Genre: Information/Explanation

Odyssey Papers 48 An Iron Cannon Salvaged from the Marquise de Tourny , Western English Channel Nico Brinck Ordnance Specialist , Terschelling , Netherlands The wreck of the Marquise de Tourny was discovered in the western English Channel in 2008 by Odyssey Marine Exploration and subjected to a ferrous metal FADE survey in 2009 . The site is 80m deep and 100km southeast of Plymouth . The presence of 25 iron cannon combined with discovery of the ship's name and date embossed onto its bronze bell , La Marquise de Tourny ' 1744 ' , identified the wreck as the remains of an armed privateer built in Bordeaux and lost during the War of the Austrian Succession . The corsair sank around the mid-18th century . An unknown European organisation is believed to have salvaged the cannon from the wreck . It was subsequently found in a coastal scrap yard and the author of this paper notified . The gun is incised with fleur de lys comparable to those present on a swivel gun recovered from the wreck in 2008 and is identified as deriving from the Marquise de Tourny . At 242cm in length and with a bore diameter of 10 . 5cm , the gun is an 8-pounder of French origin . The cannon's salvage reflects the impossibility of supervizing and protecting historical shipwrecks located outside terriorial waters from non-authorized access , and underlines how essential it is to record and sample at risk underwater cultural heritage of international importance . © Odyssey Marine Exploration , 2015 1 . Introduction The author was recently made aware of an iron cannon salvaged from a wreck believed to be the Marquise de Tourny , a French privateer built in 1744 and lost in the late 1740s or early 1750s in the Western English Channel ( Cunningham Dobson , 2011 ) . The gun was made available for recording ( Fig. 1 ) . The cannon can be identified as an 8-pounder on the basis of its 10 . 5cm-diameter bore . It was missing its trunnions and muzzle . Further minor damage was visible . Simple ornamental rings divide the cannon into three parts : breech and first reinforce , second reinforce , and chase ( Fig. 2 ) . On the first reinforce an astragal ring with fillets marks the end of the vent field , and a similar set of rings is positioned on the neck between the muzzle and the chase ( Fig. 3 ) . A notable reduction of thickness was measured at the reinforces . Except two fleurs de lys located at the beginning of the first reinforce and three-quarters of the way along the second reinforce , no further marks were identified ( Figs. 7-8 ) . 2 . Historical Background When France started to develop a navy in the first half of the 17th century , few local foundries were capable of casting a strong iron cannon . The iron district of Perigord produced guns and even exported them , but many failed test firings ( Klein , 1965 : 218 ) . By then the Dutch had already successfully established iron foundries in Sweden , and guns from there soon found their way onto the Amsterdam arms market and onwards to France . By 1674 the first regulations regarding standards for cannon The key preserved dimensions are ( Fig. 2 ) : Breech : 19cm Barrel ( forward of the breech ) : 242cm Th . at the vent field : 37cm Th . at the muzzle astragal : 21 . 5cm Bore Diam . 10.5 cm Fig. 1 . The iron cannon discarded in a salvage yard dump . Photo : Nico Brinck . © Odyssey Marine Exploration , 2015 ; www.shipwreck.net Odyssey Marine Exploration Papers 48 ( 2015 ) Fig. 2 . The iron cannon discarded in a salvage yard dump . Length measurements in cm . Photo : Nico Brinck . appeared in French Royal Docklands management regulations ( Boudriot , 1996 ) . From time to time the regulations changed ( not unlike the English ' Establishments ' ) and new standards were fixed for French sea ordnance . Very little is known about cannon used by the French merchant navy . Foundries probably enjoyed greater independence in gun shape and size compared to orders for the fighting navy . By the mid-18th century , when the Marquise de Tourny was active , the dimensions of a gun for a royal ship , naval or privateer , the so called ' pièces légitimes ' were : circumference at the