"

 ""Benefits"" 

Can someone remove this section ? It makes no sense. 

Besides that, it's not really a ""benefit."" I've never ever seen a situation where a gear was not positively located on the shaft. Not saying it has never happened but this is not something anyone in real life would consider a benefit. 

Someone who is not lazy could also add a section to explain the fact that true herringbones are only useful for pumps. For power transmission, testing has shown that double-helicals (with the gap in the middle) deflect more evenly across the teeth and wear more evenly. They are also (important for submarine use) quieter."