fiat41b has a good point about volumes and artic trucks. I have never averaged 20 yards per truck in over 5 million yards. I run a mix of 35 and 40 ton trucks, and 17 to 18 yards is the best I have averaged, and the loads could not fit 2 spade shovels of dirt more in the bodies. The 35 ton trucks have been sideboarded to haul the same volume as the 40 ton trucks.
Just because the trucks are rated to haul 40 ton, doesn't mean 40 ton will actually fit in them. Dirt swells in different amounts depending on what type it is, how wet or dry it is, and other things.
Other than that, your spread seems right to work in those conditions. Cat 740's have good retarders, and are a good truck downhill loaded if driven within their capabilities. Train the drivers what gear and speed to run with the retarder and they will be fine.
Your 600 will probably need 5 passes to fill them, unless the material heaps well. I don't know how your glacial till is to load.
Let us know how it works out
Just because the trucks are rated to haul 40 ton, doesn't mean 40 ton will actually fit in them. Dirt swells in different amounts depending on what type it is, how wet or dry it is, and other things.
Other than that, your spread seems right to work in those conditions. Cat 740's have good retarders, and are a good truck downhill loaded if driven within their capabilities. Train the drivers what gear and speed to run with the retarder and they will be fine.
Your 600 will probably need 5 passes to fill them, unless the material heaps well. I don't know how your glacial till is to load.
Let us know how it works out