Cattewater Wreck Plymouth UK

[VOC]

Artical from local press "Western Morning News"

SHIPWRECK EXPLORED WITHOUT GETTING WET

11:00 - 11 April 2006

Clues about a shipwreck believed to date from the 16th century are being uncovered using new methods which involve no diving or excavation. Sound waves are to be used to gather information about the Cattewater Wreck, which was originally discovered opposite the entrance to Sutton Harbour, in Plymouth, during dredging in 1973. Since partial excavation in the 1970s the wreck has mostly been left undisturbed in the mud.

Experts cannot excavate the wreck because it has been protected by the Government and excavation would cause damage to the remains.

The boat was the first of more than 50 wrecks in the UK to be protected by the Government, including the famous Mary Rose, which lies off Portsmouth.

The Cattewater is of international importance as it is one of a small number of 16th-century wrecks in the world which remain unexcavated. The wooden wreck is believed to be of an unidentified armed merchantman from the 16th century, which sank in the main medieval anchorage of Plymouth. The ship was a three-masted, skeleton-built vessel of between 200 and 300 tonnes.

Pottery on board indicates links with Holland and France as well as parts of England.

Project leader Martin Read believes that this modern approach to find out more information about the vessel is the best.

He said: "All excavation is destruction. The wreck is currently well preserved in the silt a metre below the sea bed.

"Using these techniques means that we don't have to touch the site at all and it remains preserved.

"It is something of rarity and importance and must be looked after."

The three new pieces of equipment which have been used come from France, Germany and Plymouth.

Unfortunately the results from the French machine only showed that there was a mechanical fault, but results from the other two pieces of equipment are hoped to uncover more information about the hidden wreck.

The Sub-bottom Profiler from East Germany sends sound waves a metre into the sea bed and sends back information which shows the layer of sea bed including the wreck. The Sidescan sonar from Plymouth uses sound waves which reflect off of the top of the sea bed. The Magnetometre from France, which was experiencing problems, detects changes in the earth's magnetism and would pick up metal work from the ship.The equipment has been described by experts as "top of the range" and archaeologists travelled from around the country to watch it in action. The information needs to be processed further before any results can be found.

But Mr Read said "The data we have got is interesting, it's all quite exciting."

Once processed the information will be used to "re-imagine" the wreck, producing a plan of the site and 3D images of the remains of the vessel.

The information will be also used to help with the management and maintenance of the site, to prevent the wreck from eroding and make sure it is not disturbed by boats or future plans for pontoons.

 

Amazon Forum Fav 👍

Cry Of The Eagle: History And Legends Of The Cherokee Indians And Their Buried Treasure - Grab it through Amazon!

[99*]

Sounds like they need to test the equpiment more, is one of the guys involved maybe a Mr. David Bouman? Just curious. If the equipment works well then it will pave some roads, good luck, nice post and welcome to the forum.99*

 

[mariner]

Can somebody tell me what depth a sub-bottom profiler can penetrate? It doesn't strike me that the one metre quoted in this article would be enough to provide a good enough image of a wreck.

There is a site here on the Oregon coast where I think there is a 16th century wreck buried in a tidal mud flat. The hard pan is about twelve foot down, and I do not know how much of the wreck might remain, but I would be interested to know if there is a technique for determining what it looks like under that mud, which might have a high salt content. I tried White's deep penetrating metal detector, but it just started giving off a signal every time I stepped onto the mud-flat (at negative tides) and I could not get rid of what I thought was a discrimination problem. I am afraid that I do not have access to a magnetometer, and in any case, I really would like to find some way of determining what is down there in the way of a partly preserved hull, as well as metal. A family wholived close to the wreck and tried probing it a couple of years ago reckions that it is about sixty foot long, and they claim to have cored out a sample of the wood, which they say was identified as ironwood. Unfortunately, they say they cannot now find the sample. In the early part of the last century, this family kept snagging their fishing nets on this wreck, which is near the mouth of the Salmon River, just north of Lincoln City. One day, theyu say they pulled up a spar of wood with brass or bronze bolts through it, but again this piece cannot be found. In the 1930s, the same family uncovered three skeletons buried under the root system of an old spruce tree , about 200 feet from the wreck. The spruce tree was cut down and from its rings, it was about 350 years old. At least one of the skeletons was non-Native, from its very large stature. Many of the bones had been broken prior to death. The bones were taken away by a Professor from what became Oregon State University, but there is no trace of them nor of the report that he supposedly wrote, but I do have photographs of this professor at the site, holding one of the skulls and standing among the burial site. The course of the river has changed since then, which is why the wreck is belkow an easily-accessible tidal mud flat that is uncovered at very low or negative tides.

The site is in an area that has been declared as a nature reserve, so the chances of getting permission to do any excavation are almost non-existent, but it would be nice if there was some way of constructing a reasonably accurate image through remote sensing techniques. My understanding is that ground penetrating radar will not go down ten feet, and that in any case waterlogged wood becomes hard to distinguish from the surrounding mud.

The bones must be older than the spruce tee so pre-date the end of the 16th century. If the wreck and the bones are connected, the ship would date from this era. If the wood was ironwood, then it was built in Central America or the East Indies. I believe it may be the small bark that Drake captured near the Island of Cano, off Costa Rica, and which had belonged to a person called Rodrigues Tello. We know from the testimony of Drake's cousin John that Drake left this ship behind when he left New Albion.

If so, it would be historically very important.

Any advice and information would be appreciated.

Mariner

 

[99*]

Mariner,

I have used several Sub B`s the better one being KNUDSEN, you can contact Judith who is very knowledgeable. I cannot let the cat out the bag so wont divulge where I met her, however I always find myself on the Bridge of Cruise ships and the first thing I do is look for their printout, although very compact and on such a small scale its very hard to determine anything you can through practice see if there is something buried under the mud. If this site was not so monitored I would post some amazing things, with a different resolution you can definitely see a wreck under sand I have plenty I could show you. It shows a shadow under the line which usually is effected by the echo it records. email and I will send you a photo of what to look for, but to answer your question, Ive seen anchors and ribs clearly depicted and other times the shadow is poor and only indication is the area under the sand which for practical reasons could be construed as anything, unless you dig the hit! Its 50/50 for beginners, a company that offers pre-dredge or post dredge surveys will be able to tell you more, they are amazing in harbours...good luck 99*

 

[Cablava]

Mariner

Google Niel Driscoll of Woods Hole he has been deep with subbottom profiling.

Similar shallow water subbottom profilers have recently yielded detailed profiles with penetration to 45 meters (e.g. Driscoll, 1999).


I have used them commercially in the oil field looking for pipelines some success down to about 3 meters but if we had a jet barge present then we would just swing the jet sled at 90 degrees across the track then send a diver down to check the trench for the pipe, Crude but often more succesful. The oil guys like succesfull.

Mike

 

[mariner]

Cablava and 99*,

Thanks for the info. I will do more research. I am amazed that they can penetrate so deep. I am wondering is s-b profilers can be used in very shallow water, or even on the top of an exposed mud flat. I think I will contact the guy at Woods Hole.

Mariner