Robert Seppings and the Birth of Innovation in Shipbuilding
For most of the age of sail shipbuilding was a conservative affair. Naval architects began life as apprentices, learning their craft from shipwrights who used methods of construction unchanged for decades. Innovation, when it came, was slow and evolutionary. But towards the end of the 18th century the pace of change quickened as a new breed of innovators came to dominate the industry. The most significant of these was Robert Seppings.
The son of a cattle dealer, he was born in 1767 in rural Norfolk. Although his parents were relatively poor, their son showed considerable promise as a youngster. At the age of 12, for example, he organized a mail service from Fakenham to Wells carrying the letters on a mule. When his father died in 1781, he was sent to live with his uncle, a retired naval captain. It was through him that Seppings found work at the Royal Dockyard at Plymouth as an apprentice to the master shipwright in 1782. Although he had never previously had any connection with the sea, he took to his new profession with gusto.
The first sign that this new shipwright might look to break with tradition came in 1800, when Seppings devised a method for securing ships in drydock that saved considerable time. The innovation proved so valuable that his idea was quickly adopted throughout the industry, and he was awarded a prize of a thousand pounds by a grateful Admiralty. In 1803, when the post of Master Shipwright at Chatham became vacant, several veteran candidates were bypast to give the job to the 25-year-old Seppings.
Chatham was one of the most important of the Royal Dockyards – Nelson’s flagship Victory was built there, for example, but Seppings was untroubled with such a senior appointment. He took over at a period when Britain was locked in a naval arms race. Across the channel Napoleonic France controlled every shipyard from Holland to Venice, and was rapidly building warships at a pace that even the Royal Navy struggled to match. One of the key issues the new Master Shipwright had to deal with was a shortage of timber. A century of naval warfare had exhausted the supply of local oak trees, but Seppings addressed this issue by innovating in a way that none of his predecessors had done. When he discovered that the Tonnant (80) and Culloden (74) where lying idle for want of suitable oak for new knees (a particularly awkward shaped piece to source) he wrote to the Navy Board asking permission to have the parts made from iron – a startling idea at the time. The repaired Tonnant would go on to fight at Trafalgar, and Seppings would replace more and more of the structure of his wooden ships with iron as his career progressed.
As well as pioneering the use of iron to replace oak, Seppings experimented with other solutions to the timber problem. He reused old but sound wood from broken up ships for non-critical areas of new ships. He also experimented with different types of hardwood, such as oak from North America, Cape Yellow Timber, Mahogany, Teak and African Stinkwood – which despite its unpromising name he found worked very well. To get a warship back into service, almost any expedient would do, including once planking the deck of a frigate diagonally when he lacked the necessary long runs of timber to do it fore and aft.
But Seppings did much more than fire-fighting the timber problem. He also believed that the fundamental design of ships was wrong. The traditional method of ship construction was one of vertical ribs, called frames, attached to a keel and then covered over with horizontal planking, with internal decks providing rigidity. The centre of such hulls was strong, but the ends where much weaker, and as Seppings observed “partial strength [in a ship] produces general weakness.” This issue manifested itself in the problem of ‘hogging.”
Hogging is where the ends of a hull droop relative to the centre. Beneath the water, a hull has the greatest volume in the centre, providing plenty of support for the ship above, but much less support towards the ends, where the hull narrows to form the bow and the swim leading to the rudder at the stern. As warships grew in length over the course of the 18th century, carrying more and heavier armament, the hogging problem became worse.
In 1805 Seppings was supervising work on rebuilding the Kent, a particularly large 74 that suffered badly from hogging, when he came up with a novel solution. He introduced diagonal bracing in place of traditional frames, which transferred load across the hull, solving the problem. He likened his solution to adding the diagonal strut to a five-bar gate. Seppings’s new construction technique was soon being used in the design of all new ships as well, permitting them to be much larger and more heavily armed.
In 1813 Seppings was promoted again, this time to Surveyor of the Navy, a position he was to hold for the next twenty years until he retired. He was effectively in charge of all Royal Navy warship design, and under him change came quickly. 18th century warships were highly vulnerable to being raked by an enemy firing down their length through the bow and especially the stern. These weaknesses were dealt with by the new surveyor, who introduced much stronger round bows and sterns. The round stern proved unpopular with officers, as it robbed them of the spacious cabins they had enjoyed in traditionally designed ships. He also accelerated the introduction of iron in warship design, paving the way for the steam driven ironclads that would sweep away oak built ships altogether.
He died in 1840, having risen from rural obscurity to be the most prominent ship designer of his generation. He was made a Fellow of the Royal Society and in 1819 he was knighted. He managed to combine all this with a happy marriage to Charlotte Milligen with whom he had ten children.