Tag Archives: Maritime Archaeology Practicum

Finding A Shipwreck You Can’t See: Detection and Survey Methods from Hinchinbrook Island

By Kurt Bennett

I have just finished a week-long field practicum in tropical Queensland. The field practicum took place on Hinchinbrook Island between the 7th and 14th of July. Five students (including myself) from Flinders University helped the Heritage Branch of the Department of Environment and Heritage Protection (QLD) locate possible shipwreck sites. Multiple survey methods were employed to locate cultural material buried beneath the sand. This blog will focus on one site that was investigated during the field practicum. It is located on the north end of North Shepherd Bay (Figure 1).

Figure 1: Location of the ‘possible’ shipwreck and our campsite (Google 2013).

Figure 1: Location of the ‘possible’ shipwreck and our campsite (Google 2013).

Queensland Parks Service observed timbers in North Shepherd Bay after Cyclone Yasi, in 2011, removed sand from the beaches on the eastern side of Hinchinbrook Island. The GPS (Global Positioning System) coordinates were taken and passed on to Paddy Waterson, Senior Heritage Officer at the Heritage Branch. The pictures taken by Parks resembled possible ships timbers. On Monday the 8th July and Friday the 12th 2013, the GPS points were visited. The GPS points were located approximately 3.6 kilometres (km) from our campsite (South Macushla) along a walking track. The walking track finished on the southern end of North Ramsey Bay and required a 1.6 km walk along the beach to the approximate area. No cultural remains were visible upon arrival and therefore certain archaeological methods were needed to locate the previously seen cultural material. The following will discuss the methods employed in order to find the cultural material and determine what remains on the beach.

The first step was a mixture of two methods using both a GPS and a metal detector. The aim was to locate the original marks with the GPS and establish a central point for what was originally witnessed. A 20 metre (m) square was placed around the central GPS point, marking an area to be metal detected. The metal detector, Excalibur II, was set to exclude non-ferrous metals. This enabled the metal detector to detect iron concentrations. The metal detection was systematically executed, with the user following an east-west pattern every one metre along the 20 m grid. Every ‘hit’ was marked with a pin flag and measurements taken using the baseline offset method (Figure 2).

Figure 2: Metal detector hits with baseline. Photo facing NE, North Shepherd Bay (Kurt Bennett, 8 July 2013).

Figure 2: Metal detector hits with baseline. Photo facing NE, North Shepherd Bay (Kurt Bennett, 8 July 2013).

Once the designated area had been covered and all the hits were marked, the next step was to probe the points of interest (hits). This was to determine whether solid material was buried beneath the sand. Both metal and wood were detected, with metal being distinguishable from wood due to the vibrations and the sudden jolt felt by the probe, as opposed to the stickiness felt with waterlogged wood. The probing also indicated the depth of cultural material. The wood and metal was located at a depth of approximately 30 centimetres (cm) below the sediment surface. The sand proved to be a challenge to probe as it was wet and compacted due to being located in the intertidal area.

Once the probing indicated there was material below the beach surface, a 1 m square was placed around the GPS point; this also proved to be a concentration of iron from the metal detection survey. The trench was then excavated with shovel and trowel until material was found. Timber was uncovered, which was possibly a ship’s timber with an iron brace and a treenail (Figure 3). Photographs and measurements were taken of the timber. The trench could not be excavated any deeper than 30cm due to water seepage caused by the intertidal zone. Therefore only the top face of the timber and iron brace was seen, with the rest left submerged in watery sand. The trench also uncovered rocks that were thought to be metal when detected by the probe. This posed a challenge when trying to distinguish between metal and rock, as the rock had the same reaction as metal when probed.

This became more evident when the site was revisited on Friday the 8th.  Photographs were taken of the uncovered timber and the trench was backfilled. Our investigation was limited due to the tide and daylight dictating the time we could spend at the beach. The trench could not have been dug if the tide was in and therefore the site had to be visited during low tide. This left the team approximately four hours to investigate the site. Not to mention we had to be back at camp by nightfall for health and safety reasons. Apparently dusk is the time that crocodiles come out to feed, and that is definitely not the way I planned on finishing my field practicum.

Figure 3: One metre square excavated showing ships timber, North Shepherd Bay. Timber being measured by Flinders students (Kurt Bennett, 8 July 2013).

Figure 3: One metre square excavated showing ship’s timber, North Shepherd Bay. Timber being measured by Flinders students (Kurt Bennett, 8 July 2013).

