HMS Invincible: excavating a Georgian time capsule

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In its heyday, HMS Invincible was considered one of the finest ships in the Royal Navy – and although it sank off Portsmouth in 1758, its remains represent the best-preserved 18th-century warship known in UK waters. Carly Hilts spoke to Daniel Pascoe, who headed recent excavations of the wreck, and visited an exhibition currently running at The Historic Dockyard Chatham to find out more.

Just as the Titanic’s ‘unsinkable’ nickname proved to be somewhat hubristic, naming a ship ‘Invincible’ might be seen as tempting fate. This latter designation was intended to intimidate, however, as it described a mighty warship that was among the most technically advanced of its day. HMS Invincible began life as L’Invincible, built at Rochefort in 1744, but its career in the French navy was only brief, as the ship was captured by the British fleet at the first Battle of Cape Finisterre just three years later. This was a real prize, as the vessel’s innovative design gave it many technological advantages over British ships: it was swifter under sail thanks to a wider bow and slender stern, while its narrow rudder meant the ship did not have to slow down before turning, and a long deck allowed for it to carry a greater number of heavier guns and, as such, a heavier weight of broadside. Shipwrights eagerly copied the Invincible’s form to create 74-gun vessels that would become the backbone of the Royal Navy: by the time of the Battle of Trafalgar in 1805, 16 of the 27 ships in Nelson’s fleet were ‘seventy-fours’.

Once a star of the Georgian Royal Navy, HMS Invincible sank off Portsmouth in 1758. Today, its wreck is the best-preserved 18th-century warship in UK waters, and recent excavations have revealed vivid insights into what life was like on board. Photo: Michael Pitts,

Returning to the 18th century, in 1758 HMS Invincible was packed with people and provisions, part of a Royal Navy expedition destined for Louisbourg, an important French fort in what today is Nova Scotia. Among the 690 people on board were 440 seamen, 100 marines (a fighting force armed with grenades and flint-lock muskets who were also tasked with maintaining discipline and security on the ship), and 28 servants solely dedicated to the needs of the captain, John Bentley. There were also numerous subordinate officers, from the bosun and the surgeon to the carpenter, purser, and chaplain; their assistants, known as ‘mates’; and 46 soldiers who would help to storm Louisbourg fort on arrival in Canada. Ordnance and fighting supplies, as well as stores to sustain the crew during their long voyage, filled every available space, neatly arranged and carefully labelled.

The Invincible was exceptionally fast: so much so that it used a 14-second sand timer (shown here) to calculate the ship’s speed. Sailors would have thrown a ‘log line’ into the sea, on to which was attached a rope with evenly spaced knots tied in it. They would then count the knots as the rope slid over the side, until the sand in the timer ran out normally they would use a 28-second timer, but because the Invincible was so swift, they needed a 14-second one (otherwise they would have needed a very long rope). IMAGE: Bournemouth University

The journey had barely begun, however, when disaster struck. The fleet was barely four miles from its departure point, Portsmouth Harbour, when HMS Invincible’s anchor became stuck and could not be raised. Worse, when the crew eventually managed to lift the anchor it became wedged under the bow. Meanwhile, the ship was drifting towards a sand bank (Dean Sands), and at the moment the ship needed to tack to avoid going aground, the helm jammed. Unable to steer, the ship drifted into shallow waters and became grounded on Dean Sands. Although the crew was able to refloat the vessel once, strong winds blew it back aground where it stuck fast, never to sail again. After signalling their hopeless situation with distress lights and guns, the crew was rescued and the long guns salvaged, but the Invincible itself could not be saved; over the course of the next four days, it took on more and more water, and was finally swallowed by the Solent. There it would remain, buried in silt and sand, for more than 200 years.

