Great Northern 2-6-0 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class H1 (Locobase 2656)

Most of the data comes from Railroad Gazette 18 May 1900. See also DeGolyer, Volume 22, pp. 150-151. Works numbers were 16927-

16936 in July 1899 and 17321-17325, 17355-17359 in January 1900.

Described in OS Nock (RWC III, pl 22) as generally similar in capability to Ivatt's 0-6-0s, these American engines were ordered to cover a power shortage in the West Riding. Nock comments that they were more lightly built than English engines and didn't have their "staying power ....Although they served their immediate purpose admirably, their life was short." [] adds that "Their oil consumption was high, but this was not a problem in the USA where oil as ever was cheap. Coal consumption at 75 lb per mile (21.13 kg/km) was also high but this was reduced to 55 lb (15.5 kg/km) by fitting extended smokeboxes."

The summary (based on Groves) notes their service experience as well: "The locomotives were assembled at Ardsley and many worked from there. In early 1903 they were used experimentally on King's Cross suburban services where they greatly out-performed (by 50%) the 4-4-2Ts, but they had to be turned. They were rough riding and were withdrawn between 1909 and 1915."


Class H2 / K1 (Locobase 4900)

Data from Richard Marsden's LNER Encyclopedia at [], last accessed 28 June 2006; and "Superheater Mixed Traffic Locomotive, G N Ry", Locomotive Magazine, Volume 18 (15 October 1912) , p. 206. See also O S Nock, The Locomotives of Sir Nigel Gresley, , p. .

The first of the teen series of Moguls were not much bigger than the 1900-era 2-6-0s. A big difference, however, was the superheater. As presented in the contemporary press, its 303 sq ft (28.15 sq m) is quite a bit bigger than typical British locomotive practice. Marsden's figure of 230 sq ft, which Locobase adopts, seems much more in line.

Also, Nigel Gresley applied his double-swing-link pony truck design to the class; its purpose was to equalize the loads on the two truck wheels as the locomotive entered curves. This in turn would allow more stable running at higher speeds. It must have met the need as Gresley used the design on all of his 2-n-n locomotives.

OS Nock singled out the "front end" in which 10" (254 mm) piston valves moved in response to the Walschaert gear. Marsden comments: "Due to their outside Walschaerts valve gear which was unusual with the GNR at that time, they quickly acquired the nickname of 'Ragtimers'. This nickname's fitness was enhanced by their lively nature when running at speed.

"The valve setting was carefully arranged, "said Nock," to give a large exhaust opening when the engine was running well linked-up". His verdict on the design was that despite a relatively small boiler (remedied in H3s that came soon thereafter), "as fast freight engines they were second to none at the time of their construction."

The K1 was soon superseded by the larger K2 and all ten were eventually converted to K2 dimensions.


Class H3/K2 (Locobase 3656)

Data from Richard Marsden's LNER Encyclopedia at [], last accessed 28 June 2006. See also "New 2-6-0 Mixed Traffic Engines, Great Northern Ry", Locomotive Magazine, Volume XX [20] (15 June 1913) and "New Express Goods Locomotives, Great Northern Railway", Locomotive Magazine, Volume XXIV [24], No 311 (15 July 1918); Graham Nicholas, "Design Study of the P2" at [], last accessed 11/27/2017. Doncaster supplied the first two batches, North British Locomotive Company produced another two batches in 1914, and Kitson completed the class in 1921.

These mixed-traffic Moguls preceded the bigger and better-known thre-cylinder engines, but were nonetheless a Nigel Gresley design that used a much bigger boiler with somewhat more direct heating surface. Although the switch from Schmidt to Robinson superheaters added six flues to the boiler, the superheater area grew only marginally. Their outside constant-lead radial valve gear add visible drama to the motion and inspired the nickname "Ragtimers".

Gresley designed and patented an unusual pony truck that featured swing links on the bolster above the center pin line and the one below. Two points on each bolster connected to the ends of arms above (upper bolster) and below (lower bolster). The system acted to equalize the weight on the two pony truck wheels, stabilizing and smoothing the ride.

Marsden notes that the LNER later rebuilt all the K1s (Locobase 4925) to K2 in 1918 (4635) and 1922 (4631) with the other following after a nine-year pause and appearing in 1931 to 1937. These were later dubbed K2/1 and the original K2s as K2/2 (logic would suggest the opposite ...)


Class H4/ K3 (Locobase 2342)

See Ahrons (1927) for data, supplemented by Richard Marsden's LNER Encyclopedia at [], last accessed 28 June 2006; and "Thjree-Cylinder 2-6-0 Locomotive, Great Northern Ry", Locomotive Magazine Volume XXVI [26] (15 April 1920), pp. 72-73 . See also Edward Cecil Poultney, British Express Locomotive Development (London: George Allen and Unwin, 1952), pp. 128-129. When taken into the LNER after grouping, these were designated K3.

Poultney says that these engines "form the basis upon which all the many Gresley three-cylinder engines were built." Among the features that would appear on later engines were the three cylinders that all drove on the middle coupled axle, the use of Gresley's conjugated valve gear system in which three piston valves were actuated by two sets of Walschaert valve gear arranged outside. The valves had a long lap (steam lap of 1 1/2"/38 mm) and maximum travel at full gear and 75% cutoff of 6 3/8" (162 mm).

