Entry into Inner Space
183
Laird, has devised a novel bottom—crawling manned machine.
Basically, the machine which receives its main power via an umbili—
cal from a surface tender provides the essential backup for a team of
divers operating from its lock—out pressure chamber. It can stay
below for up to 28 days without any refurbishing and has storage
batteries for any emergency, for example, if the support tender needs
to run for shelter from a severe storm. The design embodies several
unique features Which enable the sea bottom vehicle to traverse steep
inclines, to cross gullies and to crouch on the sea bed should it
encounter strong currents, say, between four and ten knots. The
vehicle descends to the sea oor by lowering an anchor weight,
ooding its buoyancy tanks until just positively buoyant and then
Winching itself down on the anchor cable. Once at its destination,
the weight is picked up and the vehicle is ready to move off at speeds
up to 2% knots with its giant wheels lightly gripping the sea oor.
This machine has obvious value for the construction of underwater
well—heads, needed if navigation in the North Sea is not to be
severely hampered or restricted. Efforts of this nature in a country
which does not have a large naval programme for underwater
machines comparable to the United States are probably the most
signicant pointers to the shape of things to come. Such companies
are not building these underwater work—horses for fun or fame, but
for an economic return on their investment.