Mermaid and Wreck Reef shipwreck objects

pulley sheath on the seafloor, Mermaid wreck site http://silentworldfoundation.org.au/mermaid.html

Silentworld Foundation• Foundation objectives

One of Silentworld’s research vessels at anchor in the Pacific Islandshttp://silentworldfoundation.org.au/other-expeditions.html

Wreck Reef expedition• Team members

http://silentworldfoundation.org.au/wreck-reef.html

Wreck Reef

http://en.wikipedia.org/wiki/Wreck_Reefs

• Location• 1803 wrecks of Porpoise and Cato

Wreck Reef

Wreck Reef• Expedition objectives

• Four wrecks: Cato, HMS Porpoise, Mahaica, Anne

anchor from the wreck of the Porpoise on the sea floor http://anmm.wordpress.com/category/maritime-archaeology/wreck-reefs-expedition/

expedition team off Porpoise Cayhttp://anmm.wordpress.com/category/maritime-archaeology/wreck-reefs-expedition/

Mermaid• Location • 1826 wreck

of HMCS Mermaid

Surveying the wreck of Mermaidhttp://silentworldfoundation.org.au/mermaid.html

Frankland Islands

Objectshttp://silentworldfoundation.org.au/wreck-reef.html

Handmade bricks joined by mortar

Copper alloydrawer handles

Copper sheathing

Lead shot ball

Canister shot

Bilge pump housing

Block of coal

Glass shards

Desalination baths for copper, glass and ceramic

glass

ceramic

copper

• Copper in 2.5% w/v sodium sesquicarbonate solutions• Ceramics and glass in deionised water only

Coal and lead in long term storage

• Not treated• Documentation and monitoring• Climate controlled storage• Museum quality storage materials

Canister shot• Anti-personnel

ammunition designed to be shot from a cannon

• Complex conservation issues

• Thick marine concretion• Unknown material types• Composite object

Canister shot x-ray• Industrial x-ray• Exterior enclosure and shot visible• Materials not positively identified

Scanned x-ray of whole object showing small spherical shot inside a canister

Detail showing the canister and shot ball protruding through canister wall. Canister has presumably corroded through.

Cutting open• Cut open with a circular saw

• Great majority of questions answered as object becomes visible and directly analysable

XRF (X-ray Fluorescence)• Australian Museum Bruker XRF instrument

• Iron only detected

XRF analysis of a shot ball

Canister shot treatment• Desalination

• 2% w/v sodium sulphite

Conclusion

Conrad Martens Mermaid off Cape Banks December 4 1820, ca. 1840 NLA collection http://nla.gov.au/nla.pic-an2390741