RNMWS Minewatching Posts
With the establishment of the Royal Naval Minewatching Service (RNMWS) in 1952, twelve minewatching posts were built around Portland Harbour in 1953. In the event of war, the posts were to have been used by volunteer personnel of the RNMWS to spot and report mines dropped by enemy aircraft within the harbour and its approaches.
History
The Royal Naval Minewatching Service (RNMWS) was formed in 1952 as part of the auxiliary forces of the Naval Service. It was considered that, in the event of a future war, Britain would be highly vulnerable to enemy aircraft dropping aerial mines within its coastal and inland waters. In order to protect naval and merchant shipping and keep shipping lanes and harbours open, the RNMWS was established with the wartime role of identifying, plotting and reporting any such mines. The service was a civilian organisation administered by the Royal Navy and its volunteers could be of either sex aged 26 or over.
In wartime, RNMWS personnel would either man fixed shore-based minewatching posts or operate afloat on minewatching vessels. The posts were positioned overlooking harbours, navigable rivers, estuaries and other strategic waterways across the UK, including at Portland. Twelve posts were built in the vicinity of the harbour in 1953 and most of these were positioned along its four breakwaters. The posts were positioned from north to south accordingly:
Each post was fitted with range finding equipment to determine the bearing and range of a dropped mine. The personnel manning them originally reported by telephone to the Seaward Defence Headquarters (SDHQ) at HMS Osprey and later, with the closure of the SDHQ after the abolition of Coastal Defence in 1956, to a plot and logging centre, most likely situated in the naval base. The mine plot, time of observation and last accurate position would be reported to the SDHQ, who would then plot the details on their own mine plot. This unfiltered information would be sent to Port HQ at Portsmouth (the Portland unit fell under Portsmouth Command) and they then provided the SDHQ with all filtered mine plots. With this information, a danger area could be identified, allowing shipping to be warned and diverted as necessary, and the plotted mines could be cleared by a minesweeping vessel under the control of the Naval Officer-in-Charge. In times of war, mine plots were expected to be also reported by the area's coast artillery including gunners and personnel in battery observation posts.
Most of the RNMWS personnel's training was conducted in localised training centres, but Portland's posts were used during exercises and competitions. They were manned for "Seaport II" on 29 and 30 August 1953, a major exercise involving many ships and personnel of different organisations which was undertaken to test the naval and coast artillery defences of Portland. It centred around the scenario that Portland and other ports along the south coast were under the threat of attack, with the harbour to be defended and an expeditionary force to be assembled to sail against the enemy. For their role in the exercise, the RNMWS was tasked with identifying, plotting and reporting dummy mines which were dropped by aircraft of No. 3 Group RAF Coastal Command. The similar "Seaport III" followed on 28 and 29 May 1954 and "Seaport IV" on 4 and 5 June 1955. On 24 and 25 September 1960, Exercise "Brandy Snap" was carried out at Portland, with approximately 100 volunteers of the service, including from Chatham, Plymouth, Portsmouth and Portland, manning both minewatching vessels and the posts. Helicopters from RNAS Portland were used to drop the dummy mines (sandbags).
Portland's volunteers were successful in a number of inter-unit and inter-command competitions when they were launched in 1956. On 19 May 1956, Portland was the location for the finals of Portsmouth Command's inter-unit competition. The efficiency of various units was tested under "action conditions" during both day and night and Portland's select team of twelve minewatchers were the winners. A team from Portland's unit won the competition again at Portsmouth on 25 May 1957, scoring 241.6 out of a possible 270 marks. Later in the year, on 7 September 1957, a team from Portland performed as one of four finalists in the inter-command annual efficiency competition at Chatham. They came in second with 261 marks, behind Hastings with 276 marks, out of a possible 325 marks. On 31 May 1958, Portland won the inter-unit competition, held at Portland, scoring 207 out of 250 marks. At the inter-command competition finals in Edinburgh in October 1958, Portland placed third with 247 marks, behind Hastings with 249 and Barrow with 250. For the inter-unit competition held at Gosport on 23 May 1959, Portland won with 208 out of 250 marks.
As the Cold War progressed, the RNMWS was reformed into the Royal Naval Auxiliary Service (RNXS) in 1962. The new service retained minewatching as one of its roles, but it now had a wider range of wartime duties in response to the increasingly more likely threat of nuclear warfare. These included assisting in the evacuation of major ports and the dispatch of merchant vessels to safe anchorages overseas in the event of an attack, and providing support staff to naval organisations operating from commercial UK ports in wartime. As the danger of aerial mines continued to diminish, the minewatching posts became disused later in the 1960s.
