Earth pressure shielding machine

Mud adding type shielding machine

PURPOSE:To ventilate while confirming safety by providing plural ventilating openings bored in a deck above the partitioned rooms of a working platform vessel, then providing each ventilating opening with a closable ventilating device in the state of not protruding from the deck, and performing gas detection and forced ventilation before starting work, with the ventilating device opened and left open during work. CONSTITUTION:The inside of a working platform vessel 1 is partitioned by bulkheads 3, and plural ventilating openings 6 are bored in a deck 5 above partitioned rooms 4. Each ventilating opening 6 is provided with a closable ventilating device 7 in the state of not protruding from the deck 5. The ventilating device 7 is formed of a lid 8 screwed into a lid fitting member 9 having a recessed part at the center part thereof, a tie chain 10, packing 11 and a hand hold 12. Before starting work in the working carrier 1, the lid 8 is removed to open the ventilating opening 6, and gas detection in the partitioned room 4 is performed to confirm safety. Forced ventilation with nitrogen gas mixture is then performed toward the inside of the partitioned room 4. During work, the lid 8 is left removed, and after terminating work, forced ventilation with nitrogen gas is performed again toward the partitioned room 4. The lid 8 of the ventilating device 7 is then fitted back to close the ventilating opening 6.

Matsushita Seiichi

Papers

Earth pressure shielding machine

Mud adding type shielding machine

Working platform vessel ventilating method