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Wreck Check members commence work on project ‘Who or what sank HMS Sirius at Norfolk Island in 1790?’
The Sirius trapped on the reef, with supplies drifting ashore, 1790, by George Raper, British Museum, London

The Sirius trapped on the reef, with supplies drifting ashore, 1790, by George Raper, British Museum, London

Who or what sank HMS Sirius at Norfolk Island in 1790?

Introduction

During July 2017 Wreck Check members commenced working on a Commonwealth Government Community Heritage and Icons Grant project titled ‘Who or what sank HMS Sirius at Norfolk Island in 1790?’ The loss in 1790 of HMS Sirius, principal consort to Australia’s First Fleet and chief protector for the New South Wales Colony, was arguably the infant colony’s most threatening single incident. So it is worthwhile exploring the reasons for its loss.

Traditional arguments

Eighteenth century observers and modern historians, commenting on the reasons for the loss of HMS Sirius at Norfolk Island after it became embayed in Sydney Bay and failed to tack, have pointed to sea conditions (an onshore, shifting wind and an onshore current), and hinted at some culpability on the part of people at Norfolk Island at the time, namely Sirius’ Captain John Hunter and Norfolk Island’s Lieutenant Governor, Philip Gidley King. In regard to Hunter, historian John Bach has written that:

“…the master of a sailing vessel had to get a job done and usually had to strike a compromise between excessive caution and obvious rashness. To put it more bluntly, danger could always be avoided by staying hove-to at sea or by remaining on one’s moorings, but in both cases the ship would have been rendered useless for the particular project in hand.”

King had hoisted a signal flag at Sydney Bay indicating to Hunter that it was safe for longboats to bring provisions ashore.

An alternative argument

Hunter was court-martialled, as was usual when a Navy ship was lost, and he was acquitted of all blame. So a later comment by King is of interest. Writing to the Comptroller of the Navy Board about the importance of the correct ballasting of ships to stiffen them sufficiently to enable them to steer effectively, sail upwind and avoid going ashore, he went on to comment that, ‘the Sirius was lost from not answering her helm’, that is, from not being able to be steered through a tacking procedure. King was suggesting an unmanageable vessel, pointing the finger not at Hunter, but at some aspect of the ship itself, or its fitout.
Perhaps because King was generally negative about the Sirius, this comment about its deficient steering has not attracted attention. Historians have assumed that the vessel failed to tack simply because of environmental conditions – the wind turned directly onshore at the wrong time. King, however, was effectively saying that the Sirius was cranky, or unstable. William Falconer, in his 1780 Universal Dictionary of the Marine, defined ‘crank’ as ‘the quality of a ship, which for want of a sufficient quantity of ballast or cargo, is rendered incapable of carrying sail without being exposed to the danger of oversetting’. Instability in a square rig sailing ship can make steering difficult.
King later wrote to Sir Joseph Banks about HMS Porpoise, another Navy ship that was to come to grief off the east coast after failing to tack, warning that it was a bad sailer and extremely cranky, not answering its helm. He elaborated in another letter several days later,

“…the Porpoise would neither sail nor steer going large, and … when beating to windward … fell bodily to leeward, while every other vessel was carrying a proper sail for the weather, and getting fast to windward.”

Why might the Sirius have been in want of sufficient ballast, or cranky? The dockyard officers at Deptford knew how much iron ballast in the form of Kentledge (1 cwt rectangular blocks fitted snugly together) was necessary for a ship to maintain correct balance (and steerage) while sailing. Navy ships were assigned ballast plans according to their rate. In 1782 the 511 ton Navy storeship Berwick carried 80 tons of iron ballast and 40 tons of coal, which clearly suited it well during performance trials, the dockyard official noting that, ‘she soon answers her helm and is quick about and makes just little way’.
During the 1786 refit which transformed the Berwick into the 20-gun 6th rate warship HMS Sirius, the hold was cleared and Captain Arthur Phillip, anxious to maximise stowage of provisions for the new colony, replaced just 28½ tons of iron ballast, later supplemented with approximately 75 tons of the less stable, less compact, shingle ballast and coal. The Agent for Transports, Captain George Teer, explained to the Navy Board:

“…the proportion of iron ballast warranted for the Sirius was 80 tons, the quantity supplied her when fitted from hence in 1782, of which they have received but 28½ tons, optional in her Commander, who at the time [it] was taken on board observed if that was not sufficient he would apply for more.”

Two days later Teer had more to say on the subject:

“… she [Sirius] was governed by no proportion, her supply of all kinds of stores being entirely at the will of Captain Phillip and therefore we did not think it necessary to acquaint you with the ballast he thought proper to take short of what she was before supplied with as a common storeship.”

In summary, Captain Arthur Phillip, as the Senior Captain and Governor designate of the proposed British penal colony of New South Wales, through a desire to maximise the supply of provisions for the men and women under his command, ignored the established ballast plan for HMS Sirius knowing full well that Second Captain John Hunter, once in the antipodes, would not have been able to source Kentledge. So the question arises: does the historical record and archaeological evidence support the Sirius having been insufficiently ballasted on 19 March 1790, resulting in the vessel failing to answer its helm? If so, this would reflect poorly on Arthur Phillip’s judgement.

We propose to answer this question archaeologically, through a detailed seabed count of the iron ballast blocks on the Sirius wreck site, followed by assessment of their weight, comparison with the required weight, and consideration by a naval architect of whether such variation of the ballast would affect the vessel’s ability to tack.

In-water methodology required

The ‘Practice of Stowing a Ship’s Ballast’ diagram for a 20-gun 6th rate ship shows the required number (and by calculation the weight) of ballast blocks for a vessel such as the Sirius. During earlier on site survey work Bill Jeffery was able to count a number of blocks by eye, but it is expected that photogrammetry of the site will reveal more. Through acquisition of multiple overlapping photographs by Norfolk Island Maritime Archaeological Association divers, and its computer analysis by Andy Viduka in collaboration with Andrew Hutchison of Curtin University, the mass of the ballast blocks on the seabed wreck site will be assessed. The mass assessment will allow calculation of the number of ballast blocks and their original weight. Comparison can then be made with the Navy’s diagram of the appropriate ballasting. Calculations will also need to take account of changes to the coal and shingle ballast and the number of guns and anchors, and men aboard, at and subsequent to the performance trials.

Naval architect input required

How great a deficiency of ballast would it take for the Sirius to become unmanageable in circumstances such as it faced at Norfolk? Naval architects and experienced square rig sailors have the skills to provide advice on safe stowage and manoeuvrability of ships. The chapter titled ‘The practice of working ships’ in David Steel’s The Elements and Practice of Rigging and Seamanship, (www.hnsa.org/…/the-elements-and-practice-of-rigging-andseamanship) page 283, goes into the issues of centre of gravity etc. Curator Nick Ball of the National Maritime museum in the United Kingdom has offered assistance in virtual modelling of the ship in conjunction with the University of Greenwich.
Graeme Henderson

Ballast arrangement for a 20 gun ship of the 1790s. From David Steel, Steel’s Naval Architecture.

Ballast arrangement for a 20 gun ship of the 1790s. From David Steel, Steel’s Naval Architecture.

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