Today eight of the twelve posts survive: one on the northern breakwater, those at A, B and C Pier Heads, the one at the Breakwater Fort, two along the outer breakwater and one at D Pier Head. Six of the remaining posts conform to the same design and are built of concrete with a single entrance at the rear and two corner embrasures for observation. The one at B Pier Head is similar but has three embrasures rather than two. The post on the northern breakwater is of a different design. It is built of brick and has an embrasure in each corner, allowing observation over the harbour and seawards.
History
The Royal Naval Minewatching Service (RNMWS) was formed in 1952 as part of the auxiliary forces of the Naval Service. It was considered that, in the event of a future war, Britain would be highly vulnerable to enemy aircraft dropping aerial mines within its coastal and inland waters. In order to protect naval and merchant shipping and keep shipping lanes and harbours open, the RNMWS was established with the wartime role of identifying, plotting and reporting any such mines. The service was a civilian organisation administered by the Royal Navy and its volunteers could be of either sex aged 26 or over.
In wartime, RNMWS personnel would either man fixed shore-based minewatching posts or operate afloat on minewatching vessels. The posts were positioned overlooking harbours, navigable rivers, estuaries and other strategic waterways across the UK, including at Portland. Twelve posts were built in the vicinity of the harbour in 1953 and most of these were positioned along its four breakwaters. The posts were positioned from north to south accordingly:
- Two along the northern breakwater
- One at C Pier Head
- One at B Pier Head
- One at the centre of the north-eastern breakwater
- One at A Pier Head
- One at the Breakwater Fort
- Two along the outer breakwater arm
- One at D Pier Head
- One within Portland's naval dockyard (on the coaling pier)
- One on the pier by the Mere Oil Fuel Depot
Each post was fitted with range finding equipment to determine the bearing and range of a dropped mine. The personnel manning them originally reported by telephone to the Seaward Defence Headquarters (SDHQ) at HMS Osprey and later, with the closure of the SDHQ after the abolition of Coastal Defence in 1956, to a plot and logging centre, most likely situated in the naval base. The mine plot, time of observation and last accurate position would be reported to the SDHQ, who would then plot the details on their own mine plot. This unfiltered information would be sent to Port HQ at Portsmouth (the Portland unit fell under Portsmouth Command) and they then provided the SDHQ with all filtered mine plots. With this information, a danger area could be identified, allowing shipping to be warned and diverted as necessary, and the plotted mines could be cleared by a minesweeping vessel under the control of the Naval Officer-in-Charge. In times of war, mine plots were expected to be also reported by the area's coast artillery including gunners and personnel in battery observation posts.
Most of the RNMWS personnel's training was conducted in localised training centres, but Portland's posts were used during exercises and competitions. They were manned for "Seaport II" on 29 and 30 August 1953, a major exercise involving many ships and personnel of different organisations which was undertaken to test the naval and coast artillery defences of Portland. It centred around the scenario that Portland and other ports along the south coast were under the threat of attack, with the harbour to be defended and an expeditionary force to be assembled to sail against the enemy. For their role in the exercise, the RNMWS was tasked with identifying, plotting and reporting dummy mines which were dropped by aircraft of No. 3 Group RAF Coastal Command. The similar "Seaport III" followed on 28 and 29 May 1954 and "Seaport IV" on 4 and 5 June 1955. On 24 and 25 September 1960, Exercise "Brandy Snap" was carried out at Portland, with approximately 100 volunteers of the service, including from Chatham, Plymouth, Portsmouth and Portland, manning both minewatching vessels and the posts. Helicopters from RNAS Portland were used to drop the dummy mines (sandbags).
Portland's volunteers were successful in a number of inter-unit and inter-command competitions when they were launched in 1956. On 19 May 1956, Portland was the location for the finals of Portsmouth Command's inter-unit competition. The efficiency of various units was tested under "action conditions" during both day and night and Portland's select team of twelve minewatchers were the winners. A team from Portland's unit won the competition again at Portsmouth on 25 May 1957, scoring 241.6 out of a possible 270 marks. Later in the year, on 7 September 1957, a team from Portland performed as one of four finalists in the inter-command annual efficiency competition at Chatham. They came in second with 261 marks, behind Hastings with 276 marks, out of a possible 325 marks. On 31 May 1958, Portland won the inter-unit competition, held at Portland, scoring 207 out of 250 marks. At the inter-command competition finals in Edinburgh in October 1958, Portland placed third with 247 marks, behind Hastings with 249 and Barrow with 250. For the inter-unit competition held at Gosport on 23 May 1959, Portland won with 208 out of 250 marks.
