[Varley]

GM Dave, I am not sure what monitoring can provide such assurances.

I have two other hang ups. Special test features and automatic reverting to MSB supply. Of the failures that have reached the investigation stage only one I remember was due to hidden failures attributed to inadequate endurance at load testing. The others have been down to the unnecessary showing-off of the designers. Why do we want the emergency set to shut down and the ESB to revert to MSB simply on re-establishment of MSB supply? That supply might be unstable and wouldn't it be a good idea for an engineer to give the emergency set the once-over when on proper duty?

The automation required adds components and therefore is less reliable. The failure modes are more extensive too. One of these was responsible for a grounding in the St Lawrence which a simple auto start and connect would have likely avoided. A failure which was discovered during testing (a Maersk Chartered box boat) was down to the 'test' selector switch being defective. They should be tested simply by kicking out the MSB feeder, no other test is fully valid. The one that I remember that pointed to cold corrosion caused by inadequate test running condition meant a casualty in the Far East could only use the satcom for 10 minutes every hour or so while the set cooled down. A hole was found in one piston crown most likely caused, I understand, by pooling of acidic condensate.

We have been approached by suppliers of dummy loads to test at MCR. Too much control gubbins for that to be a one-act solution. I would have an ESB which powered a number of ancillary as well as the emergency loads. The ancillary MCBs would have no-volt trips so that they cleared on any blackout but could be manually restored once the emergency bus was live (when fed from either the MSB or its generator).

That was going to be on the next ship that I didn't get to 'do'!

(My first drawing approvals, which included the above grounding, I was more interested in being able to follow the interesting showings-off of the yard's designers. The standby start circuitry had a vast number of relay controlled logic. Very little of it necessary. The emergency switchboard similar. The warm glow of being able to follow and know like the back of one's hand is useful when showing off but evaporates over time being replaced with the realisation that one is stupid and so simplicity is better. Those unnecessary features of starters are now standard. They are tolerable - perhaps? - as they are executed on a PCB or computer. That doesn't make them any more necessary only impossible to repair onboard).