Ashmore Reef Expedition 2015 – Part Four

Overcast weather on Ashmore Reef

Looks like we have a change in the weather. Photo courtesy Xanthe Rivett, Silentworld Foundation.

Although the Bureau of Meteorology had indicated that we were in for a long spell of great diving conditions — with blue skies and calm seas — the team woke up this morning to grey overcast skies and a stiff breeze from the north-west resulting in a considerable surf building up on the northern edge of the reef. After assessing the situation and finding conditions onsite a little bumpy but workable, the first groups of divers re-commenced work.

The two major tasks for today consisted of completing the assessment of the various artefact clusters found on the site and the commencement of an overall site plan which would hopefully allow us to build up a more thorough picture of the wreck. Importantly, it would also allow us to identify it from our list of vessels known to have been wrecked in the vicinity of Ashmore Reef.

Peter Illidge recording the bore of one of the iron carronades

Peter Illidge recording the bore of one of the iron carronades. Photo courtesy Xanthe Rivett, Silentworld Foundation.

Yesterday, divers identified the two cannons found on the site as being a type of cannon known as a carronade. Named after the Carron Iron Company the ‘carronade’ was a short, stubby cannon developed in the mid-1770s that quickly gained a reputation for reliability, ease of loading and, at short range, incredible muzzle velocity earning them the nickname of ‘smashers’.

After a more detailed examination the carronades on the Ashmore Reef wreck were recorded as having a reinforced loop under the second reinforce (joint), rather than having typical ‘trunnions’ — cylindrical protrusions which act as pivots — mounted on the side. The loop allowed the carronades to be mounted on a slide rather than on a gun carriage and made the weapon more portable and easier to use.

Schematic drawing of late model carronade c. 1795

Schematic drawing of late model carronade c. 1795. Source: arc.id.au

The carronades on the site also had very pronounced foresites and back gunsites for improved accuracy along with iron loops cast into the upper most portion of the back or ‘breech’ of the cannon. This is known as a ‘Bloomfield Pattern’ breech, which was first used in the early 1820s.

With the major features recorded in detail, the rest of the day was spent setting up a series of baselines running out at set compass points along the seabed from the two sets of anchors. These baselines were then used by the divers to run a series of transits out from the baselines recording site features as they went.

Using this method the dive teams reported back that they had located several iron and lead hawse pipes (cylindrical tubes mounted in the bulkwarks of the ship through which the anchor cable runs out from chain locker to the anchors), lead scuppers (a lead tube mounted at deck level that drains the deck of any seawater that comes on board), an iron winch axel and numerous short lengths of stud-link anchor chain.

A lead hawse pipe complete with iron anchor cable (chain)

A lead hawse pipe complete with iron anchor cable (chain) – hawse pipes can be useful indicators of the size of a ship. With this hawse pipe indicating a vessel in the region of 300 – 400 tons. Photo courtesy Xanthe Rivett, Silentworld Foundation.

An examination of the hawse pipes and their relative position to the anchors seems to indicate that both pipes had been torn out from the bulkwarks of the ship during the wrecking process. The isolated sections of stud-link anchor chain — once plotted onto the overall site plan — revealed that anchor cables had been run out from the two larger anchors and across the reef top for 50 metres or so before ending in a jumble of iron knees and crutches.

This concentration of structural material, along with numerous copper-alloy fastenings, sheathing tacks and sheathing fragments, seems to indicate that the crew attempted to run out the anchors during the wrecking event — possible in an attempt to stabilise the vessel or prevent it drifting off the reef and sinking in the deeper water only twenty of so metres away from where the ship finally broke up.

Find out more in part five of the Ashmore Reef Expedition series.

Kieran Hosty
Manager – Maritime Archaeology Program

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About Kieran Hosty

I started diving in Western Australia in 1976 and after a few years of mucking around on shipwrecks joined the Maritime Archaeological Association of Western Australia in order to try and make sense of what I saw on the seabed. My love of diving and maritime history made me pursue a graduate degree in history and anthropology from the Western Australian Institute of Technology followed a few years later by a post graduate diploma in maritime archaeology from Curtin University also in Western Australia.

After 18 months as an archaeological field volunteer I took up a position with the Maritime Archaeology Unit at the Victoria Archaeological Survey. I was the Commonwealth Historic Shipwrecks Officer in Victoria for six years before coming to the Australian National Maritime Museum in 1994 to take up the position of Curator of Maritime Archaeology and Ship Technology. At the Museum I was responsible for the Museum’s maritime archaeology program as well as curating the Museum’s collection relating to convicts, 19th century migrants and ship technology. My expertise in convict related material was further enhanced, when I took up a temporary position as Curator / Manager of Hyde Park Barracks Museum for eighteen months in 2004 followed by a further 18 month contract at the Barracks where I curated an exhibition on the history and archaeology of convict hulks and another on the World Heritage listing of Australian convict sites.

In 2012 my role at the Museum shifted focus when I became the Manager – Maritime Archaeology Program – reflecting an increased emphasis on the importance of the maritime archaeology program at the Museum.

I have worked on many maritime archaeological projects both in Australia and overseas including the survey and excavation of the Sydney Cove (1797), HMS Pandora (1791) and HMCS Mermaid (1829), the Coral Sea Shipwrecks Project (sponsored by the SiILENTWORLD FOUNDATION and the ARC) and the hunt for Cook’s Endeavour in the USA.

I’m the author of the book Dunbar 1857: Disaster on our doorstep, published by the Museum along with two books on Australian convicts and 19th century migrants published by McMillan.

4 thoughts on “Ashmore Reef Expedition 2015 – Part Four

  1. Kieran, the pedant in me forces me to bring to your attention that the plural of “cannon” is just that no “s”. A colleague of mine happened to find Eastern Fields in the early seventies by grounding there when passaging from PNG to Aust. Fortunately the patrol boat survived! We were entirely reliant on astro navigation in those days & often in the tropics, partic in the wet season. one couldn’t take any sextant sights so we were entirely reliant on dead reckoning.

    • Dear CMDR Storrs, well spotted and duly noted. I will try and correct the spelling this afternoon. Interesting to hear about the patrol boat grounding on Eastern Fields – I have always been amazed at how difficult it is to spot huge reef systems on calm / overcast days. Did your colleague notice any shipwrecks during his stay on the reef?

      • He was lucky Kieran & was able to get off quickly & continue the passage. The cardinal rule when we were operating in reef waters was to wait until the sun was moving towards its zenith so we wouldn’t operate outside the 1000- 1400 bracket & always wore polaroid sunnies. You operated in reef waters in overcast conditions at your peril.

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