Bomb Squad called to USS Constitution

[Evil Dog]

From the Boston.com:

Bomb squad called to USS Constitution
September 22, 2005

A black-powder shell failed to fire from a cannon on board the USS Constitution during a routine blast at 7:13 p.m. yesterday at the Charlestown Navy Yard, prompting officials to call in the Boston Police Department's explosives unit, Officer John Boyle said. The shell was transported to a Boston police range on Moon Island, where it was rendered safe, Boyle said.

I wonder what kind of "shell" they could have been using?

[claypipe]

Actually, from what I heard on the television report it was a live exploding projectile that was removed.

As for the cause of the misfire, I blame Massachusetts firecode for it. By law, in Massachusetts, the load must first be bagged in a plastic baggie, then wrapped with aluminium foil to form the "powder cartridge". This, is then, rammed down the bore of the barrel and pricked through the vent with a gimlet.

This particular type of cartridge is nortorious for misfires and very unsafe for the following reasons.

1.)When pricked with a screw tip gimlet the plastic from the baggie will catch on the threads and often be pulled into the vent. When the fuse burns down the vent, the plastic will melt around the burning fuse, extinguishing the ember and plugging the vent.

2.) You don't want to run a gimlet down the vent in case the ember is still smoldrering. In which case, the gimlet would be blown into the air to be come a dangerous projectile, and the gunner's hand, wrist and forearm would be exposed to the escaping burning gases from the vent on discharge.

3.)As powder charge is contained in a baggie, the contained powder is protected from the water poured down the vent and bore and is usually dry as a bone when pulled from the bore.

My personal preference is the use of waxed paper bakery bags instead of plastic baggies. No danger of static electricity or melted plastic to cause mischief.

[Double D]

The Massachusetts Fire code does not require the plastic bag
http://members.tripod.com/New_England_Brigade/Artilleryinfo/527022.doc
527 CMR:   BOARD OF FIRE PREVENTION REGULATIONS   8/25/95

527 CMR 22.00:   CANNON OR MORTAR FIRING...
22.06:   Magazines and Powder...(5)   All charges shall be made up of commercially manufactured black powder only, and such charges prepared for the demonstration firing shall be made of completely combustible material or a non combustible material such as foil.  The completely combustible charge shall be encased in aluminum foil or other spark proof material which shall be removed at the muzzle of the cannon in the case of display firing.  No wadding of any kind is permitted in blank firing.


It would seem that if the gimlet pulled plastic up the vent that it would be felt coming out.  Then when the fuse was inserted it would encounter the blockage and not go in. It would also seem that it would take a substantial amount of plastic to block the vent or surround the fuse and "snuff it out".  Not to say  it isn't possible.

I know that I first encountered the plastic bag in foil cartridge method of in the Summer of 1984. I know that because I still have the copy of Summer 1984 "The Muzzleloading Artilleryman"  that introduced me to the technique.  Properly constructed there is little or no "slack" to get pulled up the vent.    I have never encountered the problem nor have I  ever heard any reports of the problem.  That of course doesn't mean that the problem hasn't occurred.  

What I have heard of is foil and plastic debris up the vent from firing, but that is cleared during the cleaning step of loading.

The purpose of the plastic bag is to contain the powder and keep it from getting into the folds of the foil cartridge and holding a spark after firing.  

That being said as noted above above Massachusetts does not require the plastic bag and neither does N-SSA.  N-SSA requires only the foil cartridge

I do like the idea of the paper inner bag to contain the powder.  My concern with the plastic bag has been more that melted plastic debris would adhere to the bore than be blown up the vent. Use of the paper bag would eliminate both worries.

The safety rules of the American Artillery Association  give proper loading sequences and  techniques and tell how to deal with misfires.  The rules specify wait  periods between loading, firing and correcting misfires. The rules should be strictly adhered to.

[GGaskill]

"Actually, from what I heard on the television report it was a live exploding projectile that was removed. "
 
I think we have to consider the source here (television) before believing this to be true.  After all, where in Boston harbor could one safely fire an exploding projectile, let alone where would they find a 24 pounder shell to fire?  Since the USS Constitution is still a commissioned Navy ship, it would appear to me that Massachusetts fire law is not applicable.  My concern is that a military organization is not prepared to deal with something predictable like this.