Re: Orbital Cannon

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).

Michael

____________________________________________________________
Do You Yahoo!?
Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk