A spot of engine trouble

When on on board TQ at Christmas, as part of the daily checks, I noticed the generator and the two alternators would turn easily by hand whilst the engine was stationary - Not by much, but enough to be concerned. I rang Beta Marine and they were very helpful as always, and advised we get it sorted as soon as possible. They put me in touch with Gary at Heyford Fields and he advised the same as Beta Marine. So today we're taking a sprint up the M5 to our marina to take TQ to Heyford Fields and act on the advice given. I've heard of this problem before, it occurs when there is a heavy load on the mains 240v circuit with the engine on tick-over. It induces opposing and alternating torsional forces between the pulley and the crankshaft, placing wear on both. Ultimately, total crankshaft failure would be the result, and having heard of this happening on another vessel in the fleet, it is something which must not be ignored. Hopefully I've caught it early, before too much damage is done.