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<gallery caption="The Arade 1 Site" widths="180px" heights="120px" perrow="4">
<gallery caption="The Arade 1 Site" widths="180px" heights="120px" perrow="4">
Image:<div style="text-align: center;">
Image:<div style="text-align: center;">Fig. 3 - Arade 1 site after the 1970 dredging operations (Drawing: P. Caleja).</div>
Image:A1-32.gif|<div style="text-align: center;">Fig. - Arade 1 site (Drawing: P. Caleja).</div>
Latest revision as of 23:49, 13 December 2010
(this article is under construction)
After the discovery of a number of shipwrecks at the mouth of the Arade River, during dredging operations, in 1970, two diving teams - Centro Português de Actividades Subaquáticas (CPAS) and Federação Portuguesa de Actividades Subaquáticas (FPAS) - visited some of the Arade shipwrecks and produced reports, pictures, and sketches of two of the sites. The report issued by CPAS was signed by José Farrajota, a civil engineer, archaeologist, and sport diver, and contained a detailed description of the shipwreck with two sketches and a scantling list. Jorge Albuquerque, an architect and a pioneer of sport diving in Portugal, was the author of the two sketches in Mr. Farrajota's report. In these sketches the Arade 1 vessel has a full, flush laid hull, with a small keel and a large keelson or mast step. Further documents in CPAS archives contained important data, such as 24 pictures, 18 taken by Rui Pina and 6 by Jorge Albuquerque, and a map with the precise location of the Arade 1 shipwreck from alignments taken on the coast.
The information gathered by the team from FPAS was also very important, although we were never allowed to see the pictures taken by this group at the time. The photographer, Mr. Helder Mendes, is an historian, journalist, and television director who filmed a series of over 50 documentaries about the sea in the 1960s and 1970s - under the titles Segredos do Mar, and A terra, o Mar e a Gente.
The CPAS pictures show a shipwreck built with flush laid planks fastened with treenails to the frames. On top of the upper ceiling strake there is a row of filler pieces in between the frames.
In 2002 CNANS and the Nautical Archaeology Program at Texas A&M University carried out a joint excavation season.1 Following the 2002 field season the ship was disassembled and all its timbers raised and stored at the CNANS laboratory, where they underwent an extensive study.2
The 1970 report described the Arade 1 shipwreck hanging from the upper part of the embankment created by the dredging works, and filled with 1 to 1.5 m of sediment. The frames were 13 x 16 cm in section, the room and space between 16 and 35 cm. The hull planking was 5 cm thick and varied between 25 and 34 cm in width. The ceiling covered both the lower part of the hull, and its sides - the sketch showing no stringers - and was terminated with a series of filler pieces that closed the room between futtocks, as shown in FPAS' pictures.
There was a large keelson - or mast step - preserved at least along 5 m. It was surmounted by a rather small keel in the sketch by Mr. Albuquerque. According to the report a large part of the ship was torn apart by the dredge and laid scattered on the seabed. It is possible that the falling sediment quickly covered this part of the ship during the following weeks, as the embankment, originally cut at a 1/6 inclination, re-arranged itself into a more stable slope.
A wood sample taken by Mr. Helder Mendes was sent to Groningen, in the Netherlands, and was dated by radiocarbon to the 13th century. As this date is not calibrated, and we do not know exactly where the wood sample was taken, it must be taken very carefully. Another sample - probably from the planking - was sent by Mr. Farrajota to Laboratório Nacional de Engenharia Civil, for species identification, and was found to be from a tree of the oak family (Quercus sp.).
The pictures taken by the FPAS team show a very interesting feature. It seems that the upper ceiling strake is a stringer, thicker than the one that lies below it. The pictures taken by the CPAS team were given to us by Mrs. Margarita Farrajota, the director of that diving club in 2002. She kindly let us see her notes and took on the work of assigning captions to each one of the 18 pictures lent to us, based upon her notes and sketches, placing them on the hull remains as they were seen at the time.
In the summer of 2002 the excavation and recording of the Arade 1 shipwreck was entrusted to a team from the Nautical Archaeology Program at Texas A&M university.
