Ahah. Allow me to elaborate.Batman wrote:Actually the primary mechanism by which grenades injure people are fragments, not concussive force.
The grenades involved were almost certainly concussion grenades (which do), as they were thrown in a confined space (sewers) at cybermen who seemed to be a very short distance away from the UNIT soldiers (and only effective when they landed at the cybermen's feet - and one cyberman took no less than six to kill!) which generally suggests concussion grenades as opposed to fragmentation grenades. One of them appeared to produce a gout of flame, though that could have been the cyberman itself being damaged of course, rather than representing an incendiary grenade.
They certainly don't appear to have anything like the blast radius of fragmentation grenades, but then, TV grenades rarely do, but in this case I'd guess it was intentional. That episode (The Invasion) had rather a lot of British army involvement, to the point that a platoon was supplied for the final fight against the cybermen (in which more grenades are used, some have no effect at about two or three meters, some do; a near miss from a "bazooka" - typically unimpressive explosion - causes one cyberman to apparently malfunction and stagger backward in a daze before collapsing SLRs are completely ineffective throughout)