Last weekend marked the 76th anniversary of the D-Day landings and, as the pages of this forum attest, Coastal Forces played key roles during the assault, with the division’s ships and crews taking on a multitude of tasks including navigation leaders, escorts and position markers. Many Coastal Forces vessels also operated as mine sweepers — ML 207s role. During the early stages of Operation Neptune, the military codename for the first phase of the invasion of Normandy, ten channels were cut through the German mine barrier by ships sailing ahead of the main assault fleet. Each of the ten mine sweeping flotillas, tasked with cutting these vital passageways, was led by mine sweeping MLs from Coastal Forces. One of the mottos of the fleet minesweepers, relating to D-Day, proudly proclaims, ‘They led the way’
. The motto is even the title of a book that details the fleet sweepers actions on that fateful day in June 1944. Actually, they didn’t lead the way, Coastal Forces did. Coastal Forces vessels swept the mines for the fleet sweepers.
Whilst researching my father’s book, I came across information relating to Operation Neptune that I found particularly interesting. One detail also had special significance to ML 207’s exploits and confirmed something my father described in his writings and which he told me about. I thought members would be interested in this fascinating aspect of the D-Day mine sweeping operation and ML 207’s part in it.
The information I came across takes the form of charts, known as Micky Mouse Diagrams. The name resulted from the large circles drawn on charts that looked a bit like the outline Micky Mouse’s head and ears. Each chart shows ship positions in relation to H-Hour on D-Day, i.e. the exact hour at which the Allied troops landed on the Normandy beaches. H-Hour was slightly different in the American and British/Canadian sections due to the tides. However, this difference has been incorporated into diagrams, so the ship positions are correct according to the particular H-Hour for each beach. The small circle to the south east of the Isle of Wight on each of the charts, officially designated as area ‘Z’, was a maritime cross-roads and assembly area that became known as Piccadilly Circus to those involved.
The charts were included in the original top-secret operation orders issued for Neptune, copies of which can be viewed in various archives, libraries and museums. Some can also be found online. The first of the charts below depicts the situation at H-18, i.e. eighteen hours before the troops landed on the Normandy beaches. The second is at H-12, the third at H-6 and the last at H+6. As you will see from the last diagram, at H+6, groups scheduled to arrive on the second day are already on their way from the Thames, Bristol Channel and even further afield.
The Allied forces were arranged into task forces and each was given a reference code. The initial assault forces used the first letter of the landing beach they were heading for. Force ‘U’ was heading for Utah beach, Force ‘O’ for Omaha, ‘G’ for Gold, ‘J’ for Juno and ‘S’ for Sword. Each of these forces was further subdivided, and a sequential number added, according to when and where the sub-group was scheduled to arrive. Taking Gold Beach as an example, G1 was the first of the assault forces to arrive, G2 the second, G3 the third, etc. The maps below show the positions of each of these subgroups in relation to H-Hour. Other specialist task forces, and follow up forces, were given their own unique references too. Though, these were not necessarily related to the beach names. For example, naval bombardment forces used the designation letters A, C, K, E and D and were assigned to task forces, U, O, G, J and S respectively. Here is a detail from the chart describing the situation at H-18 showing the first of the 'G' and 'J' invasion forces leaving The Solent and heading for 'Piccadilly Circus'. The first of the 'O' forces are also on their way to the 'cross-roads' having set sail from a port to the west.
The effort that went into planning the invasion was truly incredible, an awe-inspiring masterpiece of logistics. The loading, sailing and arrival time of every man and piece of equipment, whether commando, tank, mulberry harbour caisson or water barge was determined to the last nut and bolt, with room to make adjustments according to operational requirements - and this wasn’t just for D-Day but for the many weeks that followed!
As mentioned earlier, initially, ten shipping channels were cut through the German mine barrier, two for each of the named landing beaches. Later, as the invasion progressed, the areas between the channels were also cleared. Specialist Dan Layers were deployed just behind the mine sweepers. These vessels dropped Dan Buoys to mark either side of the swept channel making it easier for those following to identify the safe mine-free route.
