Tires are the weakest link here . . .
Tires are the weakest link as noted previously. Too soft and they wear too easily and too hard and the haul truck shakes itself apart over time. You could protect the tires to an extent from RPG's with armored skirts, but mines will still get through. Here in Arizona all the "normal" sized haul trucks wear industrial sized "snow chains" to reduce wear in the copper mines (They are not really snow chains but you get what I mean). The real weakness with the tires however is availability There is a global shortage of large construction and mining equipment rubber tires. The linked article is a few years old but covers the topic well:
http://www.equipmentworldmagazine.com/apps/news/articleeqw.asp?id=47127
It is so bad that new equipment has been delivered from factories on wooden blocks held together in the shape of wheels by metal bands. This is the bare minimum to load and unload the equipment for shipment and It is up to the dealer to source tires for the customer (This actually makes sense in many cases because the customers individual needs determine what kind of tires are best needed). The reasons for the shortage (which is easing up for various portions of the market) are many, but like steel, concrete and high rise cranes, its mostly the fantastic construction booms in China and the Persian Gulf.
Any way, my two cents (its the tires that will prevent our haul truck overlords from conquering everything).
Biting the hand that feeds IT
