Angra C

From NAPwiki
Revision as of 23:53, 20 November 2010 by FilipeCastro (Talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

(This article is incomplete)



Possibly a 17th century Dutch shipwreck, this was one of two wooden hulls found during a survey carried out between September 1996 and February 1997, this shipwreck consisted of a segment of the bottom of the hull of a very large ship, measuring 14.75 meters in length and 6 meters at its maximum width. It was located under 2 meters of sediment, which consisted of fine silt and sand, at an average depth of 7 meters. The wreck had a northeast-southwest orientation.

Excavation begun by clearing away the sand and loose ballast stones in the central area of the shipwreck. The site was gridded into 4 square meters as a framework for recording of the shipwreck. The sand overburden was removed by three water and two 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 dig a trench around it's perimeter, 4-5 meters away from the hull, with a 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.

Hull remains


A 10.5 m long segment of the keel 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 tapered down, narrowing to form a lower surface 16 cm sided. The surviving fragment of the keel showed no outer planking rabbets.

Rising timber

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 first three floor timbers, counting from the northwest end of the wreck, were notched in order to fit over the rising timber. 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.


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 molded at the carving used to sit over the futtocks, and 21 cm molded in between the dents.

Floor timbers and first futtocks

Floor timbers alternated 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. Two of the floor timbers were connected to the first futtocks by one dovetail mortise or even two dovetail mortises on each of the futtocks.

The floors were fixed to the keel, to an existing rising timber 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 first futtocks alternated 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 molded. The floors and futtocks were not laterally connected by fasteners.

Ceiling and 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. 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 ceiling 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.


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.


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.


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.


Personal tools