in 1758, the plymouth and portsmouth fortifications act provided the means to construct a permanent landward defence for the dockyard complex. the devonport lines were a bastion fortification which consisted of an earthen rampart with a wide ditch and a glacis. the lines ran from morice yard on the river tamar, enclosing the whole dockyard and town, finally meeting the river again at stonehouse pool, a total distance of 2,000 yards (1,800 metres). there were four bastions, marlborough bastion to the north, granby bastion to the north-east, stoke bastion to the east and george bastion to the south east. there were originally two gates in the lines, the stoke barrier at the end of fore street and the stonehouse barrier. a third gate called new passage was created in the 1780s, giving access to the torpoint ferry. after 1860, the fortifications were superseded by the palmerston forts around plymouth and the land occupied by the lines was either sold or utilised by the dockyard.