| Queensland Railways 1800 class railmotor | |
|---|---|
 A new 1800 Class railmotor on the traverser at Commonwealth Engineering Granville NSW 1952. | |
| Manufacturer | Commonwealth Engineering |
| Built at | Granville |
| Constructed | 1952–1954 |
| Number built | 24 (12 railmotors and 12 trailer passenger) |
| Number in service | 2 (one railmotor, converted to a trailer passenger and one trailer passenger) |
| Number preserved | 5 (one complete railmotor, three privately owned railmotor bodies without bogies and one privately owned trailer passenger without bogies) |
| Number scrapped | 17 (7 railmotors and 10 trailer passenger) |
| Diagram | M1800 P47 Queensland Railways Mechanical Engineers Branch Ipswich Qld. drawn 26/11/1952 |
| Fleet numbers | Rail motors 1800 1803 1804 1807 1808 1811 1812 1815 1816 1819 1820 1823 Trailer passenger 1801 1802 1805 1806 1809 1810 1813 1814 1817 1818 1821 1822 |
| Capacity | 55 passengers |
| Operators | Queensland Railways |
| Specifications | |
| Car length | 14.885 mtrs (48 ft 10 1/4 inches) |
| Width | 2.83 mtrs (9 ft 3 3/8 inches) |
| Height | 3.763 mtrs (12 ft 4 1/16 inches) |
| Floor height | 1.041 mtrs (3 ft 5 inches) |
| Doors | Railmotor, 4 side doors plus 1 rear end door. Trailer passenger. 4 side doors plus 2 end doors, one at each end. |
| Wheel diameter | Front power bogie 762 mm (2 ft 6 inches). Rear bogie 838 mm (2 ft 9 inches) |
| Weight | 23.217 tonnes (22 tons 17 cwt) |
| Prime mover(s) | Single Gardner 6L3 diesel |
| Power output | 114 kW (153 hp) |
| Transmission | Hydraulic Coupling Wilson Epicyclic Type 5.8. 4 speed electro pnematic self selecting 4 speed gearbox. |
| Bogies | Front: Drewry Power Bogie. Rear: Ride Control A.3. bogie. |
| Coupling system | Double buffer and chain link. |
| Track gauge | 1,067 mm (3 ft 6 in) |
The 1800 class railmotors were a class of self-propelled diesel railmotors built by Commonwealth Engineering, Granville for the Queensland Railways.