The naval operations before Sebastopol and Cronstadt proved by no means satisfactory to the attacking vessels. The latter were not weak as fighting ships, for they constituted the most powerful line-of-battle ships ever constructed up to that period, and nearly all of them were screw-propelled. The principal guns in the Russian forts were heavier than any carried afloat by the allies, and not only fired a heavier and more penetrating shot, but shell also--this being the first war in which modern explosive shells were used--and had an effective range far in excess of that of the ships’ guns. The great three-deckers which assailed the fortifications of Sebastopol and Cronstadt were prevented by the shallowness of the water from getting near enough to inflict serious damage irrespective of what they might themselves sustain, a course which was certainly urged, if channels could be found, especially by some strategists who, being at home, would not be exposed to the danger, and ignored the fact that the ships, if stranded, could be shelled at leisure. In the fleets’ attack upon Sebastopol the sailing warships were provided with attendant steamers lashed alongside to render them assistance when their positions had to be changed. But the range at which, for the most part, the allies’ warships had to operate rendered them comparatively ineffective, and when Kinburn, like Cronstadt, proved a tougher nut to crack--a characteristic it shared with many of the Russian defences--than the allies expected, the English and French could do nothing but blockade the places and adopt other means of reducing the fortresses than by bombarding them from their big wooden battleships. Two fresh problems had thus been created for solution. The first and most pressing was to provide the type of ship best fitted to cope with the Russian batteries. Hitherto, engagements between fortresses and battleships had been fairly equal because the guns employed by one side would be much the same as those of the other, while the ships had the further advantages of being able to shift their positions as suited them best, and to concentrate the fire of their broadsides wherever necessary. The majority of shore and battery engagements ended in victories for the ships.