Category: Efficient operation

Is when the shovel is not loading and production stops. Here are the gaps that affect production:

1. No trucks to load – a gap in truck coverage
2. Time the shovel waits for a truck to back into loading position
3. When the shovel moves to a new cut

The gap in truck coverage affects shovel utilization. High utilization translates to high production. The target is 85% shovel utilization.

Most mines utilize double-side loading over single-side loading because it eliminates truck spot times which increases shovel utilization for higher production.

Advantages of Double-side Loading

1. Eliminates the wait-time for trucks to back into loading position for 100% shovel utilization
2. Divides the dig-face in half reducing dig-to-dump swing distance to 90 degrees max thus optimizing shovel output
3. Allows more time in the cut before having to move due to the wide swath of the dig
4. Allows dozer clean-up without affecting shovels’ output ie; dozer cleaning the floor on one side while the shovel is loading on the other side
5. Reduces tire damage due to more available clean-up time without affecting production

Double-side loading keeps the shovel fully utilized resulting in more production.  The shovel never stops loading to wait on trucks to position themselves for loading.  With single-side loading the shovel typically has to wait on the truck to back into loading position. 

Note a poorly positioned truck that repositions will void any gains achieved in double side loading.  Truck drivers must be proficient to quickly get into the correct loading position at the shovel. Remember: when the shovel has to wait for a truck – production stops!

Mines that utilize single-side loading typically have hydraulic shovels. The reason is that the hydraulic shovels’ cab is on the left side of the machine and the cab of the truck is on the left side so both the truck and the shovel have direct eye contact to each other.

Advantages of Single-side Loading

1. It’s easier for the truck operators because it’s on their cab-side
2. It’s safer due to cab to cab eye contact with the hydraulic shovel
3. Have less incidents due to truck / shovel contact
4. Often times quicker spot times due to direct eye contact with shovel

Single side loading puts more emphasis on the trucks to quickly get into position. They typically have 30 seconds from the time the loaded truck is honked out and for the next one to get into position.

* Note Truck drivers must be proficient to quickly get into the correct loading position at the shovel. Remember: when the shovel waits for a truck to get into position – production stops!