In 1653, a small Cromwellian warship was lost off the west coast of Scotland. Excavated between 1992 and 2003, the wreck of the Swan yielded finds that tell stories of cutting-edge weaponry, mishaps on board, and plunder. Now the full report has been published, Colin Martin reveals the ship’s secrets and explains why wrecks are such a valuable archaeological resource.

Buried beneath the waves around the British Isles are many lost vessels, each with a number of characteristics that make them archaeologically special. First, a shipwreck provides a watertight (forgive the pun) context. Everything in it was associated with a self-contained, functioning entity at the moment of loss and deposition. Sometimes the identity and background of a wreck will be known from historical sources; otherwise dating will depend on typological studies (of coins, pottery, clay pipes, and so on). However obtained, once a date is established for the site as a whole, contextual association will extend that date to everything it contains. The value of this for checking and refining artefact typologies is unparalleled, with the only caution to be observed being the possibility of later contamination, although proper archaeological procedures should negate this risk. A shipwreck has contexts and stratigraphy, just as any site on land.

An important feature of shipwrecks (unless they attract salvage operations) is that, if conditions are right, everything on board has a chance of entering the archaeological record, regardless of utility or value. Terrestrial assemblages rarely include valuable or reusable objects, for these tend to be retained by their owners or appropriated by others. Most land sites thus contain a preponderance of what was abandoned or discarded. This does not, of course, diminish the value of these finds to researchers, but what was once rubbish tends to dominate the archaeological record, while more useful and attractive items are often lacking. We might be forgiven for assuming that the material most valued by terrestrial societies was broken crockery.

Another skew with land sites is their general paucity of organic items, even though they would have dominated the material culture of most past societies. Even today we use an awful lot of it – just look around your own home. Shipwrecks, and other waterlogged sites such as crannogs, often lie in anaerobic environments conducive to organic preservation, and so help to correct this imbalance.

Shipwrecks also provide coherent groups of finds that relate to particular activities and specialist skills. The organisation and functions of the ship itself naturally predominate, but their domestic assemblages mirror in many ways those of their parent cultures ashore. While there are clear differences – for example, in most periods and cultures seafaring has been a largely male activity – this is to some extent balanced by the fact that sailors often perform tasks traditionally associated with women, such as food preparation, domestic chores, and the maintenance of clothing and textiles.

Just how comprehensive and revealing shipwreck assemblages can be is demonstrated by major maritime archaeological discoveries such as the Mary Rose or Vasa, but every historic wreck can contribute to wider archaeological studies. Take the case of the Swan, a small Cromwellian warship lost off the west coast of Scotland in 1653. She had been part of an expedition to nip a Royalist revolt in the bud. While attacking the Maclean stronghold of Duart Castle on a headland overlooking the Sound of Mull, the ships were dispersed by a violent storm. Three were wrecked. The Swan’s remains were discovered in 1979, and the site was later designated a protected historic shipwreck. In 1992, erosion began to expose vulnerable archaeological deposits, and a controlled programme of partial excavation, consolidation, and protection was completed in 2003 (see CA 197). The results have recently been published (see the ‘Further information’ box on p.37).

Plundered pewter Several unexpected and revealing archaeological byways were opened up in the process. Excavation revealed three pewter flagons of a distinctive Scottish type known as ‘tappit hens’. These are liquid measures, and include a Scots pint of 1.7 litres (almost three times the Imperial equivalent), a chopin (½ pint), and a half-mutchkin (⅛ pint). What is remarkable about these pieces is that their secure terminus post quem of 1653 identifies them as the earliest tappit hens known to exist. Pewter is a soft alloy easily damaged in use, so items are frequently recycled, explaining a dearth of early examples. But catastrophic loss, like a shipwreck, freezes them in time.

Luckily documentary sources for early Scottish pewter have survived, together with the touch-plates of the Edinburgh guild on which the marks of newly inducted freemen of the Incorporation of Hammermen were struck. The same marks appear on their subsequent work. The Swan’s pint measure bears the mark of Robert Somervell and his induction date of 1633, the chopin that of John Harvie (inducted 1643), while the half-mutchkin has no identifiable mark. Letters on the lids carry the initials of the owners – in the case of the pint two pairs of letters indicate a husband and wife – while the fact that all three lids bear different initials indicate that they are not parts of a set.