A ‘deadeye’ from the wreck of the Invincible, so-called because its holes (used to guide rigging) were thought to make it look like a skull. IMAGE: Bournemouth University

Rediscovering the wreck

It was not until the 1970s that the wreck was rediscovered, and then only by chance. In 1979, fisherman Arthur Mack snagged his nets on an underwater obstacle that proved to be a series of massive timbers. It was the remains of the Invincible. The ship was still remarkably intact – in fact, the wreck remains the best-preserved 18th-century warship found in UK waters – and in 1980 the site was formally designated under the Protection of Wrecks Act, which had come into effect just seven years earlier. This legal protection could not guard against time and tide, however, and the Invincible remained under threat from strong currents that were gradually pulling away the sands covering its timbers, exposing the vessel to erosion and the attention of nibbling sea creatures. The case for excavating and recording as much as possible, before vital archaeological evidence was lost forever, was clear.

The story of the Invincible’s loss, rediscovery, and excavation is told in an exhibition currently running at The Historic Dockyard Chatham, having transferred from the National Museum of the Royal Navy in Portsmouth. IMAGE: National Museum of the Royal Navy.

The story of the Invincible’s loss, rediscovery, and excavation is told in Diving Deep: HMS Invincible 1744, an exhibition currently running at The Historic Dockyard Chatham (see ‘Further information’ at the end), where many of the Royal Navy’s ‘seventy-fours’ were constructed. Having recently transferred from Portsmouth Historic Dockyard, it features many of the artefacts recovered from the wreck, using them to explore both life on board the warship and the painstaking process of excavating its remains. As the displays attest, the first phase of investigations took place in the 1980s, headed by Commander John Bingeman. This work confirmed the then still-anonymous wreck’s identity and demonstrated the impressive extent of its preservation, documenting large portions of the ship’s port side. Equally impressive was the array of objects left untouched for centuries, from the sailors’ provisions and coiled quantities of rigging and rope, to trays of grenades with their fuses still attached and ready for use, accompanied by the flints used to strike them alight.

Some of the items recovered during recent excavations on the wreck site: large pulley-blocks, a rammer head from one of the Invincible’s 24-pounder guns, and a tampion (a wooden plug that would have fitted into the barrel of a gun). IMAGE: Bournemouth University

In 2010, Dr Dan Pascoe (now of Bournemouth University) took over the licence for the wreck from John, and while surveying the site he could see that far more of its timbers survived in situ than were depicted on plans from the 1980s investigations. This might sound like an exciting development, but it was in fact a cause for concern: the layers of sediment that had previously shielded the archaeological remains had completely shifted so that the wreck, which had once rested in the middle of a bed of sand, now lay right on its northern edge. The timbers of the Invincible’s starboard side, which had not been documented in detail before, were exposed to view, as were numerous artefacts that now scattered the surface. Historic England commissioned further surveys from Dan between 2010 and 2016, and this work made an inarguable case for more detailed investigations. As a result, between 2017 and 2019 Bournemouth University, MAST (Maritime Archaeology Sea Trust), and the National Museum of the Royal Navy teamed up to carry out one of the largest maritime excavations in British waters since that of the Tudor flagship Mary Rose in 1982 (see CA 218 and 272). It was a race against time to document what had been uncovered – and was continuing to emerge – from the bed of the Solent, and to recover as many at-risk artefacts as possible.

Recording the remains

Dan was the site archaeologist for the recent investigations, and while speaking to CA about what the excavations had revealed, he described the extent of the ship’s preservation. About 75-80% of the hull still survives, albeit broken into large chunks. These pieces are still easily identifiable, though, and a key part of the project has been to document the timbers using photogrammetry, which has allowed the team to piece its form back together digitally. (An interactive model of the results is displayed in Diving Deep: HMS Invincible 1744.) On the port side, the Invincible is largely intact from stern to bow, and from the height of the gun deck all the way to the bottom of the ship. The starboard side survives to a similar extent, though broken into several pieces. ‘We also found the bottom of the keel around midships, where all the cannonballs had been stored,’ Dan said. ‘The weight of these had pinned the bottom of the ship in place, and the two sides had then peeled away. So the ship was no longer intact, but it had not been reduced to matchsticks – the fragments were all still coherent.’

This is an extract of an article that appeared in CA 389. Read on in the magazine (click here to subscribe) or on our new website, The Past, which details of all the content of the magazine. At The Past you will be able to read each article in full as well as the content of our other magazines, Current World ArchaeologyMinerva, and Military History Matters.

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