Blackbird, again.

[Agaricus bisporus]

SR-71 development began using a coal slurry powerplant

I knew that coal could, in theorey, be used to fuel a gas turbine, but does anyone have specific info or links to this ever being done?

And more to the point, any details to flesh out the extraordinary claim quoted above?

Has it ever been tried in an aviation context?

[chiglet]

Has it ever been tried in an aviation context?

Germany 1944-45 various ramjet proto-types and a couple of jets [Luftwaffe '46 is a reasonable book,describing a/c if not the technicalities]

[gruntie]

There's nothing new under the sun: Lippisch (http://en.wikipedia.org/wiki/Lippisch_P.13a)

[Noah Zark.]

A little known experimental aircraft from years ago involved a team of non-striking miners laid off from work due to the strikes prevalent at the time.
These guys were trying to come up with an alternative to burning coal products in the home, and came across the idea of converting an old Bedford lorry engine to run on nutty slack, hopefully to then fit it into the latest aircraft to be produced by the Snirdley Aircraft Development & General Industrial Theorists (SAD-GITS).
It quickly became evident that this was not a feasible proposal, and so the idea was dropped.
However, a remarkably ingenious idea ensued. An single cylinder aircraft engine was created that did not require induction manifolds and associated valve gear, thus saving on the weight and complexity of such. It also did not require an ignition system, a saving again.
Initial tests showed that starting was instantaneous, and it produced phenomenal power, which didn't decrease with altitude, all of which were attributes to the proposed interceptor to which it was intended to be fitted.
The first engine run was a little traumatic, however. All that was needed to start this revolutionary engine was for the pilot to carefully advance a small lever in the cockpit. This in turn opened a small valve on top of the cylinder, which allowed a drop of fuel, nitro glycerine, to drop onto the piston crown, and away it went. The piston, that is. It went down the cylinder, out of the crankcase, taking the crankshaft with it, into a large hole it made in the apron underneath the aircraft.
The potential of these proceedings was not lost on the assembled potentates, and it was terminated. :)

[Double Zero]

Agaricus,

Despite Noah's rather tongue in cheek reply ( and I suspect he knows much more than he's letting on ) coal dust HAS been tried, & used to at least proving test standard, on a number of British ( presumably others as well ) aircraft including some current serving fast jet powerplants - don't know if any have actually flown with it, but the 'proving standard' alluded to may well suggest it's been done.

This was news to me, having led a life around conventional jet fuel ( kerosene based ) like AVTUR, until last year when I happened to 'work' with a very experienced ex-Rolls Royce engineer.

DZ

[VX275]

Many years ago (before the accountants took over) there was an English translation of German research papers in the science Library at Boscombe Down. It covered all the jet and rocket research that had been carried out, but the one idea that struck me as 'barking but with potential' was the lump coal rocket! It relied on an oxidiser gas being pumped over a grate of coal which is not a million miles away from the rocket motor that will power the Virgin Spaceship 2.

[Agaricus bisporus]

So is the general idea to process the coal dust in some sort of separate gas producer module and feed the resulting gas into a turbine rather like the Lippisch barbecue and stovepipe method, rather than squirting black dust through injectors directly into the combustion chamber?

I have a bizarre picture in my head of a "covert" SR71 leaving a vast black smoke trail behind it as it showers klinker over the USSR to the accompanyment of a mournful "Whooo Whooo" whistle.
How would the poor hobos have ever got aboard at M3.2?

[Double Zero]

As to the separate gas producer module, sounds sensible to me, but frankly it wasn't mentioned.

I know the person to ask but don't have his no. - Still I can get in contact with him relatively easily, give me a day or two; the coal dust thing was almost mentioned in passing at the time as we were busy, but unless it's some sort of secret ( and believe me, no B.S. He did move in the highest circles ) I'm sure he'd be happy to give the gen'; will try to get him to contribute here in his own words, always better - may be a quiet member of Pprune already, we certainly discussed this website.

[oxenos]

Shackleton - some of the more observant of you surely noticed that of the rear crew, some wore AE brevets, some wore S brevets - Stokers.