South Eastern class Q
South Eastern & Chatham class Q1
Great Britain 1881 118 produced
For new suburban lines in London, James Stirling designed a tank locomotive with a 0-4-4T wheel arrangement, which was based on the G&SWR class 1, which he had designed earlier. The 34 locomotives that were built first still had a bogie that could not be moved sideways, while the bogie of all the others could be moved sideways. Some of the locomotives had a lower chimney and a condenser for use in tunnels. After the transition to the SE&CR, 55 locomotives were rebuilt to class Q1. The last machines were gone by 1930.
Technical data
General
| Property | Q | Q1 |
|---|---|---|
| Built | 1881-1897 | 1903-1917 |
| Manufacturers | Neilson & Co., Ashford, Sharp, Stewart & Co. | Ashford |
| Wheel arrangement | 0-4-4T (Forney) | |
| Gauge | 1,435 mm (Standard gauge) | |
Dimensions and weights
| Property | Q | Q1 |
|---|---|---|
| Wheelbase | 6.71 m | |
| Service mass | 49.4 t | 50.1 t |
| Adhesion mass | 30.1 t | |
| Rigid wheelbase | 2.26 m | |
| Axle load | 16.3 t | |
| Water capacity | 4,773 l | |
| Fuel capacity | 1.5 t (coal) | |
Boiler
| Property | Q | Q1 |
|---|---|---|
| Grate area | 1.463 m² | |
| Firebox surface | 8.57 m² | |
| Tube heating surface | 77.086 m² | |
| Evaporative heating surface | 85.657 m² | |
| Total heating surface | 85.7 m² |
Power plant
| Property | Q | Q1 |
|---|---|---|
| Driver diameter | 1,676 mm | |
| Boiler pressure | 9.7 bar | 10.3 bar |
| Expansion type | simple expansion | |
| Cylinders | two, 457 x 660 mm | |
Power
| Property | Q | Q1 |
|---|---|---|
| Power source | steam | |
| Estimated power | 261 kW (355 PS) | 336 kW (457 PS) |
| Starting effort | 67.6 kN | 72.4 kN |
Calculated values
| Property | Q | Q1 |
|---|---|---|
| Factor of adhesion | 1 : 4.37 | |
| Optimal speed | 24 km/h | 29 km/h |
| Power-to-weight ratio | 5.3 kW/t | 6.7 kW/t |
| Heating Surface Equivalent | 128.5 m² | |
| Cylinder volume/HSE | 1 : 1,687.39 | |
| Adhesive weight/Total | 1 : 1.64 | |
| Tractive force/Heating surface | 1 : 16.47 | |
| Grate area/Heating surface | 1 : 58.55 | |
| Firebox/Tube surface | 1 : 8.99 |
