Why Do We Need a Torque Converter for Diesel Engines to Start Gas Turbines?

[mectarek]

why do we need to add a torque converter to diesel engines used to start gas turbines knowing that the diesel engine has a higher torque than a pneumatic starter?

and if we want to change the starting system from a diesel engine to a pneumatic starter, what are the components that need to be added or removed from the starting system?

 

[HowlerMonkey]

To protect the mechanism from shock loading.