The Aqueducts of Patras

GPS coordinates: Bridge on Aroe Valley: 38°14’48.30”N; 21°45’11.25”E Bridge in Folois/Artemidos street: 38°14’53.18”N, 21°44’55.93”E Water channels in Asirmatos: 38°15’0.65”N; 21°45’6.22”E

Basic bibliography: ArchDelt45 1990 (1995), 136; Petropoulos‐Risakis 1994; Petropoulos 2006; Petropou‐

los 2007

Fig. 3.200 Patras. The Aroe valley bridge: A) Roman aqueduct B) medieval aqueduct (after transfer from the original position further to the left of the picture)

Remarks

First of all it has to be noted that both thin and thick bricks were used within the same construction, as in the fortification of Nicopolis (fig. 4.23). Second, that the thicker bricks were selected for the vault and for the architectural frame of the façade. Third that bricks used in the stone/brick reticulatumdid not have an aesthetical purpose, such as in the ex‐

terior façade, but were also used to create a pattern around the stones placed according to the incertum technique (fig. 3.198).

water conduit had stone vaults and was dug into the hillside. Two other bridges have been discovered²⁶²: the first close to the source, not far away from the villa of Rufus; the second close to the hospice at Gravià.

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Building techniques of the bridge on the Aroe valley

The Aroe valley bridge is the largest scale aqueduct of the Peloponnese, with its three tiers of arcades and massive walls buttressing the bridge (fig.

3.201). The thickness of the piers of the bridge in‐

creased from top to bottom. The lower tier was ca.

3.80x4.20 m thick and the thickness of each side was reduced by 30 cm every tier, with the upper tier being 2.34x3.00 m thick (fig. 3.205). The span of the arcades became wider in the higher of the three tiers, with the piers at the bottom of the bridge ca.

4 m apart. The bridge was buttressed on both sides by massive walls ca. 6 m long. The thickness of these walls reduced in a similar fashion and supported the arcades up to ca. 90 cm above the impost of the arch of the higher tier. The lower tier of the bridge is still partially buried and the foundations cannot be seen.

The brick facing (M=65 cm) was for some reason different where the bridge was lower, i.e. where the specusrun up against the slope and is tunnelled into the hill. Here the mortar joints were higher and the modulus was M=72‐75 cm.

The masonry of the bridge on the Aroe Valley was made of mortared rubble faced with bricks (fig.

3.202). The calcareous rubble was poured into the brick facing to form the thick piers and buttressing walls. Sometimes the collapsed masses broke along the discontinuities which occurred every ca. 90 cm (3 RF), where larger bricks were placed as headers into the wall facing (fig. 3.203).

For the brick facing and the solid‐brick arches two sizes of bricks were used (fig. 3.204):

‐ bricks 40x30x5‐6 cm. On one side these bricks had a large groove (1,5x0,5 cm) either along the di‐

agonals or dividing the surface in two smaller rec‐

tangles (fig. 3.204) while on the other side they had grooves made with three fingers with several linear patterns. The large grooves were intended for cut‐

ting the bricks while the finger grooves served to in‐

crease the bonding of the mortar to the bricks;

‐ bricks 28.5‐29x20x4‐5.5 cm. These bricks were

Fig. 3.201 Patras. The Aroe valley bridge: sketch of the buttres‐

sed arcades (plan)

Fig. 3.202 Patras. The Aroe valley bridge: second tier’s pier and remains of the buttress

Roman vaulting and construction in the Peloponnese: case studies 169

Fig. 3.203 Patras. The Aroe valley bridge: rubble masonry faced with 30x40 cm brick stretchers and 30x40 cm brick hea‐

ders. Headers are highlighted

Fig. 3.204 Patras. Sketch of brick used in the Aroe valley bridge

Fig. 3.205 Patras. The Aroe valley bridge: sketch of the elevation with construction detail

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Fig. 3.206 Patras. View of the 75 cm solid‐brick arch of the first tier of the Aroe valley bridge

Fig. 3.207 Patras. Aroe valley bridge. View of the second and third tier of the aqueduct with the 60 cm solid‐brick arch of the second tier

half the size of the 40x30 cm bricks and had deep grooves made with a trowel along the diagonals.

The brick facing was made with the 29x20 cm bricks placed as stretchers (fig. 3.205). Every five courses there was one made of the 40x30 cm bricks placed as headers. In this way the side of the brick facing the exterior was always 30 cm long. Putlog holes for the scaffolding were 2.12 m apart and the courses were 1.50 m.

