What's Wrong With This Joke was TandemSpeed Limit 2153

The cores probbably. What makes today's jetliner engines so efficient is the ever increasing bypbutt ratios. This doesn't apply to a turboshaft, of course.

I'll see if I can dig it up. I'm guessing there's a theoretical limit that can be predicted, but it certainly isn't 100%.

50% has been achived in HUGE marine diesels, but it's a fuction of turning so slow - 200 rpm, which gives the thing darn near forever to get a lot of energy out of each boom. I think some smaller diesels can hit near 40%, but it's harder as size goes down.

Ahhh, here we go:

p

I was somewhat off on my dates predicted, but, hey, they STILL show it as being a linear drop, though the data points don't match up well :)

But, still. They're showing it as a straight line. Keep running it along and hey, isn't that a neat trick?

The best I can figure, rail diesels slowly got better at a somewhat linear pace, gas turbines jumped a few times but have leveled off in recent years.

It's interesting to note that a rebuild of 70's vintage gas turbine powered trains in NY recently was a disaster - the units were still unreliable, and still sucked fuel. Actually, they just plain sucked, but that's another story...

As of late, Railpower's been backing off on their turbine plans (no more dreamy charts!). I suspect their Green Goat might get a niche as a yard switcher, but mainline uses for hybrid locomotives in general are probbably limited at best. They sure have been good at buzzword compliance, at least. In the US market, they might have a niches they can carve out and live in. Worldwide, I suspect plantardier, etc would crush them in an instant.