M&M wrote:

> Damn Dana, It's 2:30AM and I just got all nasty from measuring
> the bottom grates in my NBS. They're 10.5" X 13.5" X 2 = 283.5".
> With the 492 Sq In on top that gives you 775.5 Sq In of cooking
> area in the smoking chamber.

So, I just had to measure mine, too. I have a stock Charbroil
Silver Smoker, essentially an NBS. Three grates were supplied;
two of them are slightly larger than 16" x 16", or in^2.
The third grate is narrower (so it can be inserted into the
firebox opening) at 16" x 15" or 240 in^2. It wouldn't
surprise me if the 492 in^2 number was determined using the
slightly narrow grates or some allowing for spacing around
the edges of the cook chamber were made.

The firebox grate seems to be almost exactly the 238 in^2
I'd expected.

Cheers!
Dana