Tag Archives: Shipwrecks

Victoria’s Most Wanted

Posted on September 13, 2016 by Cameron Mackay | Comments Off on Victoria’s Most Wanted

By Cameron Mackay, Graduate Diploma in Maritime Archaeology

As stated previously, I am creating a list of Victoria’s top 20 undiscovered shipwrecks. This is the second instalment of my four-part blog series. In the previous instalment I addressed significance and the role it plays within archaeology and cultural heritage.

This time I shall focus on the main aims of the project and how significance values have been used in developing the list. The intention of the list is to direct the limited resources of both Heritage Victoria and interested community groups, such as the Maritime Archaeology Association of Victoria ( MAAV), to research the sites that have potential to contribute most to the understanding of Victoria’s maritime heritage.

The MAAV is an active group of divers, historians and archaeologists who research, survey and promote maritime history and archaeology. It is hoped that producing a list of the State’s “Most Wanted” wrecks will provide a focus for community engagement with Victoria’s most significant shipwrecks.

Since my previous post I have modified my methodology. Instead of including the requirement that all sites in the list meet at least one significance criterion, I have increased the number of criteria that need to be met to a minimum of six. This has enabled me to quickly reduce the total number of sites being examined from 450 to 60 of the most potentially significant sites. This approach has also allowed me to continue to work within the project’s tight time frame.

From this first, fairly coarse, ranking system I have attempted to develop a more nuanced ranking within each defined significance criterion. The intention of the ranking is to filter the remaining 60 sites in the most objective way. My method has been to identify a number of subcategories under each of the main significance headings and assign each a value of between one and five, based on defined definitions addressing each value, thus providing a possible maximum score of 105 overall from the seven significance categories. The final score is multiplied by a factor of 0.9524 to reduce the score to a percentage (value out of 100). When it comes to examining the 60 sites this value of 100 will assist in providing an overall ranking and a degree of separation between wrecks to create a list of the top 20.

It is important to note that, while my method attempts to provide an objective measure of significance by assigning values to subcategories within each significance criterion, the value assigned to each will still ultimately depend on the person assessing the information available for each wreck.

It’s also important to note that, for a list of the top 20 most wanted wrecks, significance will not be the only factor that needs to be considered. Other factors will also need to be taken into account to generate the final “Most Wanted” list. Some of these are:

  • Mystery;
  • Environment; and
  • External Interest.

Mystery is a factor that should be considered, as there will be more public interest in a ship that may have been carrying gold or that mysteriously disappeared, or that we know little about. The environment is another factor: a vessel that is recorded as being buried under large amounts of sediments or existing in a high energy environment will be more difficult to record than one that sits in a low energy environment. Finally, external interest from other parties should be considered in case research is already being focused on certain wrecks, or an industry has formed in relation to the shipwreck that may increase its importance or the interest that is generated around it. An example is the Curlip shipwreck. The Curlip has had a cruise industry built in memory of the ship, in addition to a replica vessel, Curlip II, due to the importance it had in the local area.

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The Paddle Steamer Curlip II at sunset on the Snowy River. http://www.abc.net.au/local/videos/2008/11/28/2431977.htm accessed 8/9/16

If the site was discovered it could possibly generate interest and media, while also providing support for the Curlip II; this means that the importance of the site could be increased.

http://www.paddlesteamercurlip.com.au/

http://home.vicnet.net.au/~maav/

http://www.abc.net.au/local/videos/2008/11/28/2431977.htm

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Establishing significant shipwrecks in Victoria

Posted on August 21, 2016 by Cameron Mackay | 1 comment

By Cameron Mackay, Graduate Diploma in Maritime Archaeology

This is the first of four blogs to be written in conjunction with my directed studies research topic taken with Heritage Victoria.

The main aim of the research is to create a list of the top 20 undiscovered shipwrecks within Victoria by using significance criteria to prioritise sites within the Victorian Heritage Database (VHD).  The sites prioritised will be those that can yield the most public interest, contribute to Australia’s cultural/local area history and establish possibilities for further understanding of shipbuilding and experimental building techniques.

