1. stuart philpott has had a 25-year love affair with the
Valentines tanks of Poole Bay, and he jumped at the chance
to join a scientific survey of these unique wrecks
Photographs by Stuart Philpott
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bemy
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Valentinestank
T
hey say that every wreck tells a story,
but there are very few stories more
intriguing than the‘top secret’Valen-
tines tanks of Poole Bay. When I heard
that Bournemouth University were planning
a scientific survey of these unique World War
Two amphibious tanks, I was eager to find
out more.
Dave Parham, senior lecturer in Maritime
Archaeology, had organised a two-week
underwater survey (ten days diving) spon-
sored by Bournemouth University’s‘fusion’
fund (basically means training and research
combined). Dave said:“I quite fancied diving
on the Valentine tanks. I’m really interested in
the history of modern shipwrecks and what
they can tell us about their past. This is one of
the only places in the world where you can
dive on a tank - it’s very unusual”.
The core survey team consisted of six ma-
rine archaeology students, four of which were
studying for a Master’s degree, one was an
undergraduate, and a part-timer completed
the line-up. Other students turned up on a
day-to-day basis, including one of Dave’s ex-
PhD students, well-known wreck-finder Innes
McCartney. Dave said:“The purpose of the
survey is to find all the tanks and record what
is left, to study how modern wrecks disinte-
grate and carry out some marine archaeology
student training”.
The story began in World War Two, when
Nicholas Straussler, a Hungarian-born
engineer from London, came up with a hair-

2. March 2015 Sport Diver 67www.sportdiver.co.uk
“Thereisplentyofnutrient-richtidalflowsoanythinggoes
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brained scheme to float a 17.5-ton Valentines tank. Using Archimedes’
principle, he designed a rubberised canvas screen that sealed around
the main body. When fully raised, this displaced enough water to float
the armoured fighting vehicle. The addition of a three-bladed propeller
transformed the tank into a cunningly disguised boat. The intention
was to use Straussler’s invention during the D-Day beach landings,
whereby an unassuming boat would suddenly transform into an‘all
guns blazing’tank giving Allied troops the element of surprise against
German defences.
The war office rubber-stamped Straussler’s project‘top secret’, keep-
ing all tests and training behind heavily guarded barbed wire fences.
But tragedy struck during a simulated assault on Studland Beach code-
named Operation Smash 1. At dawn on 4 April 1944, two amphibious
tank squadrons from the 4th/7th Royal Dragoon Guards were launched
from landing crafts several hundred metres offshore. Sea conditions
rapidly deteriorated and waves began to slop over the top of the can-
vas screens. Bilge pumps couldn’t cope with the continuous deluge, so
the commanders, anticipating the inevitable, ordered all crew members
including drivers up on deck (there was an auxiliary steering mecha-
nism outside). The sea eventually broke over the screens, sending the
tanks plummeting to the seabed. Some of the crew got trapped under
the collapsed screens. Six men drowned and six tanks were lost (records
show that a seventh tank went down later).
During the early 1990s, Royal Navy clearance divers blew the turrets
off five of the Valentines tanks. I can only guess that the tanks were
identified as shipping hazards or the live 75mm shells were considered
a danger for recreational divers. The sixth tank got decapitated by a
trawler’s boom, so moving forward to present day there is only one Val-
entines tank left with a turret and gun barrel attached (the gun barrel
was damaged several years ago and is now much shorter).
Dave’s team were granted access to Bovington Tank Museum’s
archive library and exhibit halls, which really helped with their research.
Information gleaned included copies of rare photographs and‘top
secret’blueprints of the amphibious DD (duplex drive) design. Dave
said:“The outcome of operation Smash 1 played an important role on
D-Day”. The museum has a number of surviving Valentines tank variants
(not a DD version) on display so the students got to see a fully intact
tank before trying to piece together the underwater remains. Tom
Cousins, who helped co-ordinate the two-week survey, was fortunate
enough to meet John Pearson, owner of the one and only working
Valentines DD tank in existence. John had even promised that Tom
could drive the tank next time he visited (Tom driving a tank would be
a serious threat to life!)
With some help from English Heritage, Dave managed to get
his hands on an ultrasonic gauge to measure the thickness of the
armoured plating, a bathycorrometer to check the level of active corro-
sion and a hand-held magnetometer to search for metal components.
