Victorian Railways DD Class Locomotive was built at Newport Workshops 1902 and entered service 17 Oct 1902, this e-spec is for the DD's built at Newport Workshops.
Although the DD Locomotive was built to handle both light lines and main lines they also suffered from poor steaming due to the boiler being under sized, this e-spec is set to the real values of the loco, keeping the coal level 50% or lower will keep the boiler cool and prevent excessive steam discharging through the safety valves, the blower should be used while the loco is stationary and to help keep boiler pressure up while working slow speeds.
The cut-off should be close to mid gear and regulator full while assending grades to keep the steam chest at full pressure, while desending grades the cut-off should be full gear and regulator open slightly to prevent cylinder back pressure.
Updated: Acording to what Zec told me the DD to D3's use very short cut-off timing and go to about 25% at 13~15mph, I've reworked the e-spec to to run like that, if the cut-off timing is too long then it'll run out of pressure, the cut-off is also used to adjust the speed while running regulator 100%, move the cut-off forward to increase speed and lower boiler pressure, decrease cut-off to slow speed and increase boiler pressure.
Boiler Type: saturated
Boiler Tubes: Unknown at 2 inches diameter
Boiler Volume: 3,664 Litres
Firebox: 120.00 sq ft
Tubes: 1288.00 sq ft
Grate Area 22.50 sq ft
Boiler Press: 175 PSI
Safety Valve Low: 175 PSI
Safety Valve High: 178 PSI
Bore x Stroke: 18in x 26in
Driving Wheels: 5ft 1.75in
Tractive Power: 20,000lbs 'Nominal' @ 80% MEP WP
Cut-Off Range: 75%~26% 0~12mph / 25%~20% 55~50mph
Top Speed: 50mph
Main Res: 87 PSI Max
Brake Pipe: 72 PSI Max
Brake Cylinder: 68 PSI Max