That 'Operation Neptune', the naval section of 'Operation Overlord' - the invasion of France at Normandy, originally intended for 5th June 1944 but because of bad weather, postponed for 24 hours and taking place on the 6th - was probably the largest and most complex of all naval operations in World War II, there can be little argument. Part of this operation, and one on which the whole success or otherwise of 'Overlord' would depend, was that involving the minesweeping force, in which a total of 325 naval vessels participated, of which 273 were from the Royal Navy. Among these 325 were 109 Fleet Minesweepers, the vessels given the major task of clearing the way through the German mine barrage which lay across the path of the invasion force heading for Northern France.
Operation 'Neptune' was the codename for the naval part of 'Operation Overlord' and covers the period from the 5th June to 30th June 1944 even though Fleet Minesweepers were still very much engaged through July and August. It wasn't only the Fleet Minesweepers which were engaged in mine clearing operations. There were other smaller vessels including danlayers, some specially built for the task and others converted from fishing vessels. Some of these, together with motor launches of Coastal Forces carried out shallow mineweeping ahead of the big Fleet Minesweepers. There were also those whose job it was to assist in the destruction of swept mines and the many other, small specialist minesweepers, who would follow in the days after D-day to take on the enormous job of clearing the inshore areas of mines, particularly the ground/influence mines (magnetic and acoustic) in order to allow transport and supply vessels to operate in safety. These specialist minesweepers were the BYM's (American built wooden sweepers) and the MMS's (Mickey Mouses) and their work, superbly carried out clearing close inshore and the mouths of rivers were vital to the success of the invasion.
The oldest of the Fleet Minesweepers taking part were the eight 'Hunt-class' ships of the 4th Minesweeping Flotilla (MSF), KELLETT (SO), ALBURY, LYDD, PANGBOURNE, ROSS, SALTASH and SUTTON. These were known as the 'Smokey Joes', being coal-burners. Another, ELGIN would have been there but was damaged by an acoustic mine a few weeks before the event.
Next in age, but larger, were the 'Halcyon-class' of the 1st MSF, HARRIER (SO), HALCYON, GLEANER, HUSSAR, JASON, SALAMANDER, BRITOMART and SPEEDWELL. These had been in service since the outbreak of war and some had also assisted in the evacuation of allied troops at Dunkirk in 1940.
The third group was by far the largest. These were the early wartime 'Bangor-class' - smaller than the Halcyons but very efficient nonetheless. Some of the class had already had experience and proved their usefulness in the Mediterranean at the landings at Sicily, Salerno and Anzio. One flotilla, the 9th MSF, had been chosen to carry out the sweepimg for the ill-fated Dieppe raid in August 1942. In addition, the Bangors had been used on a number of occasions as escort vessels and had taken part in both Russian and Malta convoys. The 'Bangor' flotillas involved in 'Neptune' were:
9th MSF, SIDMOUTH (SO), TENBY, BRIDPORT, BANGOR, BLACKPOOL, BOSTON, BRIDLINGTON and EASTBOURNE.
14th MSF, ROMNEY (SO), SEAHAM, GUYSBOROUGH (RCN), KENORA (RCN), POOLE, RYE, VEGREVILLE (RCN) and WHITEHAVEN. In addition, PETERHEAD and GEORGIAN (RCN) were to act as danlayers for the sweepers.
15th MSF, FRASERBURGH (SO), ARDROSSAN, BOOLE, LYME REGIS, (2nd SO), WORTHING, FORT YORK, DUNBAR and LLANDUDNO.
16th MSF, SHIPPIGAN (SO), TADOUSSAC, WEDGEPORT, PARRSBORO, QUALICUM, BEAUMARIS, DORNOCH and ILFRACOMBE.
