During the last week, the Finisterre team continued the underwater survey until the bad weather made impossible to keep diving. However, new materials have been discovered, photographed and mapped.
The new artifacts include three new syringes that probably were part of the surgeon’s chest of this ship. In total, six syringes have been documented since the archaeological survey works started.
One of the this season’s most interesting discoveries has been a bronze cannon that was previously covered by a thick layer of sediment. It seems that during the last periods of bad weather, the sea carried away the sand and this cannon was exposed. This is teh second cannon found this season.
Another interesting discovery has been tentatively interpreted as a sword hilt. It is made of wood and wire wrapped. It is an unusual piece that looks extremely well-preserved. We should not be surprised taking into account that several swords have been located in previous surveys, however, it is a very exciting find!
These are not the only artifacts documented during this season. We will upload more images in our next post. Don’t miss it!
The Finisterre Team
PS: Yes, the water is even colder…
Well, after an (undesired) eventful summer, the Finisterre team is back in business! We have not been able to carry out our planned fieldwork during the summer due to unexpected circumstances but, as we say in Spain, “better late than never”. The team is back in the water and we could not be happier about what we are discovering this season.
On the other hand, the summer was also very productive but in a different way. Although we did not get in the water, we conducted our planned research at the General Archive of Simancas (Valladolid, Spain). We located several original documents related to the organization, outfitting, ships, and fate of the 1596 fleet. What can we say? It is amazing to read the letters that Martin de Padilla wrote to Philip II, and many other documents which provide so much information about the fleet. Yes, archival research is one of the pillars of underwater archaeology for this period.
As I said, we intended to carry out the underwater survey during the summer but we had to postpone it. Then, we thought about October, but we had to postpone it again due to… guess it? The weather!!! Ironically, last October marked the 417th anniversary of the sinking of Padilla’s fleet, which was destroyed by a storm on October 28, 1596. Finally, we have been able to dive in November!
We must admit that we were not very sure about what we were going to find apart from very cold water (in Finisterre the water is cold in summer, and colder in fall). As we have mentioned in previous posts, the main problem we face when surveying this area is the thick layer of sand that covers the shipwrecks remains (not always). On the other hand, the sand ensures the protection (in theory) of the archaeological remains but makes more difficult our work. In any case, we went for our first dive and…
We found another iron cannon… Yes, the cannon had been covered by the sand but the storms have taken the sediment away since our last visit to this site! So, there it was. This has been our first “surprise” that has made us to forget about the low temperature of the water. But then…
A sword appears in front of us! Despite the concretion that covers it, its shape is very obvious. However, this is not the first sword we have found during our previous surveys at Finisterre so we are not that impressed. Okay, okay, we are…
But then we come across of a pewter porringer! (Another one?) I insist, this is the first dive of the season in order to assess the condition of the sites since the last summer, and to evaluate the impact of the storms that affected the area. If someone had told us what we were going to find, we would not have believe it. So far, so good but then, once again…
A metal helmet! Yes, the typical helmet that soldiers wore during this period. Unbelievable! Such an amazing dive. The season could not have started in a better way! So we have mapped and photographed the new finds while we are still wondering about what we are going to find next…
On the other hand, we cannot forget that the concretions on the artifacts reveal that they have been covered and uncovered periodically. So, what about the UNESCO recommendations in relation to the protection “in situ” of the underwater cultural heritage? We have no doubt that these sites illustrate perfectly the exception to this recommendation (http://www.unesco.org/new/en/culture/themes/underwater-cultural-heritage/protection/in-situ-protection/)
If you want to know what we found in our next dive, do not miss our next post. Here, at the INA blogs!
The Finisterre Team.
In the summer of 2012 three bronze breech blocks were recovered from the Ribadeo ship, a likely 16th century vessel (http://nauticalarch.org/blogs/finisterre/2012/11/) The blocks presented a similar size and weight, 25-27 cm long and 12-15 kg. They were covered with a concretion caused by iron corrosion products and calcareous depositions from various marine organisms which had to be removed in order to perform a series of conservation treatments to stabilize them, and to prevent their deterioration.
The first step was to mechanically clean the surface to remove the concretion. Although it may sound a little extreme, this operation was carried out with a hammer and chisel. The breech blocks were not at risk in any moment because the concretion was much softer than the metal beneath it. During the cleaning phase, some marks etched on the surface were discovered. These are now under study.
