WreckMap Portland 2003
The NAS Training WreckMap
Portland 2003 project took place in and around Portland Harbour,
Dorset between the 19th and 23rd of May 2003. The project evolved
through consultation and collaboration between NAS Training, the
Dorset Coast Forum and the Weymouth Museum, with the aim of
involving recreational scuba divers in the recording of wreck
sites of historic interest in Weymouth and Portland.
Weymouth and Portland were chosen
for the NAS WreckMap project for several reasons, the primary
reasons being the existence of a maritime SMR held and maintained
by Dorset County Council and the proactive marine life recording
undertaken by the Dorset Wildlife Trust. This maritime SMR
database currently consists of 1473 records of wrecks, 91 records
of structures, 47 records of single finds and 137 records of
strandings.
The project aimed to contribute
to this database by providing current information on the
condition of existing entries and by highlighting new sites not
present on the database.
The WreckMap Portland 2003 project aimed to:
- Utilise skills & involve amateurs: Provide an opportunity
for those involved in the NAS Training Programme to put their
newly acquired skills into practice.
- Record sites & add information to SMR/NMR: Provide
information for the Dorset Maritime Sites and Monuments Record
and the National Monuments Record (Maritime).
- Disseminate information: Publish the project results among the
participants, supporting bodies and more generally in the wider
public domain.
- The WreckMap Portland 2003 project was divided into three
broad phases:
- Diver assessment and recording using DWAP recording slates,
cameras and video,
- Geophysical survey of sites using a side scan sonar
system,
- Dissemination of the information acquired through the Sites
and Monuments Record and publication.
- The diver survey system used during the WreckMap project
primarily utilised the Diving with a Purpose diver recording
slate. To complement the recording undertaken using the DWAP
slates, the recording system employed also used still photography
(including digital) and digital video on all the sites
visited.
Participants used Sea & Sea
cameras (donated by Dive Master Insurance) and their own
photographic kit to record the sites. An evening class in
underwater photography took place on the 19th of May 2003 so that
all participants knew how to use the cameras.
NAS staff used the NAS digital
video to record all the sites visited during the project. The
video with its low light capability provided usable footage when
poor visibility (as experienced) might hinder the use of the
still photographic equipment. This digital video record allows
image capturing for the site archive as well as providing a
documentary archive of the project.
The geophysical survey was also
undertaken during the course of the project. The aim of the
geophysical survey was to complement the diver descriptions and
surveys of each wreck and to potentially highlight additional
seabed anomalies and potential targets of archaeological
interest. The survey system used was the CMAX side scan sonar
kindly donated by the Dorchester based company CMAX Sonar
Systems.
The side scan sonar system
produces an image, based not on depth, but on the signal
strength of the returned sound energy, providing a very clear
indication of seabed relief, highlighting anomalies that could
potentially be archaeologically important. The survey vessel
Divetime was mobilised with the side scan sonar system with the
tow fish trailed behind the survey vessel at a predetermined
depth (dependent on the site) to give an acoustic image of the
seabed. Positioning for the system was given by the boat's onboard
Differential GPS. The data was collected and integrated with the
navigation system in the CMAX survey computer.
The information gained during the
course of this project has been disseminated in the following
ways:
- Report distributed to participants, sponsors and
supporters
- Report on the NAS website
- Report in the NAS quarterly Newsletter
- New data added to the Dorset Maritime SMR
- New data added to the National Maritime SMR
Countess of Erne
50 35.18 N; 02 25.18 W
Statistics:
- Dates visited: Monday 19th May 2003; Friday 23rd May 2003
- Total number of dives: 20 man-dives
- Total minutes underwater: 1064 minutes
- Total number of photographs: 33 photographs
- Total minutes of video: 30 minutes
History:
Extracted from Dive Dorset, John & Vicki Hinchcliff,
1999:
"An old paddle steamer, this 830 gross ton 241ft long iron
vessel was used as a coal hulk in Portland Harbour from around
1890 until, in a gale in September, 1935, she broke her moorings.
After drifting across the harbour, she hit the inner wall of the
north-eastern breakwater, was badly holed and sank. She still
lies exactly as she sank, upright with her hull mainly intact,
but, like most of the wrecks here, rather silty."
The wreck of the Countess of Erne
has been adopted under the NAS "Adopt a Wreck" scheme by the
Scubaplus Dive School, Bracknell. As one of the most highly dived
sites on the south coast of England this wreck offers an
excellent opportunity to monitor the effect of divers on wreck
sites as well as presenting a model for the survey and recording
of an upstanding metal ship. Because of these factors the
Countess of Erne was selected as one of the key sites to be
recorded during the project and two members of the project team,
Simon Hanmer and Joe Bailey, came from the Scubaplus Dive School.
