I posted some pictures and accounts about how dirty the process of coaling was here. Since then, I have trawled the internet some more, and have found some more and found some more brilliant pictures, mostly of American ships.
I also discovered this diary entry, from a former coal passer, Sailor Frederick Wilson, commenting on their lot in life in his diary:
1908-1917 Sailors on board USS Isla de Luzon shovel coal.
Sailors of the battleship USS Rhode Island mug for a photo, covered in coal dust. C1913
1896-1901 Sailors stoke boilers in the fire room of the cruiser USS Brooklyn.1
Coaling ship at Honolulu, Hawaii, circa 1909-1910.
Some of the ship's firemen, apparently after coaling ship, circa 1909-1910. 2
Cleaning up the warship after coaling.3
Coaling the HMAS Melbourne at St Lucia. Note the native workers bringing the coal onto the ship.4