vent 11 calibres ; forward of the trunnions 9 calibres ; and at the chase astragal 7 calibres ( the diameter of the bore is one calibre ) . The centre of the trunnions had to be positioned at 3 / 7th of the length of the gun ( excluding the breech ) ( Boudriot , 1996 ) . All thickness measurements of the salvaged 8-pounder adhere to these regulations , and the center of the trunnions differs by only a few centimetres from the standard . Further , this piece exhibits two fleurs de lys . A third one was probably originally engraved onto the muzzle swell , but the gun is broken at this point so that about 15cm of the muzzle is missing . The armament of a ship could change over the years . Generally a royal ship would receive new cannon when fitted out after launching . However , during her service damaged and worn cannon would be replaced on an as needed basis , and not always with identical pieces . After a long career the armament could be mixed in appearance , if not in calibre . A comparable ship to the Marquise de Tourny is the Machault , a French frigate lost in 1760 down the River Restigouche in Canada ( Bryce , 1984 ) . Two of her cannon were salvaged , including a 12-pounder produced in France and engraved three times with the royal fleur de lys . The second cannon is a Swedish Finspong gun , most likely bought in Amsterdam . This gun does not feature the fleur de lys , but rather the anchors' symbol of the French navy . The Machault cannon are not comparable to the Marquise de Tourny's 8-pounder . A French 8-pounder is known from Valletta , Malta , however , where it stands in front of the Auberge de Castilia , and exhibits almost the same dimensions and shape as the gun from the English Channel ( Fig. 9 ) . The rings and trunnions are all set in the same place , its trunnions are still © Odyssey Marine Exploration , 2015 ; www.shipwreck.net Odyssey Marine Exploration Papers 48 ( 2015 ) conical and the length is 258 . 5cm , which may also have been the length of the gun in question . Regulations preferred a length of 256cm for an 8-pounder , which is close to the length of the Valletta gun . After 1766 the regulations demanded shorter guns for the navy and trunnions were always straight cylinders . Thus , the English Channel cannon and the Valletta piece both date to the earlier half of the 18th century . The Channel 8-pounder fits very comfortably with the timeframe of the privateering actions of the Marquise de Tourny ( Cunningham Dobson , 2011 : 98-101 ) . 3 . The Marquise de Tourny The wreck of the Marquise de Tourny ( designated as Site 33c ) was discovered by Odyssey Marine Exploration in 2008 , 100km southeast of Plymouth , at a depth of around 80m in the western English Channel ( Cunningham Dobson , 2011 ) . A pre-disturbance survey was conducted , including the recording of surface features and the production of a photomosaic . The presence of a blue glass flaçon bottle and fleur de lys decoration along an iron swivel gun suggested a possible French nationality for the vessel . The discovery of the ship's bronze bell , inscribed with the name La Marquise de Tourny and the date of 1744 , confirmed that Site 33c was a Bordeaux-based privateer . Other than dense concretions surrounding iron ballast and cannon , the wreck is poorly preserved in shallow sediments , compounded by trawler damage . The survey revealed a spread of 25 iron cannon intermixed with 13 large concreted masses ( 0 . 85 x 0 . 25m to 3.5 x 3 . 0m ) , some of which cover areas of 2-10 square meters and appear to consist of approximately 1m-long cylindrical iron concretions . A minimum of 167 linear concretions are visible on the site's surface , although the merging of concretions and unseen stratigraphy severely complicated identification . The total volume of ballast ingots may have been closer to 500-600 pieces . Some red galley brick fragments are present , but no potsherds . No visible wooden ship structure survives , other than minor sections of timbers in shallow pockets of sediment and gravel . The site offered no visible indication as to which part of the wreck signifies the bow or stern . The shipwreck measures approximately 35 x 25m . Taking into account the number of cannon present , the wreck may be interpreted as the remains of a moderately armed 25-gun sailing vessel . Conservation identified a recovered cannon as a halfpounder swivel gun ( L. 85 . 