Granite taken from gas turbine by commercial transport (3)
I believe the answer is:
bus
'transport' is the definition.
(bus is a kind of transport)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for bus that I've seen before include "Public transport vehicle" , "Use transport" , "Large passenger vehicle - small business!" , "Road vehicle able to carry many passengers" , "Charabanc" .)