The contribution of Western Approaches to Operation Overlord
This week marks the 80th anniversary of D-Day – the allied invasion of Normandy and the beginning of the end of the war in Europe. It was the biggest and most ambitious military operations in all of history, with over 5,000 ships and landing craft transporting over 150,000 troops and their equipment across the English Channel to a 50-mile stretch of the Normandy coast in France.
Remembrance events are for obvious reasons focused upon the beaches of France and on the crucial maritime centres of Portsmouth and Plymouth where the campaign was planned and launched from. However, the city of Liverpool, some 250 miles away from the front-line had a crucial but largely forgotten role in the success of the mission which was codenamed Operation Overlord
Twelve months prior to the events of D-Day, the Battle of the Atlantic had finally turned in favour of the allies and German Navy commander Grand Admiral Karl Doenitz was forced to withdraw most of his U-boats from active duty, never to recover the upper-hand they’d enjoyed earlier in the war.
This turning point is credited to technological advancements, longer-range aircraft capable of providing better air cover to ships, and most crucially the growing proficiency of Royal Navy ‘escort groups’ which accompanied and protected the merchant convoys. Not only had the crew of the escort groups become more experienced, but they had begun to successfully apply experimental new anti-U-boat tactics that were devised by the Western Approaches Tactical Unit based in a secret command bunker in Liverpool.
WATU consisted of a group of highly intelligent young women recruited from the Women’s Royal Navy Service and led by the unorthodox but effective Captain Gilbert Roberts – a Naval officer forced due to tuberculosis to retire from service in 1937 but recalled to desk duties in 1940.
By 1942, the U-Boat threat was so great that Churchill personally appointed Roberts to set up a new tactical unit in Liverpool to analyse how U-Boats were operating and attacking at sea, then using this intelligence to develop counter-tactics that were played out as a wargame on the floor of Derby House before training Escort Group Captains to apply them out at sea.
The impact of Roberts and his team was swift and significant, with the new counter-tactics helping to drastically reduce the amount of merchant ships sunk whilst destroying U-Boats faster than the German Navy could replace them.
On the last day of 1943 Roberts was appointed a Commander of the British Empire (C.B.E.) for his distinguished services, but now his skill and experience honed in the Atlantic conflict was about to be tested in the English Channel as preparations were made for the Normandy invasion.
In March 1944 , Roberts was informed about the plans for Overlord, and charged with using his experience in the Atlantic to nullify the threat posed by U-Boats to the thousands of ships taking part in the operation.
Roberts devised a three-day course including shallow water patrols, escort duty to unusual objects (later revealed to be Mulberry Harbour – a temporary portable harbour build for the invasion), tideway tactics, attacks on U-boats in confined waters and defence in same, all carefully planned without revealing details of timings or locations.
After six weeks, Roberts was to report to Maritime Headquarters in Plymouth where plans were to be finalised. A long table occupied the centre of the planning room, and Roberts was told to stand against the wall between their Air Vice-Marshall Slatter and an Army Officer.
As people filed in, Roberts did his best not to show his surprise as Eisenhower, Bradley, Montgomery and de Gaulle came in together, then Churchill with his Staff and last to walk in King George VI to be debriefed on the final plans.
After plans were shared, the King asked Admiral Horton what arrangements had been made to prevent U-boats coming down around Scotland and the west coast of Ireland and getting at the supply convoys.
Horton replied,
‘Roberts will answer that, sir.’
So Roberts found himself explaining his tactics devised in Liverpool to the King and a room full of world leaders and military top brass. He received a smile and a ‘Thank you’ from His Majesty.
Despite efforts, U-boats managed only a few successes against the vast D-Day invasion armada. Without doubt the pre-emptive planning of Captain Gilbert Roberts and the WATU school in Liverpool was a significant factor in this outcome.
Alongside his CBE, Poland honoured Roberts with the Cross of the Order of Polonia Restituta and France made him an Officer of the Legion of Honour.
It was amazing how much French wine suddenly became available in Liverpool!