I have a dead short on a buried cable feeding a lampost in a car park, digging a trench isn't an option.
would there be any reference to using a catenary wire to feed a lampost?
Not sure what you mean by 'any reference to using a catenary wire'.
With a dead short can you not locate the area of the fault and dig to cable and joint? What is the cable?
No need to trench and replace the entire cable