Other more‘mundane’equipment included tape measures and un-
derwater cameras to complete a photographic survey. Each diver was
also equipped with a slate showing a technical drawing of a Valentines
tank, which would make it easier to identify certain parts underwater.
The whole ten-day survey was carried out under strict HSE guidelines
so everyone wore a harness, spare air supply, followed log in/out
procedures, etc.
The overall plan was to take readings and measurements from
all seven tanks, record the data and then compare the results with
a known exhibit, which in this case would be one of the Bovington
display tanks.

3. 68 Sport Diver March 2015 www.sportdiver.co.uk
“AtthisrateIcalculatedthatthelastremainingtankwill
probablydisintegratewithinthenexttenyears”
But first off they had to find the Valentines tanks. Tom had got hold of
an MCA geophysic 3D map of the seabed and highlighted 40 or more
anomalies that could be possible tank positions. Some of the tanks
were already known dive sites and had marker buoys, which made life
much easier but, from my own previous experience, I knew that the
Boscombe tank would be difficult to find. This had been abandoned
by its crew and left to drift away on the tide. Warships were ordered
to destroy the tank before it ventured too close to the public beaches.
Straussler’s design had to remain secret at all costs.
Surprisingly, the survey team found all seven tanks in just four days.
Dave was also suitably impressed with their performance. He said:“The
tanks are only the size of a Transit van, so it’s difficult to find them with
a sounder”. The exact specs were six metres long and nearly three me-
tres wide, which is an extremely small target to find, even with known
GPS co-ordinates. Dave praised Trevor Small, experienced skipper and
owner of dive charter boat Rocket, for the speedy finds. Trevor runs
regular trips out to the Valentines tanks and other local wreck sites.
Tom had marked up a chart giving each Valentines tank an ID
number, so No.1 tank had the turret and gun barrel still attached (this
is buoyed). A guide rope connects No.1 and No.2 tank, which lies ap-
proximately 200 metres away. The turret and gun barrel of No.2 tank
is upside down in the shingle right next to the main body. No.3, 4, 5
and 6 tanks are all located around the Hook Sands area. No 3 and 4 are
in reasonably good condition apart from being‘turretless’. Dave said:
“They look just like a skip on wheels”. No.7 tank lies off Boscombe Pier,
the turret and barrel are close by. As I suspected, this tank took them a
little longer to find.
Dave said:“We had good weather and a good group”. Underwater
conditions turned out to be far less favourable. Massive tides whipped
up the seabed into a silt storm, which reduced visibility to a mere two
to three metres. It wasn’t easy to‘model’for pictures in these condi-
tions, so my thanks to students Orestes Manousos and Irini Malliaros
for their extreme patience. I watched them take readings with the
ultrasonic gauge and the bathycorrometer. Tom said:“The equipment
is easy to use. It’s just a case of making contact with the structure and
reading off the screen”. On one particular dive we missed the tank site
altogether but, as consolation, found some solid brass clamps that fit-
ted to the top of the rubberised canvas screens.
The group’s initial findings were quite alarming. The armour thick-
ness on the turret was originally 60mm. Readings from the ultrasonic
gauge were consistently registering around 15mm. Dave wasn’t
entirely happy with the figures and thought there might be some slight
inaccuracies, but nonetheless this shows a considerable reduction in
plate thickness. At this rate I calculated that the last remaining tank will
probably disintegrate within the next ten years.
For the past 25 years I have been a regular visitor to all seven Valen-
tines tanks, especially the popular permanently buoyed No.1 and No.2
tanks. The dive sites are located relatively close to shore, so there are no
long arduous boat rides to contend with (charter boats from Swanage
and Poole offer shuttle services), and at a maximum depth of 15m they
are not too taxing.
The Valentines tanks of Poole Bay really are a national underwater
treasure. Dave said:“The tanks should be designated as ancient monu-
ments”. But the sea is an extremely harsh environment for man-made
steel objects, there is no easy way of preserving the tanks or reducing
the rate of decay. Slowly but surely the last remaining tank will lose its
distinctive shape and collapse into nothing more than a pile of scrap
metal. n
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