The 2002 Field Season
The 2002 field season in Portugal comprised two months of work developed by a joint CNANS / TAMU-INA team, which ran from July the 1st to August the 31st.
A team from Texas A&M ( Filipe Castro, Dante Bartoli, Starr Cox, P. Eric Flynn, Gustavo Garcia, and Michael Jones) worked from early July to mid August on the Arade 1 site, diving twice a day, five days a week. Saturdays were used to fix the equipment and update the reporting. Sundays were taken to rest. After the Texas A&M team left, a team from CNANS closed the site and covered the shipwreck.
During the two months in Portugal, students interested were offered a number of weekend excursions, which included visiting Dr. Shelley Wachsmann's work at the castle of Castro Marin, looking for the 80-gun vessel Océan, lost near Salema beach in 1759, during the French and Indian War, or visiting locals of interest on the southern coast of Portugal, such as Sagres and Boca do Rio.
All lodging costs were assumed by the Portuguese government, through its Centro Nacional de Arqueologia Náutica e Subaquática, and by the municipality of Portimão. The team was lodged at Portimão's commercial harbor, in a camp built with modified shipping containers. The camp was located 200 m from the pier where the boats were docked, with all diving and excavation equipment kept in containers rented for that purpose. Food was delivered to the site daily by a local catering company. General cleaning and maintenance was also provided by the municipality, who contracted a company to carry out the daily cleaning of the camp. The kitchen was maintained by the students.
Underwater works were carried out five days a week. Two dives were performed each day. The INA / Texas A&M University team was given two boats for that purpose. The main objective of this field school was to expose all students to a real life underwater archaeological excavation. Students were expected to try several different excavation and recording techniques. All the students refined their skills in a low visibility environment, with a slight current, and over a real shipwreck site, dealing with fragile and decaying organic materials, and learning how to work in a group, taking a share of the less pleasant part of the work: cleaning tools, filling diving tanks, and carrying the heavy equipment.
The working schedule encompassed the following operations:
- Removal of the sandbags and plastic cover that protected the shipwreck;
- Cleaning, tagging, and positioning of the datum points fixed in the 2001 season;
- Fixing the 10 x 10 m working area marked around the shipwreck in 2001;
- Excavation of the sediment deposited over the shipwreck;
- Cleaning the hull timbers;
- Excavation of four trenches in areas previously chosen around the shipwreck;
- Identification, tagging, and positioning of all concretions and artifacts found in the area;
- Verification of the accuracy and completion of the existing partial drawing of the hull;
- Compilation of a map with the depths of the area;
- Drawing all concretions and loose timbers at a 1/1 scale;
- Raising all artifacts;
- Raising all loose timbers;
- Recording transverse profiles across the hull remains.
As for the recording work in dry environment, the tasks assigned were:
- Analysis of the 2001 site plan, drawn at a 1/10 scale;
- Drawing the 10 x 10 m working area at a 1/10 scale;
- Drawing the hull remains at a 1/5 scale;
- Drawing transverse profiles of the hull remains;
- Drawing ship's timbers at a 1/1 scale;
- Transposing the 1/1 scale drawings to 1/5 and 1/10 scales.
In 2000 and 2001 CNANS and GEO had gathered a collection of rare papers and reports pertaining to the story of the Arade River estuary and the dredging works performed during the 20th century. The consultation of these documents was essential for the understanding of the site geomorphology and history. All doubts and questions were quickly answered by the 2001 team. Particularly useful was the information supplied by the members of the local teams, Alberto Machado from GEO and José Sousa from the IPSIS Project.
In the summer of 2001 a joint survey carried on by CNANS and the GEO group, with the help of Mr. Helder Mendes, lead to the discovery of several ship remains near the Arade 1 shipwreck area marked on CPAS report of 1970. The areas defined on this survey were designated as A1, B1, B2, and C, and several trenches were opened around them during the 2001 field season. Area A1 yielded the remains of a ship's hull, and its excavation started immediately under the direction of CNANS director, Mr. Francisco Alves, carried out by a joint CNANS / GEO team. On area B2 a frame from a lapstrake hull was found together with some lapstrake planking.