The question also arises as to what wreck remains will still exist at the sites and what these remains could reveal, in addition to what cargo may have survived.  These questions are to be addressed later in the research, however, and will be an underlying factor throughout the research.

As the research is focused on the idea of significance it is important to understand what that actually means to begin with.

Significance

“the quality of being significant or having a meaning.”

Macquarie Dictionary. 2016. [Online]

Significance in the context of archaeology is difficult to define with absolute certainty, and is subject to change. This is due to the changing information, opinions and requirements individuals may have at any time, which changes the meaning of significance.  As such, significance may be defined as a fluid, ever-changing idea that is based on changing individual views, beliefs, opinions, needs and objectives. It is important to note that significance must be constantly reviewed, revisited and checked.

Significance plays an important role in archaeology, particularly in assessing cultural heritage, in terms of the creation of criteria to assess sites and establish values in different areas. With its fluctuating meanings, however,  significance criteria to assess sites and establish values must be reviewed constantly to ensure that all aims and objectives are being met. Such review also ensures that the significance stays relevant to the research being conducted.

In assessing significance, my project is influenced by the works of:

  • NSW Environment and Heritage: Evaluate the significance of shipwrecks (2012)
  • Victoria State Government Department of Environment, Land, Water and Planning: Criteria for assessing cultural heritage significance (2015)
  • MacLeod, Harvey: Management of Historic Shipwrecks Through a Combination of Significance and Conservation Assessments (2014)
  • Russel, Winkworth: Significance 2.0, A guide to Assessing the Significance of Collections
  • Marquis- Kyle, Walker: The Illustrated Burra Charter. Good Practice for Heritage Places.

These sources use significance criteria in order to prioritise or rank sites to establish significance. This methodology will form the foundation of my research and assist in forming a path for the research to travel.

These assessments all use a similar process, beginning with researching the history of sites for information. This information is then assessed against a defined set of criteria, and expressed as a statement of significance.

For my project, instead of writing a statement of significance, I will use the defined set of criteria to rank sites. This will allow me to establish a list of the top 20, while removing as much subjectivity as possible through a grading system.

A major issue will be combing through the VHD, and correctly being able to research and place sites against each criterion, while reducing subjectivity. This is so that no site is overlooked and all steps in a site’s ranking are clear and logical.

Criteria are fundamentally the same across all significance assessments. I have been able to form a set of basic criteria to begin with, which will be reviewed and refined at a later date. My criteria list is:

  1. Historic
  2. Technical
  3. Social
  4. Archaeological
  5. Scientific
  6. Interpretative
  7. Rarity
  8. Representativeness

As a note, for a site to be deemed significant it isn’t required to meet all criteria, but only needs to meet a minimum of one.

It is this basic list which the HVD will be placed against, to begin forming a significance list. This criteria will be revised and refined at a later date in order to create a ranking system and create a top 20 shipwrecks list for Victoria.

References

NSW Environment and Heritage 2012 Evaluate the Significance of Shipwrecks. Retrieved 10 August 2016 from

Victoria State Government Department of Environment, Land, Water and Planning 2015 Criteria for Assessing Cultural Heritage Significance. Retrieved 10 August 2016 from

MacLeod, I. and P. Harvey 2014 Management of historic shipwrecks through a combination of significance and conservation assessments. Conservation and Management of Archaeological Sites 16(3):245-267.

Russell, R and K. Winkworth 2009 Significance 2.0. A Guide to Assessing the Significance of Collections. Adelaide: Collections Council of Australia.

Marquis-Kyle, P. and M. Walker 2004 The Illustrated Burra Charter. Good Practice for Heritage Places. Melbourne: Australia ICOMOS.

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Three shipwrecks for the register!: DEWNR Southeast Coast Shipwreck Survey, SA

Posted on December 4, 2014 by | Comments Off on Three shipwrecks for the register!: DEWNR Southeast Coast Shipwreck Survey, SA

Date: 27 November–­4 December 2014

Staff/Volunteers: Amer Khan (DEWNR); Simon Carter (DEWNR); Guy Williams (DEWNR); Anthony Virag (DEWNR); Dr Brad Duncan (NSW Office of Environment and Heritage); Kurt Bennett (Flinders University Volunteer); Daniel Petraccaro (Flinders University Volunteer) and David Hanna (DEWNR).

