About Rebecca Dallwitz

ANMM Senior objects conservator

Capturing a lighthouse in 3D

The Cape Bowling Green lighthouse, at the museum in 2017. Image: ANMM.

The Cape Bowling Green lighthouse, at the museum in 2017. Image: ANMM.

Conservators rarely have the opportunity to access made-for-conservation equipment, software, tools or chemicals. We borrow and adapt things intended for other environments. Conservation labs are often populated with dental tools and equipment, surgical scalpels, entomological stainless steel pins, book binder’s presses and felts, as well as a tradesman’s array of socket sets, drills, punches and pliers. We put Tyvek® Homewrap® covers over collection objects as it is breathable and keeps off dust. We transport small objects in prawn crates and often display costume on off the shelf mannequins.

When it came time to document the Cape Bowling Green Lighthouse prior to major conservation work, our conservation team turned to technologies which are often used by insurance companies and real estate agents to photograph buildings and record damage.

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How to build a lighthouse

The timber structure of the lighthouse going up. The photograph was taken from aboard the visiting vessel <em>Cape Grafton</em>, 24 March 1994. Image: Deborah Gillespie.

The timber structure of the lighthouse going up. The photograph was taken from aboard the visiting vessel Cape Grafton, 24 March 1994. Image: Deborah Gillespie.

In 1993, the Australian National Maritime Museum was ready the rebuild the Cape Bowling Green Light.  After some discussion, a site near the wharf was selected.  Reconstruction of the lighthouse started in late 1993.  This visual story shows how the lighthouse was rebuilt piece by piece at Darling Harbour.

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How to move a lighthouse

Cape Bowling Green Lighthouse prior to dismantling 1987. Credit: Mike Lorimer (Ove Arup and Partners).

Cape Bowling Green Lighthouse prior to dismantling, 1987. Credit: Mike Lorimer (Ove Arup and Partners).

How do you move a building from a remote cape in far north Queensland? In 1987 the 113-year old Cape Bowling Green Light was superseded by radar beacon, decommissioned and sold to the Australian National Maritime Museum. Somehow, the museum had to transport a 22-metre structure from Cape Bowling Green to Darling Harbour, Sydney. So, how does a lighthouse travel over 2000km?

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A wandering light: Cape Bowling Green lighthouse

Ever wondered how a lighthouse came to be at the museum? Image: Kate Pentecost / ANMM, 2017.

Ever wondered how a lighthouse came to be at the museum? Image: Kate Pentecost / ANMM, 2017.

At 22 metres tall Cape Bowling Green Lighthouse seems a solid, immovable structure. In fact, it was designed for ready disassembly and has been moved at least three times in its 150-year life.  It has also been continuously modified throughout its history.  The lighthouse at the museum is only partially the lighthouse that was built at Cape Bowling Green in 1873-4. The lighthouse and its changing history challenges ideas about the preservation of immovable cultural heritage. Continue reading

Hidden in plain sight: revealing the Sirius anchor

If you read my previous blog, you might know that we’re currently treating the Sirius anchor while it’s on display inside the Australian National Maritime Museum.

Sometimes, actions taken to protect objects change their appearance.  When the Sirius anchor was prepared for its original conservation treatment in 1986, a thick layer of marine concretion and organic growth acquired during nearly 200 years underwater was removed with hammer, chisel and a descaling gun.  This exposed the corroded metal of the anchor and allowed it to be treated by electrolysis – this process converts corroded iron to black metal and removes salts.  When treatment was completed the Sirius anchor was painted with an anticorrosive coating.  The thick, black, glossy paint flowed into the crevices and channels throughout the anchor, rounding off the anchor’s surface and filling in some of its texture.

A newly recovered anchor in its treatment tank, clothed in marine concretion and organic growth.  This image appears to be the Sirius anchor on display at ANMM.  Image courtesy Jon Carpenter, WAM.

A newly recovered anchor in its treatment tank, clothed in marine concretion and organic growth. This image appears to be of the Sirius anchor on display at ANMM. Image courtesy Jon Carpenter, WAM.

Now that the coating has reached the end of its life and we are removing it, the Sirius anchor is slowly being re-revealed.  The exposed surface has the characteristic ‘eroded wood’ appearance of corroded wrought iron.  We can now see the complex texture of the anchor, with its chains of islands, undulating channels, serrated points and small hollows.  We have also found the holes drilled into the anchor to take the cathode rods used in the electrolysis process.

direction of bars

The construction of the anchor is visible again. The hole drilled for the cathode rod has also been revealed (at the top of the image).

