The Parish Magazine September 2022

feature — 2
The Parish Magazine - September 2022 21
Live war wreckage lurking on the Thames
Estuary and the English Channel seabed
By Claude Masters
'U-boat on the starboard skipper'
cried the hydrographic surveyor
when she spotted the image of a
wreck on the seabed in the English
Channel — the bright colours in the
picture (right) indicate the depth.
She was using a Multi Beam Echo
Sounder (MBES) aboard the survey
ship EGS Ventus.
Surveys such as these could be for
finding cross channel cables, wrecks,
unexploded bombs or any other
debris. Dredging operations and
checking sea and river walls can also
be mapped using MBES.
There are dozens and dozens of
cables crossing the channels and
river estuaries, not only in the UK
but worldwide.
They are carefully mapped but the
purpose of some has been lost in the
annals of time.
Worldwide, there are hundreds of
survey boats, both large and small,
owned by companies, employed by
governments, or agencies, to inspect
the sea bed for a variety of reasons.
WHALES AND DOLPHINS
My 23 year old granddaughter,
Charlotte, who was one of the
surveyors that spotted the U-boat,
has also surveyed the SS Richard
Montgomery in the Thames Estuary
on the EGS Watchful. She has
surveyed the seabed on offshore
wind farms and mapped pipelines
across streams and rivers from Perth
to Cambridge.
MBES uses the same echo
sounding system as whales and
dolphins so they get attracted to
the survey ship to see what’s going
on. While the ship's crew like to see
them, it does mean that time has to
be spent cleaning out all the chatter
from the sea creatures before the
data can be given to the client.
The pictured boat (above) is the
Images (top down): An aerial view of the Thames Estuary, Anna Yordanova, dreamstime.com;
A colour of the seabed showing the depth of U-boat in the English Channel; Charlotte on dry
land; Wind farms near the Thames Estuary, Nicola Pulham, deamstime.com; SS Richard
Montgomery, which sank in the Second World War with its live cargo of ammunitiion,
SS Richard Montgomery, which sailed
from America to London in the
Second World War. A large storm
meant that it could not go up the
River Thames so it anchored in the
estuary. The anchor was dragged
onto a sandbank and the old liberty
ship broke its back and split in two.
Its cargo of ammunition was prefused
and live so it could be loaded
straight onto bombers.
The ammunition was not removed
and the fear is that the masts could
collapse onto the wreck and trigger
an explosion.
The worst case scenario is the
tidal wave created from the explosion
would clear the Thames Barrier and
flood London. Once every 6 months,
a survey boat with an experienced
captain is allowed to survey it to
check for any changes.
When you realised that 70%
of the world's surface is covered
with water — most of it being in
oceans with, as yet, unexplored sea
beds, there is plenty of work for
hydrographic surveyors to do.
One of the things on Charlotte’s
bucket list is to visit all the
continents of the world and somehow
I think she will do so.