Originally Posted by Olaf_the_blue
Lao Pan is probably pretty close to the mark with his "maybe for the last 5 years the valves have been working as sacrificial anodes." The ……...………….........….be an oops at the design end or running the ICCP to aggressively.
I don't agree with your last ('aggressively'). The only real meaning of overprotection is to generate gas bubbles and blow off the paint. De-zincification would only occur if it were being sacrificial (ie underprotection).
Denholm's had relinquished Mr. Rappaport's fleet to Acomarit and this included two Russian built bulk carriers with enormous and unstable ICCP power unit. One each side every hatch break! Were the wielder of the terminal screwdriver to have had the touch of a midwife he would still have been hard pressed to adjust the output in the very small band between sod all and very much all.
Not long after I got a call from Dick Swindall (formerly my line manager and now deserted to Acomarit) asking innocently if I had ever seen an ICCP'd hull with a 'sort of etched look' and no paint. Havin already reported that the best use of these vessels' ICCP, if not subject to expert attention, would be to anchor-off the vessel prior to her next drydock and use it to blow the paint off and save on blasting.
Sure enough the question was about one of the subject bulkers.