# What's the most powerful jet engine ever designed (not built)? **URL:** \ **Category:** Factual Questions\ **Created:** [September 24, 2007, 6:14pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335 "2007-09-24T18:14:05Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [September 24, 2007, 6:14pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/1 "2007-09-24T18:14:05Z")
The [General Electric GE90 turbofan](http://en.wikipedia.org/wiki/GE90) is the most powerful jet engine ever built, capable of producing 127,900 lbs of thrust. This is a bit over one and a half times as much as the Redstone rocket used in the first two Mercury flights. My question is: is there anything _]better_ out there (not counting ramjets) that never left the drawing board? No matter how far along the planning was—I’m looking for anything that wouldn’t be completely physically impossible to build or operate, and at least had some _rough_ estimates on engine thrust. So…are there any crazy Luftwaffe, Cold War, or budding Burt Rutan designs out there that would fit the bill? ---
**Author:** ![David\_Simmons](https://avatars.discourse-cdn.com/v4/letter/d/9de053/32.png) [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)\ **Post date:** [September 24, 2007, 10:20pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/2 "2007-09-24T22:20:03Z")
It’s hard to find out what the biggest design is. People quite often don’t talk about their new designs until the build them and put them on the market. As of 2004, the biggest jet engine was the [GE engine that drives the Boeing 777.](http://www.geae.com/aboutgeae/presscenter/ge90/ge90_20041116.html) GE90’s have developed as much as 123000 lb. of thrust. I was driving up US 395 north of San Bernardino one day when I came up behind a flatbed with a big thing on it. The truck carried “WIDE LOAD” signs and the thing hung over the sides of the truck by at least a foot or maybe a tad more. As I passed I could see that it was the rotor out of a jet engine. It must have been 10’ wide. I don’t think it could have been much wider because then it would have needed escorts. ---
**Author:** ![Shamozzle](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shamozzle](https://boards.straightdope.com/u/Shamozzle)\ **Post date:** [September 24, 2007, 10:48pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/3 "2007-09-24T22:48:38Z")
For interest’s sake, check out these little [dudes](http://www.sitewavesstores.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=JetCat&Category_Code=TURB). The smallest is about the size of a man’s shoe. ---
**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\ **Post date:** [September 25, 2007, 6:57pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/4 "2007-09-25T18:57:55Z")
The S209FA gas turbine built by General Electric for fixed power plants delivers 825,000,000 Watts, well over a million horsepower. I think aviation jets are more than an order of magnitude smaller. I know a much smaller GE turbine was installed in France last year and weighed over 300 tons. Does this count? ---
**Author:** ![VunderBob](https://avatars.discourse-cdn.com/v4/letter/v/839c29/32.png) [@VunderBob](https://boards.straightdope.com/u/VunderBob)\ **Post date:** [September 25, 2007, 7:19pm UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/5 "2007-09-25T19:19:26Z")
Does a [ramjet](http://www.merkle.com/pluto/pluto.html) count? ---
**Author:** ![Ranchoth](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ranchoth/32/1066_2.png) [@Ranchoth](https://boards.straightdope.com/u/Ranchoth)\ **Post date:** [September 26, 2007, 7:07am UTC](https://boards.straightdope.com/t/whats-the-most-powerful-jet-engine-ever-designed-not-built/420335/6 "2007-09-26T07:07:19Z")
[QUOTE=Napier] The S209FA gas turbine built by General Electric for fixed power plants delivers 825,000,000 Watts, well over a million horsepower. I think aviation jets are more than an order of magnitude smaller. I know a much smaller GE turbine was installed in France last year and weighed over 300 tons. Does this count? [/QUOTE] It could…I’m looking for something that could potentially be adapted to an aircraft—an [exceedingly huge](http://forums.x-plane.org/index.php?showtopic=28075) aircraft, not an exceedingly _fast_ aircraft. That’s why I’m not looking for ramjets or rockets. Actually, something like the Kuznetsov “NK-116” powerplants proposed for the [Be-2500](http://en.wikipedia.org/wiki/Beriev_Be-2500), I just found. They don’t seem to exist, yet, but the concept gives them over 200,000 lbs of thrust, each.