New South Wales classes C79, C80 and CC79
New South Wales classes Z12 and Z13
The class C79 was a 4-4-0 locomotive built for express and mail service. Introduced in 1877, it was the first locomotive of the NSWGR ordered in larger numbers. The first 30 were built by Beyer-Peacock between 1877 and 1879, followed by 26 from Dübs in 1880 and 1881. Four more were delivered by Beyer-Peacock in 1881. Eight more were built locally by Atlas Engineering Works at Haymarket, a suburb of Sydney.
With the arrival of the 4-6-0 class C32 (the later P6) in 1892, the C79 was increasingly used in secondary roles. Between 1896 and 1902, 20 locomotives were rebuilt into the 4-4-2T class CC79 for suburban service, with the others being renamed to class C80. From 1901, most got a new boiler with a larger Belpaire firebox instead of the round-topped one.
With the new class scheme of 1924, the C80 became class Z12 and the CC79 became Z13. 23 of the original 4-4-0 which had been in use in suburban service were withdrawn between 1928 and 1933. The remaining locomotives soon left the Sydney area and were used on branch lines. Most survived until the fifties and some until the sixties. Three each of the classes Z12 and Z13 have been preserved.
Technical data
General
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Built | 1877-1882 | 1901 | 1896-1902 |
| Manufacturers | Beyer, Peacock & Co., Dübs & Co., Atlas Engineering Works | Eveleigh Railway Workshops | |
| Wheel arrangement | 4-4-0 (American) | 4-4-2T (Atlantic) | |
| Gauge | 1,435 mm (Standard gauge) | ||
Dimensions and weights
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Wheelbase | 5.94 m | 8.08 m | |
| Total wheelbase | 11.18 m | ||
| Service mass | 39.7 t | 41.3 t | 49.9 t |
| Adhesion mass | 25.8 t | 27.2 t | 29.9 t |
| Total mass | 62 t | 63.6 t | |
| Rigid wheelbase | 2.45 m | ||
| Axle load | 12.9 t | 13.9 t | 15 t |
| Water capacity | 9,093 l | 5,001 l | |
| Fuel capacity | 5.1 t (coal) | 2.3 t (coal) | |
Boiler
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Grate area | 1.37 m² | ||
| Firebox surface | 8.083 m² | 8.733 m² | |
| Tube heating surface | 91.695 m² | 95.412 m² | |
| Evaporative heating surface | 99.778 m² | 104.144 m² | |
| Total heating surface | 99.8 m² | 104.1 m² | |
Power plant
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Driver diameter | 1,676 mm | ||
| Boiler pressure | 9 bar | 9.7 bar | |
| Expansion type | simple expansion | ||
| Cylinders | two, 457 x 610 mm | ||
Power
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Power source | steam | ||
| Estimated power | 261 kW (355 PS) | 298 kW (405 PS) | |
| Starting effort | 57.9 kN | 62.4 kN | |
Calculated values
| Property | as built | rebuilt | rebuilt Z13 |
|---|---|---|---|
| Factor of adhesion | 1 : 4.36 | 1 : 4.28 | 1 : 4.71 |
| Optimal speed | 27 km/h | 29 km/h | |
| Power-to-weight ratio | 6.6 kW/t | 7.2 kW/t | 6.0 kW/t |
| Heating Surface Equivalent | 140.2 m² | 147.8 m² | |
| Cylinder volume/HSE | 1 : 1,427.75 | 1 : 1,354.17 | |
| Adhesive weight/Total | 1 : 1.54 | 1 : 1.52 | 1 : 1.67 |
| Tractive force/Heating surface | 1 : 12.12 | 1 : 12.51 | |
| Grate area/Heating surface | 1 : 72.83 | 1 : 76.02 | |
| Firebox/Tube surface | 1 : 11.34 | 1 : 10.93 | |