If trains have to haul such heavy loads, why don jet-powered locomotives exist?
Simply because they wouldn’t work very well. An aircraft can be held in place just using its brakes, even if the aircraft is at full power. I have seen this during noise tests on twin-engine military fighter: the brakes held while the engine was running at full power and on full afterburner. The tarmac melted a bit, but the aircraft stayed put. A jet engine would be unable to generate enough thrust to overcome the rolling resistance of a stopped train. Little test sleds are one thing, ten thousand tons – not even a particularly heavy train – is quite another. Not to mention the cost of doing this. A large gas trubine is a very expensive item, far more costly than diesels. And you would need more than one. They are also very expensive to run – and not just in fuel costs. How would you mount the gas turbines on a train? You need to provide a path for the exhaust – they are thrust engines. If you mounted them on top, the locomotive would be very tall and top heavy. If mounted on the sides
