Spent quite a bit of time today creating a sieve with 2mm holes.
Then crushed up some coal in a plastic bag and then hitting with a hammer.
Then sifted through the new sieve.
Then sifted through a tea strainer to remove the finer dust to leave pieces of coal of a suitable size.
Then carefully placed pieces in all the coal bunkers on all 3 locos before dropping in a touch of diluted PVA glue.