From their earliest days until late in the 20th century, the railways carried a significant number of large, awkward, "one-off" loads. They had a variety of special wagons for the purpose. Flat wagons could carry rails, machinery or steel plates. "Trolley" wagons had a lowered central well, to carry very large items - steam boilers, propellers for ships, and so on.
| Number | Description | Date Built | Builder |
| 40 ton Bogie Trolley Wagon, Caledonian Railway | 1896 | ||
| 170 | Bogie Flat Wagon, Caledonian Railway - Babcock & Wilcox | 1913 | St.Rollox |
| 212 | Bogie Rail Wagon, Caledonian Railway - Babcock & Wilcox | 1913 | St.Rollox |
| AD40002 | Flat Wagon (ex10 ton van), Ministry of Defence Army Department | 1913 | Midland Rly. |
| * | 30 ton Bogie Heavy Weight Wagon, Caledonian Railway | b.1915 | |
| 84005 | 35 ton Bogie Rectank Wagon, Lancashire & Yorkshire Railway. Ex army. | 1918 | Newton Heath |
| 221 | Flat Wagon (ex tank wagon) Babcock & Wilcox | c.1930 | |
| 50 | Flat Wagon (ex GWR cattle wagon) Royal Navy, RNAD Bandeath | c.1930 | |
| 78 | Flat Wagon (ex GWR cattle wagon) Royal Navy, RNAD Bandeath | c.1930 | |
| 3ft gauge Flat Wagon, British Aluminium Co., Fort William | c.1930 | ||
| 3ft gauge Flat Wagon, British Aluminium Co., Fort William | c.1930 | ||
| Roll Wagon, British Aluminium Co., Alcan, Falkirk (internal user) | |||
| MOS/P/2 Tank Wagon underframe | c.1940 | ||
| B904586 | 25 ton Lowmac Machinery Wagon, British Railways | 1954 | Swindon |
| B507115 | 13 ton Conflat A Wagon, British Railways | 1958 | Pressed Steel |
| B531008 | 38 ton Rectank Wagon, British Railways | 1958-60 | |
| B904141 | 20.5 ton Lowmac SG Wagon, British Railways | 1958 | Swindon |
| B900123 | 21 ton Flatrol Wagon, British Railways | 1959 | Darlington |
| B948251 | 42 ton Boplate bogie Wagon, British Railways | 1960 | Derby |
| B510044 | Condor Container Bogie Flat Wagon, British Railways | 1964 | Ashford |
| 110349 | OTA Timber Wagon, EWS | 1978 | Ashford |
