The city of Safi is located in the West African coast, about 150 km from the city of Marrakesh
and 300 km south of Casablanca, Morocco. The main economic activities of this city corres-
pond to fishing and exportation of phosphate, textiles and ceramics. Figure 1a shows its loca-
Figure 1: Safi Cathedral location: (a) Morocco map; and (b) location of the Safi Cathedral in the Medina.
During the 15th C., Safi was an important trading port. Between the years 1488 and 1541, the
city was governed by Portuguese and became the name of Safim. Amongst the Portuguese con-
structions from the Manueline period which still remain and stand out are the Cathedral of Safi,
the Castle of the Sea and the Fortress of Safi.
Safeguarding of the Portuguese Heritage: the Case Study of Safi
Luís F. Ramos
SISE,University of Minho, Guimarães, Portugal
CG, Calouste Gulbenkian Foundation, Lisboa, Portugal
António Ramos, Fernando Marques
3R – Gabinete de Projectos. Lda, Póvoa de Varzim, Portugal
Thomas Sturm and Paulo B. Lourenço
SISE,University of Minho, Guimarães, Portugal
ABSTRACT: The city of Safi is located in the West African coast, about 150 km from the city
of Marrakesh and 300 km south of Casablanca, Morocco. The Cathedral of Safi was the firs
Portuguese cathedral outside Portugal during the Expansion period and it is the most importan
example of the non-military Manueline architecture that still remains outside Portugal. The con-
struction of the cathedral started during the decade of 1520. It was originally a three nave
church and is believed to be similar to other temples of the time such as the Funchal or Guard
Cathedrals. During its history, the cathedral was occupied by Muslims who eliminated the
naves, leaving only the main altar, one lateral chapel and an outside wall. The space of the
naves was used to add several residential buildings and they turned the altar in a bathhouse fo
women (hammam in Arab). The altar, crowned by a ribbed vault, the lateral chapel whose roof,
also vaulted, is missing and one alone standing external wall are the only original parts of the
structure that are left. The Cathedral will be soon submitted to a structural intervention. The
intervention includes the preservation of the original remains of the Cathedral, the correction o
existing problems in the structure, improvement and installation of new infrastructure to suppor
tourism and cultural events. Therefore, safety conditions and the conservation of the built herit-
age as a museum space must be assured.
The Cathedral of Safi was the first cathedral constructed beyond Portuguese borders. Similar-
ities with other Portuguese cathedrals constructed during that period, such as the cathedral of
Funchal or Guarda , can be admitted. This cathedral is located in midst of the Medina of the
Safi, by side of the Great Mosque, as can be seen in Figure 1b.
The Cathedral of Safi was constructed around 1520 by Master-builder João Luís under the
promotion of archbishop D. João Subtil. The Cathedral was occupied by Muslims, which trans-
formed the space of the main altar into a hammam. The vault of the main chapel (with exception
of constructions of the military field), remains the best example of the Manueline architecture
subsisting outside Portugal .
Following the departure of the Portuguese in 1541 and the ascension to power of Sultan
Cheikh, the Mosque was largely enhanced in a place of high historical, religious and social val-
ue for the city of Safi.
THE SAFI CATHEDRAL
The remaining structure of the Safi Cathedral is the main chapel, the right lateral chapel and an
exterior wall. The main chapel is almost squared and is crowned by a ribbed vault. Its dimen-
sions are approximately 8.2 × 7.8 m width in plant, with a maximum height of 9.7 m measured
from the existing pavement to the center of the vault. The lateral chapel is also rectangular with
approximately 4.5 × 5.4 m width. This part of the structure is exposed to the outside on its upper
part, since its roof cover does not exist anymore. The remaining walls are 6.9 m high. The ex-
ternal wall is 15.1 m long, 0.9 m thick and 9.6 m high (from the inside).
Because the cathedral was built in the same period as the Funchal cathedral, it is believed that
the Safi Cathedral had a similar structural organization. In this case, the Safi cathedral would
have been an arrangement of three naves and two lateral chapels, covered by a light wooden
roof. Figure 2a shows the actual structural configuration of the remaining Cathedral (colored
areas), the adjacent structures and the probable original configuration is presented in Figure 2b.
A brief description of the Funchal cathedral is given in the next Section, in order to give the
reader an idea of how the original Safi Cathedral may have looked like.
Figure 2: Plant of Cathedral : (a) Plant of street level of the existing structures; (b) Possible former
outline of the original Cathedral.