A clue concerning how the flagons came to be on the ship is scratched on the base of the chopin measure. The mark can be identified as a ‘mountain inflamed proper’: the crest of the Mackenzie clan. It symbolises the network of fire beacons in the Highland landscape that linked a maritime clan’s castles to its galley fleets. Prior to the Cromwellian fleet’s arrival at Duart, it had seized two Mackenzie castles, and it is likely that this item was plunder from one of them.

More significantly, these finds have shown pewter experts that 17th-century tappit hens were manufactured using a different technique from that of later periods. Because early examples had not been examined, this was not previously known. By the start of the 18th century, the distinctive tripartite shape was made up of three moulded circular pieces, joined around their horizontal seams. Base, handle, and hinged lid were added at the end. The Swan examples, in contrast, were cast as two semi-circular vertical halves. The base element was an integral part of each casting, and each had a semi-circular cut-out in the centre. When the sections were joined, a hole was left in the base, which was used, together with the narrow mouth, to centre the vessel against the headstock and tailstock of a lathe. This enabled the exterior of the body to be finished by turning, followed by burnishing to give its surface a high polish. Finally, the hole in the base was filled with a plug, the inside of which bore an enlarged version of the pewterer’s mark.

The investigation of one of the ship’s guns has thrown unexpected light on the technicalities of early modern metallurgy. Seven iron guns lay exposed on the site at the time of discovery. They were heavily concreted and evidently much corroded, so a decision was made to leave them in place, and they now serve as way-marks and points of interest on a heritage trail set up for visiting divers. During the excavation of the collapsed stern structure, however, a small iron gun was found buried and in good condition, together with its wooden carriage. Both have been raised and conserved.

When a light covering of concretion had been removed from the gun, it was found to be in pristine condition, with the wipe-marks from the clay casting pattern still crisp on its surface. Cut into the breech are the initials of the founder, identified as John Browne of Horsmonden in Kent. Its weight is marked as 415lbs (188kg), and a modern weighing with the concretion removed showed that the piece had lost only 1.7% of its original weight to corrosion – an extraordinarily low figure for iron that had been immersed in oxygenated seawater for three-and- a-half centuries. Analysis of the metal by Dr Ian Macleod of the Western Australian Museum and Professor Hans Preβlinger of Vienna revealed that it had strength and resistance to corrosion similar to that of modern cast steel. But their studies show that these properties were not achieved by extracting the impurities, as is done today, but by adding just the right balance of neutralising substances to counteract them. How a 17th-century Kentish iron-founder gained the knowledge to do this remains a mystery.

Much is known from documentary sources about John Browne and the excellence of his work. During the early 1620s, a new type of lightweight gun called the drake was introduced to England and, as master-gunfounder to James I and Charles I, Browne was its principal manufacturer. Drakes were much shorter than conventional guns, which saved a good deal of weight, but their lightness mainly depended on their tapered powder chambers. This was not to reduce the gunpowder charge, as often supposed, but tapering the chamber allowed the outer part of the breech – the rear portion of the barrel – to be reduced in diameter while still remaining strong at the point of maximum pressure. Finally, Browne used what he described as ‘refined’ iron for his castings, and charged double for it. It has been suggested that this saved weight because it was a lighter alloy, but we now know that it was not lighter but much stronger, so less was needed. In combination, these factors meant that the weight of drakes was less than half that of other guns of the same calibre. The Swan piece is the only cast-iron drake by Browne known to exist, so analysis of this find has cracked a 350-year-old industrial secret.

One of the most important activities on board was navigation, and this too is represented in the assemblage. A wooden box-like construction was identified as the back part of the ship’s binnacle or compass housing. It is fastened with oak pegs to avoid affecting the compass needles, as iron nails would have done. The binnacle is divided into three compartments, the outer two of which held compasses. Two compasses were needed because the steersman operated the tiller, which controlled the rudder and thus the ship’s direction of travel, by means of a long lever or whipstaff, which he could move from one side of the deck to the other. As such, a compass had to be visible from whichever side he happened to be. The base of one compass was still in its compartment, while a second complete example was found some distance away.

