Similar guns had been supplied by the manufacturer, Sir W. G. Armstrong, Whitworth & Co., Ltd., to the Italian Regia Marina and fitted in the Andrea Doria and the 1,800 pound (816 kg) projectile could penetrate any thickness of armour afloat at that time.

This was done to reduce target area in a naval engagement but had a deleterious effect upon seaworthiness, and was an important factor in Victoria sinking within fifteen minutes following a collision since it allowed the water to quickly reach the gun turret ports.

[citation needed] The most successful innovation of the class was the introduction of triple expansion steam engines into Royal Navy battleships.

These engines had been developed as a result of the introduction of steel in boiler manufacture, which in turn had led to higher steam pressures.

In trials, HMS Thunderer, which had been re-engined with triple-expansion engines in 1889–1891,[2] showed that the coal consumption at 80% power was roughly halved.