Amer Khan, SA state maritime heritage officer presenting the project to the Carpenter Rocks community. Courtesy of Anthony Virag.

Figure 1. Amer Khan, SA state maritime heritage officer presenting the project to the Carpenter Rocks community. Courtesy of Anthony Virag.

On Monday 1 December, the Carpenter Rocks community hall hosted Amer Khan who gave a talk about the Southeast Shipwreck Survey Project (Figure 1). A number of the local community turned out for the presentation and later shared their knowledge about the area. This provided Amer with new leads, which will hopefully warrant further investigations along the southeast coast. Brad Duncan also gave a presentation on the William Salthouse archaeology project in Victoria. This demonstrated to the community what maritime archaeologists actually do and how unlawful salvage damages everyone’s cultural heritage. When shown pictures of destruction caused by relic hunters, many shook their heads in disbelief. Both presentations were well received by the attendees.

The research team revisited Pisces Star on Tuesday 2 December. Kurt prepared himself for snorkeling out to the shipwreck to assess the condition of the vessel. Due to the currents surrounding the vessel, the snorkeler was tethered to a divers assistant onshore (Figures 2 and 3). Using an offset method from a shore based datum, the onshore team recorded three points marking the stern, midships and bow section. Pisces Star, although shipwrecked in 1997, will be registered on the South Australian shipwreck database and information made accessible for future research.

Next, the team surveyed an area northwest of Pisces Star, where a local abalone diver reported ship timbers. A swim line search consisting of five snorkelers, spreading 25m, covered an area of 150m to search for the timbers (Figures 4 and 5). No one located the reported timbers, but snorkelers observed five iron poles measuring 1m in length. Whilst the poles are cultural, they could not be linked to a shipwreck in the area. Carl and Gary von Stanke, local shipwreck enthusiasts, joined the team for the snorkel and shared their knowledge and history of the local shipwrecks.

Kurt Bennett, Carl von Stanke and Daniel Petraccaro recording Erie. Courtesy of Brad Duncan.

Figure 6. Kurt Bennett, Carl von Stanke and Daniel Petraccaro recording Erie. Courtesy of Brad Duncan.

Erie, the last vessel recorded on this expedition, is a 1940 clinker built transport vessel located at the north end of Lake Bonny in Canunda National Park. The survey team recorded the port (left) side of Erie measuring 5.25m in length. Unfortunately, the vessel was damaged by recent vandal activity where the port side had been pushed over and the keel snapped. Daniel, Kurt and Carl recorded the stem and planking using the baseline offset method (Figure 6).  In the short video below, Amer Khan talks about the construction and features of the vessel (*note—audio is quiet, it is recommended to turn up your volume).

 

On Wednesday 3 December, the survey team followed a lead of a possible shipwreck located in Cape Douglas. The site consisted of two timber posts, 4.25m apart. Daniel and Anthony excavated a 1m by 1m square trench around one of the posts to see if it was connected to other covered timbers (Figures 7 and 8). No other timbers were uncovered and concluded the posts were likely part of a slipway, jetty or fencing.

The project finished on Thursday 4 December, with the team driving back to Adelaide. In all, the project was a success with three vessels surveyed and will now be added to the shipwreck database. Other leads from the local community means, DEWNR will be visiting the southeast in the near future. Thank you to all the staff, volunteers and local community who have made the project go swimmingly. The whole week has been both educational and a joy—Carpenter “Rocks!”

by Kurt Bennett and Daniel Petraccaro

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An Anchor and Pisces Star: DEWNR Southeast Coast Shipwreck Survey, SA

Posted on December 2, 2014 by | Comments Off on An Anchor and Pisces Star: DEWNR Southeast Coast Shipwreck Survey, SA
google earth

Survey Area. Google Earth. Accessed 02/12/14.

