The Service Corridors of Bath A

GPS coordinates: 37°37’52.23”N; 22°43’11.07”E

Basic bibliography: Preliminary report in BCH: R. Ginouvès (78 (1954), 173‐175; 79 (1955), 323‐328) P.

Aupert (98 (1974), 764‐782).

Fig. 3.23Argos. View of room (J2) of the service rooms of Bath A

Fig. 3.26Argos. Detail of the north wall of room (J2). A) putlog holes; B) holes for the beams supporting the centering.

Roman vaulting and construction in the Peloponnese: case studies 57

Fig. 3.24Argos. Plan of bath A with the service corridors and the access ramp

Fig. 3.25Argos. View of the entrance to the service corridors from east

Fig. 3.27Argos. Detail of the wall on the passageway between (J1) and (J2)

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alised with ø22cm terracotta pipes (fig. 3.30).

Description of the vaults

The description focuses on the three vaults in serv‐

ice corridors sc S1 and sc S2 and in room J2. These vaults present different technical details and could also belong to different periods.

Corridor sc S1. This barrel vault was 16 m long, 1.47 m wide and 2.47 m high. The walls supporting the vault were made in opus testaceum, though the south one was built against the supporting wall of the phase 1 colonnade.

Construction phases (fig. 3.29):

Centering: vault built with centering. The beams supporting the centering were inserted in 16x20 cm putlog holes (fig. 3.29‐E), located at the impost of the vault. They were set in place at the start of the construction of the vault, but centering was laid on them only after the construction of the first sector.

Radial‐brick vault between the impost and the haunches (fig. 3.29‐D): the first 10 courses were laid according to the radial‐brick technique without a formwork, since the joints are smooth and are dif‐

ferent from the section above, built on a formwork.

Radial‐brick section between haunches and crown‐

ing (fig. 3.29‐C): more courses of bricks set radially were built on a formwork, since the joints are rough.

On the north side there are seven brick courses, on the south are ten.

Crowning arches with radial‐brick technique (fig.

3.29‐B). At both the ends of the vault and along the length of the vault were arches made with 30 cm bricks set radially. They separate sections built with the vertical‐brick technique.

Crowning vault with vertical‐brick technique (fig.

3.29‐A). The bricks used for this section were thin‐

ner (22x22x2.7) cm. The ventilation pipes were in‐

serted in the vault simultaneously to its construction (fig. 3.30).

The construction was organised in such a way as to optimise time and materials. The first radial‐brick

Fig. 3.28Argo. Service corridors of Bath A at Argos. View of the vault in the corridor (sc S1) with a lunette and a vent

Fig. 3.29 Argos. The vault of service corridor (sc S1): A) verti‐

cal‐brick crown; B) radial‐brick crown; C) radial‐brick section laid on centering; D) radial brick haunches built without cente‐

ring; E) location of the beams that supported the centering in‐

serted in (D)

Fig. 3.30Argos. Detail of the vent in the vault of service corri‐

dor (sc S1)

section was realised in continuity with the wall, and centering was only used for a smaller section of the vault. Before the construction of the part which needed centering the walls of the upper rooms were completed. In this way the scaffoldings could be seen directly on the solid ground. Once the elevation of the bath rooms was complete, the service corri‐

dor vaults were finished and the extrados filled with

mortared rubble, with a twofold objective: to create horizontal surface and limit possible deformation of the brick shell.

Corridor sc S2was wider than sc S1 (3.05 m), but had same height and length. Consequently the bar‐

rel vault had a segmental profile. The vault has col‐

lapsed except in a small section⁴⁶. The vault and the

Roman vaulting and construction in the Peloponnese: case studies 59

Fig. 3.31Argos. The vault of service corridor (sc S2): A) location of the timber beams supporting the centering; B) radial brick haun‐

ches built without centering; C) radial‐brick section laid on centering; D) vertical‐brick crown; E) wall faced with bricks built before the vault

Fig. 3.32Argos. The vault of service corridor (sc S2): 1) wall faced with bricks; 2) radial brick haunches built without centering; 3) wall built above (2) before the completion of the vault; 4) radial‐brick section laid on centering; 5) mortared rubble filling

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abutments⁴⁷are similar to sc S1, though there are differences in the building sequence and in the bricks of the crowning (reconstruction?).

Construction phases (fig. 3.32):

The beams supporting the centering were inserted under the impost of the vault, and were as high as three brick courses. They were not aligned to the putlog holes used for scaffolding (figs. 3.31‐A and 3.32‐1).

Radial‐brick vault between the impost and the haunches (fig. 3.32‐2) built without centering using square bricks: 30x30x3.5 cm.

The putlog holes (23x16 cm) of the wall above the haunches were aligned with the ones of the wall under the impost of the vault, meaning that the con‐

struction of the vault was interrupted to complete the elevation of the wall (fig. 3.32‐3).