The arch of the first tier was 75 cm thick and spanned 3.90 m (fig. 3.206). It was made with the 40x30 cm bricks placed as stretchers and headers in order that the joint of every course alternated with the neighbouring one to create a single solid‐

brick arch. The arches of the second tier were 60 cm thick and spanned 3.92 m. (fig. 3.207). They were made with the 30x20 cm bricks placed as stretchers and headers similar to the first tier arches.

The arches of the third tier were 60 cm thick and spanned 4.70 m. They are not preserved but can be restored the same as the second‐tier arch.

Building techniques of the bridge at Folois/Artemidos crossroads

The second section is closer to the Acropolis, ca. 300 m away from the Aroe valley. This section of the aqueduct was built differently. The bridge in fact was lower and had only one tier of arcades opening

Roman vaulting and construction in the Peloponnese: case studies 171

Fig. 3.208 Patras. Brick facing made exclusively with stretchers at the bridge on Folois/Artemidos crossroads. A) Specus: B) Concrete; C) brick facing

into the wall that supported the specus. Smaller walls set further apart buttressed the side towards the valley. The arches were wider.

The wall was built with rectangular bricks as well, but they had no headers and created a solid cladding separated from the mortared rubble wall (fig. 3.208). The arcades were also different.

One arcade, preserved only at the impost and facing the modern road, has sesquipedales (44 cm), bipedales (60 cm) and 20x30 cm bricks. These bricks were thinner (3.3‐3.5 cm) than those of the bridge on the Aroe Valley. However, the construction was realised in a similar fashion, with stretchers and headers that created a single ca. 70 cm solid‐brick arch. Two other arcades were created by two sepa‐

rate arches, which did not bond together. Only one of these is partially preserved (fig. 3.209), since most of the bricks were looted to be re‐used.

Remarks on the bridges

The different techniques used for both the arches and the brick facing cannot be detailed without fur‐

ther study on the aqueduct. However, these differ‐

ences warrant some preliminary remarks.

The first regards the brick facing. In the bridge over the Aroe valley, bricks were used as a facing for pouring the mortared rubble but since they were

not triangular in shape, they did not bond with the core of the wall. For this reason the builders created courses of bigger bricks placed as headers which regularly, every five courses penetrated deeper in the core of the wall. To give a greater bond with the mortar they had grooves on one face, while the other had different grooves made to facilitate cut‐

ting into triangular or rectangular form. Since no tri‐

angular brick has been found so far in this section of the aqueduct it can be envisaged that none was produced expressly for the aqueduct.

The mortared rubble was poured after the construc‐

tion of the brick facing with stretchers, but before the construction of a course of headers, which oc‐

curred every ca. 50 cm. This technique cannot be compared to the opus testaceum, where triangular bricks bonded with the concrete core. In fact in the opus testaceum technique the concrete core was placed layer by layer, and not poured, in order to fill the volume between the brick triangles. However, it is similar to the brick facing in the fortificatin of Nicopolis (fig. 4.20). The higher modulus (M= 72‐65 cm) of the brick facing used in the lower piers, i.e.

those close to the ends of the bridge, compared to the more dense brick facing of the upper piers (M=65 cm), shows more care in the construction of the piers to support the three‐tier bridge, the mor‐

tar joints being thinner in this section.

In the bridge in the Folois/Artemidos crossroads the brick facing was even less accurate than in the Aroe valley bridge, since headers were not used at all and the brick facing did not bond to the core of the wall.

It was thus a uniform cladding used only to pour the mortared rubble.

The arches were all made of solid‐brick construc‐

tion. Bricks were laid radially, but while in the arches above the Aroe valley they created a single solid structure and the desired thickness was achieved creating a header and stretcher pattern, in the Folois/Artemidos crossroads section the thick‐

ness of the arches was achieved with the construc‐

tion of two solid‐brick arches one above the other.

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If we suppose that both the techniques belonged to the same building phase it is possible to suggest that the different construction was related to a distinct structural character. In fact the Aroe valley bridge needed to be stronger because of its ca. 35m height.

Not only was the brick facing more carefully built, but the piers were also closer together and had mas‐

sive buttressing walls. The builders were concerned about the imposing dimension of the structure and the bonding of the bricks in the arches to create one solid arch, instead of two separate arches, was de‐

signed to improve the overall strength of the bridge.