Date: 27 November–­4 December 2014

Staff/Volunteers: Amer Khan (DEWNR); Simon Carter (DEWNR); Guy Williams (DEWNR); Anthony Virag (DEWNR); Dr Brad Duncan (NSW Office of Environment and Heritage); Kurt Bennett (Flinders University Volunteer); Daniel Petraccaro (Flinders University Volunteer) and David Hanna (DEWNR).

This is our second blog on the archaeological study of newly identified shipwrecks at Carpenter Rocks in South Australia’s southeast. If you missed out on previous blog on the Hawthorn shipwreck; click here for the link.

Our next site of interest is a reported historic anchor located in Gerloff Bay at Carpenter Rocks. Abalone diver, Bryon Deak reported an anchor and general location to Amer Khan, the state maritime heritage officer. We launched Rapid, DEWNR’s research vessel at Buck’s Bay and anchored near the reported site. Amer and Brad geared up in dive gear on the boat and lead by Byron, they searched for the anchor. There was sadly no anchor identified from the survey. Increasing wind and ocean swells ceased the days dive activity all the team returned safely to Buck’s Bay.

Anthony guiding Brad and Amer who are diving near the possible anchor location. Photo courtesy of Daniel Petraccaro.

DCIM100GOPRO

Brad and Amer geared up for diving. Photo courtesy of Daniel Petraccaro.

 

 

 

 

 

 

Due to the more favourable weather conditions in the afternoon, Anthony, Kurt and Daniel later snorkelled the area. A survey search was undertaken but still no anchor. At the end of the day, the team decided that there was a high possibility the anchor was buried and a metal detector and air probe survey of the area was necessary.

DCIM100GOPRO

Eagleray swimming in gerloff bay. Photo courtesy of Daniel Petraccaro.

Due to good weather condition, the team decided to revisit gerloff bay. Daniel and Anthony snorkelled to the site location and placed a buoy while Amer and Kurt dived the potential targets. Amer and Kurt used a metal detector along multiple survey lines, but there was no sign of the anchor.

Our next plan was to record the shipwreck of the yacht Pisces Star, located at Cape Banks. The wreck is located 30 metres offshore in a strong tidal zone. We were able to take photos of the vessel, a GPS position and compass bearings. We would have liked to take measurements of the wreck but it was not possible due to the strong swell and the danger of a diver being caught in the strong currents.

anthony2

Pisces Star near Cape Banks. Photo courtesy of Anthony Virag.

anthony3
Recording the Pisces Star. Photo Courtesy of Anthony Virag.
anthoy

Looking out to the Pisces Star. Photo courtesy of Anthony Virag.

a thhony 4

Cape Banks lighthouse and Pisces Star to the right. Photo Courtesy of Anthony Virag.

Over the next couple of days, we will be recording the Pisces Star, revisiting gerloff bay, and hopefully looking for a wreck at Lake Bonnie.
Stay in tune for more updates.

Kurt Bennett and Daniel Petraccaro

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Discovering the already discovered – It’s OK to still be excited!

Posted on November 19, 2014 by | 1 comment

The problem with some maritime sites is that they are only intermittently visible, and relocating them once they are recovered can require the use of specialised equipment such as a magnetometer; especially if the area is physically changing and you lack precise coordinates. Relocating an elusive wreck often requires as much work as finding one that has never been sighted – but it’s rediscovery can be met with underwhelming responses of ‘so what –someone had already found it!’

As part of magnetometer trials being conducted by the Department of Environment and Heritage Protection (Queensland) we thought it would be beneficial to examine two similar wrecks off the Gold Coast to determine how comparative signatures could be used to locate obscured wrecks. The first wreck is that of the Scottish Prince, an iron barque of 850 tonnes that ran aground in1887 and is now a popular dive site. The second wreck, the Cambus Wallace, is an iron barque of 1650 tons that also ran aground, but is now quite collapsed and usually covered in sand. The two are often referred to as the whiskey wrecks, as they were both carrying large consignments of bottled whiskey which were heavily salvaged by helpful locals keen to clear the beach of debris.
EHP maritime archaeologists and rangers from the Department of National Parks Recreation Sport and Racing (NPRSR) went out under overcast but calm conditions and commenced the survey over the known location of the Scottish Prince wreck. The north south transects took in a wide area around the wreck to ensure we could effectively assess the detection range. The side scan imagery and signal return during the survey were as expected, with a very strong concentrated magnetometer signal that was detectible up to 180 metres away from the main section of the wreck (see images 1 and 2).