Figure 3 shows an elevation of the original remains of the main chapel with its ribbed vault,
and the lateral chapel, now without vault. It also can be appreciated in this figure, that the level
of the alley is 1.4 m higher than the pavement of the Cathedral. This is very usual in old cities,
since the cities have been built progressively over time. Therefore, streets and alleys are mainly
composed of infill material which has accumulated over centuries. Finally, these old streets and
alleys can be up to some meters over the level of the former ground floors.
Figure 3: Elevations of Cathedral: (a) Elevation of main chapel in north-east direction; and (b) elevation
of main chapel and lateral chapel in south-east direction.
Figure 4 shows some general views of the inside of the Manueline ruins . As it can be ob-
served in Figure 4a, the structure is made of two types of stone masonry. The walls are in gen-
eral of masonry with limestone units and lime mortar joints. Nevertheless, several joints with
cement mortar could be observed, which correspond to recent reparation works. The vault of the
main chapel has ribs made of local stone with joints of poor lime mortar. The remaining wall
corresponds to porous limestone.
(a) (b) (c)
Figure 4: Main chapel: (a) elevation in south-west direction; (b) inner view in south-west direction (for-
mer hammam); and (c) detail of encounter of pointed arch, diagonal rib and partition wall of south west
The inner space, shown in Figure 4 corresponds to the place where the hammam was installed
after the Portuguese left Safi. The narrow door that can be observed on the left side, leads to the
lateral chapel and to the present access of the cathedral. On Figure 4 also modifications intro-
duced by the Muslim community can be observed. This modification correspond to the closing
of the windows with masonry, as shown in Figure 4a. Also the space beneath the arch of the
north-west elevation was closed with a masonry wall, as seen in Figure 4b and c. This part is
believed to have been completely open towards the main corps of the ancient church. A detail of
the encounter of the arch, the column and the infill wall can be observed in Figure 4c.
In Figure 5 general aspects of the Cathedral are shown. The alley that limits with the Cathe-
dral is shown in Figure 5a. It presents the left side of the exterior wall of the Cathedral that can
be seen from the Grand Mosque of Safi. The entrance of the cathedral is shown in Figure 5b and
c. Again, a difference between the level of the street and the pavement of the ground floor of the
Cathedral can be observed. In Figure 5d the lateral chapel is shown. The view is in the north-
west direction in which (probably) the naves of the Cathedral were placed. This arch was not
closed with a masonry wall like the main chapel was.
(a) (b) (c) (d)
Figure 5: General aspects: (a) alley and exterior wall of the Cathedral; (b) north-east façade of the lateral
chapel; (c) present entrance to the ruins of the cathedral, through the lateral chapel; and (d) view of the
lateral chapel in the direction of the former nave.
As it was shown in Figure 2, the space that belonged to the naves is today occupied by dwel-
lings with thick stone masonry walls, concrete pavements and is covered with wooden roof-
terrace structures. Also a big public bath and toilets are available in that zone.
The ground floor of the rest of the housings surrounding the original structure is at least 1.5 m
higher than the Cathedral ground floor. These buildings are structurally connected with the Ca-
thedral, guaranteeing a significant interlocking between the structural ensembles.
THE FUNCHAL CATHEDRAL
Funchal is located on the Portuguese island of Madeira. The island is located 720 km from the
West African coast, almost on the same latitude of Safi. The construction took place between
1493 and 1516. The Funchal Cathedral still has its original Manueline structure intact and which
has not been substantially modified or restored. Some minor restoration works took place during
the decade of 1940 .
Each nave of the three which compose the main corps of the temple is separated by a series of
columns which are joined through five arches in the longitudinal direction. The arches start at
the façade and run along until they meet the wall of the abside. Both the main and the lateral
chapels are vaulted. Next to the cathedral on the western part, an independent array of housing
and courtyards which serves to the cleric uses the space of the remaining block. The distribution
of the main parts of the cathedral can be seen in Figure 6a.
Figure 6: The Funchal Cathedral : (a) distribution in plant of ground floor; and (b) views of the cathe-
The majority of the walls are rendered with lime plaster, as can be seen in Figure 6b. In the
interior all walls are plastered, except the stone arches. This was also probably the case of the
Safi Cathedral. The vault of the main chapel is highly decorated. It has ribs which cross the
vault transversally and diagonally and there are keystones where the ribs encounter, just as in
the case of the Safi Cathedral (see Figure 6b). The roof which covers the naves is an orna-
mented light wooden roof. In the central nave the roof is pitched, while the ones of the lateral
naves are lower and have a single slope. The roof of the main altar and the lateral chapel is flat,
consequently the extrados of the vault is carrying an infill, recently provided.
