Locomotive artist Peter Ormsby -- [] (visited 25 October 2003) -- is the source of some of the data for this mighty class. The diagram at [] amends and adds to the Ormsby account.
Bigger than any British Pacifics, these engines had a relatively high axle loading as well. They were more than a match for a service that had relatively modest speed limits. (Ormsby comments "...although 80 mph (129 kph) was rumoured to have been exceeded on more than one occasion.") At first beset by unreliability, the class soon established a good record.
Most worked out of Tailem Bend at the head of expresses and freights. Five eventually received automatic stokers and the other five were converted to oil burning with tenders carrying 1,912 Imperial gallons (2,294 US gallons/8,685 litres). The class also received "elephant ear" smoke lifters flanking the smokebox as well as improved boilers. The last was retired in 1960.
Data from [] . Light Pacific designed by FJ Shea of the SAR. The museum-railroad site [] (visited on 20 October 2003) says these engines were designed to pull the "East-West" Adelaide-Port Pine Express.
Designed to an axle loading similar to the 4-8-4 520 class, these engines ran on the same roads at speeds up to 50 mph (80 km/h). When the 520s took over the mainline expresses, the 620s took on the Willunga, Bridgewater and Tailem Bend passenger trains and powered the Limited Mixed trains to Pinnaroo and Renmark. ("A limited mixed", Steamranger explains, "is a passenger train with goods loading attached, the maximum load of the train being less than that of a goods load and shunting enroute being restricted to the major locations."
Although the initial years of the Blue Bird railcars that replaced the 620s saw so many breakdowns that some of the Pacifics were brought back in service, most were gone by the late 1950s.
Data from Douglas Colquhoun's entries presented in the Australian national railway museum site: [] (visited 14 October 2003).
TS Roberts suburban passenger tank engine design known as "Dollys". Islington shops built 21 (works number 3 in 1902,. 8-12 in 1908-1909, 20-24 in 1912, and 30-39 in 1914), James Martin & Co. of Gawler produced 12 (works # 184-185 in 1904, 221-230 in 1914-1915), and Perry Engineering of Mile End added 10 (works # 231-240 in 1922).
Colquhoun's table shows that most of these locomotives were converted to oil-burning in the late 1940s, fitted with a heating coil soon after and reconverted to coal-burning some time later. Most were retired in the late 1950s, early 1960s.
[] , a museum-railroad site visited on 20 October 2003, says they were "...primarily used for working the suburban lines to Semaphore, Outer Harbor, Henley Beach, Belair and Marino prior to the introduction of the Red Hen Railcars in 1955-56." When heading up the Adelaide-Alberton Alberton Flyer, Fs could be induced to hit 60 mph (97 km/h). They served other lines and later went into switching service in the Adelaide yards and Islington shops.
Principal Dimensions by Steve Llanso of Middle Run Media | |||
---|---|---|---|
Class | 600 | 620 class | F |
Locobase ID | 5687 | 2420 | 2425 |
Railroad | South Australian Railways | South Australian Railways | South Australian Railways |
Country | Australia | Australia | Australia |
Whyte | 4-6-2 | 4-6-2 | 4-6-2T |
Number in Class | 10 | 10 | 43 |
Road Numbers | 600-609 | 620-629 | 167-189, 236-255 |
Gauge | 5'3" | 5'3" | 5'3" |
Number Built | 10 | 10 | 43 |
Builder | Armstrong Whitworth | Islington | several |
Year | 1926 | 1936 | 1902 |
Valve Gear | Baker | Baker | Stephenson |
Locomotive Length and Weight | |||
Driver Wheelbase (ft / m) | 13.67 / 4.17 | 12.17 / 3.71 | 13 / 3.96 |
Engine Wheelbase (ft / m) | 35.84 / 10.92 | 32.92 / 10.03 | 30.92 / 9.42 |
Ratio of driving wheelbase to overall engine wheelbase | 0.38 | 0.37 | 0.42 |
Overall Wheelbase (engine & tender) (ft / m) | 69.67 / 21.24 | 69.67 / 21.24 | 40.59 / 12.37 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 53,032 / 24,055 | 35,616 / 16,155 | 27,552 / 12,497 |
Weight on Drivers (lbs / kg) | 158,536 / 71,911 | 105,840 / 48,008 | 78,960 / 35,816 |
Engine Weight (lbs / kg) | 262,024 / 118,852 | 182,560 / 82,808 | 132,160 / 59,947 |
Tender Loaded Weight (lbs / kg) | 179,200 / 81,284 | 132,384 / 60,048 | |
Total Engine and Tender Weight (lbs / kg) | 441,224 / 200,136 | 314,944 / 142,856 | 132,160 / 59,947 |
Tender Water Capacity (gals / ML) | 9000 / 34.09 | 5200 / 19.70 | 1440 / 5.45 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 14.40 / 13 | 9 / 8 | 2.80 / 3 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 88 / 44 | 59 / 29.50 | 44 / 22 |
Geometry Relating to Tractive Effort | |||
Driver Diameter (in / mm) | 75 / 1905 | 66 / 1676 | 63 / 1600 |
Boiler Pressure (psi / kPa) | 215 / 1480 | 204.50 / 1410 | 185 / 1280 |
High Pressure Cylinders (dia x stroke) (in / mm) | 24" x 28" / 610x711 | 18.5" x 28" / 470x711 | 17.5" x 24" / 445x610 |
Tractive Effort (lbs / kg) | 39,299 / 17825.75 | 25,239 / 11448.23 | 18,346 / 8321.62 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.03 | 4.19 | 4.30 |
Heating Ability | |||
Tubes (number - dia) (in / mm) | |||
Flues (number - dia) (in / mm) | |||
Flue/Tube length (ft / m) | |||
Firebox Area (sq ft / m2) | 270 / 25.09 | 175 / 16.26 | 130.70 / 12.14 |
Grate Area (sq ft / m2) | 55 / 5.11 | 33.40 / 3.10 | 18 / 1.67 |
Evaporative Heating Surface (sq ft / m2) | 3213 / 298.61 | 1735 / 161.25 | 1335 / 124.03 |
Superheating Surface (sq ft / m2) | 743 / 69.05 | 421 / 39.13 | |
Combined Heating Surface (sq ft / m2) | 3956 / 367.66 | 2156 / 200.38 | 1335 / 124.03 |
Evaporative Heating Surface/Cylinder Volume | 219.16 | 199.17 | 199.81 |
Computations Relating to Power Output (More Information) | |||
Robert LeMassena's Power Computation | 11,825 | 6830 | 3330 |
Same as above plus superheater percentage | 14,072 | 8196 | 3330 |
Same as above but substitute firebox area for grate area | 69,080 | 42,945 | 24,180 |
Power L1 | 20,623 | 16,524 | 5781 |
Power MT | 860.36 | 1032.57 | 484.23 |