North Shepherd Bay was revisited on Friday the 12th and this time the aim was to establish the full extent of the site. Again the metal detector was employed and this time we extended our square to 20 m north south of Monday’s metal detection area. To our disappointment the hits did not resemble the shape of a ship’s hull, but more a scatter of debris. This was still exciting, as it could still resemble a wrecking event. The only way to find out was to dig and dig we did!

Several holes were dug, with the longest being over four metres in length (Figure 4). This trench was a continuation from the previous ship timbers. Two additional timbers were uncovered and what appeared to be the beach substrate with a rocky base. It proved to be a little frustrating, since we set out to find a shipwreck. The timbers uncovered were measured and detailed drawings were produced, providing an accurate recording of what had been found. The lengths of the two timber were approximately 1.5 m. The rest of the metal detector hits uncovered a mixture of items that may have washed in over time, including a chain block and pulley, and buried car batteries. The metal detection survey was extended a further 250 metres, walking south along the beach, but it had to be cut short due to daylight running out.

Figure 4: Red arrows indicating points of interest dug for material. Photo facing SE, North Shepherd Bay (Kurt Bennett, 12 July 2013).

Figure 4: Red arrows indicating points of interest dug for material. Photo facing SE, North Shepherd Bay (Kurt Bennett, 12 July 2013).

The aim of visiting North Shepherd Bay was to investigate the known GPS marks. The timbers uncovered and seen after the cyclone may be a result of washed up material, possibly from a shipwreck in another location, or they could be the last remaining pieces of a shipwreck. The methods employed were systematically executed to try and determine if a shipwreck lay beneath the sand, however our thorough searching and non-stop digging proved it was a beach littered with cultural material that could span a whole century. The methods mentioned above will provide a basic plan for any archaeologist wishing to investigate buried shipwrecks on a beach.

The Three Hour Trench

Forget any ideas you’ve got about lost cities, exotic travel, and digging up the world. We do not follow maps to buried treasure, and ‘X’ never, ever marks the spot. Seventy percent of all archaeology is done in the library. Research. Reading.

Indiana Jones in Indiana Jones and the Last Crusade

Indiana Jones may not have great credibility within the archaeological world, but he did get one thing right: no matter what you discover out in the field, you will inevitably be required to read, research and question what you find.

This blog post is about the contents of a trench, just one of many that were dug during the July 2013 Flinders University Maritime Archaeology practicum. But the contents of this trench proved difficult to identify and taught me a valuable lesson.

This year’s practicum took place on the beaches of Hinchinbrook Island, one of the largest island national parks in the world, with an area of 39,350 hectares (Thorsborne 1988). It lies almost exactly midway between Cairns and Townsville and is just offshore from the sleepy coastal town of Cardwell. On February 2011, this area lay directly in the path of Cyclone Yasi, the first cyclone since 1918 to hit the coast with the maximum intensity of category five (The Australian 2012).

Cardwell was almost completely flattened and Hinchinbrook Island was badly damaged, with trees pushed over and sand dunes literally washed out to sea. Out of the devastation, however, appeared an archaeologist’s dream – the timbers of an almost complete ship’s hull on the beach of Ramsay Bay on the north-eastern side of the island.

Archaeologists from the Queensland Department of Environment and Heritage Protection (QEHP) inspected the hull in June 2011 and completed a baseline-offset survey of the wreck. Timber samples helped determine that this was the wreck of the Brigantine Belle (Waterson 2012). But there are at least eight recorded wrecks or remnants of shipwrecks along this stretch of the island’s coast (Barrie 2003:115). So what else could be here?

Hinchinbrook Fieldwork Ramsay Bay June 2011

Results of June 2011 survey. Metal artefact debris field located at the bottom left. Wreck site of Belle is located to the north. Photo courtesy of QEHP.

During the 2011 investigations, a concentration of metal artefacts, dubbed the ‘debris field’, was observed south of Belle’s hull. Only basic recording was completed on the visible sections of these artefacts at the time. Part of our task was to attempt to identify the nature and purpose of the artefacts in the area; perhaps they were a part of Belle, perhaps another wreck. Our job was to identify key targets using metal detector surveys, then excavate, record and re-bury  what we found – all within one tidal cycle (Waterson 2013:3). Including travel time to and from site, that gave us approximately three hours.

Since 2011, the sand has started to wash back onto Ramsay Bay’s beach and once again covered Belle’s hull. When we arrived at the GPS marks this year, no part of the debris field was visible anymore either.