Image 1: A screen shot of the side scan image of the Scottish Prince.

Image 1: A screen shot of the side scan image of the Scottish Prince.

Image 2 : The concentrated magnetometer signal for the wreck of the Scottish Prince (the central red spike).

Image 2 : The concentrated magnetometer signal for the wreck of the Scottish Prince (the central red spike).

Despite the Cambus Wallace being a larger and slightly later ship, its position closer to the shore and within the prevailing swell has meant that it has suffered considerably more damage and is now broken up. The wreck was relocated in the 1970s and artefacts removed from it; there have also been regular reports from people who claim to have historically fished it and people have regularly fished on it, however its exact position has remained elusive because it is only intermittently exposed and official position references are based on triangulations from land marks that no longer exist. It is also located near the surf zone and Jumpinpin bar, meaning it can only be safely surveyed and dived during westerly winds or in very calm conditions – which occur only periodically.

Image 3: The Cambus Wallace - courtesy John Oxley Library

Image 3: The Cambus Wallace – courtesy John Oxley Library

Image 4 : The wreck of the Cambus Wallace just offshore - (Queenslander 14 September 1938 Page 6).

Image 4 : The wreck of the Cambus Wallace just offshore – (Queenslander 14 September 1938 Page 6).

After completing the Scottish Prince geophysical survey, there was sufficient time to conduct a speculative survey for the Cambus Wallace. Interim transects were developed, but the very shallow nature of the environment meant that the skipper was forced to follow the submerged sand bank to avoid risk to the vessel and the mag.

Image 5: The magnetometer signal obtained during the survey for the Cambus Wallace.

Image 5: The magnetometer signal obtained during the survey for the Cambus Wallace.

A strong concentrated signal was located, although the return pattern was not as defined as the Scottish Prince (see Image 5). When the coordinates for the possible Cambus Wallace were cross referenced with historic aerial imagery, a clear darkened shape was intermittently visible approximately 200m from the magnetometer signal. The shape of the object was consistent with the dimensions and reported alignment of the wreck (see Image 6).

Image 6: The darkened shape (marked by the red box) later identified from aerial imagery very near the magnetometer signal.

Image 6: The darkened shape (marked by the red box) later identified from aerial imagery very near the magnetometer signal.

Although yet to be confirmed with a dive inspection, this is a very promising lead that corresponds with historic records and public information.
Although the magnetometer reading is strong and relatively confined, the strength of the signal is not as great as for the smaller Scottish Prince. If the signal does represent the Cambus Wallace, the slightly weaker signal could be indicating that the wreck is closer to shore where the survey vessel could not safely travel; this is potentially consistent with the aforementioned darker shape being the wreck. There is also the potential for the Cambus Wallace site to have a larger debris field, given the dynamic nature of the site environment and the more collapsed nature of the vessel’s upper deck. Certainly there is still work to be done, but if we confirm the signal is the Cambus Wallace, it will be an exciting ‘rediscovery’.

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Tagged Cambus Wallace, debris fields, Department of Environment and Heritage Protection, Department of National Parks Recreation Sport and Racing, Gold Coast, , Scottish Prince, , Side-scan sonar

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Nice Day for a Fish

The problem with perfect conditions is that everyone has the same idea – let’s get out there! Of course the popular idea of fishing was not the same as ours—i.e. towing a magnetometer fish as part of the Department of Environment and Heritage’s magnetometer trials. The initial focus of the trials was to perfect the hardware and software ‘set-up’ and investigate the detection range and signature profiles for different known wreck types. The four wrecks selected for initial testing were:
1. Tiwi Pearl: a modern fishing trawler sunk as an artificial reef.
2. S.S. Dover: a former ferry converted to a machine gun platform
3. The wheel house of the Captain Nielsen, a suction dredge that capsized in 1964.
4. Grace Darling: a wooden schooner that ran aground in 1894.

