00:11 Aug-03-2004 John O'Brien Consultant, - Chevron ETC , USA, Joined Jan 2000 278
Re: UT Thickness testing on VLCCs Access issues vary greatly dependnet upon vessel design and age. Needless to say most vessels were never designed for in-service inspection access. Many internal tanks have nothing more than one access ladder and staging at one side of each tank.
Others may have internal structural steel work which provides a fixing platform for rope access technicians.
A number of specialist access companies have designed custom solutions to assist in solving these problems.
Working off rafts etc. has a number of safety issues regarding how well the tanks are cleaned and vented during operations. Also how much access you have to get a raft in through an access hatch. Working off inflatable rafts is not the most satble of platform.
Recently a lot of work is done with magnetic crawlers depending upon the type, number and distribution of measurements required to satisfy the classification society.
On double hulled tankers there may be some access through the void spaces agaion dependent upon design.
Our experienceis that ship owners want you to provide everything and do it as quickly and cheaply as possible.