After more than 30 years exposed to Western Australia’s extreme elements, the Dornier flying boat engine was retrieved from Wrecks off the Broome coast and has since been on display at the Broome Historical Museum, before its recent restoration.
The engine is one of five Dorniers wrecked off the northwest coast and only one of two that have been retrieved, after a daring Japanese air assault during World War II.
The story behind this first assault on Broome is generally unheard of in Australia’s aviation history, despite thrusting Western Australia into the second World War. Broome, in Northern Australia, had become a significant war port because of its close proximity to Java. It also had an airstrip and Roebuck Bay, ideal for use by flying boats.
On the 3rd of March 1942, nine Japanese Mitsubishi Zero fighters made an air bombardment on Broome; 24 aircraft were targeted and destroyed including 15 flying boats that were sitting in the Bay, having stopped to refuel. During the heroic rescues by locals and aircrew, many lives were saved, however, the exact death toll remains unknown. It is believed that at least 89 people died during the raid, including Dutch military personnel and civilians.
The attack also left no usable aircraft in Broome.
The Bay still contains a sunken armada of historic flying boats, which act as a unique archaeological resource, and which are heritage-protected due to them being war graves of the many lives lost. Due to Broome having the 4th highest tidal range, the plane wrecks are only visible 23 times a year.
No other place in the world has such a collection of rare and historically significant flying boats, but for this Dornier engine, years of being buried in the water and mudflats had left the engine in an extremely poor condition. The bomber had suffered considerable erosion and the metal engine was rusted and flaking.
Metals Conservator Vanessa Roth was part of a restoration team specializing in industrial repair and metal restoration. Ms Roth travelled hundreds of kilometres to take part in bringing the engine back to life, but she knew instantly that the conservation team had a huge job on their hands due to the level of deterioration.
“When things go into the water, there’s a period where deterioration happens very quickly,” she said.
“A calcium carbonate crust starts to help things settle … but if you disturb it again, then it starts to deteriorate quite quickly.”
In order to save the engine, they had to work quickly and meticulously, while carefully trying to maintain its authenticity.
“We are trying to preserve the significant qualities of an artefact and its history, we don’t necessarily try and make it look brand new,” she said.
The harsh climate of Broome, plus its remote location, were going to be the main issues, but Ms Roth remained open to trying new processes to treat the engine. The team decided that a sponge blasting method that could remove the corrosion and take out chlorides from the metal would be the best approach.
“There was a big risk that it could all fall apart in a solution, so we looked to what other methods could be used.”
Exposing historical details
Upon completion of the restoration, previously hidden serial numbers buried under layers of rust were revealed.
The serial numbers will be vital for further research into the Broome air raid and the World War II era.
Various grants, including support from the Consulate General in Australia and the Netherlands Embassy, have aided the museum to fund the conservation, which has been on the agenda for a number of years.
“I’m really thrilled that the sponge-blasting has been able to preserve and reveal a lot of detail,” Ms Roth said.
With regular lanolin coatings and protection from the elements, the engine is expected to stay in good condition for another 40 years.