5cm , bore Diam . 4 . 0cm ) . As with the salvaged cannon in question , the swivel gun's first and second reinforces featured a single incised fleur de lys , which were the only markings present ( other than a Fig. 3 . Full-length view of La Marquise de Tourny's salvaged 8-pounder . Photo : Nico Brinck . Fig. 4 . Detail of the cascable and button of the salvaged 8-pounder . Photo : Nico Brinck . Fig. 5 . Detail of the cascable and button of the salvaged 8-pounder . Photo : Nico Brinck . © Odyssey Marine Exploration , 2015 ; www.shipwreck.net Odyssey Marine Exploration Papers 48 ( 2015 ) Fig. 6 . Detail of the broken bore of the salvaged 8-pounder . Photo : Nico Brinck . Fig. 7 . Detail of a fleur de lys on the first reinforce . Photo : Nico Brinck . gunner's ' V ' near the muzzle ) . This form of versatile ordnance was mainly situated on stanchions or on rails at the high ends of a vessel and along the main deck . On warships they were mounted on platforms between the lower mast and topmast . In these positions they could be used effectively to rain fire down on a vessel's main deck . The Marquise de Tourny's 25 iron cannon confirm that it was armed very similarly to its brother ship Le Grand Marquis de Tourny , which carried 24 guns and had an approximate 460-ton burden . The iron ingot ballast defining the site's surface , in addition to an absence of identifiable cargo , suggests that the ship was likely transporting an organic cargo when she foundered , which has now deteriorated . The seizure in 1757 and description of another Bordeaux privateer , Le Grand Marquis de Tourny , reflects the common import of sugar , coffee , indigo and logwood , of which the first two products would certainly not remain preserved within Site 33c's marine environment . The Marquise de Tourny may have been sailing short-haul between Bordeaux and the French Channel ports when she was lost during a storm in the late 1740s or early 1750s . Beyond two outstandingly preserved wrecks undergoing excavation off St. Malo , France ( the 300-ton royal frigate La Dauphine lost in 1704 and 400-ton L ' Aimable Grenot sunk in 1749 ) , and the comprehensive excavation of the French Machault by Parks Canada , Site 33c is the only other privateer of this period to have been examined archaeologically . The date of 1744 on the Marquise de Tourney's bell coincides with the year when France joined the War of the Austrian Succession ( 1739-48 ) . The ship would have actively participated in the protection of trade and the art of privateering . Privateers like the Marquise de Tourny deployed their own resources to attack and seize vessels and the goods of foreign subjects , over which they acquired the rights to the property appropriated . The practice was not random , but was officially sanctioned under the law of the sea . During the war around 2,828 British privateers went to sea and just over 6,800 English , French and Spanish craft were seized by all sides ( Kingsley , 2011 ) . 4 . Recording & Protection Fig. 8 . Detail of a fleur de lys on the second reinforce . Photo : Nico Brinck . The majority of cannon recovered from seabeds in the modern era can be divided into three basic groups : those landed by fishing vessels , found by dredgers , and thirdly removed by salvors , whether professionals or amateurs . By far the greater volume of guns have been brought ashore by fishing vessels as part of the unwanted daily haul that often includes explosives , such as sea mines and airplane bombs from World War II . The number of trawled up cannon runs into the hundreds ( Kingsley , 2012 : 17 ) . © Odyssey Marine Exploration , 2015 ; www.shipwreck.net Odyssey Marine Exploration Papers 48 ( 2015 ) Fig. 9 . An 8-pounder French iron cannon at Valletta , Malta , of the salvaged Marquise de Tourny form . Photo : Nico Brinck . Trawling can be a hazardous job in the European coastal seas . Many fishermen have lost their lives after