WAC 296-36-065
General operating
requirements -- Communication. A telephone intercommunication
system ready for use at all times shall be maintained between
the working chamber, the power house, the source of compressed
air, the place of compressed air control, the first-aid room
and the superintendent's office.
Exception:
Where the working chamber of a caisson is less than 150 square feet in area, such system shall be maintained between
the working chamber, outside the lock and the place of compressed air control or the superintendent's office.
[Rules (Part III H), filed 12/28/62; § 8, filed 3/23/60.]