The battle known as Third Ypres was intended, among other things, to recapture the Belgian coast and bottle up the marauding U-Boats. This part of the plan was known as Operation Hush.
The flat, low-lying Flanders coast, with harbours such as Nieuport, Ostend and Zeebrugge, exercised a great fascination for the British, even if some of them were occupied by Germans at the time. The British saw the seas as a great highway, particularly their great highway, while to the majority of Germans it was a boundary. Ports such as Ostend and Zeebrugge, leading into a network of broad canals, provided an outlet for U-Boats, uncomfortably close to the British coast.
Ostend in particular was seen as a key target since a canal from Bruges, where some of the U-Boats were hiding, led straight there. Rear-Admiral Sir Reginald Bacon, then commanding the Dover Patrol, seems to have come up with the idea, he had already suggested an infantry raid on Ostend but this latest idea implied a more permanent affair.
Since landing craft, such as existed at the time, weren’t big enough, Bacon suggested what he termed a floating pier (later called a pontoon) over 500 feet long. This was pushed ashore from the sea, controlled by two large warships, known as ‘monitors’, mounting a pair of 12 inch guns.
The pier/pontoon had to be long so that the propelling craft had enough water to float in, and the pontoon was tapered at its seaward end to fit between the bows of two monitors. Strong chains held the pontoon rigid against the ships so that it could be manoeuvred. At the forward end of the pontoon was a wooden raft, which dried out as the tide fell, enabling the attacking force to come ashore.
Planning and Preparation
Trials for Operation Hush were held in the Swin Channel in the approaches to the Thames Estuary and off the Essex coast, and once these had been perfected, two more pontoons were built (probably at Chatham Dockyard) and more monitors acquired since the plan was to land at three points, west of Ostend – which they were planning to capture – between Middelkerke and Westende. Aircraft flew over the beaches and photographed the fall of the tide so that the depth of water at each stage could be calculated while a C Class submarine lay submerged off the coast and measured the depth of water overhead as the tide rose and fell.
The plan was that the pontoons would go ashore at the top of the tide and land as the sea withdrew and the beach dried out. Each pontoon would carry troops, transport, Clyno motorcycle sidecars and handcarts, along with three tanks, a female and two male.
No precise date for the Operation Hush landing was ever settled, because it never came to pass. Sir Douglas Haig insisted that the main attack had to reach Roulers, five miles beyond Passchendaele before the amphibious assault could be mounted and it never got so far. And although the force was held, incommunicado, in the Swin Channel for some time it was ultimately disbanded.
Considering that tanks had first been used in action less than a year before, it was a bold plan to include them and to rely on them for so much.
Read more about the role of tanks in Operation Hush.
For a longer read about the controversy surrounding Passchendaele, have a look at the books below.