water Capacity (gals / ML) | 1320 / 5 | 1200 / 4.55 | 1168 / 4.42 | ||
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1.10 / 1 | 1.10 / 1 | 0.90 / 1 | ||
Minimum weight of rail (calculated) (lb/yd / kg/m) | 49 / 24.50 | 41 / 20.50 | 51 / 25.50 | ||
Geometry Relating to Tractive Effort | |||||
Driver Diameter (in / mm) | 67 / 1702 | 60 / 1524 | 66 / 1676 | 66 / 1676 | 66 / 1676 |
Boiler Pressure (psi / kPa) | 140 / 970 | 120 / 830 | 130 / 900 | 120 / 830 | 150 / 1030 |
High Pressure Cylinders (dia x stroke) (in / mm) | 17" x 24" / 432x610 | 16" x 22" / 406x559 | 16.5" x 22" / 419x559 | 16.5" x 22" / 419x559 | 17" x 22" / 432x559 |
Tractive Effort (lbs / kg) | 12,319 / 5587.81 | 9574 / 4342.70 | 10,028 / 4548.63 | 9257 / 4198.91 | 12,283 / 5571.48 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.75 | 5.10 | 6.05 | 6.56 | |
Heating Ability | |||||
Tubes (number - dia) (in / mm) | 131 - 2" / 51 | 184 - 1.875" / 48 | 183 - 2" / 51 | 165 - 1.75" / 44 | |
Flues (number - dia) (in / mm) | |||||
Flue/Tube length (ft / m) | 10.17 | 10.17 | |||
Firebox Area (sq ft / m2) | 93 / 8.64 | 78 / 7.25 | 84 / 7.80 | 84.85 / 7.89 | |
Grate Area (sq ft / m2) | 13.10 / 1.22 | 13.37 / 1.24 | 14.60 / 1.36 | 15.20 | 14.63 / 1.36 |
Evaporative Heating Surface (sq ft / m2) | 754 / 70.07 | 898 / 83.46 | 853 / 79.25 | 1053 / 97.83 | 853 / 79.28 |
Superheating Surface (sq ft / m2) | |||||
Combined Heating Surface (sq ft / m2) | 754 / 70.07 | 898 / 83.46 | 853 / 79.25 | 1053 / 97.83 | 853 / 79.28 |
Evaporative Heating Surface/Cylinder Volume | 119.59 | 175.40 | 156.67 | 193.40 | 147.59 |
Computations Relating to Power Output (More Information) | |||||
Robert LeMassena's Power Computation | 1834 | 1604 | 1898 | 1824 | 2195 |
Same as above plus superheater percentage | 1834 | 1604 | 1898 | 1824 | 2195 |
Same as above but substitute firebox area for grate area | 13,020 | 9360 | 10,080 | 12,728 | |
Power L1 | 3023 | 3019 | 3571 | 3646 | |
Power MT | 227.99 | 272.60 |