What is Oil Record Book or ORB ?

Every non tanker of 400 GT and above, and every tanker of 150 GT and above must have ORB part I ( Machinery space Operation ). All tankers of 150 GT and above must have ORB part II (Cargo/Ballast operation.) The ORB must be preserved for 3 years after last entry has been made.The ORB must be completed on each occasion, on tanks to tank basis if appropriate, Entries must be fully recorded without delay and each completed entries must be sign by the officer in charge of the operations concerned. Each completed page must be sign by the Master.
Entries include- any movement of oil in to ship, within ship and out of ship.