Possessing a 72" diameter boiler, three 8" (203 mm) piston valves, and a firebox heating surface of 182 sq ft, this design, says Glover (1967), "represented, in terms of power, the highest stage of development to which the Mogul was brought, then or at any other time." OS Nock (RWC IV, pl 120) would agree, noting that although they were designated "mixed traffic", they could hit 75 mph (121 kph) and stood in for express passenger engines in emergencies. Tufnell (1986) credits them with a tonnage rating of 650 tons. K3s ranged all over the system and lasted until the early 1960s. The last was withdrawn in December 1962.

Marsden notes that the class was nicknamed "Jazzers" "...due to their syncopated exhaust beat and uneven gyratory movement at the rear. The exhaust beat was a side-effect of the three cylinder design, and would become a common sound with the advent of further Gresley types." So far, so good.

"The poor riding, however, would pose problems for maintenance," says Marsden. The conjugated gear presented its own difficulties which were eventually resolved by limiting valve cutoff to 65% of the stroke. Long-lap valves, first fitted in 1928, cut coal consumption by 7 1/2 lb per mile (2.11 kg/km) and were quickly adopted for the entire class.

When the second batch steamed poorly, the LNER found the solution in cutting down the stack by 4"(102 mm), which helped greatly and led to enlarging the blastpipe orifice to 5 1/2 (140 mm)". The result was highly satisfactory and was retrofitted to all K3s.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassH1H2 / K1H3/K2H4/ K3
Locobase ID2656 4900 3656 2342
RailroadGreat NorthernGreat NorthernGreat NorthernGreat Northern
CountryGreat BritainGreat BritainGreat BritainGreat Britain
Whyte2-6-02-6-02-6-02-6-0
Number in Class202075193
Road Numbers1181-1200163043311664
GaugeStdStdStdStd
Number Built202065193
BuilderBurnham, Williams & CoDoncasterDoncasterDoncaster
Year1899191219131920
Valve GearStephensonWalschaertWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)14.75 / 4.5016.25 / 4.9516.25 / 4.9516.25 / 4.95
Engine Wheelbase (ft / m)22.67 / 6.9124.83 / 7.5725.17 / 7.6725.17 / 7.67
Ratio of driving wheelbase to overall engine wheelbase 0.65 0.65 0.65 0.65
Overall Wheelbase (engine & tender) (ft / m)51.59 / 15.7247 7.15 / 2.18
Axle Loading (Maximum Weight per Axle) (lbs / kg)40,320 / 18,28942,112 / 19,10244,800 / 20,321
Weight on Drivers (lbs / kg)85,500 / 38,782115,808 / 52,530120,512 / 54,663134,400 / 60,963
Engine Weight (lbs / kg)100,700 / 45,677138,208 / 62,690144,256 / 65,433160,608 / 72,851
Tender Loaded Weight (lbs / kg)94,000 / 42,63896,544 / 43,79296,544 / 43,79296,544 / 43,792
Total Engine and Tender Weight (lbs / kg)194,700 / 88,315234,752 / 106,482240,800 / 109,225257,152 / 116,643
Tender Water Capacity (gals / ML)4200 / 15.914200 / 15.914200 / 15.914200 / 15.91
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)7 / 6 7.20 / 7 7.15 / 7
Minimum weight of rail (calculated) (lb/yd / kg/m)48 / 2464 / 3267 / 33.5075 / 37.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)61.50 / 156268 / 172768 / 172768 / 1727
Boiler Pressure (psi / kPa)175 / 12.10170 / 11.70170 / 11.70180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)18" x 24" / 457x61020" x 26" / 508x66020" x 26" / 508x66018.5" x 26" / 470x660 (3)
Tractive Effort (lbs / kg)18,808 / 8531.1822,100 / 10024.4022,100 / 10024.4030,032 / 13622.30
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.55 5.24 5.45 4.48
Heating Ability
Tubes (number - dia) (in / mm)254 - 1.75" / 44118 - 1.75" / 0197 - 1.75" / 44217 - 1.75" / 44
Flues (number - dia) (in / mm)18 - 5.25" / 024 - 5.25" / 13332 - 5.25" / 133
Flue/Tube length (ft / m)10.98 / 3.3511.95 / 3.6412 / 3.6611.99 / 3.65
Firebox Area (sq ft / m2)120 / 11.15137 / 12.73152 / 14.12182 / 16.91
Grate Area (sq ft / m2)16.70 / 1.5524.50 / 2.2824 / 2.2328 / 2.60
Evaporative Heating Surface (sq ft / m2)1380 / 128.251118 / 103.901630 / 151.431901 / 176.61
Superheating Surface (sq ft / m2)230 / 28.16305 / 28.34407 / 37.81
Combined Heating Surface (sq ft / m2)1380 / 128.251348 / 132.061935 / 179.772308 / 214.42
Evaporative Heating Surface/Cylinder Volume195.23118.26172.42156.67
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation2923416540805040
Same as above plus superheater percentage2923487347335947
Same as above but substitute firebox area for grate area21,00027,24929,97438,657
Power L15025789310,46510,885
Power MT388.71450.77574.33535.65

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