Off hand, I'd estimate room for 3 cars past the turntable, 1 on the table, and 3 or 4 cars that don't get to the table. The switch was some distance "uphill" of the table.
I've not read of any accidents there.
The SRR got much acclaim in Europe, for the innovation of the turntable, and for being the most profitable railroad in the world for 4 years. But the profit was on a dollars of profit per mile of mainline, and there were only 18.25 miles of mainline. So when silver crashed, there really wasn't a lot of cash around.
"The Rainbow Route" is the book to buy. It's out of print, so expect to pay a premium.