On Sat, 11 Feb 2017 08:43:58 -0800 (PST), wrote:

OK some more information.
Bars will be 8 feet long with a support under each one three feet down from the top of the sloping deck. The bars will be welded to cross tubes of 3 x 3 x 1/4 inch steel at the top of the frame and bottom along with one at 3 ft down from the top of frame.
the 36,000 pound steel is what the local shop sells.
the wheel loader bucket is 8 feet long or wide, so with the cap between bars at 3 inches and each bar being say 3 inches wide the gravel will be dumped on 16 or 17 bars.

May be irrelevant for your issue, but the commercial versions I have
seen the rock is dumped in a hopper and a vibratory feeder sends it
slowly to the grizzly. Normal oversized is much smaller than you are
dealing with but winter time gravel 'ice burgs' can be much larger.

Will try to get out and take a closer look tomorrow...
--
William