Cannon vs. Flintlock ??

[roundball]

SITUATION

I've read articles about and watched reenactors perform what I understand to be a safety practice when swabbing a cannon after it's been fired.

As I understand it, the pressure from the bore swab being rammed down the bore forces a stream of exhaust, powder residue, possibly unburned powder & embers out the vent into the air where there is more fresh oxygen than inside the breech.

There is a practice where one of the artillery men holds his thumb over the vent to seal it, preventing the stream of residue from exiting the vent into the oxygen rich outside air.

The purpose of preventing the residue from exiting the vent is to prevent any possible re-ignition of this stream of residue when it hits the oxygen rich air, which could then track backwards through the stream into the vent/breech, possibly setting off a larger re-ignition of unburned powder that may still in the breech/bore, injuring/killing the man in front of the muzzle, etc.

TWO QUESTIONS:

Q1) Is this true?

Q2) If so, how is the cannon situation different from a fired flintlock, with respect to either blowing down the bore which forces hot residue out it's vent or ramming a patch down the bore which forces hot residue out it's vent?

 

[musketman]

I'll answer #2 first...
Cannon barrels are a tad too large to place your mouth over and blow down the barrel like a flintlock, with the exception of some EX-WIVES... ::

The bore swabber, as I gathered, was wet... This would help douse the remainer of the spent charge that was still in the barrel, but there is the chance of steam burns too...

The person holding a thump over the vent (#3) may have used a heavy leather pad to prevent 3rd. degree burns... #3 has on his left thumb a thumbstall.

On the back of the cannon is a vent that he must cover while #1 pushes the sponge rammer into the cannon.

If not, any remaining powder may ignite and #1 looses an arm. The cannon gets very hot, thus the leather thumbstall.

This web page goes through the procedure in great detail...
http://fhp.angelcities.com/wilsonscreek/cannon.html

 

[roundball]

MM, excellent reference site...makes it clear to me, thanks

 

I found this on the internet: http://www.civilwarartillery.com/books/GIBBON.PDF

I just started reading this document. Might have your answer in their somehwere as it is very extensive. Interesting read so far. Be advised that it is a 605 page PDF file and best of all, it is free. I have seen this manual being sold on the internet for $25.