The aims of the dives undertaken on the Countess of Erne were
tailored to their wishes and requirements.
A structure on the deck of the
Countess of Erne was highlighted by the side scan sonar image of
the wreck. After diver investigation it became apparent that this
upstanding structure was a very large stone block. The origin of
this block is unknown.
Investigation of the Countess of
Erne revealed recent collapse of the port side hull at the stern.
This collapse had taken place over the few months prior to the
project. It would appear that the corrosion of the iron hull and
the weight of the bollards has led to the buckling of the hull,
rather than the damage being caused by diving or boating activity. The
Diving with a Purpose recording slate was also used to record the
capstan of the Countess of Erne. An iron pulley block was found
lying next to the capstan on top of the sediment. Future dives on
site will record this block in more detail and look for further
examples on the wreck.
HMS Hood
50 34.10 N; 02 25.22 W
Statistics:
- Dates visited: Thursday 22nd May 2003
- Total number of dives: 19 man-dives
- Total minutes underwater: 862 minutes
- Total number of photographs: 74 photographs
- Total minutes of video: 34 minutes
History:
Extracted from Dive Dorset, John & Vicki Hinchcliff, 1999:
"A battleship of the old Sovereign class, she was sunk on 4th
November, 1914, as a blockship across the south ship channel at
the entrance to Portland Harbour. With a length of 380ft and a
beam of 75ft, she almost completely sealed the entrance. She
effectively eliminated any clandestine entry of submarines,
besides preventing torpedoes being fired at ships in the harbour.
At the last moment, after her cocks were opened and she was
flooded, she very suddenly and unexpectedly turned over and so is
on the seabed upside down."
The side scan images of HMS Hood
were hindered by her proximity to the Portland Harbour breakwater
and the presence of restricted waters nearby. Despite this, the
images show a large amount of debris on the inner harbour side of
the wreck. The enlarged side scan image shows quantities of
wreckage on the seabed lying next to the hull of HMS Hood. By
swimming over the propeller shaft and diving the inner harbour
side of the wreck the project divers were able to identify these
as the masts, yards and even a crow's nest.
Earl of Abergavenny
50 36.15 N; 02 24.95 W
Statistics
- Dates visited: Wednesday 22nd May 2003
- Total number of dives: 22 man-dives
- Total minutes underwater: 857 minutes
- Total number of photographs: 11 photographs
- Total minutes of video: 17 minutes
History:
Extracted from Dive Dorset, John & Vicki Hinchcliff, 1999:
"Built in 1796, this fine ship of the English East India Company
was on its way from London to the Far East with 400 passengers
and crew living in cramped conditions below decks. A pilot taken on
board at Weymouth sailed her straight into the Shambles Bank and
badly holed her bottom. She finally sank in 15m of water at 11pm on 5th
February 1805, in Weymouth Bay. Despite the many hours between
stranding and sinking, and the presence of rescue craft, as many
as 350 people perished."
The wreck of the Earl of
Abergavenny has been worked for over 20 years by the Chelmsford
Sub-Aqua Club and is currently one of the NAS "adopted" wrecks.
The team working the site, led by Ed Cumming and team surveyor
David Carter, have already produced a schematic site plan. As such
the purpose of the WreckMap Portland visit was to side scan sonar
the site and collect some video footage, and to give
participants a rare opportunity to dive a 19th century wooden
wreck.
Whilst visiting the wreck site of
the Earl of Abergavenny, the project participants were able to
assist David Carter in the surveying of an iron knee. Divers also
helped to rope together various pieces of structure on the
seabed. These ropes would be used later, by the Earl of
Abergavenny team, to provide navigational assistance during the
2003 diving season on the site. All the survey information and
the side scan sonar data collected during the WreckMap Portland
2003 project was deposited with Ed Cumming and David Carter from
the Earl of Abergavenny team as well as being deposited with the
Dorset Maritime SMR and the NMR in Swindon.
The side scan sonar was also able
to show up relatively small structural elements such as the iron
knee lying on the seabed. This was confirmed by divers visiting
the location.
Himalaya
50 34.70 N; 02 26.50 W
Statistics:
- Dates visited: Tuesday 20th May 2003
- Total number of dives: 6 man-dives
- Total minutes underwater: 256 minutes
- Total number of photographs: 9 photographs
- Total minutes of video: 11 minutes
History:
Extracted from Dive Dorset, John & Vicki Hinchcliff,
1999:
"Built for P&O and christened the Himalaya, she created much
excitement and interest for the attending crowds and nobility at
her launching from the Blackwall yards of C.J. Mare & Company on
25th May, 1853. This was just 8 years after the completion of the
Great Britain, a ship with which the Himalaya shared many common
features. By the time of her completion she was equipped with
masts, sails and rigging, but her main method of propulsion was a
single screw, driven by a massive steam engine.
