Fort of Santa Luzia
INNOVATIVE AND CONTROVERSIAL CONSTRUCTION In 1641, after the Restoration, the veteran Mathias de Albuquerque opened various "mines" to build a redoubt – "capable of holding three hundred soldiers" – which would have a "star-shaped form", following a plan by Sebastião Frias. Even though it was not yet completed, it was considered ineffective because it was too small to hit areas of lower elevation around the vantage point overlooking it. It was then that the Italian Ieronymo Roxeti was put in charge of building a "forte real", that is, a fort of greater dimensions (a defensive line with the Main gate effective range of the musket shot: c. 220 m) which began on 1 March 1642. The chief engineer of the kingdom, Charles Lassart, visited the site and disagreed with the project because he considered it irregular and the geometry inadequate. Cosmander, João Ballesteros, Lassart and Roxeti formed a commission appointed by the king but no start was made on the fortification due to disagreement among the engineers. Finally, in 1643, Cosmander and Jean Gilot were granted decision-making power over the project, and they opted for an "outer fortification", which was smaller than the intended "forte real". Construction was completed in 1648, with a geometry of innovative fronts that anticipates the Pagan system (1645) and the Vauban citadels of Arras and Lille (begun in 1668).
The two facilities at the W point of this ditch served as the powder-magazine and the munitions store, and the warehouse that is adjacent to them, in the ditch, served as a store for artillery equipment, as well as a powder-magazine. In the W ditch stood two stables with stalls – the Central Division and the top N - and probably more barracks with fireplaces (now the military museum). The door to the main redoubt is at the level of the covered way, to the N, with access to the open courtyard. Visible to the E are two barracks for officials (one now used as toilets), the stairs to the roof and latrines. To the S is the nave of the pre-existing chapel of Santa Luzia –incorporated into the fort – with access to the warehouse/powder-magazine, situated at a lower level. To the W is what is believed to have served as a guard-house for soldiers and as a kitchen. Beyond these stairs and visible from the roof are the openings of cisterns to the E and W , to the S the openings to the warehouse/powder-magazine, and to the W the kitchen chimney and a tank for washing, and the gutters that divert rainwater to the cisterns. The governor's house was built on the rooftop, with a fireplace, and a curious staircase giving access to the terrace which is an excellent observation point.
The oldest plan from Nicolau de Langres's book (c. 1661) Comparison with the Pagan system
The mantraps, the circular trench walls, the galleries, the barbettes, the traverses, and the barracks of the S ditch were built between the end of the 18th century and 1814.
DESCRIPTION The main body of the fort is part of an irregular polygon of 161 m x 144 m, having four angled bulwarks: Santa Isabel (NE), Santo António (SE), São Pedro (SW) and Conceição (NW). The main door is situated in the curtain of the N front (with the old drawbridge mechanism superimposed) and a postern gate in the opposite curtain. Surrounded by a ditch with ravelins to the S and E, the counterscarp gives access to the covered way in a tenailled trace. The salient angles of the S and E parts are equipped with firing platforms for artillery to fire over the parapet (barbettes). On the other hand, the reMain redoubt ditch entrant angles in the S and E sectors present sloped "drums", that is, circular trench walls, and in the W and NW sectors there are angular trenches. This system is defended by rows of pits or mantraps, except for the N part which is connected to the city by a covered way and the entrance into the fort. Countermine galleries on the S front should also be noted. Returning to the main body of the fort, it has a second ditch which isolates the main redoubt, in a rectangular plan. In this ditch, with an entrance to galleries to the E, the earthwork is abutted by three sets of facilities: to the E, the old oven (now the reception), followed by former barracks – the central division served as the guard-house – with fireplaces and wall cupboards. To the S are the vaulted barracks (now the military museum), with chimneys and cabinets. In the middle, there is a door which gives access to the tunnel of the postern gate.
Drawbridge mechanism
Plan (1700-1A-13A-1B, n.d.,18th centurie, DSE)
SPAIN
N B
T
T
B T
B
B Governor's house
R
Church of Santa Luzia
IRREGULARITIES, ASYMMETRY AND THEIR INTERPRETATION
B
R B t t
t
t t T
T
a) All parapets facing the city were weakened: they are not very thick and do not have embrasures (including the central redoubt). Rationale: if the fort was taken by the enemy, the fire from the city would destroy these parapets, preventing enemy artillery from defending themselves with merlons.
T
B
b) Only the E and S fronts have ravelins to defend their corresponding curtains. Rationale: only through these sectors could there be an enemy attack, the other fronts have the city to the N, and the Fortlet of São Pedro to the W. c) Only the N front does not feature the aforementioned extramural trenches. There is only one trench of small dimensions that defends the connection to the fort from the covered way leading from the city.
C
ELVAS Asymmetric layout of the main redoubt Weakened parapets without embrasures
B
Barbettes Capital lines
FORTLET OF SÃO PEDRO
t T R C
Traverses Circular and angular trenches Ravelins Reinforced base of the scarp Covered way to the city