It became clear that A1 vessel was the Arade 1 shipwreck of 1970, but the Arade 6, lapstrake-built, shipwreck, was never relocated.
The account of the captain of the Dutch dredge Mark suggested that in 1970 the Arade 1 vessel was exposed on the embankment created by the dredge and, while projecting beyond the embankment and full of sediment, shattered when touched by the dredge. It may have broke into two parts. The projecting part slid along the embankment and may have been immediately buried by the falling sediment, since it was not observed in 1970.
A reconstruction of the bottom of the river in this area shows a steep embankment with a slope around 1/2 in 1970, after the dredging operations, and a much smoother slope in 1997, when the latest cartography of this area was made. We must keep in mind, however, that the slope created by the dredge during its work was 1/6, much steeper than the 1/2 slope found after the Autumn of 1970, when the cartography was made.
Should the projecting half of the Arade 1 shipwreck be in a somehow cohesive form, it was certainly covered by several meters of sediment in 1970.
As for the upper half of the Arade 1 shipwreck, it was reported covered with a thin layer of sediment - between 50 cm and 1 m - a few weeks after the visit of the CPAS team. One of the two tasks of the Texas A&M University team was to assess whether or not the A1 ship was the Arade 1 of 1970, and if so, how much of it was preserved. The other was to carry out a full recording of its hull.
Excavation and Recording
As mentioned above, in 2001 part of the A1 hull structure was exposed and recorded at a 1/1 scale. Most of the ship's hull was drawn on 1 x 1 m plexiglas slates, in horizontal projection. The drawings obtained were then assembled in larger sheets of transparent plastic and then reduced over a grid into a 1/10 scale drawing. However, to save valuable time, the portion of the hull over the keel axis was recorded directly over a sheet of plastic nailed to the structure.
A series of pictures - excellent, when the general visibility is considered - were taken by Portuguese Navy Capt. Augusto Salgado, who is at the same time a navy officer, a historian, a skilled photographer, and a long time friend and collaborator of CNANS. As it was uncovered during the 2001 field season, the A1 hull remains comprised part of a keel, one post, 18 frames, four ceiling strakes, two hull strakes on port side, and eight on starboard side. The hull was clearly broken around amidships, and only half was preserved.
In order to answer the questions stated above, regarding the possible identification of A1 as the Arade 1 shipwreck of 1970, and the evaluation of the extent of the hull remains preserved, the 2002 field season was developed in three phases:
The first phase consisted of a rather quick cleaning operation, which entailed the removal of the layer of sandbags and plastic cover that protected the hull remains during the winter, and a repair of the 10 x 10 m square that had been positioned around the area in 2001. This square was marked by a series of iron spikes tagged according to its position on the perimeter, and connected by a nylon cable and a red and white tape. As in the previous year, these spikes proved to be very useful, given the low visibility of the site - inside the river mouth - for the orientation of the divers. On the second phase of the work the spikes mentioned above were used as datum points to position the hull and artifacts lying within the 10 x 10 m square where the excavation was carried out.
The second phase consisted of the positioning of all archaeological features inside the 100 m2 area. The mapping was performed at a 1:10 scale with the help of the WEB computer program. The positioning of the hull was not difficult once we established a number of points that could be accurately positioned on the 2001 drawing, and identified in the shipwreck in situ, such as treenails and iron bolt concretions. The extremities of the timbers were damaged during the winter by wood boring worms in spite of all the protection measures taken by CNANS before closing the field season in September 2001. In fact, several octopuses - at least four! - found their way under the plastic cover that protected the shipwreck, and established themselves in the spaces between the sandbags that covered the whole wooden structure. This action favored the penetration of numerous mollusks and worms to the area between the timber upper surfaces and the plastic cover, and promoted a not negligible destruction of the upper surfaces and extremities of the timbers.
The third phase consisted of the verification of all measurements of the existing 1/10 scale hull drawing on an enlarged scale (1/5), the positioning of the hull in relation to the datum points set in the previous year, and the excavation of four trenches around the hull structure.
