# Submarine mining units of the Royal Engineers

The Submarine Mining Service was a branch of the Royal Engineers (RE) tasked with defending Britain's dockyards using fixed mines (also known as 'torpedoes' in the early days) and later electric searchlights. From 1871 the RE formed a number of submarine mining (SM) companies, stationed at defended ports in the UK and around the Empire. 30th Submarine Mining Company at Plymouth acted as the depot company for the Submarine Mining School.
As the commitments of the service expanded the Regular RE companies were supplemented by SM companies (later 'divisions') formed within the Militia. The first was raised in 1878 as the Hampshire Engineers (Submarine Miners) at Gosport, expanded in 1883 to form the Southern Division Submarine Mining Militia of four companies stationed at Portsmouth, Plymouth and Chatham dockyards. By 1892 these had been expanded to 10 divisions covering the main naval dockyards in the UK. A high level committee on RE manpower chaired by Lord Sandhurst in 1885–6 recommended a rapid expansion of the SM service, including the Militia.
A few SM companies were also formed in 1883–4 within Engineer Volunteer Corps (EVCs) of the Volunteer Force. However, the War Office decided in 1886 that the higher standard of training required by submarine miners made it more convenient to treat these companies as separate units, and seven Volunteer SM divisions were formed.
After the submarine mining branch was abolished in 1907, the Regular units were converted into Fortress Companies, the Militia units were disbanded and most of the Volunteer units were reduced to small units working the searchlights for the gun defences. The following year these were incorporated into the Fortress Royal Engineer units of the Territorial Force.

## List of RE Submarine mining units
### Regulars

Units formed in the Regular RE:
| Title | Formed | Station | Disposal |
| 4th Submarine Mining Company | 1887 | Gosport and Spithead | 4th Fortress Company 1905 |
| 21st Submarine Mining Company | 1885 | Harwich | 21st Fortress Company 1905 |
| 22nd Submarine Mining Company | 1886 | Gosport, later Yarmouth, Isle of Wight | 22nd Fortress Company 1905 |
| 27th Submarine Mining Company | 1888 | Halifax, Nova Scotia, and Bermuda | 27th Fortress Company 1905 |
| 28th Submarine Mining Company | 1887 | Chatham Dockyard and Gravesend, later Malta | 28th Fortress Company 1905 |
| 30th Submarine Mining Company | 1886 | Gosport and Spithead | 30th Fortress Company 1905 |
| 33rd Submarine Mining Company | 1888 | Cork Harbour | 33rd Fortress Company 1905 |
| 34th Submarine Mining Company | 1885 | Malta, later Gravesend | 34th Fortress Company 1905 |
| 35th Submarine Mining Company | 1887 | Pembroke Dock | 35th Fortress Company 1905 |
| 39th Submarine Mining Company | 1888 | Chatham and Sheerness Dockyard | 39th Fortress Company 1905 |
| 40th Submarine Mining Company | 1888 | Halifax, Nova Scotia | 40th Fortress Company 1905 |
| 48th Submarine Mining Company | 1900 | Esquimault Dockyard and Victoria, British Columbia | 48th Fortress Company 1905 |

### Militia

Units formed in the Militia:
| Title | Formed | Station | Disposal |
| Hampshire Engineers (Submarine Miners) (Southern Division 1883) | 1873 | Portsmouth | |
| 1st (Hampshire) Submarine Mining Company | 1878 | Portsmouth | Portsmouth Division |
| 2nd (Hampshire) Submarine Mining Company | | | Portsmouth Division |
| 3rd (Devonshire) Submarine Mining Company | 1885 | Plymouth | Plymouth Division |
| 4th (Kent) Submarine Mining Company | 1884 | Chatham | Thames and Medway Division |
| Portsmouth Division | From Hampshire Companies 1888 | Gosport | Disbanded 1908 |
| Needles Division | From Portsmouth Division 1894 | Fort Victoria, Isle of Wight | Disbanded 1908 |
| Plymouth Division | From Devon Company 1888 | Plymouth | Disbanded 1908 |
| Thames & Medway Division | From Kent Company 1888 | Chatham | Separate Thames and Medway Divisions 1902 |
| Thames Division | From Thames & Medway Division 1902 | Gravesend | Disbanded 1908 |
| Medway Division | From Thames & Medway Division 1902 | Sheerness | Disbanded 1908 |
| Harwich Division | 1888 | Harwich | Disbanded 1908 |
| Milford Haven Division | 1888 | Pembroke Dock | Disbanded 1908 |
| Severn Division (South Wales & Severn 1889, Western Division 1894) | 1888 | Pembroke Dock | Disbanded 1908 |
| Humber Division | From Volunteers 1891 | Paull-on-Humber | East Riding Fortress Royal Engineers (TF) 1908 |
| Falmouth Division | From Volunteers 1892 | Falmouth | Disbanded 1908 |

### Volunteers

Units formed in the Volunteers:
| Title | Formed | Station | Disposal |
| Severn Division Submarine Miners | 1886 from 1st Gloucestershire EVC 1885 | Cardiff | Glamorgan Fortress Royal Engineers and Welsh Divisional Telegraph Company 1908 |
| Humber Division Submarine Miners | 1886 | Hull | To Militia 1891 |
| Tees Division Submarine Miners | 1886 | Middlesbrough | North Riding Fortress Royal Engineers 1908 |
| Falmouth Division Submarine Miners | 1888 | Falmouth | To Militia 1891 |
| Forth Division Submarine Miners | 1887 | Leith | City of Edinburgh (Fortress) Royal Engineers 1908 |
| Tay Division Submarine Miners | 1887 | Dundee | Disbanded 1907 |
| Tyne Division Submarine Miners | 1888 from 1st Newcastle upon Tyne and Durham EVC | North Shields | Durham Fortress Royal Engineers 1908 |
| Clyde Division Submarine Miners | 1888 from 2 companies 1st Lanarkshire EVC | Greenock | Renfrewshire Fortress Royal Engineers 1908 |
| Mersey Division Submarine Miners | 1888 from K Company 1st Lancashire EVC | Liverpool | Lancashire Fortress Royal Engineers 1908 |