Add to that they also are big players in jet turbines. Most people know the from their cars but they definitely have the big engineering chops to build a reactor!

Edit: I think they are technically a different company now according to some other comments. The cars are now owned by bmw. Doesn’t change the fact that the actual rolls Royce company has a lot of big engineering expertise.

Their turbines are ass to work on from all the mechanics ive talked too.