| Name: | H 45 & H 46 |
| Type: | Submarine |
| Keel: | n/a |
| Launched: | n/a |
| Completed: | n/a |
| Builder: | Armstrong, Whitworth & Co |
| Yard: | High Walker |
| Yard Number: | 944 & 945 |
| Dimensions: | 440disp surf, 500disp subm, 164.6 x 15.75 x 11.30ft |
| Engines: | 2 x diesel engines, 480hp; 2 x elecric motors 320hp |
| Engines by: | Ruston & Hornsby, Lincoln |
| Propulsion: | 2 x Screws, 13.0knots surf, 11.0knots subm |
| Construction: | Steel |
| Armament: | 4 x 21.0ins bow torpedo tubes |
| History: | |
| British Royal Navy | |
| Cancelled | |
| Comments: | Member of the H Class of submarines |
| 1917: Order cancelled |