Even to a greater extent was this last feature true of Ostend, though here the whole problem was somewhat simpler, there being no Mole, and therefore no necessity—though equally no opportunity—for a subsidiary attack. Covered, of course, from the shore by guns of all calibres—and here it should be remembered that there were 225 of these between Nieuport and the Dutch frontier—the single object in this case was to gain the entrance, before the block-ships should be discovered by the enemy, and sunk by his gunners where their presence would no do harm. Since for complete success, however, it was necessary to seal both places, and, if possible, to do so simultaneously, it will readily be seen that, in the words of Sir Eric Geddes—the successor, as First Lord of the Admiralty, to Mr. Balfour and Sir Edward Carson—it was "a particularly intricate operation which had to be worked strictly to time-table." It was also one that, for several months before, required the most arduous and secret toil.
Begun in 1917 while Sir John Jellicoe was still First Sea Lord, the plan ultimately adopted—there had been several previous ones, dropped for military reasons—was devised by Vice-Admiral Roger Keyes, then head of the Plans Division at the Admiralty. From the first it was realized of course, by all concerned that the element of surprise would be the determining factor; and it was therefore decided that the attempt to block the harbours should take place at night. It was also clear that, under modern conditions of star-shells and searchlights, an extensive use would have to be made of the recent art of throwing out smoke-screens; and fortunately, in Commander Brock, Admiral Keyes had at his disposal just the man to supply this need. A Wing-Commander in the Royal Naval Air Service, in private life Commander Brock was a partner in a well-known firm of fire-work makers; and his inventive ability had already been fruitful in more than one direction. A first-rate pilot and excellent shot, Commander Brock was a typical English sportsman; and his subsequent death during the operations, for whose success he had been so largely responsible, was a loss of the gravest description both to the navy and the empire.
The next consideration was the choosing of the block-ships, and for these the following vessels were at last selected—the Sirius and Brilliant to be sunk at Ostend, and the Thetis, Iphigenia, and Intrepid to seal the canal entrance at Zeebrugge. These were all old cruisers, and they were to be filled with cement, which when submerged would turn into concrete, fuses being so placed that they could be sunk by explosion as soon as they had reached the desired position; and it was arranged that motor-launches should accompany them in order to rescue their crews. Unfortunately Lieutenant Ivan B. Franks, who was responsible for the block-ships, was laid aside, the day before the event, by an attack of appendicitis, and, at his urgent request, his duties were undertaken by his friend, Lieutenant Billyard-Leake—a very able young officer, then barely twenty-two years of age.
So far these general arrangements were applicable to both places; but, as regarded Zeebrugge, it was decided to make a diversion in the shape of a subsidiary attack on the Mole, in which men were to be landed and to do as much damage as possible. Such an attack, it was thought, would help to draw the enemy's attention from the main effort, which was to be the sinking of the block-ships, and, apart from this, would have valuable results both material and moral. For this secondary operation, three other vessels were especially selected and fitted out—two Liverpool ferry-boats, the Iris and Daffodil, obtained by Captain Grant, not without some difficulty, owing to the natural reluctance of the Liverpool authorities and the impossibility of divulging the object for which they were wanted—and the old cruiser Vindictive. This latter vessel had been designed as a "ram" ship more than twenty years before, displacing about 5,000 tons and capable of a speed of some twenty knots. She had no armour-belt, but her bow was covered with plates two inches thick and extending fourteen feet aft, while her deck was also protected by hardened plates, covered with nickel steel, from a half to two inches thick. Originally undergunned, she had subsequently been provided with ten 6-inch guns and eight 12-pounders.
This was the vessel chosen to convey the bulk of the landing-party, and, for many weeks, under the supervision of Commander E. O. B. S. Osborne, the carpenters and engineers were hard at work upon her. An additional high deck, carrying thirteen brows or gangways, was fitted upon her port side; pom-poms and machine-guns were placed in her fighting-top; and she was provided with three howitzers and some Stokes mortars. A special flame-throwing cabin, fitted with speaking tubes, was built beside the bridge, and another on the port quarter.