The point relating to ML 207, which I find particularly fascinating, relates to the position of the minesweepers at head of the invasion force. ML 207 was at the front of channel 5 heading to Gold beach, the fifth channel counting from the west. The mine sweepers, designated as ‘m/s’, are omitted from many of the ‘Micky Mouse’ charts but the direction arrows on chart number 3, at H-6, indicates that, at this point, the mine sweepers were all sailing backwards away from France and towards the task groups that were following in their wake.
This is exactly as my father described. They were sailing backwards to lose time. It all had to do with preventing the mine sweepers from sailing too far ahead of main invasion fleet and being spotted on enemy radar, which would have given the game away well before the Allies were ready to launch the assault.
The mine sweepers needed to sail at a minimum of seven knots to cut mines safety. At speeds lower than this, the sweeps and cutters would not function properly and mines could easily get caught and dragged into contact with the ships — with the obvious fatal consequences. On the other hand, ships sailing with the main assault forces needed to operate as a convoy, sailing at the speed the slowest vessel could maintain, about five knots. During the long journey to Normandy, this difference in speed would result in the sweepers ending up many miles ahead of the main fleet. Obviously, something needed to be done to prevent this. The solution was for the mine sweepers to stop, turn and sail backwards towards the following assault forces, losing time in the process, before turning again to resume the sweeping operation. However, several factors complicated matters. The turning maneuver needed to be completed in the middle of the German mine fields, at night, without lights, whist holding formation, when the tide was changing direction and right under the noses of the German forces.
When the fleet set out on its way towards France, the tide and current in the English Channel was running from starboard to port across the direction of travel, by the time it arrived the current was running from port to starboard. This meant the ships had to change the sweep they were using along the way, port initially and starboard later, to ensure the cables and cutters were always carried away from their hulls and propellers.
They Navy’s solution to the conundrum went like this: When the mine clearing operation commenced, south of ‘Piccadilly Circus’, the lead ship in each of the mine sweeping flotillas, one of the MLs, deployed its port sweep. The ships following did the same taking up ‘G’ formation, an offset ‘follow my leader’ pattern, which ensured each ship was sailing in water cleared by the sweep of the vessel in front, whilst its own sweep broadened the channel (see illustration below).
The minesweepers also needed to keep precise separations to ensure they didn’t sail over another vessel’s sweeps and to allow enough time to deal with any mines cut free ahead of them. To achieve such precise maneuvering, each ship had to regulate its speed on the basis of the rpm of its propellers, whilst simultaneously taking account of the prevailing current and weather – using fractions of full speed given by the Engine Order Telegraph simply wasn’t good enough. The minesweepers were fitted with RADAR but it wasn’t accurate enough to navigate by either.
At the point when the flotilla needed to lose time, and take account of the changing tide, each ship retrieved its sweep and formed up line astern until all were sailing behind the lead ML on the starboard side of the channel protected only by the leader’s sweep. This done, starting at the rear, each ship turned, sailed a set distance back along the mine free ‘corridor’ just created, then turned again to face the original heading. Whilst sailing back, all the ships also swapped over to the opposite side of the channel. So, the flotilla had now retreated a set distance, turned to face direction it had started from and formed up line astern once again but this time on the port side of the mine free corridor. At this point the lead ML deployed its starboard sweep, the opposite of the one it had been using originally, and started sweeping again. The other mine sweepers followed, taking up a “G” formation behind but now off to starboard, a shape that was a mirror image of the one the flotilla had been in before the manoeuver began.
ML 207 and the other minesweepers practiced the intricate maneuver many times prior to D-Day. My father described it as follows:
"The whole exercise was the equivalent to the minesweeping version of formation dancing, only carried out blindfold, with the added incentive that, if you put a foot wrong, you and your partner risked being blown to kingdom come."
