On the other hand, the system described in the book is not shaft-less, so it still doesn't correspond to this new Chinese technology!

> "They called it a tunnel drive. You know how out West they have lots of hydroelectric power plants? Mostly dams. The water spills onto wheels that turn generators. Now there's a few new ones that kind of turn that around. They tap into underground rivers, and the water turns impellers, and they turn the generators instead of a modified mill wheel. An impeller is like a propeller, except the water drives it instead of the other way around. There's some minor technical differences, too, but nothing major. Okay so far? "With this design, you turn that around. You suck water in the bow and your impellers eject it out the stern, and that moves the ship." Tyler paused, frowning. "As I recall you have to have more than one per tunnel. They looked at this back in the early sixties and got to the model stage before dropping it. One of the things they discovered is that one impeller doesn't work as well as several. Some sort of back pressure thing. It was a new principle, something unexpected that cropped up. They ended up using four, I think, and it was supposed to look something like the compressor sets in a jet engine."

The drive in the Red October itself is never described in any detail though. That description is of a US experimental system that American engineer was familiar with, not the actual Russian system. Other than the fact it sucks in water and ejects it out the back, we know nothing else, and that fits the Chinese system fine. So nitpicking like this is simply not justified.