The bore of one of the breech blocks was filled with a homogeneous black substance, wich lead the conservator Victoria Folgueria that it might be gunpowder remains. Some samples were analyzed by X-ray diffraction and X-ray fluorescence to determine the composition and mineral phase. The results were inconclusive, but since it would not affect the future conservation of the piece, Victoria decided not to remove the contents of the bore to allow further investigation.
Once cleaned, the main concern regarding conservation was the removal of the chlorides produced by the salts in the marine environment. The best removal rates are obtained with electrolytic techniques, so we applied a cathodic polarization treatment of several months. An electrolytic cell was built with the breech blocks as cathode and a stainless steel mesh as anode, and immersed in an electrolyte. A low density, rectified current was applied to start the reaction.
Once the chlorides were removed, the pieces were thoroughly rinsed and inhibited. Two protective layers were applied to isolate the metal from the atmosphere: a first layer of acrylic resin and a second one of microcrystalline wax to dull the shine.
I hope you enjoyed the post!
Conservator – Finisterre Team
Last week, the members of the Finisterre Project met at the 1st National Conference of Nautical and Underwater Archaeology that took place at the ARQVA – Museo Nacional de Arqueología Subacuática (http://en.museoarqua.mcu.es/index.html) in the city of Cartagena (Spain) between the 14th and 16th of March 2013.
During the Conference, the team members presented 5 papers about the different shipwrecks that are currently under study. Moreover, the results of the conservation of the materials recovered during the last seasons were also presented. The Conference was a great opportunity to share the preliminary results of the research conducted at the Punta Restelos shipwreck (1596), the Ribadeo wreck (16th century), and the SS Great Liverpool (1846).
We have realized that the Finisterre Project is becoming established as a leading project in relation to the study of the 16th century shipwrecks in the northwest coast of Spain. This would not have been possible without the determination and effort of the Spanish archaeologist Miguel San Claudio and the support of Archeonauta S.L., Regional Government of Galicia, Institute of Nautical Archaeology, and the J. Richard Stefffy ShipLAB of the Center for Maritime Archaeology and Conservation of the Anthropology Department at Texas A&M University. However, there is still a lot of work to be done and we cannot afford to be complacent.
The Finisterre Project faces multiple difficulties every season, especially funding limitations, but we have no doubt of the great scientific and social value of our research. Having the opportunity to present the preliminary results of our research at the National Conference, and the interest showed by the conference attendees in relation to our project, make us realize that we are moving in the right direction.
The Finisterre Team
As we promised in our last post, here it is the second part of the post about the conservation of some of the coins found in the SS Great Liverpool site, and a bit of history about the ship.
The SS Great Liverpool was a wooden British paddle steamer built in 1838 by Humble & Milcrest and owned by the Peninsular & Oriental Steam Navigation Co. This passenger ship had a displacement of 1.540 tons, and was powered by two side lever engines of 468 n.h.p. with a maximum speed of 12 knots. It had a length of 250 ft (73.2 m), beam of 56 ft (17.1 m), and height of 21 ft (6.4 m) (fig. 1).
While returning to Britain from Alexandria (Egypt), on February 24th, 1846, at about 4 a.m, the ship was between Corcubion and Cape Finisterre, steaming at 10 knots through dark and hazy weather with a rough sea. Suddenly, it struck on a reef and was heavily damaged below the waterline. The ship still managed to steam for some distance till the fires of the boilers were extinguished by the rising of water level in the hold. The ship drifted at the mercy of the seas towards Corcubion and, finally, went ashore. Captain McLeod ordered to launch the boats and all the passengers, with the exception of two women and a child who were drowned in the capsizing of a boat, came safely to shore. The whole of the mail was also saved (Hocking, 1989).
More than 150 years after the sinking of the steamer, the archaeologists surveyed the site and found some interesting artifacts, including different types of coins which have been treated by conservator Victoria Folgueira. Three of them are Queen Victoria coins. It has to be noted that two of them are not the usual British currency, but rupees printed by the East India Company. One is a silver shilling dated in 1844 (fig. 2), the other two are a rupee (fig. 3) and a half rupee (fig. 4), both in silver and dated 1840. All the obverses show a young Queen Victoria. These coins were in a relatively good condition, with enough metal core and well preserved surface details and their appearance was greatly improved with electrolytic reduction.
