This enormous building is situated between the basins of Claudius and Trajan, on side VI of the hexagon, and to the south-east of the Imperial Palace. The nature of the building has been clarified by the Portus Project, through geophysical research and limited excavations.
On the plan of Portus published by Rodolfo Lanciani in 1868 the building is depicted as consisting of three long rows, each row consisting of rooms back-to-back. Next to it is the text "Magazzeni Annonarii", Warehouses for Foodstuffs. There is no mention of the actual ruins, so this part of the plan may be based largely on fantasy.
The building on the plan of Rodolfo Lanciani from 1868.In 1935 the building was discussed briefly by Giuseppe Lugli. Unfortunately his description is confusing, because he believes that the building, number 29 on the accompanying plan by Italo Gismondi, forms an entity with the south part of the Imperial Palace, number 28. Translated from the Italian:
[Warehouses of the port of Trajan, 28-29] They are almost entirely covered with earth. Lanciani drew them as three parallel buildings, surrounded by access roads; in the Constantinian age they were included in the walls that leaned against the external side of the western warehouses, closing all the openings that gave onto landing-stage n. 14, adjacent to the harbour of Claudius; they enter the hill for a considerable depth, covered with cross vaults and with partition walls towards the harbour. The opus mixtum is beautiful. A few rooms of the upper floor, built in the same way, also remain. After a hundred meters the building bends, but immediately afterwards it remains buried. Nearby lie fragments of large bases and Corinthian capitals of white marble. It appears that building n. 29 was detached from n. 28. In the Trajanic walls restorations from the time of the Antonines can be seen, carried out with small flakes of tufa without a facing; it stays at a small distance from the basin and was covered, like the previous one, with large cross vaults.
[Area to the north, 14] This part is covered with many bushes and cannot be recognized well. Lanciani draws on his plan a landing-stage towards the basin of Claudius, behind which the line of the city-wall with its towers extends for a certain distance. In the few points where the wall emerges from the mound of ruins, the same type of Constantinian masonry already noted can be observed, with shallow buttresses measuring 1 x 0.60 m.
The building on the plan by Italo Gismondi from 1933: nr. 29 to the right, nr. 28 to the left.The excavations by the Portus Project began in 2011. Building 5 was defined, 240 meters long and 58 meters wide, beginning at the east side of the Imperial Palace and ending at the corner of side VI of the hexagon. At the east end it is continued by building 7, about which very little is known. It is 40 m. long and lies just beyond the angle of the hexagon. Building 5 was erected during the reign of Trajan, a date deduced from ceramics, a brick stamp, and the facing of opus mixtum.
Building 5 to the east of the Imperial Palace. Plan: Portus Project.The building is not made up of three rows behind each other, but by north-south running passages and halls: seven passages (P1-P7), triple narrow bays subdivided by brick piers measuring 2.5 x 0.5 m. (NB1-NB10), and three wide bays (WB1-WB3). The passages are 4.5 m. wide, the narrow bays are on average 12.3 m. wide, the wide bays 20 m. The crown of the vaults may have stood at c. 15 m. North-south running lines of post-holes were found in the narrow and wide bays. Among the finds were many bronze and iron ship nails. The floors were apparently covered by sand, and had a gentle slope from north to south, towards the hexagon. The building is at a distance of some 42 m. from the edge of the hexagon. On the quay on the other side of the building are holes that may be related to wooden cranes for unloading wood.
Buildings 5 and 7. Plan: Keay et al. 2012, fig. 10.The excavators have suggested that the building consisted of a series of slipways. The covered part would then be shipsheds, in Latin navalia. The interpretation is based on the sandy, sloping floors, and supported by the many metal nails, which are of a kind normally used to affix lead to the outside of the hulls of cargo ships. The stakes that were inserted in the post-holes would have supported the ships. Shipsheds are known especially as a shelter for warships, that were kept out of the water to avoid rot and the dreaded shipworm. Building 5 and the area in front would also have been used for the repair or construction of ships. These could have been military ships or cargo ships (warships could be up to 44 m. long and up to 5.7 m. wide; a large cargo ship was 40 m. long and some 10 m. wide).
Computer reconstruction of the building, behind the Terrace of Trajan and the Imperial Palace. Image: Portus Project.
Computer reconstruction of the building. Image: Portus Project.
A depiction of shipsheds on a mosaic from Rome, Via Ardeatina.
First century BC. Vatican Museums. Photo: www.marine-antique.net.Portus had its own guild of ship carpenters, the corpus of the fabri navales Portuenses. It had as many as six chief officers (quinquennales), an exceptionally large number (a dedication by these men is discussed on a page about the Torlonia relief). In Portus a guild roll was found from the late second or early third century AD (originally assigned erroneously to Ostia). It contains 353 names, of entrepreneurs, team leaders and technicians. To these should be added many regular workmen. Many members had their roots in the Imperial household, witness the frequent names Aelius and Aurelius. One of the members was aedituus, so responsible for a shrine of the guild. A special officer called tribunus fabrum navalium Portensium is documented in 195 AD. This title is recorded only once and does not occur among the regular officers. The title suggests Imperial control, perhaps also a semi-military character of the guild.
Relatively soon after the first building phase, some time after 150 AD, the building was given a new function. The entrances to some of the passages and bays were blocked. Some narrow bays were then subdivided into a series of rooms. A new upper floor was installed, witness a staircase that was added at the north end of passage 2. In the early third century and in the fifth century raised floors (suspensurae) were installed. This type of floor is characteristic for grain warehouses. The early-second century date reminds us of a statement in the Historia Augusta (23,2) about Septimius Severus: "At his death he left a surplus of grain to the amount of seven years' tribute, or enough to distribute seventy-five thousand pecks a day".
The staircase in passage 2. Photo: Portus Project.
