A very heavy whats - it

[Chillylulu]

@40.8 lbs. per sqft 1" depth it would weigh 405 lbs, less the grooves and holes.

Chilly

[oldtools]

item overall is 22 long by 13 wide by 5 inches deep.

three round holes are 1 1/2, 1 inch and 3/4 in diameter and go all the way thru

the divots are 4 1/2 wide

one is 13 inches long  the other is 15 inches long

both are 1 inch deep at he lowest point

If you know the sagitta length and arc width (length of the chord) you can find the radius from the formula: where:

s is the length of the sagitta
r is the radius of the arc
l is one half of distance across the base of the arc (half the chord length)

r= s2 + i2
        2s

Based on your dimensions, the "Chord" of 15" & "Sagitta of 1" the radius should be 28.625" or ~ 57.25" dia.

13" & 1" sagitta= 21.625" R.  or ~43.25" Dia.

[Aunt Phil]

Twilight, that's a picture of what happens when a center of train assist locomotive that is radio controlled from the front end gets the wrong message.   The train was parked and the assist loco got the wrong idea in its computer.  That set of divots took a while to accomplish, and nobody noticed until they tried to move the train.

It's also a picture the railroad and loco manufacturer didn't want made public.  It proves what train crews have known for a long time, radio controlled chochoos ain't as safe as management claims.

[skipskip]

It rings a bit, not like a good anvil, but not a thud either.

It might weigh more than I guessed, two people put it into the truck, but I suppose they could lift 150 pounds each, they were young 

not hollow in back