Bill in the train transported coal (10)
I believe the answer is:
anthracite
'coal' is the definition.
(anthracite is a kind of coal)
'bill in the train transported' is the wordplay.
'bill' becomes 'ac'.
'in' indicates putting letters inside.
'transported' indicates an anagram.
'the'+'train'='thetrain'
'thetrain' with letters rearranged gives 'anthrite'.
'ac' going inside 'anthrite' is 'ANTHRACITE'.
(Other definitions for anthracite that I've seen before include "Hard variety of coal" , "kind of fuel" , "High-grade hard coal" , "Hard type of coal" .)