I'm not sure 1 and 3 apply in this case unless the solution is to allow those with small cracks to be used with heavy monitoring or weld those with small early stage cracks (say less than 4-5mm) to reset the clock* to give time for a permanent fixed to be worked on and applied across the whole fleet. * the cracks will grow quicker next time post reweld so it is a short term solution.When I was doing my chartership one of my mentors was a very experienced, very well respected, fleet manager who went on to become a TOC ED before he retired.
He gave me three very sage, and in this case apposite, mantras by which to work - as a rolling stock engineer - by.
1. Don't go looking for a problem until you know what you are going to do when you find it.
2. Never assume you've got one problem.
3. Only ground a fleet if you know how you are going to put them back in to service, if you ground them without knowing how to get them back into service it'll be the end of your career in the railway.
Given he'd had to ground two large fleets in his career I took it that he knew of what he spoke....
2. I have a feeling it is going to be at least 5 or 6 problems (a couple being minor but enough to make the difference and accelerate crack growth given the other bigger issues.)