Operation Hush was a British plan for amphibious landings on the Belgian coast in 1917 during the First World War. The landings were to be combined with an attack from Nieuwpoort and the Yser bridgehead, left over since the Battle of the Yser in 1914. Plans were considered in 1915 and 1916, then shelved due to operations elsewhere.
Operation Hush was intended to begin once the Third Battle of Ypres, the main offensive at Ypres, had advanced to Roulers, Koekelare and Thourout, with advances by the French and Belgians in between. On 10 July, Marine-Korps-Flandern conducted Unternehmen Strandfest (Operation Beach Party) a spoiling attack to forestall an Allied coastal operation. The Germans used mustard gas for the first time, captured part of the bridgehead over the Yser and annihilated two British infantry battalions.
Operation Hush was cancelled on 14 October 1917, as the advance at Ypres was too far behind schedule. In April 1918, the Dover Patrol raided Zeebrugge to sink blockships in the canal entrance to trap U-boats, which closed the canal for a short time. From September to October 1918, the Belgian coast was occupied by the Allies during the Fifth Battle of Ypres.
Background
Strategic developments
The German occupation of the Belgian coast in 1914 caused the Admiralty swiftly to advocate their removal. On 26 October 1914 the First Lord, Winston Churchill wrote to Sir John French, commander of the British Expeditionary Force (BEF) "We must have him off the Belgian coast". Churchill offered naval fire support for an army operation and French adopted the idea for the main effort of 1915. The army would advance between Dixmude and the sea while the navy provided bombardments and a surprise landing near Zeebrugge. The plan was cancelled by the British government in favour of the Gallipoli Campaign.
In early 1916 the idea of a coastal attack was revived and talks began between Sir Douglas Haig the new BEF commander-in-chief and Rear Admiral Reginald Bacon, commander of the Dover Patrol. Haig appointed Lieutenant-General Aylmer Hunter-Weston, who had commanded the 29th Division and then VIII Corps at Gallipoli, to work with Bacon on the plan. An offensive from Ypres and the landing operation, superseded an offensive on the coast. Bacon proposed to land 9,000 men from six monitors and 100 trawlers in Ostend harbour, with decoys towards Zeebrugge and Middelkirke, as a coastal assault began from Nieuwpoort. Hunter-Weston rejected the plan because the front was too narrow. Ostend harbour was in range of German heavy guns and the harbour exits were easy to block. Bacon began work on a new plan for a landing near Middelkirke, which incorporated Hunter-Weston's recommendations and Haig's desire for tanks to be used in the landings.
The Battle of the Somme in 1916 forced Haig to postpone an offensive in Flanders until 1917 and the coastal attack depended on retaining the Yser bridgehead, because the river was deep, tidal and 100–200 yd (91–183 m) wide. Lieutenant-Colonel Norman MacMullen (GSO I) and a small planning group formed in January 1917 at General Headquarters (GHQ), recommended that the operation should not begin until a general advance from Ypres had reached Roulers, which Haig accepted. A coastal offensive was to be conducted if one of three conditions were met, that the offensive at Ypres had prompted a collapse in the German defence, if the Germans took troops from the coast to replace losses in a long battle in the Ypres area or if the Allied advance at Ypres had reached Passchendaele ridge and the Fifth Army was advancing on Roulers (now Roeselare) and Thourout (now Torhout).
Tactics
To land troops swiftly, retaining the benefit of surprise, Bacon designed flat-bottomed craft which could land on beaches. The pontoons were 550 ft × 32 ft (167.6 m × 9.8 m), specially-built and lashed between pairs of monitors. Men, guns, wagons, ambulances, boxcars, motor cars, handcarts, bicycles, Stokes mortar carts and sidecars, plus two male tanks and one female tank, were to be embarked on each monitor. HMS General Wolfe and the other monitors would push the pontoons up the beach, the tanks would drive off, pulling sledges full of equipment, climb the sea-walls (an incline of about 30°), surmount a large projecting coping-stone at the top and then haul the rest of their load over the wall.
The Belgian architect who had designed the wall was a refugee in France and supplied his drawings. A replica was built at Merlimont and a detachment of tanks under Major Bingham rehearsed on it, using "shoes" on the tank tracks and special detachable steel ramps carried on the tanks, until they could climb the wall. In experiments on the Thames Estuary, the pontoons performed exceptionally well, riding out very bad weather and being easier to manoeuvre than expected, leading to hopes that they could be used again after the initial assault to land reinforcements. Night landings were also practised, with wire stretched between buoys to guide the pontoons to within 100 yd (91 m) of their landing place.
After Unternehmen Strandfest (Operation Beach Party), a German spoiling attack, 52 Squadron Royal Flying Corps (RFC) and the Fourth Balloon Wing, developed III Wing methods of co-operation during artillery observation, by having balloon observers direct preliminary ranging until shells were landing close to a target, then handing over to the aeroplane observer for the final corrections of aim. When the air observer had ranged the guns, the balloon observer took over again. The new method was economical on aircrew and had the advantage of telephone communication between the ground and the balloon, since aircraft wireless could only transmit.
Air co-operation with Royal Engineer sound ranging was also practised. A line of microphones was connected to a receiving station further back and activated by a forward observer. Air observers routinely sent "NF" by wireless and a position report when German batteries were seen to be firing; German shelling often cut off the ground observer from contact with the rear and the sound-ranging station was equipped with a wireless receiver and used receipt of "NF", to activate the sound ranging apparatus. The device could also be used to identify the position of German artillery when the air observer was unable accurately to indicate the position of the guns; balloon observers also assisted the ranging section by reporting gun flashes.
