300 loads is a lot for a 50 ton machine to load. If you have a top notch operator, and easy digging conditions, you may get it from time to time, but I would never count on it.
8 passes is way to many to productively load trucks. If you need that kind of daily production, you need a bigger hoe to load with. If the digging is easy, a bigger bucket on the 480 will help, look for something sized to load in 5 passes, and you will get closer.
I hope your distance is .5 to 1 Km, or you will be killing tires, as Stock mentioned. ADT tires are no good for a long haul in hot weather.
To figure how many trucks, you need to know the travel time, dump time, return time, and load time. remember, load time includes spotting, and is properly counted from when the loaded truck leaves, until the next loaded truck leaves. when you know the true loading time, divide that into the total cycle including the load time. Say 1.5 min load, 3 min haul, 1 min dump, 2 min return. The total in my example is 7.5 min per load. Divide by 1.5 min load, and you get 5. That is how many trucks you need. If it doesn't work out even like my example, and it rarely does, and you get a number like 5.5, then always round up for the trucks needed. This gives you a truck all the time.
Remember the job efficiency. You can never get a job to run 100% production. It just doesn't happen. Things get out of order, drivers stop to take a restroom break, weather plays a part, flat tires, plugged filters, no show operators, sickness, and any number of things go wrong. A good job will run close to 90% of max, and an average is closer to the low 80's. Things like how well the crew works together, how the supervision sets things up, and a number of other things come into play. The biggest of these is the skill of the operator in the production machines.
A big mistake people make is committing to an unrealistic production number based on what is theoretical, but not really likely in the real world.