It was thus to be the task of the Vindictive and her consorts to lay themselves alongside the Mole, land storming and demolition-parties, and protect these by a barrage as they advanced down the Mole; and, in order to make this attack more effective, yet a third operation was designed. This was to cut off the Mole from the mainland, thus isolating its defenders and preventing the arrival of reinforcements; and, in order to do so, it was decided to blow up the viaduct by means of an old submarine charged with high explosives. Meanwhile, the whole attempt was to be supported from out at sea by a continuous bombardment from a squadron of monitors; seaplanes and aeroplanes, weather permitting, were to render further assistance; and flotillas of destroyers were to shepherd the whole force and to hold the flanks against possible attack.
This then was the plan of campaign, one of the most daring ever conceived, and all the more so in face of the difficulty of keeping it concealed from the enemy during the long period of preparation—a difficulty enhanced in that it was not only necessary to inform each man of his particular role, but of the particular objectives of each attack and the general outline of the whole scheme. That was unavoidable since it was more than likely that, during any one of the component actions, every officer might be killed or wounded and the men themselves become responsible. Nor was it possible, even approximately, to fix a date for the enterprise, since this could only be carried out under particular conditions of wind and weather. Thus the night must be dark and the sea calm; the arrival on the other side must be at high water; and there must above all things be a following wind, since, without this, the smoke-screens would be useless. Twice, when all was ready, these conditions seemed to have come, and twice, after a start had been made, the expedition had to return; and it was not until April 22, 1918, that the final embarkation took place.
By this time Vice-Admiral Keyes had succeeded Vice-Admiral Bacon in command of the Dover Patrol; and he was therefore in personal charge of the great adventure that he had initiated and planned with such care. Every man under him was not only a volunteer fully aware of what he was about to face, but a picked man, selected and judged by as high a standard, perhaps, as the world could have provided. Flying his own flag on the destroyer Warwick, Admiral Keyes had entrusted the Vindictive to Acting Captain A. F. B. Carpenter, the Iris and the Daffodil being in the hands respectively of Commander Valentine Gibbs and Lieutenant Harold Campbell. The Marines, consisting of three companies of the Royal Marine Light Infantry and a hundred men of the Royal Marine Artillery, had been drawn from the Grand Fleet, the Chatham, Portsmouth, and Devonport Depots, and were commanded by Lieutenant-Colonel Bertram Elliot. The three block-ships that were to be sunk at Zeebrugge, the Thetis, Intrepid, and Iphigenia, were in charge of Commander Ralph S. Sneyd, Lieutenant Stuart Bonham-Carter, and Lieutenant E. W. Billyard-Leake; while the old submarine C3 that was to blow up the viaduct was commanded by Lieutenant R. D. Sandford. In control of the motor-launches allotted to the attack on Zeebrugge, was Admiral Keyes' flag-captain, Captain R. Collins, those at Ostend being directed by Commander Hamilton Benn, M.P.—the operations at the latter place being in charge of Commodore Hubert Lynes. Also acting in support was a large body of coastal motor-boats under Lieutenant A. E. P. Wellman, and a flotilla of destroyers under Captain Wilfred Tomkinson, the general surveying of the whole field of attack—including the fixing of targets and firing-points—being in the skilful hands of Commander H. P. Douglas and Lieutenant-Commander F. E. B. Haselfoot.
Included among the monitors were the Erebus and Terror, each mounting 15-inch guns, to operate at Zeebrugge; and the Prince Eugene, General Crauford, and Lord Clive, carrying 12-inch guns, and the Marshal Soult, carrying 15-inch guns, to assist at Ostend. To the old Vindictive Admiral Keyes had presented a horse-shoe that had been nailed for luck to her centre funnel; and, to the whole fleet, on its way across, he signalled the message, "St. George for England." Few who received that message expected to return unscathed, and in the block-ships none; but it is safe to say that, in the words of Nelson, they would not have been elsewhere that night for thousands.