That’s all folks!
The Finisterre Team
Hocking, C. (1989), Dictionary of disasters at sea during the age of steam including sailing ships & ships of war lost in action 1824-1962.
During the winter, the members of the Finisterre Project spend their time processing and studying the data and artifacts gathered during the summer season. This work includes finishing the digital site plans, cataloging the finds, writing reports, and ensuring the conservation of the finds collected during the fieldwork. This is a very important task since, without proper conservation, the artifacts raised from the sea will rapidly deteriorate.
In previous posts we have showed some outstanding examples of the conservation work carried out by the conservator of the Finisterre Team, Victoria Folgueira. Today we will be presenting the results of the conservation treatments applied to the coins from the SS Great Liverpool, a British steamer that sunk in the Finisterre bay in 1846.
Among the objects recovered from the Great Liverpool, there were a few British coins from King George III, King William IV and Queen Victoria. Their condition was diverse, from the relatively well preserved and recognizable coins of Queen Victoria, to the coin of William IV which was in such a poor condition that was impossible to identify before being treated.
The oldest coins are a couple of 1797 copper pennies from the reign of George III, known as cartwheels because of their large size and weight. They were severely eroded and were covered in corrosion products, making their identification very difficult. After treatment by electrolytic reduction they proved to be in better condition than expected, and were easily identified (fig. 1-2).
The coin identified as belonging to the reign of William IV was in such a poor condition that, at first, it seemed to have lost any detail that could help identify it. It was badly corroded, with only a thin metal core remaining, and most of the corrosion products were gone. After treatment by electrolytic reduction, few surface remaining details were revealed. With the aid of side light, a head facing right was visible on the obverse and a heraldic drapery on the reverse (fig. 3). The only Great Britain coins which had these features were a half crown, a crown and a sovereign from the reign of William IV. Since our coin is not made of gold it cannot be a sovereign and must be a crown or half crown.
Do not miss the second part of the post! Soon!
The Finisterre Team (Victoria Folgueira)
Although it has taken a while, here it is the second part of the post about Ribadeo ship. As you can see, the variety and state of preservation of the different materials documented during the last season are exceptional.
Together with the materials mentioned in the previous post, several wooden balusters of a probable stairs handrail, or even the gallery railing, were documented at the stern area of the shipwreck (fig. 1). The preservation of some of the balusters is simply amazing (fig. 2) In addition, numerous fragments of rope were located on the port side and at the stern area of the ship (fig. 3).
It has to be noticed that fragments of what seemed a wooden barrel were also mapped (fig. 4). Pottery fragments from Spanish olive jars among other ceramic types were also recovered to be studied (fig. 5).
Finally, 29 wooden samples of different parts of ship were taken to conduct dendrochronological dating and species identification (fig. 6).
The visible wooden remains of the shipwreck were mapped using 3D triangulation, photogrammetry, and traditional underwater drawing techniques. The mapping was conducted despite of the difficult conditions posed by the strong tidal currents. In some cases, the superficial sand layer which covered the wooden remains was removed using a water-dredge to facilitate the mapping. Once the remains had been measured and photographed, they were covering again to ensure their protection.
The Finisterre Team.
During the past field season, the Finisterre team also conducted the preliminary assessment of an unknown 16th century shipwreck found in the Ribadeo Inlet, which is also in the Galicia region (fig.1).
This shipwreck was discovered earlier last year during a routine dredging of Ribadeo’s inlet canal. As the dredging was being monitored by an underwater archaeologist, Miguel San Claudio, the shipwreck could be detected before being damaged by the dredge (fig. 2). The remains discovered indicated that it was probably a 16th century ship. Since the main objective of the Finisterre Project team is the study the remains of 16th century shipwrecks. As such, we decided to include the new Ribadeo’s shipwreck in our project.
During two weeks the archaeological team members surveyed and mapped the remains of what it seemed a 16th century shipwreck sank in the inlet of Ribadeo, besides the canal to access the port of the town.
Two or three dives were conducted on daily bases in the shipwreck in order to survey and map the remains. It seemed that the ship was preserved from bow to stern although is covered by a thick layer of sand carried out by the tidal currents. That meant that the ship was only partially visible although different parts of the hull can be identified.
