Hybrid class 37 ?
 

A UK technology company is working on transforming a class 37 diesel locomotive from the 1960s into a hybrid motive power unit that could see service into the 2060s. Motive Zero, the company behind the project is also working on an even earlier design, the pre-war shunter designated class 08, with the same ambition.

https://www.railfreight.com/technolo...week%202021-39

Well the 37 has electric traction motors, with a diesel engine which turns a generator. So it's conceivable to feed electricity to the control circuits.

Personally I'd be delighted to see 37s get an extended life, but I'd really miss that 'growl'. ;)