It is important to point out that horizontal metal ties have been installed along the main nave
on the upper part of the longitudinal arches in 1971 . This work was probably done to prevent
future damages due to earthquakes, since the columns and arches are very slender. In this case
the ties are intended to make the two longitudinal systems work jointly, since the light wooden
roof cannot be considered as a stiff diaphragm and therefore a high probability of out-of-plane
Comparing the Safi Cathedral and the Funchal Cathedral some similarities and differences
arise. On one hand, the proportion and configuration of the main chapel and the lateral chapels
are the same. Also both probably had a main nave and two lateral naves with a light wooden
roof, but there are no signs of transept in the remains of the Safi Cathedral. A tower close to the
main altar of the Safi Cathedral is also missing. The original roof of the Safi Cathedral and the
lateral chapel are lost. However it is possible to state that the lateral chapel of the Safi Cathedral
also possessed a vault, as the stone ribs of the rise of the arches in the corners, and some others
in the subsisting walls are partially in situ.
INSPECTION AND DIAGNOSIS WORKS
Prior to the design projects, inspection and diagnosis works were carried out to evaluate the
stability of existing buildings, to detect possible structural damages, and to guide the design
processed in terms and recommendations for actions to be undertaken.
To achieve these objectives, a visual inspection and nondestructive testing between 13 and 15
May 2009 were carried out . In order to obtain more information about the structural beha-
vior and the state of conservation of the Cathedral, two non-destructive tests (NDT) were car-
ried out at the main chapel: dynamic test and sonic tests. During the dynamic tests also envi-
ronmental parameters were measured. Additionally, laboratory test were carried out to deter-
mine the type of mortar used originally in the construction of the Cathedral.
The inspections were pursued in what remains from the original construction of Safi Cathedral
and in the surrounding buildings to identify the typology of the structural elements, the mate-
rials and the existing damages of the structure. This inspection followed a three-dimensional
survey of the structure made by Miranda . Attention was only given to the original parts of
the Cathedral, since part of the remaining structures are going to be demolished, according to
the existing rehabilitation project. Inspection windows were done on the external wall in order
to determine the thickness and the morphology of the walls.
During the visual inspection no relevant cracks in the masonry walls which are going to be
maintained by the new rehabilitation project were detected. Regarding the vault of the main
chapel, a zone with large vertical displacements was observed (see Figure 7a). This zone limits
with an old perforation of the vault which was introduced for the hammam chimney.
The existence of a chimney which crossed the vault exactly at one of the main-stones of the
ribs was already documented in 1929 by the General Head Office of Arts and Historical Monu-
ments of France . The consequence of this alteration is the opening of some joints of the ribs
and the opening of cracks in stones, justifying the earlier insertion of metal clamps as rein-
forcement. The deformed zone (marked in red) and the metallic reinforcement are shown in
Figure 7b. However, the corrosion of the clamps has provoked the expansion of the metallic
elements, generating new cracks and aggravating the stability of that zone of the vault. It can
also be observed that the ribs of the vault do not present a perfect symmetry. This is most prob-
ably a construction defect.
Figure 7: Main chapel vault: (a) general view with deflected zone (red); (b) detail of metallic strengthen-
ing works; (c) extrados of the vault with vegetation that induces cracks in the cover material; and (d) the
The vault is covered from the outside with a cement layer that has large cracks, in which even
vegetation grows, see Figure 7c. These defects permit the infiltration of water, washing out fine
material and deteriorating the lime mortar of joints of the vault and walls beneath. Finally, Fig-
ure 7d summarizes the anomalies of the main chapel which were previously mentioned.
Dynamic test of the vault
A dynamic test was performed on the extrados of the vault. The objective of this test is to gain
valuable information about the dynamic behavior of the structure. The aim is to identify more
relevant modal frequencies and modes, damping or to be able to estimate the rigidity of the
structure. These results can help to calibrate numerical models, such as FE models, through a
process called numerical optimization. In this particular case study, taking into account that the
geometry of the structure is known, the FE model can be calibrated for the following purposes:
locate zones with possible anomalies, determine for different levels of excitation dynamic coef-
ficients and to determine boundary conditions of the structure.
(a) (b) (c)
Figure 8: Dynamic tests: (a) location of accelerometers; (c) accelerometers on the perimeter of the vault;
and (d) accelerometer on top of the vault.
The dynamic test consisted in the measurement of accelerations in different points of the
extrados. Accelerometers were installed with the configuration shown in Figure 8. The source of
vibration was environmental vibrations (wind, traffic pedestrians, etc) and which has the charac-
teristics of white noise. The vibrations were recorded for 10 min with a sample rate of 200 Hz.
