GWR Thunderer locomotive

Content sourced from Wikipedia, licensed under CC BY-SA 3.0.

GWR Thunderer was the first of two steam locomotives built for the Great Western Railway by R. & W. Hawthorn & Co., designed by T. E. Harrison. Its design was very different from other locomotives: to meet Isambard Kingdom Brunel’s rules, the engine sat on an 0-4-0 frame while the boiler ran on a separate six-wheeled frame. The driving wheels were geared 10:27 to reduce piston speed while allowing high track speed.

Thunderer was delivered to the GWR on 6 March 1838 and worked until December 1839, covering about 9,882 miles (15,904 km). After withdrawal, its boiler section was kept as a stationary unit.

Key specifications:
- Gauge: 7 ft 1/4 in (2,140 mm)
- Driver diameter: 6 ft 0 in (1,829 mm)
- Wheelbase: 7 ft 0 in (2.13 m)
- Cylinder size: 16 in × 20 in (406 mm × 508 mm)
- Builder: R. & W. Hawthorn & Co.
- Serial number: 235
- Build date: 1838
- Total produced: 1
- Operator: Great Western Railway
- Status: Scrapped