"With a length of 372ft 2in, a beam of 44ft 4in and a gross
tonnage of 3,438 she was, at the time of her launch, probably the
largest ship ever built. At the outbreak of the Crimean war, the
Government chartered her as a troop ship and her accommodation
was increased from 200 berths to a less luxurious 1850. Later,
the Government purchased her outright and she continued as a very
popular troop ship, but sadly she was eventually converted to a
coaling hulk and re-christened HM Hulk C60. It was during an air
raid on Portland on 5th June, 1940, that her career finally came
to an end. A Junkers Ju 88 dropped a stick of bombs across her,
and despite her originally much vaunted six bulkheads, the "Old
Warhorse" sank by the stern to the seabed on her moorings".
The side scan sonar image of the wreck of the Himalaya
illustrated a large amount of debris lying on the seabed. When
divers visited the site the visibility was quite poor and few
useable photographs were taken.
During the ascent from the Himalaya, project divers reported
seeing a large jellyfish and were able to take a number of
photographs. The jellyfish has been identified as a Rhizostoma
octopus jellyfish. As only a minimum amount of survey information
was produced from the diving activity on the Himayala, NAS
Training will be encouraging the recording of this site by diving
groups visiting Portland Harbour.
Hartlepool
50 36.49 N; 02 25.47 W
Statistics:
- Dates visited: Monday 19th May 2003
- Total number of dives: 9 man-dives
- Total minutes underwater: 381 minutes
- Total number of photographs: 16 photographs
- Total minutes of video: 3 minutes
History:
Extracted from Dive Dorset, John & Vicki Hinchcliff, 1999:
"...remains of the 5,500 ton merchant ship Hartlepool. She was
the victim of a torpedo fired on 5th July, 1940, in a daring
attack by a German E-boat. Although she was partly removed, her
remains were dispersed by heavy explosive charges and now lie in
two areas."
Unknown dredger
50 34.03 N; 02 25.45 W
Statistics:
- Dates visited: Tuesday 20th May 2003
- Total number of dives: 10 man-dives
- Total minutes underwater: 460 minutes
- Total number of photographs: 58 photographs
- Total minutes of video: 28 minutes
The side scan sonar image of the
unknown dredger shows the wreck in two separate sections
approximately 25m apart. It is thought that the top section seen
here is the bow Lying against the breakwater. Dive Dorset
(1999: 109) reports, "approximately 50 yds outside the dredger
is a Lada car". Both the side scan sonar survey and the dives on
the site failed to locate this on the seabed.
M2 submarine
50 34.60 N; 02 33.93 W
Statistics:
- Dates visited: Monday 18th August 2003
- Total number of dives: 10 man-dives
- Total minutes underwater: 354 minutes
- Total number of photographs: 46 photographs
- Total minutes video: 9 minutes
History: Extracted from Dive Dorset, John & Vicki Hinchcliff,
1999:
"The M2 was built by Vickers in 1918 and sank on 26 January, 1932
with the loss of her full crew of 60 officers and men. A massive
but abortive operation to lift her started as soon as she was
located 8 days after her sinking. It was lost until 8 December,
but was finally beaten by the weight of the vessel, strong tides
and bad weather.
"She originally had a 12in gun on her foredeck, but this had
been removed in 1927 when she was adapted to carry a small
folding-wing seaplane manufactured by Parnell, and named the
Parnell Peto. A small hangar was fitted forward of the conning tower.
Still plainly visible is the jib of the winch over the hangar
door which was used to lift the aircraft back onto the launching
ramp after landing on the sea."
The side scan sonar of the M2 was undertaken by Emu
Environmental Ltd of Southampton, under the expertise of marine
geophysicist Angela Proctor. The system was slightly different from
the one previously used although the towfish was still towed
behind the survey boat and results were displayed in real-time on
a digital display. Investigations on the wreck of the M2 focused
on the study of various features highlighted by the submarine
researcher Innes McCartney. These included:
- Any evidence of open hatches
- Any sign of a lifeboat being present (as visible on the
original line drawings)
- Any evidence of the retracting stern gun (as visible on line
drawings)
- Whether the rudder was still in position on the wreck
- Whether the propeller(s) were still present on the
wreck
- Any evidence of salvage gear surrounding the wreck
- NAS added several other features for recording
- Exact measurement of orientation
- Exact measurement of inclination
- Angle of inclination on the diving planes
- Any evidence of oil leaking from the wreckage (as reported in
environmental studies of the wreck)
- Any evidence of damage from diving activity such as graffiti
or shot-lines
The brief diving survey carried out by the team was able to
answer some of the questions posed by both Innes McCartney and
NAS Training.