During the 2002 field season the portion of the hull excavated and partially recorded in 2001 was tentatively identified as the bow of this vessel, because of the gentle curvature of the post, and because no remains of any steering device - rudder, gudgeons or pintles - were found anywhere nearby.
Around July 15, once the first part of this third phase was finished - the verification of scantlings and fastening holes - the TAMU / INA team started the excavation of the four trenches defined within the 100 m2 working area.
Trenches 1, 2 and 4 yielded a small number of artifacts, some rigging elements, a few loose timbers, and unidentified concretions. These have greatly contributed to the understanding of the site, and suggest a late 16th century date for the A1 shipwreck. The most interesting find occurred however on trench 3, where a second portion of this hull, showing a clear fracture area, plunged at a 45º degree slope into the sediments.
The portion of the hull found in trench 3 was recorded in a sketchy way for lack of time, and covered with sediment to be studied as soon as the full recording of the portion of the hull already exposed is completed. However, this discovery contributed decisively to the identification of A1 as the Arade 1 shipwreck, mostly due to the details preserved, such as the filler pieces photographed in 1970.
The stratigraphy found along these four trenches was the same described by the 2001 team while exposing the hull:
Layer 1 - a first layer of fine, dust-like sediment, with a clayish consistency, dark brown color, and littered with seashells and ceramic shards. This was presumably deposited very recently, certainly after the construction of the jetties that have closed the Arade estuary from the sea environment. This layer was 5 to 10 cm thick.
Layer 2 - bellow layer 1 was dark clay, from dark-grey to black, presumably also deposited after the construction of the jetties, when the current speed was drastically reduced in this area. It showed an impressive amount of live worms and mollusks, undoubtedly responsible for the degradation of the hull timbers during the period between the summers of 2001 and 2002. Layer 2 is also littered with ceramic shards of diverse proveniences, as observed throughout the whole estuary area. This layer was between 10 and 30 cm thick.
Layer 3 - under layer 2 was a layer of white sand with little organic material. The thickness of this layer was impossible to determine. Potshards in this layer may be associated with the shipwreck. We have excavated 0.80 to 1.20 m into it.
Layer 4 - this layer was only touched in trench 4 and consists of white limestone round rocks. It is not known if this layer is a geologic stratum, or if it is just a ballast pile. It should be noted that no ballast was found in 2001 over the A1 hull, nor reported in the 1970 survey.
Trench 1 was excavated to a depth of around 50 cm along the southeast side of the iron gun found on the eastern corner of the 10 x 10 m square (Fig.6).
The artifacts found in this trench are described in the Volume 3 of this report. They consisted mainly of potshards of various proveniences, as it is frequent in the Arade estuary, and included a few fragments of a Spanish olive jar.
Trench 2 was dug to northwest of the iron gun and extended to west, in the direction of the presumed bow of the vessel. This trench was extended to the west in order to fully expose a loose ship timber (A1-10) whose tip was found within its primary area. In this trench two large concretions were found, as well as a large number of potshards of different natures, and a complete Spanish olive jar. Shards of at least one other olive jar were found in the area where this trench joined trench 1, under the muzzle of the iron gun, and concreted to the large concretion, which received number A1-12.
Trench 3 was dug across the fracture zone. As mentioned above, the second half of the ship's hull was uncovered, slightly displaced laterally, and heavily inclined along what seems to have been the 1970 embankment.
A few potshards - again of many different types - were found at several levels, between the shattered timbers.
Trench 4 was dug along the west side - port side - of the hull remains. Below layer 2 appeared a number of heavily eroded hull planks, displaced and lacking preserved seams.
Below these planks was found a long timber (A1-36) of roughly square section - possibly of pinewood - that showed no fastening holes. Under this timber there were three deadeyes and remains of rope (Fig. 7).
In the lower strata of layer 3 a few potshards were found, immediately above layer 4. Three heart blocks - in Portuguese sapatas dentadas - were found immediately below timber A1-36, laying over archaeological layer no. 4, together with remains of rope.
