Hope this helps:
I was a 'fettler' myself in my early railway career. It involves placing smallish stones under the sleepers to provide a level track for the trains to run on. The level is measured across the rails and longitudinally along the rails. This was usually done by the 'Ganger' as it is/was a skilled task on the railway. The fettlers were more of a labourer who moved the ballast (stones) from between the sleepers in readiness for the ganger to place the 'chippings' (small stones) under the sleepers when the track had been lifted using mechanical jacks. In some cases it just involved ramming the stones under the sleepers using a pick like tool or the end of a shovel.
Mostly done by machines now that cost upwards of £2 million a time.
Oh those were the days, dodging trains and the supervisors!
This is why RootsChat is so good. You find people who have SO much knowledge in certain fields.
meles