- No evidence seen of open hatches
- No sign of a lifeboat being present
- The stern gun was visible in its retracted position. It was
only visible to the divers due to the covering plates of the hull
being holed
- The rudder was still in position on the wreck and was clearly
visible on the side scan image
- The propellers are no longer present on the wreck
- Divers saw no evidence of salvage gear surrounding the
wreck
- The wreck is oriented at 330 degrees
- The wreck is inclined at an angle of less than 5 degrees to
starboard. A difference of 0.3m depth was measured on either side
of the conning tower
- Stern hydroplanes inclined upwards at about 35%
- Divers did not see any evidence of oil leaking from the
wreckage
- Divers did not see any evidence of graffiti on the wreckage;
however, the hull plates on the deck did show considerable
evidence of damage. In part this could be due to corrosion.
However, such corrosion was not visible in other parts of the
hull, and as such is probably due in part to shot-lines being
dropped from the surface by diving boats. This damage was also
seen on the port side hydroplane and recorded by the divers on
the Diving with a Purpose recording slate.
Project Outcomes
The project outcomes for WreckMap Portland 2003 include:
- New data to be added to the NMR and the Dorset Maritime
SMR
- Public involvement and development of stewardship, especially
through the Adopt a Wreck initiative
- Successful use of the Diving with a Purpose diver recording
slate
- Increased public awareness (evening talks by Gordon Le Pard
and Peter Tinsley)
- Educational value for project participants
- Public involvement in archaeological recording process
- Understanding of process of marine geophysical
assessment
The Future - WreckMap 2004
NAS Training is committed to
continuing its involvement in Dorset and would like to enter
into discussion with all interested parties concerning any of the
issues raised above and the possibility of running a similar
project in 2004. Future WreckMap Projects would continue to
nurture the interest generated during the 2003 project and
continue the monitoring process on wrecks such as the Countess of
Erne and HMS Hood that are clearly deteriorating. NAS Training
would also hope to dive the additional sites surveyed using the
side scan sonar during WreckMap 2003.
Monitoring - Adopt a Wreck
NAS Training will be encouraging
the future monitoring of the condition of the wrecks in and
around Portland Harbour. Trying to get more of the wrecks
"adopted" through the DWAP Adopt a Wreck initiative will achieve
this requirement.
This initiative is aimed at those groups, clubs or individuals
who regularly dive a site, have developed more than a passing
interest and are keen to get involved in research or site survey.
The scheme will appeal to those wanting to take on a club
project which will have a genuine scientific outcome.
Information resulting from these projects will then be passed,
with the name of the contributor, to the appropriate agency. NAS
Training will be actively trying to source suitable groups or
clubs that might undertake this work.
Acknowledgements:
The NAS would like to thank the following for making the
project possible:
Paul Pike and his boat Divetime, who coped admirably with a
group of divers with more camera kit than David Bailey and who
managed to steer straight survey lines despite strong winds.
Peter Robinson from CMAX Ltd for kindly supplying the sonar
system free of charge, and marine geophysicist Euan McNeill for
expertly running the system.
For the M2 trip the NAS would like to thank Richard Cooke and
Angela Proctor from Emu Environmental Ltd for the use of the side
scan sonar equipment.
Thanks also to Gordon Le Pard from the Dorset Coast Forum for
all his help and contributions; Rodney Alcock at Weymouth Museum;
Janine and Bos at Old Harbour Divers; John Hinchcliff; David
Carter and Ed Cumming from the Earl of Abergavenny team; Innes
McCartney; Peter Tinsley from the Dorset Wildlife Trust. Credit must
also go to Scuba World magazine for their contribution towards
the cost of the side scan sonar equipment and Frank Raines from
Scuba World for his enthusiasm for the project.
Last, but no means least, thanks and a big well done to all the
project participants for their enthusiasm despite the weather -
Euan McNeill, Sarah Hardy, Dave Johnston, Simon Hamner, Judith
Butler, Joe Bailey, Peter Smith, Andrew Wagstaff and Stuart Kenney,
Frank Manigrasso; and for the M2 survey thanks to Zoe Barefoot,
Marc Botterill, Matt Breton, Matt Astill, Simon Stagnell and
Micah Newman.
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