Penlee Quarry / Penrhyn Quarries / Penryhn Quarry 0-4-0 Locomotives in Great_Britain


Class Details by Steve Llanso of Sweat House Media

Class Koppel (Locobase 10727)

Data from "Narrow Gauge Locomotive, Newlyn Quarry Ry", The Locomotive Magazine, Vol XV (14 August 1909), p. 163.

A classic O & K locomotive, this tiny engine had a tall, slender stack with flared muzzle, and a oversized cab. At the time, Koppel rated the locomotive with following loads:

Level 154 tons

1 in 500 (0.2%) 108 tons

1 in 200 (0.5%) 73 tons

1 in 100 (1.0%) 46 tons

1 in 80 (1.25%) 40 tons

1 in 50 (2.0%) 25 tons

1 in 30 (3.3%) 14 tons

1 in 20 (5.0%) 8 tons

Koppel was renamed Penlee in 1914 and operated for another 32 years. After its retirment in 1946, it was preserved at Newlyn harbour. In the 21st Century, Leighton Buzzard Heritage Railway began restoring this engine.


Class Lady Penryhn (Locobase 20560)

Data from "The Penryhn Quarry Railway", Locomotive Magazine, Volume XXIII [23] (15 May 1917), pp. 89-93, locomotives on p. 91.

The extensive slate quarries belonging to Lord Penryhn most likely began being exploited as early as the 16th century or before. Arrayed along the north side of the Glydr Vach near Bethesda, the deposits were mined on a relatively small scale for the first two hundred or so years with yearly production seldom exceeding 1,000 tons. The slate had to be packed out on mules and it was only in the 1780s that the quarries began producing slate in large amounts with 15,000 tons being exported from Port Penryhn in 1785.

A horse tramway served to move the slate until well into the 1800s, but steam railway operation came well before it closed in 1874. As the quarry's cleavage planes were nearly vertical, it was extracted from galleries cut into the sides. Each gallery would be replaced by a second, higher one and at the time of the 1917 LM report, 19 galleries were in use "hewn with formal regularity in the shape of an enormous amphitheatre". General Warburton, proprietor of the site in 1765, classified the standard slate sizes according to noble rank ("duchesses", "countesses", "ladies". It's not clear if baronesses ever made the cut.)

These vertical-boiler engines, named for Lady Penryhn, George Henry, and Kathleen, were obviously tiny. The driver could easily rest his arm on a lever on top of the boiler and firebox. The drivers were solid, the front set being driven by a vertical shaft connecting directly with the crank.


Class Large Engine (Locobase 5985)

Data from quarry tank described by Mark Adlington in the Quarry Engines of North Wales website -- pws.prserv.net/mdsme/Hunslet/Penrhyn_Large_class.htm. See also "The Penryhn Quarry Railway", Locomotive Magazine, Volume 23 (15 May 1917), pp. 89-93. (Many thanks to Ellis Tammeleo's group for creating the "October 2022" Google doc with a series of corrections and questions about Locobase's information, including this entry.)

Three early quarry engines were also among the largest produced for such use. Charles (1883, works #283) had 10" diameter cylinders and was for 10 years the only one in the class. According to Adlington: ""Charles" has always been one of the 'main-line' engines of the Penhryn Quarries Ltd. He explains that the Penrhyn line brought slate from Bethesda to the shipping port at Port Penhryn, near Bangor. The slate was then shipped by water or later by standard-gauge lines.

Blanche and Linda (1893, 589-590) came together. The compact design had sharply raked cylinders. Both Blanche and Linda were transferred to the Ffestinog Railway in 1961-1962.

Both were later converted to 2-4-0ST with tenders and acquired superheaters when rebuilt by Hunslet in 1969. A delightful account of a ride behind Linda shows up on [] in which Erik Gray Ledbetter describes this powerful little locomotive scaling a 1%, 12-mile grade "...at a brisk, invigorating 25 miles an hour." Having noted the tight constraints the Ffestinog's original engineer labored under (namely the need to provide gravity-powered downhill running and a "moderate" upgrade of 1%), Ledbetter adds:"[James] Spooner would have been proud.".


Class Large Quarry (Locobase 5984)

Quarry tank described by Mark Adlington in the Quarry Engines of North Wales website -- pws.prserv.net/mdsme/Hunslet/Alice_class.htm. (Many thanks to Ellis Tammeleo's group for creating the "October 2022" Google doc with a series of corrections and questions about Locobase's information, including this entry.)

Based on the earlier "Small Quarry" type, these had larger cylinders and more weight on the drivers.


