Angra C wreck

Paulo Monteiro

  

Descending to Angra C.

Photo: Peter Waddell

 

Overview

    Angra C, a segment of the bottom of the hull of a very large ship, measuring 14.75 meters in length and having 6 meters at its maximum width, was located below 2 meters of sediment, made of fine silt and sand, at an average depth of 7 meters MSL. The wreck had a northeast-southwest orientation.

 

Angra bay, with the buoys marking Angra C and D sites

Photo: Paulo Monteiro

    Excavation begun by clearing away the sand and loose ballast stones in the central area of the wreck. The site was grided off into 4 square meters as a framework for accurate recording of the shipwreck. The sand overburden was removed by 3 water dredges and 2 air dredges, while the ballast stones were removed by hand. Divers did sample collecting of bilge sediments for micro-analysis, of organic remains for species studies, and of wood sections for dendrocronology and species identification.

    The team removed all the overburden, excavated until the wreck's level was reached and then proceeded to dug out a trench around it's perimeter, 4-5 meters away from the hull, with a ship borne high suction pump, in order to achieve maximum working visibility and to speed up the sediment excavation.  Since the main objective of the project was to examine, record and dismantle the ship, the excavation strategy was directed toward uncovering specific features of the hulls.

 

Preliminary photomosaic of Angra C.

Photos: Peter Waddell

 

Ballast

    Angra C ballast was in surprisingly small quantity for the size of the ship - estimated at 600 to 800 tons - which points to the hypothetical use of shingle as a primary ballast resource. The surviving ballast stones were calcareous in nature, rough-shaped, white colored, with a maximum weight of 50 kg and a maximum diameter of 50 cm.
 

Keel

    A segment of the keel, 10.5 m long, was still in situ at Angra C's southwest end, with both it's extremities ending in a scarf. The keel was 28 cm moulded and 33 cm sided at it's upper surface. Ten centimeters lower, the sides of the keel would taper down narrowing to form a lower surface 16 cm sided. The surviving fragment of the keel showed no outer planking rabbets.
 

Keelson

    The keelson was missing, although a segment of it was pinned below the hull, on it's northwest side. The dented keelson was upside down, and was 45 cm sided, being 15 cm thick at the carving used to sit over the futtocks. and 21 cm thick in between carvings.
 

The pinned down keelson segment. Note the carved lower surface and the ballast stones.

Photo: Paulo Monteiro

  

Floors and first futtocks

    Floors alternate between 55 cm (maximum) and 24 cm (minimum), with an average of 32.4 cm sided. They are between 30 cm (maximum) and 20 cm (minimum), with an average of 25.4 cm moulded. Floors are between 2 m and 4 m long. Floors are spaced between 25 and 40 cm.
 

Pairs of floors and futtocks, after the removal of the ceiling planks

 Photo: Paulo Monteiro

  Two of the floors were connected to the first futtocks by one dovetail mortise or even two dovetail mortises for each of the futtocks.
 

Floor with a central limber hole over the keel.  Mortise on the upper surface of the floor to receive the keelson.

  Photo: Paulo Monteiro

    The floors were fixed to the keel, to the rising deadwood and ,eventually, to the keelson by iron nails. All floors had centered limber holes and had a semicircular cut, either on one face or on both faces, that was used to receive the keelson. This mortise was, in average, 40 cm long by 4.5 cm in width.
 

The dismantling of a floor from Angra C.

  Photo: Paulo Monteiro

    The first futtocks show alternate between 34 cm (maximum) and 20 cm (minimum), with an average of 28.6 cm sided. They are between 35 cm (maximum) and 14 cm (minimum), with an average of 23.1 cm moulded. The floors and futtocks were not laterally connected by fasteners.
 

Planking

    Angra C has a double layer of outboard planking, each layer being between 6 and 8 cm thick, making the whole outboard side between 16 and 18 cm thick. The west side garboard, 10 cm sided, had been lowered by 3 cm so as to make a bilge waterway, in a manner comparable to the dutch SL4 wreck.
 

 

West side of Angra C. Double layer of outboard planking.

  Photo: Miguel Aleluia

 

    The average side dimension of the outboard planks is 30 cm. No evidence of sheathing was found. Three bilge stringers run on each side of the hull. They were in between 35 to 60 cm sided to 8 cm moulded.
 

The 1:1 tracing of the details of the outboard planking

  Photo: Paulo Monteiro

    The inner planks were, in average, 6 cm thick. Several limber boards were in place, near the axis of the wreck. An opening, carved in between a bilge stringer and a ceiling plank, may correspond to an insertion for the pump well.
 

Dismantling the ceiling planks

  Photo: Paulo Monteiro

Rising deadwood

    On the northwest extremity of the wreck, a rising wood was sandwiched between the floors and the missing keel. It was made of one piece of wood, being 75 cm sided at it's northwest end an 4.5 m long.
 

 

 

The northwest end of the wreck with the rising wood. Note the garboards and the notched floor.

  Photo: Paulo Monteiro

 

    The first 3 floors, counting from the northwest end of the wreck, were notched in order to fit over the rising wood. The remains of two iron bolts were clearly seen in the terminal part of this element. A parallel for this structural element can be found on the wreck of the H.M.S. Dartmouth.
 

Fasteners

    Angra C shows, ballast level, more than 1300 treenail heads. These trunnels were the main fastening element and had an average diameter of 3 cm. Iron bolts were used, as stated above, only to fix the floors to the keel and to the rising wood. Iron nails, with a square cross-section of 1 cm, were used to fasten the outboard planks, although the trunnels were the main means of connecting both outboard and inboard layers to the floors and futtocks.
 

Doing the photomosaic of the wreck

  Photo: Francisco Alves

Artifacts

    The ship was obviously salvaged at the wrecking event and artifacts recovered were scarce, with leather soles, a copper cauldron, a pipe and shreds of ceramic coarse, light and blue being the most notable.  Organic material, like fruit pits, grains, corn, straw and a tar-like caulking substance, was also recovered.