This has nothing to do with the 16 to 1, but still very interesting.
I just read a great new book, called "The Bonanza King" by Gregory Crouch. It tells the story of John Mackay, and his silver mines in the Virginia City/Carson City areas, Nevada. The author goes into great detail describing the various silver mines there. The numbers were staggering, and it is truly amazing what they were able to do back then. (one mine used 52 cords of wood per MONTH, and 200,000 feet of timbers!!) Many mining techniques used to this day were invented in these Comstock Lode area mines.
I highly recommend the book for anyone interested in underground mining techniques and history.
$2.5M including alot of equipment! https://sacramento.craigslist.org/for/d/25-mil-gold-mine-fully/6462863240.html
Irwin has a substantial mining history. Perhaps it started building equipment used in the California gold mines but today the size of the equipment I see on the website is larger than rail equipment typical in California high-grade operations operating or planned. A ten to thirty ton ore car could be efficient over long haulage underground but it will come at a very excessive and unwise cost: heavier rail, wider passageways and high energy locomotives.
Perhaps an engineer will suggest this equipment to a new project where no use of old workings is under consideration. The down time and expense of retro fitting old workings is not advisable.
The Sixteen uses one ton and two ton ore cars in different applications and the use is very practical. The locomotive pulling the two ton runs well on the 20 pound track and is much larger than the trammers in use now. I will keep an open eye for any Irwin equipment used in the past.