Radial‐brick sector between haunches and crown‐

ing (figs. 3.31‐C and 3.32‐4) set on a formwork.

Construction of lunettes at the crossing with the openings which lead to room J2. Here the vault was entirely built with the radial‐brick technique laid on centering (figs. 3.31 and 3.33).

Crown with vertical‐brick technique. The bricks used for this section were thinner (20x21x2.5 cm) and had two grooves on each diagonal made with a finger (fig. 3.31‐D).

Filling of the extrados with mortared rubble (fig.

3.32‐5).

Room J1 had a different vaulting technique, since it was made in only two sections: from the impost to the haunches (radial bricks without centering) and from the haunches to the crowning (vertical bricks with centering) (fig. 3.23). The room was wider than the service corridors (span: 3.42 m).

The vault was built with centering only in the verti‐

cal‐brick section. The beams supporting the center‐

ing laid at the same height as those of sc S2. They laid on beams passing through holes (25x28 cm) right through the thickness of the wall separating sc S2 from J2 (fig. 3.34) and inserted in the wall sepa‐

rating from room J1 only 20 cm.. The part on the formwork can be recognized because of the im‐

prints left on the mortar (fig. 3.35). At the ends were one‐brick‐thick radial arches, built before the verti‐

cal‐brick section (fig. 3.34).

Construction phases:

Construction of the wall supporting the vault up to the impost. The beams supporting the centering were placed on the top of the wall (figs. 3.26 and 3.36‐E).

The first sector between the impost and the haunches was built without centering with radial‐

brick technique (bricks: 30x30x3.5 cm) (fig. 3.36‐

C).

The second sector above the haunches was built above a centering with thinner rectangular bricks (20x21x2.5 cm) (fig. 3.36‐A e B).

Filling of the extrados with mortared rubble (fig.

3.26).

Remarks on the construction process

The service area was built uniformly though with minor differences. All the vaults were built using both the radial technique, with the section from the impost to the haunches built without centering, and the vertical‐brick technique. The beams supporting the centering were bigger in room J1, since the vault had a larger span.

The section built with bricks laid radially was like a continuation of the wall, though using square bricks instead of triangular ones. This allowed the reduc‐

tion of the centering to only the central section of the vault. The rationale for this in the corridors was also to halt the construction of the vault in order to complete the elevation of the rooms before the con‐

struction of the vaults.

The section built with bricks set vertically was built on centering. The bricks had grooves on one surface to bond better with the mortar. They were thinner than the bricks used for the radial‐vault. The reason for this was that usually lighter bricks were used in constructions without centering.

Fig. 3.35 Argos. Detail of the imprints of the formwork on the vault in room (J2)

Roman vaulting and construction in the Peloponnese: case studies 61

Fig. 3.33Argos. Detail of the vault on the passageway between (J1) and (J2)

Fig. 3.34 Argos. Detail of the vault in room (J2). The vertical brick vault is headed by a radial brick arch that was built against the end wall of the room

Fig. 3.36 Argos. Detail of the vault in room (J2). A) vertical‐

brick vault made with thinner bricks; B) radial‐brick vault made with thinner bricks; C) radial‐brick vault made with thicker bricks (without centering); D) impost of vertical brick vault; E) impost of radial‐brick vault

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Under Gordian III (238‐244)⁴⁸remarkable modifi‐

cations transformed the bath building; they in‐

cluded the addition of rooms A2, A3, B4 e B5 and the new access ramp from the agora(fig. 3.24). The first part of the ramp was made with a solid mortared structure, while the upper part was built with ram‐

part vaults with bricks set radially and covered with mortared rubble to create a horizontal surface in front of the entrance (figs. 3.37 and 3.38). This building phase made use of opus mixtumfacing⁴⁹.

Description and remarks on the vaults

The vaults cover two rectangular rooms located in the higher part of the ramp, in front of the entrance, where there was a vestibule. The rampart vault cov‐

ering room K1 (fig. 3.24) spanned 3 m, while the vault covering room K2 was 25cm smaller and, con‐

sequently, the impost was 25 cm higher.

The supporting walls were made with the opus in- certumtechnique and were topped with a bipedales (65 cm long bricks) course, used as impost for the vault (fig. 3.39).

The first sector of the vault (6 brick‐courses) was made with square bricks (28 cm, 4 cm thick) built without centering since the joints are smooth (fig.

3.41). On the top of this sector are six holes (ca.

24x24 cm), ca. 170 cm apart, where the timber beams supporting the centering were inserted. They were placed inclined, with the opposite end laying on a protrusion from the wall, at a lower level than the holes. An opening left on one side of the room made it possible to enter the room after the con‐

struction of the vault and to remove the material used for the centering.

The upper sector was built with trapezoidal bricks (21,5x24x2.5 cm; fig. 3.40). These bricks were not