3.6.1 An airlock should only
be permitted between a gas-dangerous zone on the open weather deck
and a gas-safe space and should consist of two steel doors substantially
gastight spaced at least 1.5 m but not more than 2.5 m apart.
3.6.2 The doors should be self-closing
and without any holding back arrangements.
3.6.3 An audible and visual
alarm system to give a warning on both sides of the airlock should
be provided to indicate if more than one door is moved from the closed
position.
3.6.4 In ships carrying flammable
products, electrical equipment which is not of the certified safe
type in spaces protected by airlocks should be de-energized upon loss
of overpressure in the space (see also 10.1.4). Electrical equipment which is not of the certified safe
type for manoeuvring, anchoring and mooring equipment as well as the
emergency fire pumps should not be located in spaces to be protected
by airlocks.
3.6.5 The airlock space should
be mechanically ventilated from a gas-safe space and maintained at
an overpressure to the gas-dangerous zone on the open weather deck.
3.6.6 The airlock space should
be monitored for cargo vapour.
3.6.7 Subject to the requirements
of the International Convention on Load Lines in force, the door sill
should not be less than 300 mm in height.