Great Southern & Western 2-4-2 Locomotives in Ireland

Class Details by Steve Llanso of Sweat House Media

Class 35 (Locobase 20691)

Data from E E Joynt, "The Modern Locomotives of the Great Southern and Western Railway", Locomotive Magazine, Volume XXIV [24] (15 July 1918), p. 113.

Correcting a weight-distribution problem that surfaced in the four otherwise-successful 2-4-2 tanks shown in Locobase 20690 meant cutting down the tanks just ahead of the lead driving axles. The coal bunker extended further back. The two changes removed 1.3 long tons (1,321 kg) from the lead axle and placed somewhat more weight on the other three.

Although the work achieved Ivatt's goal, he chose to complete two more engines to a 4-4-2T layout. See Locobase 20692.

Class 42 (Locobase 20690)

Data from E E Joynt, "The Modern Locomotives of the Great Southern and Western Railway", Locomotive Magazine, Volume XXIV [24] (15 July 1918), pp. 111-112.

After the last four of the 47 class entered service in 1887, the GS&W had procured enough suburban tanks for a while. But the opening of new branch lines in Kerry, wrote E E Joynt, led Henry Ivatt to produce a four-axle tank locomotive in a new arrangement. It was now a double-ender with carrying axles turning in radial axle boxes ahead and behind the two coupled axles. They proved very successful in the new service.

Kerry's lines ran from Headford to Kenmare as well as a "mountain" railway to Caherciveen and Valencia Harbour. They featured more demanding conditions, "often of a trying nature", wrote Joynt. In particular, wrote Joynt, the Killorgin-Cahercin was "one of the most interesting, one might almost say romantic in Ireland." Glenbeigh to Cahersiveen's 17 miles was almost all muntain running, traveling "for a considerable distance ...round a shelf on a ten-chain curve with continuous check rails"

Joynt paints a word picture: "The rugged summit towers above on the left, while hundreds of feet below stretch the stormy waters of Dingle Bay." There was "practically no view ahead, as the single line keeps always disappearing round the curve of the mountain." Board of Train regulations limited speeds to 10 mph (16 kph).

A particular feature of the class were the cabs, which sought to protect the crews as they confronted the "severe storms of the Kerry mountains and coast."

A few complaints surfaced. The radial trucks tended to grind on the curves and the tanks placed a "slightly undue proportion of [their] weight to fall in front." Two more engines were built with modified tanks[ see Locobase 20691.

Principal Dimensions by Steve Llanso of Sweat House Media

Locobase ID20691 20690
RailroadGreat Southern & WesternGreat Southern & Western
Number in Class24
Road Numbers35-3633-34, 41-42
Number Built24
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m) 7.92 / 2.41 7.92 / 2.41
Engine Wheelbase (ft / m)19.92 / 6.0719.92 / 6.07
Ratio of driving wheelbase to overall engine wheelbase 0.40 0.40
Overall Wheelbase (engine & tender) (ft / m)19.92 / 6.0719.92 / 6.07
Axle Loading (Maximum Weight per Axle) (lbs / kg)28,224 / 12,80228,000 / 12,701
Weight on Drivers (lbs / kg)56,224 / 25,50354,432 / 24,690
Engine Weight (lbs / kg)103,264 / 46,840103,264 / 46,840
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)103,264 / 46,840103,264 / 46,840
Tender Water Capacity (gals / ML)1356 / 5.141500 / 5.68
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.30 / 3 2.75 / 3
Minimum weight of rail (calculated) (lb/yd / kg/m)47 / 23.5045 / 22.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)68.50 / 174068.50 / 1740
Boiler Pressure (psi / kPa)160 / 11160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)16" x 20" / 406x50816" x 20" / 406x508
Tractive Effort (lbs / kg)10,165 / 4610.7710,165 / 4610.77
Factor of Adhesion (Weight on Drivers/Tractive Effort) 5.53 5.35
Heating Ability
Tubes (number - dia) (in / mm)172 - 1.75" / 44174 - 1.75" / 44
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 9.58 / 2.92 9.67 / 2.95
Firebox Area (sq ft / m2)83.80 / 7.7983.80 / 7.79
Grate Area (sq ft / m2)16 / 1.4916 / 1.49
Evaporative Heating Surface (sq ft / m2)841 / 78.13854 / 79.34
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)841 / 78.13854 / 79.34
Evaporative Heating Surface/Cylinder Volume180.70183.49
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation25602560
Same as above plus superheater percentage25602560
Same as above but substitute firebox area for grate area13,40813,408
Power L149454996
Power MT387.80404.70

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