One last comment regards the peculiar building technique used in this aqueduct compared to other similar structures in the Province. The difference in the construction system of the Patras aqueduct from the Aqueducts of Argos (see §3.1.5) and Nicopolis²⁶³, built with triangular bricks and bonding courses, cannot be explained chronologically, since the Aque‐

duct Corinth (see §3.4.1), built without bricks, dates to the same period as the ones of Argos and Nicopo‐

lis (Hadrian). The Aqueduct of Patras is a remark‐

able work of engineering which could easily date to Hadrian. It is likely that its building peculiarities

originated from the distinct building tradition which developed in Patras starting in the early years of the colony. Only a more in‐depth study of the construc‐

tions of the city, to date lacking, will shed more light on the local building industry.

The underground conduits in Asirmatos

Modern interventions on the top of the hill of Asir‐

matos, not far away from the bridges in the Aroe Val‐

ley and Folois/Artemidos crossroards, have brought to light two underground channels belonging to an additional water supply system. They apparently do not belong to the aqueduct from Romanos, since they are located higher up and are oriented north/south, while the bridges were oriented east/west. The two water conduits (fig. 3.210‐A and B) are visible now because a part of the hill has col‐

lapsed. Their orientation clearly point out that they must have been connected to a bridge, now lost. The presence of two conduits suggests that there were two aqueducts one parallel to the other, possibly not functioning simultaneously.

The lower conduit (fig. 3.210‐A) was built in mortared rubble (fig. 3.210‐D) in a tunnel dug in the

Fig. 3.209 Patras. Double‐arch arcade at the bridge on Folois/Artemidos crossroads

sandstone (fig. 3.210‐C). The upper conduit (fig.

3.210‐B), more easily accessible, was also built in mortared rubble (fig. 3.211). The walls and the vault of the water conduit were made with local rubble placed in a random way. The same building tech‐

nique was used for an inspection well, which has emerged because the rock has been dug away (fig.

3.212). Above the two water conduits, on the top of the hill, lay the possible remains of a third specus (fig. 3.213), oriented east/west. The presence of three water channels in addition to the aqueduct from Romanos shows that the city needed addi‐

tional water supply. Their convergence in this sector of the city is related to the hill of the Acropolis, the highest point close to the city centre and where there must have been a water reservoir.

Roman vaulting and construction in the Peloponnese: case studies 173

Fig. 3.210 Patras. Underground conduits of the Patras Aque‐

duct at Asirmatos: A) lower specus; B) upper specus; C) rock cut surface; D) mortared rubble masonry

Fig. 3.211 Patras. Upper specusof the Patras Aqueduct at Asir‐

matos (fig. 3.210‐B)

Fig. 3.212 Patras. Mortared rubble inspection well of the Aque‐

duct at Asirmatos

Fig. 3.213 Patras. Aqueduct at Asirmatos: remain of specus with different orientation of the two underground conduits in fig. 3.120

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The bath building is situated in the Pamisos river valley, some 10 km from the sea and ca. 30 km from Messene. The site is downhill from the Classical and Hellenistic settlement of Thouria. Pausanias wrote that the city was transferred to the plain in Roman times²⁶⁴, but up to date it has not been identified.

The only remains are the Roman bath and a ruined apse, probably belonging to the same complex, since it is only 25 m away (fig. 3.214‐L).

The structure of this bath is in excellent condition though still unpublished. It was surveyed in 2006‐

2008 as part of a research partnership between the Scuola Archeologica Italiana di Atene and the LH’

Eforia Proistorikon kai Klassikon Archaiotiton²⁶⁵. Most of the vaults are still preserved, with the ex‐

ception of the south wing, which has partially col‐

lapsed. The lower part of the building is still buried under ca. 2 m of alluvial sediments deposited during flooding from the river.

A general description of the architectural layout fol‐

lows as an introduction to discussion of the building techniques.

Description of the building

The bath complex covered a surface of ca. 550 m². The rooms were organized along a central axis, in‐

clined westwards. The building (fig. tth55) had an extension of ca. 31x22.5 m. The entrance was from the south side, with two rooms (A1) and (A2) serv‐

ing probably as apodyteriaand anointing rooms²⁶⁶. The rooms were all of the same height except the frigidarium, covered by a cross vault which was ca.

2.25 m higher. Like the northeast baths in Epidaurus (see §3.3.3), the façade of the bath was shaped with a curved layout, resulting both from the curved plan of the end walls and the curved extrados of the roof (plate 9). Each curved end was crowned with a brick cornice, only partially preserved (fig. 3.216‐d).

No documento ROMAN VAULTED CONSTRUCTION IN THE IMPERIAL PERIOD. (páginas 187-194)