Hello,

this is a model AP Mack dump truck used in the construction of the Hoover Dam. In preparation for the dam's foundation early excavators like the Marion Steam Shovel loaded blasted rock onto these trucks which would then carry it to a dumpsite.
AP Macks were heavy duty trucks designed to work in harsh environment. The one I built is equipped with a large capacity dump bed like they were used a lot during Hoover Dam construction.
Interestingly they were driven by chains connected to the rear wheels, just like some motorcycles these days.
If you were looking for a modern dump truck, I also made a Custom Pete Dump Truck.

Enjoy!