The second largest contingent of Fleet Minesweepers were the 'Algerines', the most up-to-date and considered by many to be the finest minesweepers of any Navy to take part in World War II. Prior to Normandy, two flotillas were at work in the Mediterranean, the 12th MSF had taken part in the invasion of North Africa and Sicily and the landings at Salerno and Anzio, whilst the other, the 19th MSF, was just two weeks later to be the minesweeping force for the invasion and capture of Elba, and in August for Operation 'Dragoon' - the invasion of the South of France. Both flotillas had shown that the Algerines were superbly suited to invasion sweeping. One other flotilla due to tke part in 'Neptune' was the 18th MSF, already well blooded in sweeping around the UK and more recently engaged in escorting convoys to Russia. The three Algerine flotillas available in the UK for the task were:
6th MSF, VESTAL (SO), FRIENDSHIP, GOZO, LIGHTFOOT, MELITA, PERSIAN, POSTILLION, and LARNE - incidently LARNE had the distinction of being the only British Fleet sweeper to take part in both the invasion of Normandy and the invasion of Southern France in August.
7th MSF, PELORUS (SO), PICKLE, PINCHER, PLUCKY, FANCY, LENNOX, RECRUIT and RIFLEMAN.
18th MSF, READY (SO), HOUND, HYDRA, LOYALTY, ONYX, COCKATRICE, ORESTES and RATTLESNAKE.
Another British flotilla the 40th MSF, consisting of 'Catherine-class' (or BAMs - American designed and built Fleet Minesweepers - known as AMs - similar to the US 'Auk' class) were involved in 'Neptune', their initial task being to sweep ahead of the force of bombarding battleships, WARSPITE and RAMILLIES, following after the 15th MSF of Bangors down Channel 10. The BAMs present on D-day were:
GRECIAN (SO), MAGIC, CATHERINE, CATO, GAZELLE, GORGON, PIQUE and STEADFAST with two more, CHAMOIS and CHANCE, acting as danlayers.
Also taking part were scores of auxiliary minesweeping vessels of the Royal Navy; trawler and drifter danlayers working with the Fleet sweepers and the gallant little minesweeping Motor Launches whose job it was to shallow sweep ahead of the large Fleet Minesweepers. For their part, the Fleet sweepers were the vessels given the task of clearing the way through the German barrage minefield in the Channel for the Invasion Fleet, to be followed later by other types of sweepers built for the purposes of inshore and ground-mine sweeping - the BYMs and MMSs, whose job it would be to clear the beachhead anchorages of magnetic and acoustic influence mines.
In addition to the major Royal Navy contribution to the minesweeping force, both America and Canada were represented by Fleet Minesweepers, and in the case of America, also by a number of smaller vessels - the YMs.
The eleven American AMs (the equivalent of the British Algerines) of the 7th US Minesweeping Squadron were:
AUK, BROADBILL, CHICKADEE, RAVEN, OSPREY, NUTHATCH, PHEASANT, STAFF, SWIFT, THREAT and TIDE.
Their task was to sweep ahead of the bombarding warships on the American eastern flank, which included the battleship USS NEVADA and the US cruisers QUINCY and TUSCALOOSA. Other US minesweepers to follow the main invasion fleet were 24 YMs (the same as the British BYMs).
From Canada there came sixteen Bangor-class sweepers manned by the men of the Royal Canadian Navy:
31st MSF, CARAQUAT (SO), BLAIRMORE, COWICHAN, MALPEQUE, FORT WILLIAM, MILLTOWN, MINAS and BAYFIELD.
32nd MSF, THUNDER (SO), CANSO, GEORGIAN, MULGRAVE, VEGREVILLE, KENORA, WASAGA and GUYSBOROUGH.
These, then, were the major minesweepers to be engaged in what was the largest, most complex and difficult, minesweeping operation ever. That so few ships of the Allied invasion fleet were sunk or damaged by mines during the invasion passage across the English Channel to France, is due entirely to the meticulous planning of those responsible for the minesweeeping operation, and to the ships and men whose task it was to carry the plans out.