Ffestiniog 0-4-0 Locomotives in Great_Britain

Class Details by Steve Llanso of Sweat House Media

Class The Princess (Locobase 20814)

Data from "The Festiniog [sic] and its Locomotives", Locomotive Magazine, Volume XXVI [26] (15 June 1920), pp.127-131. See also the Ffestiniog's own website at []; and "Festiniog Railway 0-4-0TT" at [], both last accessed 17 November 2020.

These were the first steam locomotives to operate on this 13 1/4 mile (21.3 km) link between Blaenau Ffestiniog and the seacoast town of Portmadoc. Although slate suitable for roofing tiles had been mined since 1765, it was only in 1834 that a horse-drawn tramway put the caldrons on 16 lb/yard (8 kg/metre) iron rails. James Spooner had considered switching to steam locmotives for some time, but it was his son C E Spooner that bought the first four.

The FR's operating area was a "wild and mountainous locality", according to the 1920 report, "one of those rare examples of a railway continually ascending from practically sea level." This ascent, which averaged 1 in 92 feet (1 3/4%) , on 30 lb/yard (15 kg/metre) rail on such a narrow gauge negotiated "succession of [parabolic] curves", two tunnels, ten-ft (3.05 m) wide embankments, "numerous" bridges and cuttings for 12 miles (19.3 km) until it reached Duffws, 700 ft (213.35 m) above sea level.

So the locomotives had to offer power and endurance. The builder delivered two (The Princess and The Prince) with high, rounded boilers and no domes with a four-wheel tender trailing behind--an arrangement dubbed a "tender-tank". Wikipedia comments that England had recommended against such a design, but was overruled. He was soon proved correct as the engines had a tendency to prime (pumping water into the cylinders) and soon had locally made domes. Mountaineer and Palmerston followed with a profile featuring a prominent brass dome over a shallower boiler.

(Welsh Pony and Little Giant arrived in 1867. Their cylinder diameters increased by 1/2" (12.7 mm) and weight grew to 22,400 lb (10,160 kg).)

After careful testing the Ffestiniog opened passenger service in 1865. All save Mountaineer remained in service long enough to receive new boilers and other updates. Mountaineer suffered considerable damage in an 1876 derailment and was scrapped in 1879.

Locobase wonders if Mountaineer's derailment was a result of too light a load on the drivers--the factor of adhesion was a very low 2.21. The FR fitted the three other engines with cast-iron weights placed on top of the boiler and resembling saddle tanks. Palmerston came first in 1880, followed by The Prince in 1881 and Princess in 1882.

Palmerston received a true 375 Imp gal (450 US gallon) saddle tank in 1886, followed by Prince in 1892 with a new 160 psi/11 bar boiler as well), and Princess in 1895 (also a new boiler). Two other signficant upgrades were weight (26,880 lb) and 32" (813 mm) drivers.

The FR's fame as a tourist railway effectively matched its renown in moving slate. So all three of the class have been restored after withdrawals. Princess's refurbishment was cosmetic, but Prince was reconditioned twice, once in 1962 while still in revenue service, and once after withdrawal. This later update added superheating as well as oil firing. A third overhaul in 2013 included restoration of coal firing. Long retired and used as a stationary boiler,

Palmerston donated some parts to Prince's restoration; the rest was sold to a Staffordshire group in 1973. The FR retrieved the Prince in 1987 and restored the engine to operations in 1993.

Principal Dimensions by Steve Llanso of Sweat House Media

ClassThe Princess
Locobase ID20814
CountryGreat Britain
Number in Class4
Road Numbers1-4
Gauge60 cm
Number Built4
BuilderGeorge England
Valve GearAllan
Locomotive Length and Weight
Driver Wheelbase (ft / m)5 / 1.52
Engine Wheelbase (ft / m)5 / 1.52
Ratio of driving wheelbase to overall engine wheelbase1
Overall Wheelbase (engine & tender) (ft / m)5 / 1.52
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)16,800 / 7620
Engine Weight (lbs / kg)16,800 / 7620
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)16,800 / 7620
Tender Water Capacity (gals / ML)
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)
Minimum weight of rail (calculated) (lb/yd / kg/m)14 / 7
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)24 / 610
Boiler Pressure (psi / kPa)140 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)8" x 12" / 203x305 (4)
Tractive Effort (lbs / kg)7616 / 3454.56
Factor of Adhesion (Weight on Drivers/Tractive Effort) 2.21
Heating Ability
Tubes (number - dia) (in / mm)140 - 1.25" / 32
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m) 7.67 / 2.34
Firebox Area (sq ft / m2)22 / 2.04
Grate Area (sq ft / m2)4 / 0.37
Evaporative Heating Surface (sq ft / m2)377 / 35.02
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)377 / 35.02
Evaporative Heating Surface/Cylinder Volume270.01
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation560
Same as above plus superheater percentage560
Same as above but substitute firebox area for grate area3080
Power L11953
Power MT512.57

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