[elihu]

If disabling the engine weren't a requirement, my first thought would be to donate it to a local non-profit that, for some reason, owns a large WWII era tug boat. Its original steam engine was removed, so it's without propulsion. A locomotive engine might be just the thing for it, though I imagine the engineering challenges might be complex.

The power train from a diesel-electric locomotive would probably be ideal, since you could just park it in the boiler room and run power cables to electric thrusters. Or something like that.