The anchor was created by hammering together a series of iron bars under intense heat.  The direction of channels and ridges in the anchor’s surface show the meeting and fusing of these bars.  The construction of the anchor, disguised for 25 years, is now becoming visible again.

The Sirius anchor has been on display in the museum since 1991.  Despite its monumental size, there is a tendency for visitors to hurry past the anchor to temporary exhibitions and perhaps not really see it.  Yet now, as we work on the anchor, visitors are stopping by for a chat and they have lots of questions about what we’re doing.

Some visitors are surprised to discover that there is such a day-job as conservation.  Indeed, one visitor asked us if we were real!  Perhaps they had never seen anything other than a manikin in a display environment.

Usually – in order not to disrupt the visitor experience – we undertake the maintenance of permanent displays before opening hours, almost secretively. But this means that the public have little opportunity to appreciate what goes into putting and keeping objects on display.

While working on the anchor we’ve met a First Fleet descendent whose ancestor came to Australia on Sirius, chemistry students studying aspects of maritime archaeology, and children fascinated by the tools and muck which are all part of large object conservation. We’re loving meeting visitors while giving the anchor the conservation care it needs.

We’ll be working on the anchor on weekdays until July 5, so be sure to stop by and meet this significant piece of Australian history and the people who look after it.

ANMM staff and volunteers at work on the anchor.
Clockwise from top left: Senior Paper Conservator Caroline Whitley, Shipwright Lee Graham, Senior Textiles Conservator Sue Frost and volunteer Jan Russell painstakingly remove the old coating.

Conservation gets dirty

These are paper conservators.

Senior Paper Conservator Caroline Whitley and Head of Conservation Jonathan London line a fragile watercolour with Japanese repair tissue.

Senior Paper Conservator Caroline Whitley and Head of Conservation Jonathan London line a fragile watercolour with Japanese repair tissue.

This is a textiles conservator.

Two women inspecting muslin dress

Senior Textiles Conservator Sue Frost (right) undertaking a condition assessment of a gown with Jane Donnelly, Property and Facilities Co-ordinator, The National Trust of Australia (NSW)

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A gudgeon’s life – from ocean floor to exhibition

Artefacts from shipwrecks have often travelled far and undergone much before being exhibited. This is true of the gudgeon was selected for display in our upcoming exhibition East of India – Forgotten trade with Australia.  It’s believed to come from the wreck of the Cato, a merchant vessel built in Stockton, Britain in 1799. Cato was carrying a shipment of coal destined for India – possibly Australia’s first coal export. Coal blocks were found at the wreck site, one of which is displayed in the East of India exhibition.

East of India curator and maritime archaeologist Nigel Erskine examines the gudgeon at the wreck site

East of India curator and maritime archaeologist Nigel Erskine examines the gudgeon at the wreck site. Image courtesy Xanthe Rivett.

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Vivienne T

Vivienne T in the conservation lab

The Commerce gallery, one of our oldest galleries at the museum, is currently being dismantled to make way for a new temporary exhibition space. Installed before the museum opened to the public in 1991, all of the objects that were on display are being lovingly taken out of their showcases and moved to collection stores. As part of the process, conservation staff will now check and photograph each object over the coming months. Even museum objects change as they age and we expect that some objects will look a little different from when they were originally put on display.

One of Vivienne T’s tyres dripping yellow fluid. The fluid is probably stabilisers which have migrated out of the rubber tyre.

Vivienne T was among the first objects to be removed from the gallery. Vivienne T is a remote controlled scale model of the 1940s Tasmanian lobster fishing craft of the same name. The model has changed a little since collection. The tiny tyres strung along her side as fenders have begun to deteriorate and have sticky surfaces. This is a characteristic way in which plastics and similar materials change over time. Now that the deterioration process has begun, it can’t be reversed. Unfortunately, the change to the tyres has stained the side of model and is damaging the paint.

After some thought, and discussion with the curator of this object, we’ve decided to cast one of the original tyres and replace them all. There are some problems with this idea. The tyres are original to the model, and we prefer to keep and repair original material where we can. But, the tyres have started to change. We expect that the tyres will only get worse from now on and may continue to damage Vivienne T. In the end, we felt that this was the right approach. The tyres will be cast from a stable material like plaster to make sure this doesn’t happen again in the future. In a couple of weeks, with a little help from our conservators and preparators, Vivienne T will look just like she did when she came to us in 1991.

Vivienne T at acquisition