A few months previously a couple of steamers had been fitted out for some such operation under another Vice-Admiral, but it will be seen that, as a result of detailed investigation of all the obstacles and factors affecting the problem, the Plan described herein differed from its predecessors in that respect; in fact the arguments against the use of merchant vessels were considered from the outset to be overwhelming.
Hazards of the Blockships
The work of surmounting such difficulties as escorting the blockships across the seas and locating their destinations would require the use of other units, and will, therefore, be described later. Speaking generally, the actual tasks of reaching their destinations when located and of sinking themselves in position, difficult though they were, could best be left to the pilotage and seamanship of the blockship officers. Here again, the author is anxious to lay special emphasis on the fact that successful results of the blocking operation—such as had never been attained in history—were absolutely dependent upon the good work of the blockship personnel; to them would the credit be due.
At Ostende, the work of the blockships, with regard to reaching their destination, was confined to that of running the gantlet of the shore batteries when once the entrance had been located, but the latter—i.e., the location of the entrance—presented considerable difficulty.
At Zeebrugge, there would be less difficulty in finding the entrance if the Mole extremity, three-quarters of a mile to seaward, could be located. But a serious factor existed here which was absent at Ostende.
Blockships proceeding into Zeebrugge would have to risk the fire of the Mole batteries during the first part of the approach. They would then have to steam in behind those batteries and run the gantlet of the batteries ashore. Now this was a pretty big proposition.
In the second chapter it was shown that the three-gun battery situated on the broad portion of the Mole at its northeastern extremity, taken in conjunction with the establishment of the barge boom and entanglement nets, rendered it extremely hazardous for the blockships to round the Mole en route to the canal entrance; in fact it was almost a certainty that they would be sunk by the Mole guns.
Nevertheless, the canal entrance was our objective. Somehow, by hook or crook, the blockships were intended to reach it. Thus, one of the first local problems requiring solution was that of removing, temporarily or otherwise, the obstacle afforded by the three-gun Mole battery. Similarly, though perhaps in a lesser degree, we had also to take into account the battery of six smaller guns on the lighthouse extension of the Mole.
Object of Attacking Mole
Considered in a general manner, there were three lines of enquiry from which a solution of the problem might be forthcoming. Firstly, that concerning the destruction of the guns or their crews, or both, or diverting their fire, by means of action from a distance. Secondly, that of attaining a similar result by action on the spot. Thirdly, that of rendering the blockships invisible during their passage. These may be dealt with briefly. The first method entailed the use of either gun-fire or poison gas. The outcome of a gun-fire duel between a ship and a battery has already been described sufficiently to show that the chances of destroying the battery guns are exceedingly small. The use of poison gas has been shown to be inadvisable. The third method—that of rendering the blockships invisible to the battery—would have entailed the use of a smoke screen. If such a screen could have the effect mentioned it is obvious to the meanest intellect that it would also have the effect of hiding their destination from the blockships just at the critical period when it would be absolutely essential to see exactly where they were going.