Figure 1: Map of Moreton Bay showing the location of the four wrecks used for initial magnetometer testing.

Figure 1: Map of Moreton Bay showing the location of the four wrecks used for initial magnetometer testing.

It took a little while to get the magnetometer and computer configuration working the way we wanted, but we eventually set out only an hour later than expected on a glorious, sunny, calm day. Upon arrival at the starting point of our search grid for the S.S. Dover it was immediately obvious where the wreck was located, as there were three recreational fishing vessels anchored in the middle of the grid. We commenced the survey and as we moved closer to the group, they became increasingly curious about what we were doing. By the time we came in close proximity they were actively enquiring why a Marine Parks vessel was trawling back-and-forth around them. When advised of our intention they freely offered to provide the marks for the wreck if we would immediately leave. Interestingly, the aluminium hulled fishing vessels caused no significant magnetic interference. Fortunately there were no hook-ups or problems on our part, but the final nail in their fishing efforts came with a large pod of dolphins, which also forced us to slow down and recover the tow-fish. Seems like everyone was taking advantage of the great conditions.

Figure 2: A large pod of dolphins passing the vessel during the magnetometer survey.

Figure 2: A large pod of dolphins passing the vessel during the magnetometer survey.

The search for the wheel-house of the Captain Neilsen was based on marks taken during a recreational dive inspection. The site was meant to be located within the centre of the grid to test detection range. However, when we finished the grid we had only a marginal reading in the top N/E corner of the grid. We immediately extended the search in that area and found a strong signature that was confirmed via side-scan sonar to be the wheel house.

Figure 3: The side scan image (left) and vessel track (right) showing the location of Captain Neilsen’s wheelhouse.

Figure 3: The side scan image (left) and vessel track (right) showing the location of Captain Neilsen’s wheelhouse.

The Grace Darling site proved quite problematic due to its shallow depth and proximity to shore. Some of the planned transects were in too shallow water and the alignment of some transects had to be adjusted to suit the topography of the seabed.

Figure 4: A print out of magnetometer readings for the Grace Darling. Note the gaps between positive returns (in red) indicating the transects were too far apart to detect the shallow and highly degraded timber wreck.

Figure 4: A print out of magnetometer readings for the Grace Darling. Note the gaps between positive returns (in red) indicating the transects were too far apart to detect the shallow and highly degraded timber wreck.

The last wreck, the Tiwi Pearl, was again immediately obvious, as there were nearly a dozen recreational fishing vessels in the immediate vicinity. Similar to the S.S. Dover, the fishing fraternity kept a close eye on proceedings as we endeavoured to run transects around them. Again, we found the recreational vessels caused minimal instrument interference. Importantly, we also found the magnetometer worked more effectively when side-on, or adjacent to the wreck, than immediately above it.
The key outcome of the initial testing was greater understanding of the detection capacities of the system and how to configure the surveys. While it was no surprise that the detection range was directly proportional to the depth of target and its ferrous concentration, it was surprising that, for the timber wreck of the Grace Darling, transects needed to be considerably reduced, as there were gaps in the positive signal. While this enabled the results to be pieced together to get an overall picture, it was reliant upon our understanding of the nature of the site and indicated that buried wooden wrecks would require tighter transects to achieve complete coverage.

During post-processing it also became apparent that the way we had configured our searches in the software prevented us from separating out certain finds during post-processing. This meant we needed to repeat some of the searches, which was serendipitous, as the revised search grid for the Captain Nielsen led to the discovery of more large pieces of wreckage nearby. The new information about transect width was also important as it forced us to revise our strategy for the planned search of the Venus. For now, though, the next step is to test the mag on a large historic iron barque and conduct a preliminary search for another of the same configuration lost nearby.