The binnacle’s middle compartment would have contained a candle or lantern to illuminate the compasses by night, and the plank above it revealed a 17th-century mishap that befell an inattentive steersman, who let the flame burn through it. The resulting hole was then repaired with a wooden patch secured – against regulations – with iron nails.

The ship’s surgeon would have possessed a chest of instruments and medicines, such as the complete example found on the Mary Rose. The only medical items recovered from the Swan, however, were tin-glazed drug pots, one of which contains a grease-based ointment with the mark of its last user’s finger still denting its surface. No medical instruments were found, but a nearby wreck, that of the near-contemporary warship Dartmouth, lost in the Sound of Mull in 1690, has produced two pewter syringes, one for the treatment of venereal disease and the other for colonic irrigation.

A deposit of bricks, tiles, coal, and peat at the Swan wreck site revealed the position of the collapsed galley, and amid this material was the large copper cauldron that would have hung over the hearth. Nearby was a rotary grindstone, an unusual find on a ship, because grain would normally have been supplied in processed form, as flour or biscuit. Its presence suggests that fresh food was obtained on shore, a conclusion supported by the animal-bone assemblage. The remains indicated a predominance of the small breeds of cattle and sheep typical of the 17th-century Highlands. Pig bones were absent, because the species was virtually absent in the area at the time. These finds suggest that the Cromwellian invaders lived off resources plundered from local shores, and explain why the campaign was conducted at harvest time.

Among the remains of the collapsed stern cabin a number of high-status items probably belonged to the ship’s captain, Edward Tarleton, who survived the wreck. These include a pocket watch made by Niccolas Higginson of Westminster, the lock-plate of a Scottish snaphaunce pistol, and a sword hilt bound with gold and silver wire.

The same deposit also contained the scattered remains of one of Tarleton’s sailors. About 60% of the main bone-assemblage was recovered, and has been studied by forensic anthropologist Professor Sue Black of Dundee University. The individual who has emerged was probably born in Yorkshire. He had suffered from rickets in childhood and died in his early 20s. Though his legs were bowed and spindly, above the waist he was physically strong, with muscle development indicative of regular, balanced work. That he was a seaman is shown by a disorder in his hip joints, suggesting frequent drops from a height of about two metres. Square-rigger sailors, after working aloft, normally slide down the rigging, dropping the last few feet onto the deck. We named our anonymous informant Seaman Swan, and his remains are now buried in consecrated ground overlooking the wreck site.

Domestic finds take us into the world of Captain Tarleton and his unknown crew member. The wreck has produced a wide range of pottery, clay pipes, turned and staved wooden vessels, pewter, knives, footwear, a seaman’s chest, military equipment, and parts of wooden lanterns. Ration issues aboard ship are indicated by a set of lead balance-pan weights, stamped with the royal cipher and the mark of the Guildhall. In addition there is the ultimate artefact, the ship herself, of which a significant part of the lower hull has survived. Unusually, much of the upper stern has collapsed as a layered deposit – a kind of archaeological lasagne – which includes parts of its interior panelled lining. Pieces of carving from the decorated rear face of the vessel (the transom) have also survived. Complementing these finds are rigging blocks, rope, and parts of the ship’s pumping system.

For all its strengths, nautical archaeology has for too long been regarded as a poor relation of its sister discipline ashore. The media capitalises on the perceived glamour of underwater treasure-hunting, for glittering recoveries still attract public attention. But claims that selling finds is a clever form of ‘self-funded archaeology’ are illusory and few such enterprises strike it rich. Financially successful or not, such activities are invariably destructive when archaeological methods are not employed and ‘worthless’ items such as organics are discarded, since conservation costs give them a negative value. Instead, appropriate methodologies need to be pursued, reports published, and permanent and accessible collections deposited. Archaeology and treasure-hunting are not compatible on land, and neither should they be underwater. In whatever environment archaeology is conducted, identical ethics and principles must apply.

Terrestrial archaeologists and museum professionals sometimes fail to recognise the potential and challenges of the underwater environment, and even on occasion overlook a salvor’s archaeological shortcomings because particular recoveries are of interest in isolation. On the other hand, nautical archaeologists often isolate themselves in narrow particularism, and fail to interact with land colleagues. It is time for more collaboration and seamless integration across this divide. The underwater resource has unarguable potential for archaeology in its widest sense, and its place is surely at the heart of the discipline, not on its periphery.

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