Since part of our task was to determine if this site was related in any way to Belle, we needed to confirm the distance between the two sites. So first steps first (if you’ll pardon the pun): one of the QLD archaeologists, Amelia Lacey, and I paced out the distance between the 2011 GPS marks of both sites. We discovered that the distance between the two was 527 paces – or 389 metres in a more useful measurement. So while I now knew  I had a standard pace of 0.75 metres, we still didn’t know if the Belle’s hull and the debris field were related—were they too far apart for wreckage to end up through the forces of nature?

While Amelia and I were pacing between sites, the rest of the crew were conducting the metal detector survey over the debris field and by the time we returned had marked out the best places to set trenches.

And so Amelia and I found ourselves turning the sand in Trench 1 of the Ramsay Bay debris field. High up on the beach, we began to dig. It took us an hour of digging before we hit metal … which spurred us on to keep going.

Amelia Lacey (top) and Jane Mitchell negotiating the space in Trench 1. Photo courtesy Paddy Waterson, 10/07/2013

Amelia Lacey (top) and Jane Mitchell negotiating the space in Trench 1. Photo courtesy Paddy Waterson, 10/07/2013

And going …

Running out of time to get to the bottom ... Photo courtesy Paddy Waterson, 10/07/2013.

Running out of time to get to the bottom … Photo courtesy Paddy Waterson, 10/07/2013.

After having to extend the trench so that it didn’t cave in on us we uncovered this:

Trench 1, Ramsay Bay Hinchinbrook Island. Photo by Jane Mitchell, 10/07/2013.

Trench 1, Ramsay Bay Hinchinbrook Island. Photo by Jane Mitchell, 10/07/2013.

As we had uncovered each piece, speculation continued. What were we looking at … portholes? Logging equipment? Ship fittings? Unfortunately due to time constraints—and safety—we couldn’t extend the trench to find the outer edges of all the artefacts, which means we don’t have the entire picture and we aren’t even sure of the size of that picture.

Many words can be used to describe fieldwork: fun, challenging, interesting, exhilarating, intriguing, even occasionally disheartening and terrifying. Because of the depth of our trench and the time it took to dig, we had approximately half an hour to record, measure, photograph and rebury the artefacts before we had to head back to camp. You get one chance to record an artefact; make too many mistakes and the information may be lost forever.  Get enough information and your research question may be answered or you might discover new information.

By the time we left, my field notebook was a tangled mess of lines and numbers and hurried notes with—fingers crossed—enough information to solve the riddle of the shapes we’d uncovered in the sand.

An archaeologist’s field notebook is a personal thing … I had 20 minutes to measure in the artefacts … the interpretation afterwards took some work! Photo courtesy Jane Mitchell, 10/07/2013.

An archaeologist’s field notebook is a personal thing … I had 20 minutes to measure in the artefacts … the interpretation afterwards took some work! Photo courtesy Jane Mitchell, 10/07/2013.

There were obviously a few different artefacts within the trench, but the two shapes in the centre—the only ones we had managed to uncover completely—intrigued me. An iron square and a circle attached by a shared centre bar. The circle had iron eyelets on either side and both shared a diameter of approximately 28 to 29 cms. They were like collars, with a width of 15 centimetres.

Closeup of both excavated unidentified artefacts, trench 1 Ramsay Bay. Photo by Jane Mitchell, 10/07/2013.

Closeup of both excavated unidentified artefacts, trench 1 Ramsay Bay. Photo by Jane Mitchell, 10/07/2013.

Close-up of unidentified artefact in trench 1, Ramsay Bay. Photo courtesy Jane Mitchell, 10/7/2013

Close-up of unidentified artefact in trench 1, Ramsay Bay. Photo courtesy Jane Mitchell, 10/7/2013

A two-hour journey back to camp provided plenty of opportunity to discuss the day and throw around theories, but we were generally stumped. The other trenches had revealed nothing other than a seemingly random collection of iron artefacts. Trench 1 was the only trench that turned out to contain something that could have a potentially identifiable use. One of the team thinks her grandfather may have an object similar to the square/circle collar artefact on his barn wall, perhaps a tool to help stack logs for transport; a possibility since logging was a common industry in North Queensland in the late 19th, early 20th centuries.