To make things worse for the MLs, unlike the fleet sweepers, they did not have the luxury of powered winches to retrieve and deploy their sweeps. They had the basic model, everything had to be done by hand in very rough seas and within enemy waters just a matter of miles off the French coast. The hauling in process was particularly onerous and took over half an hour to accomplish with the ship stationary in the water throughout – they were, quite simply, sitting ducks. Actually, ML207 had a very lucky escape during one of the night-time practice runs out in the Channel, when a large group of E-Boats were spotted on RADAR heading straight for them. The mine sweeping flotilla were ordered not to engage the enemy under any circumstances. As my father said, 'they 'were being kept for more important things'
. The Fleet Sweepers soon had their sweeps in and were heading for port, leaving ML 206 and ML 207 desperately trying to haul in their equipment by hand. It was a close run thing, they only managed to get away in the nick of time. The much faster assailants pursued the two MLs, gaining on them with every minute, until, thankfully, they finally gave up the chase as they neared the coast.
On D-Day itself, the crews of the mine sweepers were told that their sole duty was to sweep mines and they must continue to do so even if attacked. They could, of course, fire back but not alter course or stop sweeping under any circumstances. Ships were held in reserve at the rear of the mine sweeping flotillas to replace those lost at the front.
In his book, my father recounts the time when the crew were given their detailed orders for the assault. They had been told to form up on deck in readiness for their commanding office to address them once he returned from a briefing abroad the flag ship of the 6th Minesweeping Flotilla. To the crew's surprise, when the captain arrived back he was accompanied by the commanding officer of the flotilla. The reason for the unexpected visit soon became apparent when the flotilla's commander addressed them saying:
‘Men, you have worked tirelessly these past weeks and, to your credit, have become accomplished at your new role of mine sweeping. I can now reveal that your hard work and devotion to duty has already paid off. Tomorrow, His Majesty’s Motor Launch 207 will be sweeping in the van of the 6th minesweeping flotilla and, as a consequence, will have the great honour of leading the force “G” invasion fleet as it crosses the Channel and be the first allied ship to reach the assault beach designated Gold, “G for Gold”.’
However, the Commander subsequently added:
'I also have to tell you that we believe some of the mines Jerry has laid are unsweepable but, your ship, with its wooden hull and shallow draft, has a first-rate chance of accomplishing its task of coming through unscathed ... and, of course, there are only sixteen of you on the ML, whereas, there are well over one hundred soles on each of the fleet sweepers.’
My father said, 'the “honour” of leading the invasion fleet suddenly lost its gloss.'
As it turned out, ML207 and the 6th Minesweeping Flotilla encountered a major problem during the turning manoeuvre. The ships of the task groups following were sailing too close, meaning the mine sweepers could not lose the required amount of time. The only option left, to prevent the sweepers sailing too far ahead and being spotted on German Radar, was to sweep at a dangerously slow speed. Everyone on board ML 207 expected the inevitable – a mine to be dragged onto the hull at any moment. Many incredibly tense hours followed, with the crew out on deck, sweep-cutting axes in hand, scanning the night-darkened, gale-swept sea, attempting to spot mines that might be caught in the sweep wires — and hoping they could manage to cut the cables in time if they spotted one.
Having cut the channels through the mine fields, the crews could not rest. Now sailing parallel to the beaches, in full sight of the enemy, and well within range of the shore batteries, they had to clear safe anchorages for the capitol ships of the bombarding force and create mine-free manoeuvring areas for destroyers and other vessels. While the fleet sweepers returned to the German mine barrier to widen the channels previously cut, ML 207 took up a defensive role looking for E-Boats and, together with other Allied vessels, countered attacks on Normandy anchorage from a host of assailants including midget submarines, ‘Human torpedoes’ and ‘skimming dishes’, the latter being small ships loaded with explosives and set adrift so’s to float into the anchorage on the tides. In the days that followed the first landings, as well as the inevitable air and artillery attacks, new threats emerged including the hitherto unknown, and deadly, Oyster Mine.
The admiralty expected the mine sweepers to pay a very heavy price during the initial assault, with presumed loses of 30% to 50% and acceptable losses regarded as 75%. In the event, the element of surprise, the weather, skill, and sheer luck, all played a part. Just one mine sweeper was lost on D-Day, tragic though that was.