Class Small Quarry (Locobase 5894)

Data from [] gives the tractive effort as 2,450 lb, but doesn't give the cylinder dimensions. Nor does it note the track gauge. See also "The Penryhn Quarry Railway", Locomotive Magazine, Volume 23 (15 May 1917), pp. 89-93. (Many thanks to Ellis Tammeleo's group for creating the "October 2022" Google doc with a series of corrections and questions about Locobase's information, including this entry.)

Quarry tank used in North Wales for 60 years. After mothballing in 1953, it gained new life as a static display engine in 1965. Ultimately, it was restored to service and later bought by the Teifi Valley Railway.

But Gavin Hamilton came to the rescue (as he so often did in these matters) with a listing of UK narrow-gauge locomotives on [] . We find that Alan George (Hunslet works #606) had three mates -- Margaret (Hunslet 605) in the same year, and Nesta and Elin (Hunslet 704-705) delivered in 1899. These were what Mark Adlington in the Quarry Engines of North Wales website -- pws.prserv.net/mdsme/Hunslet/Alice_class.htm calls the Small Quarry model.

Information from both Hamilton and Adlington's sites also suggests that 3 earlier "Port" class (1883) -- Gwynedd, Lillian, and Winifred -- were similar, but had 120-psi (8.3 bar) boilers. Six later engines of the Large Quarry class (1904-05) had similar basic dimensions, except the cylinders were 7 1/2" in (191 mm) diameter; see Locobase 5984. Also note that the Padarn Railway's 15 quarry locomotives were built to the same design.

Principal Dimensions by Steve Llanso of Middle Run Media

ClassKoppelLady PenryhnLarge EngineLarge QuarrySmall Quarry
Locobase ID10727 20560 5985 5984 5894
RailroadPenlee QuarryPenryhn QuarryPenrhyn QuarriesPenrhyn QuarriesPenrhyn Quarries
CountryGreat BritainGreat BritainGreat BritainGreat BritainGreat Britain
Whyte0-4-0WT0-4-0T0-4-0ST0-4-0ST0-4-0ST
Number in Class13364
Road Numbers
Gauge2'60 cmStd22.75 in22.75 in
Number Built13364
BuilderOrenstein & KoppelDe Winton & CoHunslet Engine CoHunslet Engine CoHunslet Engine Co
Year19001876189319041894
Valve GearO&K patent
Locomotive Length and Weight
Driver Wheelbase (ft / m) 3.33 / 1.014 / 1.225 / 1.524 / 1.22 3.25 / 0.99
Engine Wheelbase (ft / m) 3.33 / 1.014 / 1.225 / 1.524 / 1.22 3.25 / 0.99
Ratio of driving wheelbase to overall engine wheelbase11111
Overall Wheelbase (engine & tender) (ft / m) 3.33 / 1.014 / 1.22 3.25 / 0.99
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)14,672 / 665511,200 / 508027,440 / 12,44717,024 / 772213,724 / 6225
Engine Weight (lbs / kg)14,672 / 665511,200 / 508027,440 / 12,44717,024 / 772213,724 / 6225
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)14,672 / 665511,200 / 508027,440 / 12,44717,024 / 772213,724 / 6225
Tender Water Capacity (gals / ML)125 / 0.471524 / 5.77180 / 0.68120 / 0.45
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 0.40
Minimum weight of rail (calculated) (lb/yd / kg/m)12 / 69 / 4.5023 / 11.5014 / 711 / 5.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)23 / 58420 / 50825 / 63520.25 / 51420 / 508
Boiler Pressure (psi / kPa)176 / 12.10120 / 8.30120 / 8.30140 / 9.70120 / 8.30
High Pressure Cylinders (dia x stroke) (in / mm)6.5" x 12" / 165x3056.25" x 10" / 159x25410" x 12" / 254x3057.5" x 10" / 191x2547" x 10" / 178x254
Tractive Effort (lbs / kg)3298 / 1495.951992 / 903.564896 / 2220.793306 / 1499.582499 / 1133.53
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.45 5.62 5.60 5.15 5.49
Heating Ability
Tubes (number - dia) (in / mm)28 - 1.875" / 48
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 6.25 / 1.90
Firebox Area (sq ft / m2)15 / 1.3928 / 2.6018 / 1.6714 / 1.30
Grate Area (sq ft / m2) 3.25 / 0.30 3.40 / 0.32 4.50 / 0.42 3.18 / 0.30 2.50 / 0.23
Evaporative Heating Surface (sq ft / m2)126 / 11.7181 / 7.53305 / 28.34125 / 11.61100 / 9.29
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)126 / 11.7181 / 7.53305 / 28.34125 / 11.61100 / 9.29
Evaporative Heating Surface/Cylinder Volume273.39228.11279.60244.46224.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation572408540445300
Same as above plus superheater percentage572408540445300
Same as above but substitute firebox area for grate area2640336025201680
Power L12942204019871527
Power MT884.13327.80514.64490.59

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