One disadvantage of archaeological detective work on an idyllic tropical island is the lack of access to the Internet and an inability to cart along notes and resource books. If I stood on one leg on a rock outside our camp kitchen and held my breath I might get enough internet to my phone to have a look at my emails or check the weather, but there would be no chance of serious searching of databases or library archives.

Our field library consisted of two books: The Elements of Wood Ship Construction, a reprint of a 1919 edition written by W.H Curtis, a naval architect and engineer, and Minding my Business: The History of Bemerside and the Lower Herbert River District of Queensland Australia, written by local Douglas R Barrie. Since we hadn’t uncovered any timber, the former revealed nothing obvious and there was nothing in the latter to suggest the origin of the trench 1 artefacts.

One of the difficulties with this particular artefact is context. Ramsay Bay is an exposed beach open to the sea. On our 5km walk to site each day, we observed all kinds of flotsam and jetsam: mooring buoys, marker buoys, chest freezer doors, nets and a surprising amount of single thongs (flip-flops or jandles if you prefer). One day we even encountered a set of airplane wheels. There is no obvious ship wreckage near the debris field, no timber, nothing other than a bundle of iron artefacts in a relatively small area of beach.

I had a quick stopover in Townsville on my way back to Melbourne and I went to the local history section of the city library. Still chasing the logging angle, I asked the local history librarian for any information she had, particularly images on the timber industry in North Queensland. The only logging book in their archives was The Trees that Fell: A History and Description of the Timber Industry of North Queensland from 1898 to 1988, but within its pages I found nothing that looked remotely like the artefacts we’d found.

An afternoon at the State Library of Victoria focussing on logging also yielded no results. Using logging, logging in North Queensland and logging equipment in the late 19th century as search terms I found no descriptions or images that correlated with the artefacts we found. Perhaps these artefacts were nothing to do with logging at all?

Archaeology requires an open mind. Someone suggested an affiliation with logging and I had run with it, but I had found no evidence to support that theory. And it served as a valuable reminder that other avenues shouldn’t be ignored. So in conjuction with consulting other maritime archaeologists, I sent the artefact images out to wider fields, including an aeronautical engineer, a plasterer specialising in historical restorations … even my mother.

But it was Captain Paasch all the way from 1890 (courtesy of Heritage Victoria’s Peter Harvey) who helped solved the mystery: our artefacts turned out to be lower mast caps. These caps would help connect a lower mast to the next one. The lower mast would be squared off at the top, and the square section of the mast cap would help stop the mast rotating under the strain of sailing.

Lower Mast Caps Capt Paasch plate 93

Label B: Lower Mast Caps. (Paasch 1890 : Plate 93)

It now looks like we had uncovered a salvor’s pile of iron ship fittings. In three hours we had managed to answer one question, but raised others. Are the mast caps from Belle or from one or more of the other wrecks that are known to have ended up in Ramsay Bay? Is this a salvor’s pile that was used more than once? Could this pile of iron be used to help identify other ships wrecked on the beach?

Archaeology is like that—one question answered invariably opens up others. The search for answers will continue …

References
Barrie, Douglas R. 2003 Minding my Business: The History of Bemerside and the Lower Herbert River District of Queensland Australia. S & D Barrie, Ingham

Curtis, W.H. 1919 The Elements of Wood Ship Construction. 1st ed. McGraw-Hill, New York.

Indiana Jones and the Last Crusade 1989 Motion Picture, Paramount Pictures, United States.

McKenna, Michael & Tony Koch 2012 Cyclone Yasi crosses coast in North’s darkest hour, The Australian, 17 September, accessed 18 July 2013, <http://www.theaustralian.com.au/in-depth/cyclone-yasi/norths-darkest-hour-as-monster-cyclone-yazi-bears-down/story-fn7rj0ye-1225999112395&gt;

Paasch, H. 1890, Illustrated Marine Encyclopedia. Argus Books, England.

Smith, L.W. & North Queensland Logging Association 1991 The Trees that Fell: A History and Description of the Timber Industry of North Queensland from 1898 to 1988, With Reminiscence and Factual Information from the North Queensland Logging Association. L. W Smith, Ravenshoe.

Thorsborne, Margaret & Arthur Thorsborne 1988, Hinchinbrook Island: The Land Time Forgot. Weldons, McMahons Point.

Waterson, Paddy 2012 Shipwreck Heritage: The Belle. Unpublished powerpoint report. QEHP, QLD.

Waterson, Paddy 2013 Hinchinbrook fieldwork practicum 7-15 July: Information for participants. Unpublished handbook. QEHP, QLD.