Layout Lines of Contravallation of Gibraltar

plan of lines of 1749 (north bottom). fort st. barbara on left-hand side of map, , fort st. philip on right-hand side. in between bastions of santiago, san carlos, san josé, santa mariana , san benito.

at west end, fort san felipe (spanish: fuerte de san felipe) had 28 gun positions ditch , bastion trace in gorge (rear) of fort. broad structure gave spanish gunners wide arc of fire across bay of gibraltar , provided direct line of fire town , british devil s tongue battery located along old mole. according james, parapet eighteen feet thick, faced stone, , filled earth , clay. mounted twenty iron sixteen pounders, , 4 iron 6 pounders in flanks, 4 thirteen inch brass mortars : eighteen of these guns command anchoring place , strand, other 6 open on town, , neck of land . several casemates situated under ramparts. 2 demi-bastions , curtain wall situated @ rear of fort while storehouses , guard-houses stood alongside it. solid stone sea wall ran along east side of fort. ditch, filled sea , controlled via sluice gate, provided additional obstacle. according james, normal garrison of fort 1 captain, 1 subaltern , fifty men, though accommodate 6 hundred.

fort santa barbára (spanish: fuerte de santa barbára) stood @ eastern end of line. pentagonal structure aimed arrowhead south @ gibraltar , supported 24 gun positions, bastion trace in gorge, dry ditch, covered way , glacis. 2 eastern sides of fort looked out on mediterranean sea, while south-facing side enfiladed part of eastern side of gibraltar , isthmus. james recorded rampart thirty feet broad, , mounted twelve iron fifteen pounders, , 1 thirteen inch brass mortar. had considerably stronger rear san felipe rampart continued @ same thickness around entire circumference of fort. there 4 large bombproof casemates under ramparts and, @ san felipe, sea wall held waves. peacetime garrison of fort same @ san felipe, 1 captain, 1 subaltern , fifty men.

in between 2 forts, line of fortifications took form of continuous redan line, curtain wall interrupted series of triangular bastions. lines constructed in straight line @ eastern end bulged out @ western end, intended build entrenched camp hold army while prepared launch attack on gibraltar, though rear portion of structure never completed. 5 bastions named (in order west east) after st. james (santiago), st. charles (san carlos), st. joseph (san josé), saint mariana (santa mariana) , saint benedict (san benito).