In every entry the chief engineer must record tank number, location, type of oil, description of operation, and quantity. For every operation a combined numerical and letter coding is applied. MEPC.187(59) describes the codes applicable as from 1 January 2011. According with revised MEPC.1/Circ736/Rev.2, issued 6 October 2011, additional amendments to oil record book entries have been implemented by IMO. The first part of the oil record book deals with machinery space operations for all ships. Entries shall be made in the oil record book on each occasion, on a tank to tank basis if appropriate, whenever any of the following machinery space operations take place on any ship to which this section applies— • Ballasting or cleaning of fuel
oil tanks; • Discharge of ballast containing an oily mixture or cleaning water from fuel
oil tanks; • Disposal of
oil residue; and • Discharge overboard or disposal otherwise of bilge water that has accumulated in machinery spaces. Entries shall be made in the oil record book on each occasion, on a tank to tank basis if appropriate, whenever any of the following cargo/ballast operations take place on any oil tanker to which this section applies— • Loading of oil cargo; • Internal transfer of oil cargo during voyage; • Unloading of oil cargo; • Ballasting of cargo tanks and dedicated clean ballast tanks; • Cleaning of cargo tanks including crude oil washing; • Discharge of ballast except from segregated ballast tanks; • Discharge of water from slop tanks; • Closing of all applicable valves or similar devices after slop tank discharge operations; • Closing of valves necessary for isolation of dedicated clean ballast tanks from cargo and stripping lines after slop tank discharge operations; and • Disposal of
oil residue. == Electronic oil record book ==