Help. Could this be what it looks like ?

[katana]

Originally Posted by kronckew

a grenade would be light enough to throw far enough away to keep from killing the thrower, 6in. seems a bit big for a grenade.

It may be possible that a 'larger' grenade could be used in a defensive tactic if thrown from high defensive walls (ramparts) onto an invading Army.
Alternatively the 'balls' could have been carried via the 'looped' chain and placed stratigically as explosive charges.
I always thought that the ball of a 'ball and chain' was solid and heavy ...for obvious reasons.
Most 'cast' iron grenades I have seen tend to only have one hole, to fill with blackpowder and then 'plugged' with the fuse. The 'largest' hand thrown type I can find is around 4.5 " in diameter, 6" does not seem to bad a size if the throwing was assisted by the chain (athletic hammer style).
Fernando, do you have any idea as to the weight of the ball? The 'walls' of the sphere could be relatively thin making it lighter than it would appear.

My other concern is that cast iron is relatively brittle, great for a fragmentation device but bad for a prisoner's 'ball' ......an impact on another solid object could crack/shatter it. The fixing point of the chain would be most vunerable, a sharp tap with a rock ...and your 'off and running' albeit with a length of chain ...but you could swing that around as a weapon (if the chain was long enough)

http://www.knightsedge.com/medieval-...-and-chain.htm

I suppose you could argue that using chain (to throw the 'ball') is over-engineering when a suitable sized rope could be used instead. However, a rope is more likely to fail if damaged/worn and if it broke as you were 'swinging' it .... the explosive could go anywhere I think the chain would be wiser ...and would provide more shrapnel.

Regards David

There is also the possibility that this is a mortar shell and the chain handle was used to lift and load.