- all but six being built at Barrow. The other six were built at Chatham - (First instance of Lead-Yard?).
The B and C Classes were almost identical, being larger versions of the A Class, with petrol engines for surface propulsion and batteries for propulsion when submerged.
Many improvements were made from B1 to C38, particularly in the superstructure, to improve surface running and seaworthiness.
The A, B and C Classes were designed for coastal defence work and had a limited range. They became known in naval circles as 'Fisher's Toys' - a reference to Admiral Sir John Fisher who was a keen advocate of the submarine as a weapon of war.
