Talk:JP-7
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Reason for Development
A minor error, but yet an error. Given that the article is correct in that the fuel was developed in 1955, and THAT YEAR there was a shortage of bug spray because the non-volatile components were used for JP-7 (it is) then the fulel could not have been developed for the A-12. The timeline of the A-12 article is very confusing, mixing the A-12 and the SR-71, but a close examination shows that the A-12 was not even conceived in 1955, much less built. The A-12 entry states, "With the failure of the CIA's Project Rainbow to reduce the radar cross-section of the U-2, preliminary work began inside Lockheed in late 1957 to develop a follow-on aircraft to overfly the Soviet Union
It is obvious that in 1955 the A-12 was not even conceived, let alone built, and could not be the cause of any type of shortage.
The answer is simple. The referenced documents are also wrong. As are the Wikipedia articles about the A-12 and SR-71 (but interestingly, not the U-2). JP-7 was in fact developed for the U-2, not the A-12.
This causes a sort of a quagmire. The "referenced" information, and the sources are clearly wrong, but there is no reference for the true facts, . Do we leave in the obviously wrong data because it is properly referenced? Do we change it to the true facts, even though there is no reference? or do we delete it entirely because no one knows exactly how to handle this situation? To make things worse, what do we do with the unreferenced information in the U-2 article? Maybe, kick the whole problem down the road by using the unreferenced U-2 article as the reference for this one?
This is a prime example of the fact that the most aggressive reference attempt can't compete with someone with no references, but has "been there, done that."
Any suggestions will be appreciated. — Preceding unsigned comment added by Tbonge (talk • contribs) 22:27, 11 February 2015 (UTC)
Flashpoint
If the flashpoint is only 60 degrees Celsius then there's no way a lit match will be extinguished in JP-7 (see the claim in the SR-71 Blackbird article. Which is wrong? Lisiate 22:52, 7 Jun 2005 (UTC)
- In the book "Skunk_works", Ben Rich makes the claim that a lit match dropped on the Blackbird's fuel will simply go out. I'm fairly certain he specifically called it JP-7, but I don't remember if he mentioned its flashpoint. I'll check on that tonight...
- OK:
- "[...] five noninsulated fuselage and wing tanks that would heat up during supersonic flight to about 350 degrees; we turned to Shell to develop a special, safe, high-flash-point fuel that would not vaporize or blow up under tremendous heat and pressure. A lighted match dropped on a spill would not set it ablaze. The fuel remained stable at enormous temperature ranges: the minus 90 degrees experienced when a KC-135 tanker pumped fuel into the Blackbird at 35,000 feet, and the 350 degrees by the time the fuel fed the engines." (Skunk Works, p. 205)
- "The fuel, JP-7, has a kerosene base and such an extremely high flash point that the only way to ignite it was by using a chemical additive called tetraethyl borane, injected during the start prodecure." (Skunk Works, p. 218)
- If it's "stable" at 350 degrees, I'm guessing it didn't have a flashpoint of 60F. :-) What's the source on that number, I wonder?
- On second thought, I take it back. I reread Flashpoint, and realized I didn't (don't?) really understand that -- perhaps it's possible to have a 60C flashpoint but not be ignited by a match. Chemists feel free to help me out here. :-)
- Cheers for your response. Looking at the Flash point article, apparently there is a distinction between the Flash Point, where the fuel will ignite when exposed to a spark, and 'Fire Point' where the fuel will continue to burn Perhaps this is the answer here? That would seem to fit with the stability at 350 F (around 150 C?) in the absence of a spark anyway. Lisiate 21:52, 9 Jun 2005 (UTC)
I'm not a chemist, but I do work with aviation fuels, and I might be able to offer some insight here. Flashpoint refers to the temperature at which a fuel will give off enough vapours to generate a flammable fuel/air mixture. Above the flashpoint, any spark, no matter how small, can ignite the fuel. A common source of confusion is the idea that liquids can burn (they cannot, only the vapours can). Below the flashpoint a fuel stays liquid and is much more difficult to ignite. To ignite a fuel in this state, either the temperature must be raised 'til it vapourizes, or the fuel must be aerosolized into the air. A match will not provide sufficient heat to generate the vapours that it could ignite, therefore the bucket won't blow up. On another note, the fire point is related to the flashpoint because at the fire point, the flames from the fuel can generate enough heat to sustain the generation of flammable vapours from a fuel even if the ambient temperature is lower than the flashpoint. Reading back on this, it seems heavy and confusing. Leave a note if you'd like me to try and explain something better. -Lommer | talk 20:50, 18 August 2005 (UTC)
Single malt scotch
I seem to remember an anecdote that said that JP-7 was more expensive per volume than the finest single-malt scotch whiskey. Does this have a place in the article? Rusty 00:58, 20 August 2006 (UTC)
- Sounds like an urban legend to me. In Col. Graham's book (and he worked both on the SR-71 and in the Pentagon funding department for the program) I recall that the upper cost of a mission was around $100,000. That works out to about a dollar per pound of fuel ($6.60/gallon), and that would be the upper limit as the figure also accounts for maintenance, crew, etc. -Rolypolyman (talk) 23:10, 8 November 2009 (UTC)
The reference to single malt scotch is a quote from Ben Rich's "Skunk Works" book. It refers not to the JP-7 fuel, but to the expense of the engine oil that was used in the SR-71. Brprivate (talk) 19:46, 20 July 2015 (UTC)
Contradiction: fuel composition
This article states that JP-7 contained "alkylbenzenes, indanes/tetralins, and naphthalenes." Each of these are aromatic hydrocarbons, however, the article subsequently states that the quantity of such compounds was deliberately minimized. It is unlikely that these would be deliberately blended into such a mixture, as that would raise the aromatic content. --209.189.245.112 06:57, 2 May 2007 (UTC)
Some of this article seems to be taken from http://www.bp.com/sectiongenericarticle.do?categoryId=4503664&contentId=57733. Given that website is maintained by a jet fuel supplier I would tend to beleive wikipedia is plagorizing and not BP. —Preceding unsigned comment added by 18.96.6.5 (talk) 02:56, 22 June 2007 (UTC)
Reference Tag
Added ref tag. There's only one referene listed. Seems like there's lots of info on this page that should be easily verifiable should someone take the time to do so. Mrmcdonnell (talk) 18:10, 28 November 2008 (UTC)
Obtuse Word Group
"It must operate across a wide range of temperatures, from near freezing at high altitude, to high temperature of airframe and engine parts being cooled." Can the author please clarify? (EnochBethany (talk) 23:25, 13 May 2013 (UTC))
the match will be extinguished?
In the top of the article: ..."the match will be extinguished (although this is common in any low-volatility fuel including gasoline and diesel)."
Seems partially incorrect, and it would be great to see a citation on that. I have been fire breathing with kerosene for many years, so I can vouch for such substances as diesel extinguishing a lit match, but not gasoline. You can find lots of videos on YouTube where people pour gasoline on piles of wood, and when they merely strike the match, the vapors all round them light off immediately without even throwing the match into the gasoline. Fire breathers also get hurt trying to use white gas and gasoline instead of other less-volatile materials.
So I think that the gasoline part of the statement needs to be verified or removed. Diesel part is probably correct.