Furness 4-6-4 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class 115/N1 (Locobase 2359)

"Recent British Locomotives for Home and Foreign Service", Railway Engineer, Volume 42, No 5 (May 1921), pp. 175-176; and Ahrons (1927) for data. See also Steamindex's "Furness Railway: locomotive history" at [], last accessed 17 September 2018 and "4-6-4 Tank Locomotive, Furness Railway", Locomotive Magazine, Volume XXVII [27] , No 344 (15 April 1921), p. . Works numbers were 5292-5296 in 1920-1921.

This Hudson tank is one of the few designs from Ahrons' compendium credited to a locomotive builder rather than to a chief mechanical engineer. Indeed, their design progress straddled the very end of Pettigrew's reign and that of his successor David L Rutherford. In addition to sheer size, the Baltics could claim two distinctions: they were the only Furness locomotives with a Belpaire boiler and they were the only 4-6-4Ts with all-inside motion and no superheater. Drive was divided between the outside cylinders (connecting rods 11 ft/3.35 m long turning the middle axle) and the center cylinder (6 ft 6 in/1.98 m rod cranking the leading driving axle). Their cylinders received steam through 8" (203 mm) piston valves.

Designed soley or by committee, they were, says steamindex, "highly successful, in spite of the FR not having anything like them before." Once the crews conquered the quintet's teething troubles, they were "extremely popular with the crews", who goggled at the engines' size and nicknamed them "Jumbos". Muscling the up and down mail trains between Carnforth and Whitehaven (44 miles/71 km) and hauling the up morning express from Whitehaven, they had adequate water and coal supplies and plenty of power.

Soon after delivery, the class adopted a different livery with the absorption of the Furness into the LMS (London, Midland & Scottish) in 1923. Given the favorable reports by crews and their status as "paid for" locomotives, Locobase can't say why the first of the class was retired in 1934. Most likely, LMS found other locomotives whose lighter axle loadings allowed greater flexibility in assignment.

11102 was withdrawn in November 1934. 11103 followed in May 1934, and 1101-11102 in July of that year. For some reason, 11104 survived until 1940.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID2359
CountryGreat Britain
Number in Class5
Road Numbers115-119/11100-11104
Number Built5
BuilderKitson & Co
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.25 / 4.04
Engine Wheelbase (ft / m)40.75 / 12.42
Ratio of driving wheelbase to overall engine wheelbase 0.33
Overall Wheelbase (engine & tender) (ft / m)40.75 / 12.42
Axle Loading (Maximum Weight per Axle) (lbs / kg)41,104 / 18,644
Weight on Drivers (lbs / kg)122,976 / 55,781
Engine Weight (lbs / kg)207,760 / 94,238
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)207,760 / 94,238
Tender Water Capacity (gals / ML)2640 / 10
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 4.40 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)68 / 34
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68 / 1727
Boiler Pressure (psi / kPa)170 / 11.70
High Pressure Cylinders (dia x stroke) (in / mm)19.5" x 26" / 495x660
Tractive Effort (lbs / kg)21,009 / 9529.53
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.85
Heating Ability
Tubes (number - dia) (in / mm)230 - 2" / 51
Flues (number - dia) (in / mm) - 5" / 127
Flue/Tube length (ft / m)16 / 4.88
Firebox Area (sq ft / m2)153 / 14.21
Grate Area (sq ft / m2)26 / 2.42
Evaporative Heating Surface (sq ft / m2)2003 / 186.08
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2003 / 186.08
Evaporative Heating Surface/Cylinder Volume222.88
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4420
Same as above plus superheater percentage4420
Same as above but substitute firebox area for grate area26,010
Power L15934
Power MT319.14

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