The wall on the outer side, as previously described, rose to a height of twenty-nine feet above the level of high water. This height was far above that of the deck of an average vessel. The fact that the landing would have to be made on a narrow parapet, high above the level of the Mole proper, was also hardly calculated to assist matters. The probable existence of guns on the parapet itself, so placed as to be able to rake the decks of a vessel alongside, and the possible presence of obstructions placed by the Germans on the outer side of the Mole, had to be taken into account. It has also been mentioned above that the use of smoke screens necessitated a wind blowing towards the shore; thus the Mole itself could afford no protection from the wind or sea.
The Austrian military failure on the River Piave, during the late war, afforded a good example of the disabilities resulting from insufficient room to debouch a force which has crossed an obstacle into the enemy's territory. Clearly, it might be very awkward if the storming parties were unable to descend from the parapet rapidly enough to forestall any enemy attempts at concentration near the storming point.
All these considerations led to the choice of H.M.S. Vindictive for carrying the main portion of the storming parties.
The attack on the Mole might also provide an opportunity for destroying material thereon. Although this was obviously a secondary consideration it was an opportunity not to be missed. The amount of destructive work which could be done would depend upon the circumstances of the moment, but it was decided to have a special demolition party, provided with the necessary gear, to accompany the primary attacking forces.
THE OUTER WALL, SHOWING THE PARAPET PATHWAY
16 FEET ABOVE THE FLOOR OF THE MOLE
Clearly enough, it would be somewhat futile if one only began to consider the work of demolition as soon as the moment arrived for such work to commence. With the object of being prepared in all respects careful consideration, therefore, was given to the different methods of demolition which would be most suitable under varying circumstances. Following such consideration it would be necessary to train one's demolition parties in this technical pursuit and to provide a sufficiency of suitable destructive material.
Plans for Demolition
When making preparations for an operation of this, or similar type, one is apt to allow secondary objects to loom too large unless great caution is taken to prevent it. In this particular case, however correct it might be to fully prepare, down to the smallest detail, for everything in advance, it was necessary to bear in mind that demolition on the Mole could hardly assist the blockships to seal the canal exit and, even if successful, could not bring us very great benefit. Thus it was clear that demolition should only be prepared for and undertaken provided that it did not hinder the attainment of our main object in the smallest particular.