During the survey, it was possible to identify a fragment of the stem (fig. 3), hull planking (fig. 3), futtocks (fig. 3), stringers (fig. 3-4), and bulkheads (fig. 5).
In addition, cannon stone shots of 5 different calibers were also recorded in different locations of the shipwreck (fig. 6). Five different cannon shots, one of each caliber, were recovered for further studio (fig. 7).
In the same way, three bronze breech-blocks were also located, mapped, and raised since they were at risk of being looted (fig. 8).
The breech-blocks are currently being conserved in order to study them (fig. 9).
Do not miss the second part of the Ribadeo ship. Soon here, at the INA Blogs!
The Finisterre Team
The second part of the post about Artifact Conservation in the Finisterre Project. I hope you enjoy!
Metals were classified in two groups. The first one included those objects with a sound metallic core and a well preserved original surface which were treated by electrolytic reduction. The second group was composed of those that were highly mineralized and too friable to endure the electrolytic treatment. These artifacts were stabilized by the extraction of chlorides through chemical baths. After treatment, the objects were rinsed, inhibited and protected with an acrylic resin.
Conservation of waterlogged wood has two main goals. Firstly, the incorporation of a material that will consolidate and provide mechanical strength to the wood while the water is being removed. Secondly, the extraction of the water in a manner that any shrinkage or distortion will be avoided. The methods used were two: the polyethylene glycol (PEG) method for the wooden objects and the acetone-rosin method for the composite wood-metal objects.
The most important step in the treatment of pottery was the removal of soluble salts that may crystallize within the pore system causing cracks and weakening the artifact. Once the salts were removed, the piece was allowed to dry naturally before cleaning because a wet cleaning would be too aggressive and may erode the surface.
Though the main goal of all conservation treatments is preservation over aesthetic considerations, in some cases the improvement of the appearance of the objects is spectacular. This is especially true in the collection of cutlery recovered from the Great Liverpool, where the surface was extremely well preserved under a layer of corrosion products and sand.
The Finisterre Team.
As I mentioned in a previous post, our main objective this season was to uncover some parts of the wooden hull of the shipwreck which could have been preserved under the thick sand layer that covers and protects Punta Restelos shipwreck. However, as it happens very often, the archaeologist proposes and the site formation processes dispose.
In order to locate the possible wooden remains at Punta Restelos we have been using an extremely useful device: the water-dredge. This is a basic tool in underwater archaeology (together with air-lifts and other machinery) that is used to excavate the seabed and to remove the sediments that cover the archaeological remains. However, our incredibly useful water-dredge presented one extremely annoying issue: the NOISE. Basically, every time we started the small engine of our water-dredge the noise on the RIB was unbelievably loud. It was like having a Harley-Davidson running the whole day on our small boat. In fact, communication was not possible on the surface while the water-dredge was working. That made work a bit more difficult but the job was done anyway.
On the other hand, the situation underwater was a bit better although the diver had to deal with the low temperature of the water. Basically, the two options we were having every morning were not very attractive: going deaf and crazy on the boat or slowly freezing underwater. Anyway, the job had to be done and we really wanted to find the wood remains of the shipwreck.
In order to achieve our objective we decided to excavate two trenches at the site. One was excavated along the archaeological area (N-S) while the second trench was excavated across the same area (E-W). The main problem we faced while we were excavating the trenches was related to the physical characteristics of the sediment: a thick layer of very fine sand.
Excavating this layer was a difficult task since we have to remove a thick layer of fine sand that covers most of the site. This meant to remove a huge amount of sand to get just a glimpse of the archaeological level in order to determine the presence of wood. Basically, the fine sand was constantly falling down from the top to the bottom of the trench and, sometimes, the small water-dredge could not cope with the amount of sand that was constantly falling down. In any case, we were able to uncover a decent surface of the archaeological layer.
Unfortunately, we did not found what we were looking for although we still uncovered very interesting stuff which, as usual, we mapped carefully using the photogrammetric technique. Visibility was not still good but enough. The archaeological feature uncovered was a large metal concretion that seemed to be hidden some interesting artifacts. We found what looks like a large cannon and other small weapons. The location of the cannon is very interesting since is quite close to the area where one of the gun carriage wheels appeared in a past season.
In any case we are still optimistic and we think that some parts of the hull are still preserved under the sand. The only problem is to find it but the solution is easy: keep on excavating using a proper archaeological methodology!
The Finisterre Team