Cork, Blackrock & Passage 2-4-2 Locomotives in Ireland

Class Details by Steve Llanso of Sweat House Media

Class 4 (Locobase 6402)

Data from Flanagan, The Cavan & Leitrim Railway (1968), p 87 and from "The Cork, Blackrock & Passage Railway," The Locomotive Magazine, Volume V (October 1900), p. 1156-157. Works numbers were 5561-5564.

After 50 years of operating on the Irish standard gauge using three "Sharp Singles" (Locobase 10160), the CB &P extended its line to Crosshaven and regauged the whole line to 3 feet. (That's a remarkable shrinkage in gauge - Locobase does not know of another instance like it.) To handle traffic on the new line, the company bought these four lean tanks. Painted in black with vermillion and white piping, the design looked as if it could use a bogie forward rather than a radial truck. Another radial truck trailed behind the driver set.

According to Flanagan, they had the tallest drivers and the greatest axle loading of any Irish narrow-gauge class. Locobase finds it interesting that when the locomotives were reboilered in 1911, 1914, 1913, and 1912 (because doing it in order would have been too sensible), its tube heating surface dropped by 181 sq ft (25%) represented by 114 1 3/4" tubes. Could the original layout have been too constricted?

By 1932, the CBPR was on its uppers and closed at the end of the year. The class was reconditioned and handed over to the Cavan & Leitrim line of the GSR as 10-13L in August-September 1934. Flanagan notes that the fit of locomotive to line left something to be desired" "On their homeground, the engines were excellently suited to the suburban trains from Cork but they were less capable of dealing with laden coal specials on the ascent of Lawerdale bank."

Still, once over the crest, "they had a fair turn of speed and were extensively used." Kept off the tramway portions where the tight curves bound their wheels, the ex-Corks gave good service. True, 11L was scrapped in 1939 because of a cracked firebox, but 13L lasted until 1951 and 10L & 12L held on until the C & L was closed in 1959, when they were scrapped.

Principal Dimensions by Steve Llanso of Middle Run Media

Locobase ID6402
RailroadCork, Blackrock & Passage
Number in Class4
Road Numbers4-7
Number Built4
BuilderNeilson, Reid
Valve GearStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)8 / 2.44
Engine Wheelbase (ft / m)21 / 6.40
Ratio of driving wheelbase to overall engine wheelbase 0.38
Overall Wheelbase (engine & tender) (ft / m)21 / 6.40
Axle Loading (Maximum Weight per Axle) (lbs / kg)25,872 / 11,735
Weight on Drivers (lbs / kg)48,944 / 22,201
Engine Weight (lbs / kg)83,216 / 37,746
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)83,216 / 37,746
Tender Water Capacity (gals / ML)1200 / 4.55
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 2.95
Minimum weight of rail (calculated) (lb/yd / kg/m)41 / 20.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 1372
Boiler Pressure (psi / kPa)160 / 11
High Pressure Cylinders (dia x stroke) (in / mm)14.5" x 22" / 368x559
Tractive Effort (lbs / kg)11,649 / 5283.90
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.20
Heating Ability
Tubes (number - dia) (in / mm)
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)
Firebox Area (sq ft / m2)80 / 7.43
Grate Area (sq ft / m2)12 / 1.12
Evaporative Heating Surface (sq ft / m2)801 / 74.44
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)801 / 74.44
Evaporative Heating Surface/Cylinder Volume190.50
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation1920
Same as above plus superheater percentage1920
Same as above but substitute firebox area for grate area12,800
Power L14113
Power MT370.53

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