As the Cold War progressed, the RNMWS was reformed into the Royal Naval Auxiliary Service (RNXS) in 1962. The new service retained minewatching as one of its roles, but it now had a wider range of wartime duties in response to the increasingly more likely threat of nuclear warfare. These included assisting in the evacuation of major ports and the dispatch of merchant vessels to safe anchorages overseas in the event of an attack, and providing support staff to naval organisations operating from commercial UK ports in wartime. As the danger of aerial mines continued to diminish, the minewatching posts became disused later in the 1960s.
Today eight of the twelve posts survive: one on the northern breakwater, those at A, B and C Pier Heads, the one at the Breakwater Fort, two along the outer breakwater and one at D Pier Head. Six of the remaining posts conform to the same design and are built of concrete with a single entrance at the rear and two corner embrasures for observation. The one at B Pier Head is similar but has three embrasures rather than two. The post on the northern breakwater is of a different design. It is built of brick and has an embrasure in each corner, allowing observation over the harbour and seawards.
Post #1
Post #1 was positioned on the northern breakwater close to Bincleaves and has since been demolished.
Post #2
Post #2 is positioned approximately midway along the northern breakwater. It is built of brick and has four embrasures, two facing seaward and two facing into the harbour. It was built on the site of a disused electric light directing station.
Post #3
Post #3 is positioned at C Pier Head at the southern end of the northern breakwater. It is built of concrete and has embrasures facing the north ship channel and into the harbour beyond.
Post #4
Post #4 is positioned at B Pier Head at the northern end of the north-eastern breakwater. It is built of concrete and has two embrasures facing the north ship channel and the northern breakwater, plus an additional embrasure facing into the harbour.
Post #5
Post #5 was positioned at the centre of the north-eastern breakwater and was built on top of the sergeants' mess. Both the mess and post have been demolished.
Post #6
Post #6 is positioned at A Pier Head at the southern end of the north-eastern breakwater. It is built of concrete and has embrasures facing the east ship channel and towards the Breakwater Fort.
Post #7
Post #7 is positioned at the Breakwater Fort at the northern end of the outer breakwater. It overlooks the east ship channel and the north-eastern breakwater. It is built of concrete and sits on top of the fort's regimental institute building.
Post #8
Post #8 is positioned near the centre of the outer breakwater. It is built of concrete and has embrasures facing into the harbour.
Post #9
Post #9 is positioned towards the southern end of the outer breakwater. Like Post #8, it is built of concrete and has embrasures facing into the harbour.
Post #10
Post #10 is positioned at D Pier Head at the southern end of the outer breakwater. It is built of concrete and has embrasures facing into the harbour.
Post #11
Post #11 was positioned at the easternmost end of the coaling pier within the dockyard/naval base and has since been demolished. It was either converted from a World War II observation post or built on the same spot.
Post #12
Post #12 was positioned at the end of the pier to the east of the Mere Oil Fuel Depot within the south-west region of the harbour. The pier was later absorbed into RNAS Portland as R3 Hard and the minewatching post was probably demolished during this period.
References
The following is an A-Z list of references for this page.
1) Admiralty - Official Notice: Royal Naval Minewatching Service - 11 January 1952 - notice
2) The British Newspaper Archive - various contemporary newspaper articles including the Hampshire Telegraph and Portsmouth Evening News - website page
3) The National Archives - Portland: North Eastern Breakwater - WO 192/300 - fort record book - 1939-57 - website page
4) The National Archives - Weymouth: 'C' Pier Head - WO 192/310 - fort record book - 1913-54 - website page
5) The National Archives - Weymouth: Nothe Fort - WO 192/312 - fort record book - 1929-57 - website page
6) Wikipedia - Royal Naval Minewatching Service - website page
The following is an A-Z list of references for this page.
1) Admiralty - Official Notice: Royal Naval Minewatching Service - 11 January 1952 - notice
2) The British Newspaper Archive - various contemporary newspaper articles including the Hampshire Telegraph and Portsmouth Evening News - website page
3) The National Archives - Portland: North Eastern Breakwater - WO 192/300 - fort record book - 1939-57 - website page
4) The National Archives - Weymouth: 'C' Pier Head - WO 192/310 - fort record book - 1913-54 - website page
5) The National Archives - Weymouth: Nothe Fort - WO 192/312 - fort record book - 1929-57 - website page
6) Wikipedia - Royal Naval Minewatching Service - website page
Minewatching Post map
The positions of the eight surviving minewatching posts.