The idea of multiple chamber guns was that they could keep adding velocity
without the need for one huge, very strong and very heavy chamber and allowed
a more gentle acceleration. Early models were dismal failures
- it was found the 'fire' from the early charges would
wash around the shot and prematurely detonate the later charges so they
retarded the shot and the gun had a lower muzzle velocity than a conventional
cannon.
The large German model, the V-3, built in France to
bombard London was bombed by the RAF because it looked
a bit suspicious (they were hunting V-1 launch sites).
It was then, rather suspiciously buried after the war.
Different uses need different burning rates. Pistols and shotguns use faster
burning propellent than rifles and as the calibre goes up the desired burning
rate goes down. For the big naval guns you ended up with
powders like SBC - Slow burning cocoa. Shape can be as
important as chemistry, some of the big granular powders are beautiful shapes
and one of the ACW
experts - Dahlgren I think, experiemnted with single
grain charges but they were to fragile for use.
Liquid propellent might be interesting, though I cannot imagine how you could
add it into a chamber during firing.
One idea that scared people during the Cold War was cold launched ICBMs, if
fired from a gun they would lack the characteristic launch flare that allowed
them to be detected 'easily.'
The problem with high velocity guns has always been barrel wear. The Paris Gun
(Kaiser Wilheim Geschutz?) had a numbered series of increasingly larger shells
and one of the guns was destroyed when one shell was loaded out of sequence.
British naval guns were usually larger than German guns, firing a lower
velocity shell with greater mass. This increased barrel life. German ships of
the Risk Fleet on the other hand just had to dash out into the North Sea and
hammer the Grand Fleet so they could use smaller guns of higher velocity,
barrel life was shorter but they were home quickly (I know, a gross
simplification).
Just before the Iraqi war in 1990, a fairly famous Canadian weapons maker who
had worked for the Iraqis got himself offed, probably by the Mossad.
One of his things was orbital launch using super guns.
Also, I don't know how scientifically feasible this is, but the book Firestar
by Michael Flynn, one of the companies in it uses a big tube filled with
rocket fuel and then sticks a shell, with a satellite in it and lights the
match.
Corey
> At 09:12 AM 5/28/01 +0100, you wrote:
> At 04:37 AM 5/28/01 -0700, you wrote:
That was Dr.Gerard Bull. He worked on the High Altitude Research Project
(HARP, not to be confused with HAARP) in the 60s. HARP was a joint project
involving Canada and the U.S. study the feasibility of sending scientific or
military payloads into space using ballistic or orbital trajectories.
Using modified (lengthened, smooth-bore) Navy surplus barrels bull
launched hundreds scientific packages "to study the ionosphere" on ballistic
trajectories to altitudes of 75 to 100+ miles. The payloads were
basically saboted, fin stabilized canisters, some with solid rocket second
stages, but almost all had functioning electronics. The electronics package
was
usually a solid-state set up packed in plastic or resin and sand to
survive the launch Gs. The program was cancelled before any payloads were
fired into orbit.
Bull went on to do contract work for several countries that wanted their
artillery to out range their opponents artillery. I think he landed in jail in
the US sometime in the 80s for helping the wrong people. After he got out he
moved his operations to Europe. He was contracted by the Iraqis to build 3
super guns and was then murdered. I have also heard that he helped the Chinese
develop their own super guns.
The origional question was what kind of satellite systems could survive the
Gs of being fired. Solid-state electronics and solid rocket fuel could.
Things like solar panels, liquid fuel rockets and cameras would need some
serous help to survive the thousands of Gs placed on the payload during
launch.
> Corey Burger wrote:
> Just before the Iraqi war in 1990, a fairly famous Canadian weapons
That would be Gerald Bull. Bull was so enamored with the potential cost
savings of using a gun that he would go to just about any length to get more
funding for the idea. He agreed to help the Iraqis extend the range and
accuracy of their scud missiles, and in return, the Iraqi's agreed to build a
1000mm gun. The Israelis were sufficiently distressed about longer ranged,
accurate scuds, that they were probably the ones that murdered Gerald Bull.
The barrel sections for the supergun were held up before being exported to
Iraq from the UK, because someone noticed that the "pipeline" sections were
much stronger than needed for just about anything besides a supergun barrel.
The supergun got around the multiple chamber problem by having multiple
charges seperated by wooden (?) disks. Firing the charges sequentially allowed
the overall pressure in the barrel to be maximised without increasing the
initial pressure spike. Nowadays, I suspect that they would use a variable
burn-rate
charge that maintains a constant barrel pressure for much of the projectile's
time in the barrel. [Fire, Fusion, and Steel has a marvelous diagram showing
the advangtage of that scheme]
Much earlier in his career, he used a surplus USN experimental 14" gun to fire
instrumented projectiles to great heights (High Altitude Research Project). He
also wrote a well regarded book on railroad artillery, that I have not had the
opportunity to read. His basebleed technology is what gave the coalition
forces such a headache in Desert Storm. A gas generator (not to be confused
with a solid fuel rocket motor) filled in the partial vacuum behind the shell
as it flew, reducing drag. Basebleed shells are almost as long ranged as
rocket assisted munitions, but are much more accurate. Basically, the Iraqi
artillery park was much longer ranged than anything the coalition had, except