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Posted on September 12, 2014 by in Student Posts

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Moreton Bay Magnetometer Survey – Making it Work

By Paddy Waterson

It’s always exciting, and a bit nerve racking, when you get a new piece of ‘kit’.  Will it be easy to put together? Will it work as well as you hoped?  Will it enable you to achieve the results you have promised?  You have probably seen the same piece of equipment at work and know the basics, but the onus is on you now and there are always tricks to be learnt.

In 2013, the Queensland Department of Environment and Heritage Protection invested in a new Geometrics G882 Marine Magnetometer to assist with the Queensland Historic Shipwreck Survey (QHSS). The QHSS is a five year initiative to update official records on the state’s estimated 1400 historic shipwrecks. The size of the state, and the number of historic shipwrecks, means that the fieldwork component of the survey is aimed at locating, identifying and documenting wrecks in key strategic areas, such as Moreton Bay. The initial phases of fieldwork in the QHSS used an existing side scan sonar system and had been quite successful in locating a number of wrecks. However, it soon became apparent that we need something more. The dynamic nature of the Queensland coast made locating many timber wrecks problematic, largely because they are constructed from materials that are extremely vulnerable to deterioration in the marine environment and so tend to have a lower physical profile. This is compounded by Queensland’s offshore environment that is a mixture of dense corals, thick muds and highly mobile sand, all of which can significantly inhibit the effectiveness of visual and side scan sonar searches for low profile historic shipwrecks. A business case for a magnetometer was subsequently developed and the G882 was purchased using funds from the Commonwealth Historic Shipwrecks Program—now I just have to make it work!

A project was developed to configure and test the magnetometer in local conditions to ensure we achieved the best potential outcomes when it was deployed across the state. This project has two phases:

  1. The initial testing of the magnetometer on five known shipwrecks to determine its operational limits and develop a signature profile guide for different wreck types.
  2. Conducting preliminary research into two previously un-located wrecks in the Moreton Bay Region.

The initial testing phase will use five known wrecks within the greater Moreton region. These wrecks were chosen for their comparative signature profile testing, as they are a good representative sample of the different wreck types commonly encountered along the Queensland coast. The test wrecks range in type from a small wooden schooner and a large iron hulled barque, through to steel hulled trawler. By comparing the different magnetic signatures of the wrecks, and their relative detection ranges, we will be able to refine future survey methods and better interpret results when searching for previously un-located historic shipwrecks.

Table 1. Details of the five wrecks used to test the magnetometer, build a signature profile and refine search methods. These wrecks were chosen due to their variation in size, physical profile and construction materials.

Table 1. Details of the five wrecks used to test the magnetometer, build a signature profile and refine search methods. These wrecks were chosen due to their variation in size, physical profile and construction materials.

The initial configuration and preliminary tests were conducted in November 2013. The hardware configuration for the magnetometer was relatively simple, as it came correctly calibrated for the region. Some minor assembly was required, but this was quickly achieved with the support of staff from Marine Sciences and the Queensland Parks and Wildlife Service.

The Geometrics G882 Marine Magnetometer

The Geometrics G882 Marine Magnetometer

The magnetometer being deployed from the Queensland Marine Parks vessel Caretta.  Assisting are Ranger Rohan Couch (left) and Technical Officer James Fels (right).

The magnetometer being deployed from the Queensland Marine Parks vessel Caretta.  Assisting are Ranger Rohan Couch (left) and Technical Officer James Fels (right).

The initial software configuration proved more challenging, as the magnetometer software was configured to integrate the GPS data via a ‘pin-port’ rather than the more common USB connection—this was resolved through the acquisition of an additional ‘pin-port’ aerial output cable.  The use of a specialised laptop that could cope with the movement of the vessel was also essential—many laptops simply lock up the hard drive when vibration is detected.

The laptop, data junction box and GPS configured and ready for deployment.

The laptop, data junction box and GPS configured and ready for deployment.

With the initial set-up and preliminary systems testing complete the surveys of the known wrecks could commence—and a new range of challenges could begin. More on that in my next blog.

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Posted on May 31, 2014 by in Student Posts

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