Re: [OT]Stupid question about sloped armour

Roger Books wrote:

>      /	  |
>     / 	  |
>    /		  | 1M
>   /		  |
>  / 30 degrees   |
>  ----------------
>
> <Sleepy Math mode>
>
> I have a 10cm thick plate I am using for armour.  I need to
> cover a 1M^2 area.  If I slope it 30 degrees my plate needs
> to be .1M X 1M X 2M.	That means I have  volume of 0.2M^3.
> However, if I double up the piece and stick it straight
> up it is .2M X 1M X 1M, or a volume 0.2M^3.  Incidently
> my sloped armour is affectively 20cm thick for a straight
> on shot.  My vertical armour is 20cm thick for a straight
> on shot and even thicker for a shot coming in at an
> angle.
>
> The volume arguement doesn't get it either.  I have to extend
> the bottom to get the same volume as I would have with
> vertical armour, my vehicle masses more for the same volume.

But you need less top armor.  Unless the vehicle is open topped, you
will need something on top of the vertical plate, but the sloped plate
provides its own top armor.

>
>
> It must be the glancing that makes it worthwhile, but we get
> sleight of hand advertising such as the one posted earlier,
> http://members.surfeu.fi/stefan.allen/strf9040.html, that tries
> to say you get something for nothing.
>