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The Ministry of Defence is taking an interest in a protective suit that has
been specially developed to protect technicians preserving an enormous
prehistoric logboat. The suit will enable technicians at Hull’s
archaeological museum to withstand temperatures of up to 60°C and
100 per cent humidity – conditions that would scald exposed human skin
within two seconds.

Life Support Engineering, based in Storrington, Sussex, specialises in
developing protective suits for hostile environments. It developed the suit
from scratch, bringing together knowledge about the problems facing divers,
pilots and workers in the nuclear industry. Sources close to the project say
that modified versions of the suits could be useful to the MoD because in
warm climates they would be more manoeuvrable than the conventional NBC
clothing – designed to exclude nuclear fallout, and biological and chemical
agents.

The technicians at Hull will use the suits over the next seven years to
monitor progress as the boat is continuously sprayed with a mixture of water
and a small amount of a water-soluble wax, polyethylene glycol, which slowly
replaces the water in the boat’s timbers. The temperature in the Boatlab –
the laboratory where the boat is housed – is presently about 37°C,
and the humidity 100 per cent, making work difficult and tiring. But in
future the temperature will have to be raised – perhaps up to 60°C –
to make the wax solution as fluid as possible and improve its spraying and
penetration. Spraying is done remotely, but maintenance and the need for
the occasional sampling of timber to monitor progress mean the technicians
periodically need to enter the Boatlab.

The Hasholme boat is the biggest surviving prehistoric logboat discovered
in Britain, at some 12.5 metres long. It is about 2300 years old, and was
discovered in 1984 on waterlogged land near Holme to the west of Hull.

The boat was used as a heavy barge, and sank while carrying a cargo of
wooden planks and joints of beef along the sheltered tidal channels inland
from the River Humber. It lay preserved in thick clay until its discovery.
The timber survived well because of the waterlogging, but if left to dry
naturally would split and disintegrate. Because the cellular structure of
the wood has degraded, it is being gradually impregnated with wax which will
penetrate and fill individual cells, and fill the spaces between them.

The only known similar conditions to those in the Boatlab occur in some
South African goldmines, where the temperature can reach 40°C at 100
per cent humidity. Miners work for very short periods wearing boots, shorts
and a waistcoat with icepacks. Life Support Engineering’s suit comprises a
light undersuit with pockets for icepacks. The oversuit is a dry diving suit
of rubber foam sandwiched between two layers of nylon. The helmet has a
large visor and the rubber gloves, lined with acrylic, provide enough
sensitivity for the tasks involved. Cool air is fed by a compressor into the
suit through a long tube which the technicians can plug in at several
outlets in the laboratory. In addition, they wear a safety reserve cylinder
of air that provides ten minutes’ supply in case the system breaks down.