The upper portion of the hull extended over an area 7 m long and what follows is a short description of each one of the hull elements which is intended, at this phase of the project, more as a structuring approach and an inventory of missing data than as a comprehensive description of the hull parts observed and recorded.
This part of the A1 shipwreck remains was fully recorded in plan, and several transversal sections were taken along the runs of the forward faces of the floor timbers.
The ceiling planking was disassembled, and a second map was made of the upper surface of the framing. Some interesting features were observed, such as the presence of fore-and-aft treenails running through three timbers at several places. However, only a full excavation and disassembling will show eventual patterns that will allow a discussion of the construction sequence and conception methods.
After the last field season the remains of the upper hull consisted of:
Keel - one section, as far as it could be observed @ C10/C11 level. Sided - 15.5 cm (top); 11cm (bottom). Molded - 13.5 cm. Preserved length - 6.05 m. Scarves - Not observed.
Stem post - one section. Sided - 14.5 cm (top); 9.5 cm (bottom). Molded - 13.5 cm. Preserved length - 1.49 m. Scarves - Not observed.
Apron - Not fully measured. Sided - 14.5 cm (top).
Floors - fairly well shaped. Sided - Average 17.6 cm. Molded - 16 to 17 cm.
Futtocks - roughly shaped. First and second futtocks were preserved. Sided - Average 18 cm. Molded - 16 to 17 cm.
Room and space - irregular. Around 42 cm between C1 and C8. Around 29 cm between C9 and C18.
Ceiling planking (fixed) - Carefully shaped and laid. Linked through flat horizontal scarves. Thickness - 6 cm. Width - 23 to 27 cm. Max length preserved - 3.28 m (TN3A). Scarves - Flat horizontal, 50 to 60 cm long.
Ceiling planking (floating) - Carefully shaped and laid. Thickness - 5 cm. Width - Variable. Min. 7 cm; Max. 29 cm.
Filler pieces - Carefully shaped and laid. Thickness - 5 cm. Width - Variable (=space between floors). Length - Around 18 cm.
Hull planking - Carefully shaped and laid. Thickness - 5 cm. Width - Consistently 28 cm. Max preserved length - Not recorded.
Fastenings - Both treenails and iron nails; remains of two bolts. Keel/Stempost - Not recorded; Floors/Keel - Treenails, Ø = 3 cm; Floors/Futtocks - Treenails, Ø = 3 cm; Keel/Keelson(?) - Iron bolts, Ø = 3.2 cm; Planking/Frames - Iron nails, side = 8 mm; treenails, Ø = 3 cm. Ceiling/Frames - Iron nails, side = 8 mm; treenails, Ø = 3 cm.
The results of the 2002 season are available through the reports referenced below. Work continued on this shipwreck, although without the involvement of the Nautical Archaeology Program. The lower portion of the ship's hull was recorded by a CNANS team and the entire hull was raised and stored in the CNANS headquarters, in Lisbon.
1. Castro, F., The Arade 1 Ship - 2002 Field Season - Vol. 1 - The Site - ShipLab Report 3. On file in IPA/CNANS' library, 2002, and in Nautical Archaeological Program Library, Texas A&M University, 2002. Download PDF(2.5Mb) Castro, F., The Arade 1 Ship - 2002 Field Season - Vol. 2 - The Hull - ShipLab Report 5. On file in IPA/CNANS' library, 2002, and in Nautical Archaeological Program Library, Texas A&M University, 2002. Download PDF (1.5Mb) Castro, F., The Arade 1 Ship - 2002 Field Season - Vol. 3 - The Artifacts - ShipLab Report 6. On file in IPA/CNANS' library, 2002, and in Nautical Archaeological Program Library, Texas A&M University, 2002. Download PDF (2.3Mb) Castro, Filipe, “Archaeology and Dredges: the Arade River Archaeological Complex”, International Journal of Nautical Archaeology (2005) 34.1:72-83. Download PDF (1Mb)
2. Loureiro, V., and Alves, J., “The Arade 1 Shipwreck: Preliminary Results of the 2004 and 2005 Field Seasons” The International Journal of Nautical Archaeology (2008) 37.2: 273–282.