Victorian Railways class M
Australia 1879 22 produced
The class M was a 4-4-0T tank locomotive for suburban service around Melbourne. The prototype No. 40 was built in 1879 by Beyer Peacock and delivered to Australia. 21 more were built by the Phoenix Foundry in Victoria between 1884 and 1886. To increase the supplies, they were rebuilt to the class ME with an additional trailing axle at the Newport workshops between 1901 and 1905. In this process, they also got a new leading bogie, the cylinder diameter was increased from 17 to 18 inches and the boiler pressure was raised. They became surplus with the electrification of the suburban network and were withdrawn between 1913 and 1922.
Technical data
General
| Property | as built | rebuilt ME |
|---|---|---|
| Built | 1879, 1884-1886 | 1901-1905 |
| Manufacturers | Beyer, Peacock & Co., Phoenix Foundry | Newport |
| Wheel arrangement | 4-4-0ST (American) | 4-4-2T (Atlantic) |
| Gauge | 1,600 mm (Irish broad gauge) | |
Dimensions and weights
| Property | as built | rebuilt ME |
|---|---|---|
| Wheelbase | 5.72 m | 7.70 m |
| Empty mass | 36.2 t | 40.1 t |
| Service mass | 40.7 t | 51.1 t |
| Adhesion mass | 30.3 t | 28.4 t |
| Rigid wheelbase | 2.29 m | |
| Axle load | 16.1 t | 14.4 t |
| Water capacity | 3,956 l | 8,547 l |
| Fuel capacity | 1.5 t (coal) | 3 t (coal) |
Boiler
| Property | as built | rebuilt ME |
|---|---|---|
| Grate area | 1.347 m² | |
| Firebox surface | 9.105 m² | |
| Tube heating surface | 86.121 m² | |
| Evaporative heating surface | 95.226 m² | |
| Total heating surface | 95.2 m² | |
Power plant
| Property | as built | rebuilt ME |
|---|---|---|
| Driver diameter | 1,626 mm | |
| Boiler pressure | 9.7 bar | 12.4 bar |
| Expansion type | simple expansion | |
| Cylinders | two, 432 x 508 mm | two, 457 x 508 mm |
Power
| Property | as built | rebuilt ME |
|---|---|---|
| Power source | steam | |
| Estimated power | 242 kW (329 PS) | 317 kW (431 PS) |
| Starting effort | 47.8 kN | 68.9 kN |
Calculated values
| Property | as built | rebuilt ME |
|---|---|---|
| Factor of adhesion | 1 : 6.21 | 1 : 4.04 |
| Optimal speed | 31 km/h | 27 km/h |
| Power-to-weight ratio | 5.9 kW/t | 6.2 kW/t |
| Heating Surface Equivalent | 140.8 m² | |
| Cylinder volume/HSE | 1 : 1,057.05 | 1 : 1,185.07 |
| Adhesive weight/Total | 1 : 1.35 | 1 : 1.80 |
| Tractive force/Heating surface | 1 : 10.48 | 1 : 15.11 |
| Grate area/Heating surface | 1 : 70.69 | |
| Firebox/Tube surface | 1 : 9.46 | |
