The Safe Transfer of Liquefied Gas in an Offshore Environment (STOLGOE)
The guide primarily addresses side-by-side (SBS) operations where the gas tanker moors alongside the F(P)SO. LPG is also offloaded to gas tankers offshore in other modes, such as via an SPM or in a tandem configuration. These operations are considered in depth in other OCIMF publications associated with oil transfers. Within this publication, only the differences associated with gas transfer have been highlighted.To address site-specific aspects in particular locations, the recommendations contained within this publication may be supplemented by additional requirements from development project teams, individual ship owners (or ship managers) and individual F(P)SO operators.Individual countries may have local regulations that address mooring arrangements and LPG cargo transfer operations within their territorial waters or Exclusive Economic Zone. These must be complied with and, where appropriate, these Guidelines may be referenced for additional advice. These Guidelines should not be considered contrary to, or a replacement of, any National or International Regulations or individual terminal operator’s specific procedures.This publication primarily addresses the inter-relation between the F(P)SO and conventional gas tankers operating in SBS mooring configuration. The guidance includes recommendations for mooring equipment, considers mooring loads and operations, motions of the F(P)SO and gas tanker, station keeping, cargo transfer equipment and cargo transfer operations. The guidelines are intended to assist in standardising equipment and procedures for SBS activities and to highlight general design issues in the interest of safe, efficient and reliable operations .Offshore operations involving the transfer of Liquefied Natural Gas (LNG) are not specifically addressed in this document, but will be included in a future update once industry experience is available on which to base guidance.For the purposes of these Guidelines, the gas tanker is considered to be a vessel equipped with standard mooring and cargo transfer equipment, with a conventional single propulsion system comprising of a fixed blade propeller.