striking exploding sea mines , torpedos and bombs , which surfaced in their nets . Sometimes the heavy weight snagged in a net is a harmless cannon . These are always landed , unlike some other categories of finds that are usually dumped on wreck sites . A gun in the net can deliver some easy cash for the crew and good money if it is a bronze gun . To avoid paying taxes ( import tax , income tax ) on this extra item of income , the find is typically kept as secret as possible , also because fishermen are afraid their find will be confiscated by heritage authorities . This reality is all very frustrating for the ordnance historian . Sometimes serious detective work is needed to trace a gun once it has entered the black market . Fortunately , there are exceptions when guns are sometimes reported after the trawler lands its catch . In the past dredgers and survey vessels have played a part in gun recovery from the sea . Dredging zones have to be surveyed before the dredger arrives , but the surveyors do not see what lies beneath the seabed . Guns from this group are usually reported to the authorities . Gun finds removed by salvors are also problematic . Several professional wreck salvors exist in the Netherlands , for instance , who do not focus on historical wooden wrecks . Their main goal is more recent cargos , lost anchors , trawl nets and re-floating recently stranded and foundered vessels . Sometimes during their surveys for lost anchors salvors come across wooden wreck remains with cannon , and on occasions they have brought one home ( cf. Kingsley et al. , 2012 : 5-6 for the salvage in 2011 of a 24-pounder bronze gun from the First Rate English Victory , 1744 ) . These have all been recorded by the author . Hobbyists , like sports diver groups , are also famous for discovering many more wrecks and cannon than professional archeologists . Unfortunately , these are not always reported . If bought by collectors , they still end up sooner or later under the eye of the ordnance historian . In the Netherlands a new Heritage law is under development and scheduled to come into force in 2016 . All salvage by professional and hobbyists groups will be prohibited . Finds by fishing vessels and dredgers will need to be reported by law as soon as possible . However , fishermen and dredger captains can not always know what lies in their path and avoid underwater cultural heritage . Anchored ships dragging their anchors in a gale have ripped many wrecks apart and have dispersed artefacts far and wide . Some guns are found several miles from their wreck . A 3000Hp trawler can pick up a cannon in its net without even being aware of the catch . The gun can cut though the net after a few miles and become lost once more . In conclusion , it is impossible to prevent trawlers and dredgers from catching guns . But it is necessary to convince the crews that such finds should be reported to the proper authorities . Bibliography Boudriot , J. , ' French Sea Service Iron Guns ' , The Journal of the Ordnance Society 8 ( 1996 ) , 72-94 . Bryce , D. , Weaponry from the Machault . An 18th-Century French Frigate ( Parks Canada , Ottawa , 1984 ) . Cunningham Dobson , N. , ' La Marquise de Tourny ( Site 33c ) : A Mid-18th Century Armed Privateer of Bordeaux ' . In G. Stemm and S. Kingsley ( eds . ) , Oceans Odyssey 2 . Underwater Heritage Management & DeepSea Shipwrecks in the English Channel & Atlantic Ocean ( Oxford , 2011 ) , 69-108 . Kingsley , S.A. , ' The Art & Archaeology of Privateering : British Fortunes & Failures in 1744 ' . In G. Stemm and S. Kingsley ( eds . ) , Oceans Odyssey 2 . Underwater Heritage Management & Deep-Sea Shipwrecks in the English Channel & Atlantic Ocean ( Oxford , 2011 ) , 109-42 . Kingsley , S.A. , Out of Sight , Out of Mind ? Fishing & Shipwrecked Heritage ( Wreck Watch Int . , London , 2012 ) . Kingsley , S. , Cunningham Dobson , N. and Van de Walle , F. , ' Balchin's Victory ( Site 25C ) : Shipwreck Monitoring & Cannon Impacts , 2008-2012 ' , OME Papers 24 ( Tampa , Florida , 2012 ) , 1-32 . Klein , P.W. , De Trippen in de 17e eeuw ( London , 1965 ) . © Odyssey Marine Exploration , 2015 ; www.shipwreck.net