alternatehistory.com

Excerpts from a talk by Isaac Watts (former DNC) on "The Belt and the Battery"


"...the current system of constructing broadside ironclad frigates cannot long continue. You may wonder by what confidence I state this, especially since my own Warrior is a broadside ironclad frigate and since many other broadside ironclad frigates have been built or laid down, both in this country and in France; the answer is simple. It is the belt and the battery, and the pressures they exert on warship design."

"The Warrior's belt, and her armoured battery, are protected by four and a half inches of wrought iron. This is well and good, but the danger existed that some other nation would build a ship with four and a half inches, and so guns were sought that may pierce four and a half inches and thus allow us to sink ships so protected; at the same time, we can be sure that other nations were and are working on guns that may pierce four and a half inches.
Once this gun was developed - for us it was the Somerset gun - two problems arose for the next generation of naval vessels. The first is that when the Warrior was laid down the finest armour piercing gun was the eight inch 68 pounder of 95 hundredweight, but the Somerset gun of 9.2 inches is one hundred and thirty hundredweight - and we may be sure that the weight of the guns may increase further, so that for the same weight of armament there may be fewer guns able to be loaded onto the ship.
The second problem has been made more acute by Mr. Palliser's shell, and it is that when designing a ship one must thicken the armour or accept that shot must pierce it. I am no more inclined than the next man to think a ship may be invulnerable - but if a gun that exists now may pierce the ship, then how much more vulnerable will the ship be against the guns which are in service when it finally sees service? So the armour must become thicker, and perforce must take up more weight..."


"The armour of the Warrior covered 213 feet along the ship and 22 feet up and down the side; the armour of future ships is considered to require a complete belt along the waterline, and to be thicker - but if the Warrior had a complete belt for six feet below the waterline and five above, it would weigh the same as the whole armour of the current ship, without any to protect the guns; and the guns must be protected, though the belt is as important. A ship may be sunk by damage at the waterline; she may be disabled by the loss of her guns..."



"...as the guns become heavier, and the armour thicker, then unless ships are to become far more vast there is only one solution, and that is to reduce the area that is to be protected - to focus the protection into a smaller area. This may be done as in the fine ships being now designed by Reed - my successor, yes - to be of low freeboard, so that the belt may also protect the battery; but this is not an effective solution for a ship that is to fight or sail upon the open seas, which must be high sided at least and preferably carry her guns free of waves. The alternatives, then, are to reduce the number of guns upon the broadside and armour them far more thickly - if the Warrior was to be built with a battery only fifty feet in length then the protective armour could be an insuperable eighteen inches thick, though this would not provide for a belt - or to concentrate the armour entirely into turrets, which may be so well protected as to shed almost any shell and to free up more total displacement for the belt.
I do not think this is yet essential, but that it may soon become so - that before long the day will be reached that the guns that must be carried will be so heavy that a warship may only carry ten - four for each broadside, and a pair for the chase - and if that comes to pass, why, then two turrets each of two guns would provide for the same fire both to port and starboard, while saving a little on the area of armour that must be carried and allowing it to be thicker, and saving on the guns in both weight and cost."