Prelude
British preparations
The Third (Corps) Wing of IV Brigade RFC moved north with XV Corps (Lieutenant-General Sir John Du Cane) in June and was temporarily made an independent mixed command, responsible for army co-operation and defence when the line was taken over from the French. By 10 July the Fourteenth (Army) Wing of IV Brigade had arrived, the brigade taking responsibility for reconnaissance in the area Keyem (now Keiem), Ichtergem, Bruges, Blankenberghe (now Blankenberge), Oost and Dunkirk Bains until 13 July, then Keyem, Oostcamp, Zeebrugge, Oost and Dunkirk Bains, while Royal Naval Air Service (RNAS) units reconnoitred as required. The offensive patrol front was from Stuyvekenskerke (now Stuivekenskerke) to Oost and Dunkirk Bains and by RNAS aircraft north of Nieuwpoort to 3 mi (4.8 km) west of Dunkirk. RNAS aircraft conducted night-bombing sorties in the area Dixmude, Thourout, Ghent, Retranchement and Nieuwpoort Bains. The 9th (Headquarters) Wing acted as a mobile reserve on the Flanders front.
When XV Corps took over from the 29th Division and the 133rd Division of the XXXVI Corps (36 Corps d'Armée) on the coast on 20 June. The British artillery was held back as the French would only allow their infantry to be covered by French guns. The French position had three defensive areas, St Georges on the right (inland) side, almost surrounded by water, at the junction with the Belgian army (which held the line for 13 mi (21 km) southwards to Nordschoote), the Lombartzyde area (now Lombardsijde) in the centre, with inundations on either side and Nieuwpoort Bains on the left to the coast, either side of the Geleide Brook. The sectors were linked across the inundations by bridges and isolated from the rear by the Yser and Dunkirk canals, crossed by floating-barrel bridges called Richmond, Kew and Mortlake near Nieuwpoort Bains and Barnes, Putney and Vauxhall bridges near Nieuwpoort. A permanent roadway crossed lock gates east of Nieuwpoort and another bridge named Crowder was built later near Nieuwpoort. In the centre of the front was a 2,000 yd (1.1 mi; 1.8 km) stretch with no crossing over the Yser; no man's land was 65–80 yd (59–73 m) wide. There was very little cover for artillery in the area and machine-guns were vulnerable to stoppages from wind-blown sand.
The 1st Division (Major-General Peter Strickland) and the 32nd Division (Major-General Cameron Shute) took over and had only limited artillery support for several days, while the British artillery completed the relief. Du Cane ordered that the positions were to be held at all costs but the main French defences had been built in the south bank,the bridgehead, 800 yd (730 m) deep from St Georges to the coast, being held as an outpost. Three breastworks gave some protection from artillery-fire and there were no underground shelters for reserves. Tunnellers began work on dugouts in the sand dunes but few had been completed by early July. A defence plan for the bridgehead was issued on 28 June, relying mainly on artillery but of 583 guns in the Fourth Army, only 176 had arrived by 8 July, the remainder being with the First and Second armies, in support of operations towards Lens and Lille, due to arrive by 15 July. On the night of 6/7 July, German aircraft bombed the main British aerodrome at Bray-Dunes near Dunkirk, causing nine casualties and damage to twelve aircraft. Reconnaissance flights by IV Brigade RFC and the RNAS aircraft were hampered from 7 to 9 July by ground mist and clouds down to 900 ft (270 m). Vague reports of increased activity behind the German front had been received but a special flight early on 8 July found nothing, despite the unusual amount of movement, as the Germans prepared to attack; on 9 July all aircraft were grounded by bad weather.
British plan
A landing operation would begin at dawn under the command of Rear-Admiral Bacon and an army division in three parties of about 4,500 men each, would disembark on the beaches near Middelkirke, covered by a naval bombardment and a smoke screen generated by eighty small vessels. Trawlers would carry telephone cable ashore and tanks would disembark from the landing pontoons and climb the sea-wall to cover the infantry landing. The infantry would have four 13-pounder guns and two light howitzers and each wing of the landing had a motor machine-gun battery. For mobility, each landing party had more than 200 bicycles and three motorbikes. Three landing sites were chosen, at Westende Bains, 1 mi (1.6 km) behind the German second line; another site 0.75 mi (1.21 km) beyond the German third line and a third landing 1.75 mi (2.82 km) beyond that at Middelkirke Bains, to cut off the line of retreat of the German artillery around Westende, turn the German second and third positions and advance inland as far as possible.
The northern landing brigade was to send a flying column with specialist engineers to Raversyde, to destroy the German artillery battery there and then advance east or south-east, to threaten the German withdrawal route to the south and isolate Ostend. All the landing forces were to rush inland towards Leffinghe and Slype, occupying bridges over the Plasschendaele canal and road junctions nearby. Extra transport would move with the two XV Corps divisions advancing from Nieuwpoort. XV Corps would break out of the Nieuwpoort bridgehead between St Georges and the coast, with a barrage from 300 guns with naval guns in support over a 3,500 yd (2.0 mi; 3.2 km) front. A 1,000 yd (910 m) advance would be followed by a one-hour pause. Four similar advances over six hours would take the land attack to Middelkirke, where it would link with the landing force, keeping three divisions in reserve. The German defence was expected to have two brigades in the first two defence lines as the attack began. The plan was approved by Haig on 18 June and the 1st Division was chosen to make the coastal landing.