The History of the Fort

Guns

The first soldiers to garrison the Fort were No 2 Battery Royal Artillery (Tatton-Brown's), a specialist gun emplacement unit trained in the handling of ordnance up to 18 tons, using vast sheerlegs.  They were responsible for hauling and heaving two 64-pounder, four 9-inch and six 10-inch guns into the fort.  These were rifled muzzled loaders (RMLs) with spiral grooves cut into the barrel to engage lugs on the shells and impart rotation and thus accuracy in flight.  Seven of these guns were replaced in the 1890s by massive 12.5-inch RMLs weighing 38 tons each and capable of firing 800-pound shells over a range of three and a half miles.  These shells were propelled by new smokeless powder and they were fitted with soft metal rings at the base instead of lugs to engage the rifling, which eliminated wasteful escape of gas around the sides of the shells.  All this was to meet the ever-increasing thickness of armour with which warships were being fitted.

As Portland Harbour grew in importance and became the main base of the Channel and later the Atlantic Fleets, so the Nothe remained an important link in the defences of the base.  With the advent of breech loading (BL) the RMLs were removed and 6-inch BL guns were emplaced on the ramparts.  Rapid advances in technology had produced a situation where two or three of these guns could do the same job as the twelve massive RMLs.  Their armour- piercing shells, weighing only 100 pounds, could be fired at a much faster rate to a range of some ten miles.