The acceleration records were then processed through an output-only method, since no con-
trolled vibration was induced to the structure. The data processing was done with a stochastic
method known as Stochastic Subspace Identification (SSI) method. The result shows that the
frequencies of the first 10 modes range from 5.2 to 11.7 Hz. Damping ratio ranges from 0.9% to
4.7%, with an average value equal to 3.2%.
Sonic tests on one wall
The sonic test is done with an instrument which posses two transducers. One of them emits me-
chanical impulses while the other one is able to perceive them. If the geometry of the test sam-
ple is known (for example the thickness of a wall), the velocity of propagation of the signal
within the sample can be determined.
These results can be used to determine the kind of material the test sample is composed of,
to determine the quality of the material and/or to find anomalies in the sample. It can also be
used to test in-situ the effectiveness of restoration works, such as grouting of masonry walls.
Figure 9a shows some average values for a variety of materials. With exception of steel, the
range of values of sonic velocities, due to the dispersion of the quality and density of materials,
Type of material Sonic velocity
New masonry 1.0 - 3.0
Old masonry 0.4 - 2.5
Concrete 4.2 - 5.2
Timber 3.5 - 6.0
Stone 2.0 - 5.0
Figure 9: Sonic test of the wall: (a) common values for sonic velocities; (b) location of measurement grid;
and (c) sonic velocity map.
In the case of the Safi Cathedral, the sonic test was used to determine the actual state of walls.
Three sonic tests were performed: two on two stones in the interior of the main chapel and one
on the wall that separates that compartment from the lateral chapel. Here, only the results on the
masonry wall will be presented.
To analyze the state of conservation of the walls, an area of 2.0 × 1.5 m and 50 cm over the
ground floor was chosen. Figure 9b shows the location where the sonic test was carried out.
The velocities were measured on a 40 cm horizontal and 30 cm vertical mesh. The transducers
were positioned on opposite sides of the wall, permitting direct measurements. On each point,
10 measurements were taken from both sides. The mean value of the velocities of propagation
inside the wall measured on a same spot was then taken as the real value.
Figure 9c shows a velocity map of the mean velocities of propagation of the wall. The veloci-
ties range from 0.5 to 2.0 km/s, with a mean value of 1.1 km/s. The mean value corresponds to
an expected value for old masonry walls. Nevertheless the difference between the maximum
and minimum values indicates the existence of cavities inside the wall. This fact also indicates
that the wall corresponds to a three leaf wall with smaller stones or gravel in its center.
Conclusions of the Inspection Works
The remains of the Safi Cathedral present various similarities with the dimension and in plant
distribution of the Funchal Cathedral. Therefore, the Funchal Cathedral can serve as a model for
the restoration works with respect to esthetics and structural features.
The laboratory results indicate that the stones are from calcaric origin and that the mortar
used is lime mortar of high purity.
In general, no important damages of the structural elements (such as walls or vault) where
observed during the visual inspection. However, some deficiencies have to be addressed.
The joints which present cementitious mortar should be removed and substituted by lime
mortar, similar to the original one. This will eliminate compatibility problems and permit a
more homogeneous behavior of the structure.
The extrados of the main altar vault has been covered by a cement layer. This layer presents
large cracks which host vegetation. These cracks also permit the filtration of water and the sub-
sequent washing out of fine material and degradation of mortar of the vault and supporting
walls. Humidity was detected in the environment of the main chapel, but no efflorescence on
walls nor pavement were spotted during the visual inspection, which could indicate high salt
content in the subsoil. To avoid the deterioration of the structural members, it is recommended
to eliminate the vegetation in the cracks and to protect meanwhile the extrados of the vault and
the upper part of the walls from water until a definite solution is adopted. The restoration project
proposes the solution for this problem for the long term situation.
The results of the dynamic tests reveal that the analyzed structure presents high natural fre-
quencies. This is probably due to the support of the surrounding constructions next to the main
The sonic tests and the perforation of the lateral wall revealed the existence of voids inside
the masonry wall which divides the lateral chapel and the main one. These voids could be filled
through injection grout of lime mortar, to consolidate the walls. The zones have to be deter-
mined previously, since an uncontrolled grouting is undesirable and very probable because of
the similar masonry of the adjacent structures.
The structural intervention will be carried out at two levels. Firstly to do the structural rehabili-
tation of the remaining parts (main chapel, lateral chapel and exterior wall) from the original
structure, and secondly to build a new structure for the naves, its roofs and the roofs for the
vault and lateral chapel. The design was assisted by the use of FE models.
