2.2.1 A diving system should, as a minimum, include
either one surface compression chamber with two separate compartments,
or two interconnected separate chambers so designed as to permit ingress
or egress of personnel while one compartment or chamber remains pressurized.
All doors should be designed so that locking mechanisms, if provided,
can be operated from both sides.
2.2.2 Where a surface compression chamber is to
be used in circumstances in which a person is intended to remain under
pressure for a continuous period of more than 12 hours, it should
be so arranged as to allow most divers to stand upright and to stretch
out comfortably on their bunks. The smaller of the two compartments
should be large enough for at least two persons. One of these compartments
should be a living compartment.
2.2.3 The living compartment and other compartments
intended to be used for decompression should have a lock through which
provisions, medicine and equipment may be passed into the chamber
while its occupants remain under pressure.
2.2.4 Locks should be designed to prevent accidental
opening under pressure and, where necessary, interlocks should be
provided for this purpose.
2.2.5 Each pressure compartment should have view
ports to allow observation of all occupants from the outside.
2.2.6 A surface compression chamber should provide
a suitable environment and facilities for the persons who use it,
having regard to the type and duration of the diving operation. Where
the chamber is intended to be occupied for more than 12 hours, toilet
facilities should also be provided. Toilet facilities capable of discharging
the waste to the outside should be fitted with suitable interlocks.
2.2.7 The diving system should be capable of allowing
the safe transfer of a person under pressure from the diving bell
to the surface compression chamber (and vice versa).