Starting with the existing parts to consolidate, the intervention will accomplished the follow-
ing tasks: (a) removal of existing plasters or mortars done with cement; (b) consolidation of
existing walls that have a high void ratio controlled with sonic velocity tests, by injecting lime-
grouts; (c) consolidation of the vault by closing the cracks and removing the damage metallic
clamps and substituting by new ones in stainless steel; (d) consolidation of the curved arch in
the lateral chapel; (e) filling the extrados of the vault with a lightweight material with expanded
clay and lime based mortars; and (f) introduction of a small buttresses in the arch of the main
chapel to absorb the lateral impulse.
The consolidation of the arch of the main chapel is of particular difficulty, since it presents a
pronounced deformation in the middle span, being probably supported by the masonry wall
built under the arch to create the hammam. The demolition of this wall will be monitored, spe-
cially the movements of the vault. The displacements will be compared with the FE model, al-
lowing an even guarantee safety during the works.
Concerning the new added structure, for the lateral arches and walls of the new naves, it was
proposed walls with 40 cm thickness, supported by rather slender pillars with 6 m height and
40 × 40 cm2 cross section. The bearing material is reinforced concrete. The use of slenderness
the pillars creates a difficulty level in the project, aiming at achieving a feasible solution.
It should be stressed that Safi is settled in a seismic zone; therefore the seismic performance was
also considered in the design.
To support the roof of the naves, it was proposed a steel frame structure with high stiffness in
order to reduce the buckling problems of the slender concrete pillars. The frame structure with
HEB220 cross sections has a strong continuity/connection with the reinforced concrete walls.
This solution helps to reduce the slenderness of the pillars to acceptable values, ensuring the
distribution of horizontal actions (wind and earthquakes), especially in the perpendicular direc-
tion to the side walls of the naves. With this solution, the out-of-plane deformation is closer to a
fully connected frame, rather than a pined connection.
The roof of the lateral nave and lateral chapel is made of a timber structure that ensures struc-
tural safety for the actions of gravity and wind, as well as catching the existing side wall which
is admittedly the original wall of the cathedral. Figure 10 shows a cross section of the proposed
structural intervention and an image of the FE model used for safety evaluation.
Figure 10: Structural intervention: (a) cross section; and (b) FE model.
A simpler beam elements model was also developed in order to evaluate the slenderness
lengths of the pillars. The slenderness were compared with code requirements and used to calcu-
late second order effects. A more complex model was developed to evaluate stresses and dis-
placements due to gravity, seismic and wind loads. Finally, a third and more complex model
will be built in future studies in order to take into account the material non-linear effects.
The rehabilitation project of the Safi Cathedral has been a long discussion process in its urban
and architectural frames, and from the coordination point of view with engineering. Figure 11
presents the architectural proposal.
In fact, it would only worth to operate in this patrimony if it could sustain a practical goal for
the intervention, beyond the heritage interest itself and despite its greatness.
Local quality of life was much diminished, and the project constitutes the leitmotiv to en-
hance sanitary and economic conditions for the people living in the quarter of the old Cathedral.
Without any capability to continue living in such bad dwelling zone, some dozens of persons
were moved to new residential conditions, and the area is available to implement the project,
with new urban infrastructures being constructed to serve a very dense zone of the old city.
Today, the place of the remains and the space that belonged to the ancient Portuguese Cathe-
dral, in the middle of the historic Safi, being the project a real opportunity to make the im-
provements on the quality of life of the place.
The aggregation of very strong reasons from the historical, monumental and tourism point of
view are the basis for the rehabilitation in course, coordinating and equating technical proce-
dures and decisions, in order of a better preservation of a so important heritage.
Figure 11: Architectural proposal: (a) plan; and (b) longitudinal section.
The authors would like to thank the Fundação Calouste Gulbenkian for the opportunity to study
the Safi Cathedral and for all the support during the preliminary studies, the inspection and di-
agnosis works, and in the design project.
 Campos, João, “Impérios, Patrimónios e Identidades”, In Libris, 2007.
 Ramos, L. "Relatório da Inspecção Estrutural à Antiga Sé Catedral Portuguesa de Safi – Marrocos",
Department of Civil Engineering, University of Minho, 2009.
 Inventory of the "Instituto da Habitação e Reabilitação Urbana, Direcção-Geral dos Edifícios e
Monumentos Nacionais", available at www.monumentos.pt, 2010.
 Miranda Pires, H. "Levantamento tridimensional do edifício da Antiga Catedral Portuguesa Safi –