Loading a dump truck with dirt or gravel is a pretty straightforward process. Loading a truck with huge stones, on the other hand, is much more difficult because it could end up damaging the dump truck. In this case, a Caterpillar wheel loader is dropping a huge stone over a dump truck rail from about 4 or 5 feet up. The stone is probably 1,000 pounds or more, so you can imagine the kind of impact that would make on an empty truck bed from that high up.
The Powerful CAT 966M XE Wheel Loader
With this particular loader—a CAT wheel loader that looks to be a 966M XE or close to it—there really isn’t a way to avoid just dropping the large stone from a few feet up. This machine’s lift arm clearance is just under 12 feet high, which isn’t much taller than the dump truck. The loader has no problem lifting up that heavy boulder with its powerful hydraulic system and heavy-duty bucket, but it’s not able to “reach” into the dump truck like an excavator would be able to.
While not quite as versatile as an excavator, front end loaders like this one offer tremendous power. For example, the 966M XE is rated at 39,000 lbf of breakout force. Here are a few of its other impressive specs:
• 298 horsepower and 1,275 lbf-ft. of torque
• 24.4 maximum miles per hour
• 1.4 second dump speed at max height
• Total hydraulic cycle time of 10 seconds
Some Standard Dump Truck Weights and Features
This Caterpillar loader weighs about 50,000 pounds, which would be roughly the gross vehicle weight of the dump truck. The chassis of this dump truck would likely weigh about 15,000 pounds. A standard dump truck has 1 front axle and 1 or 2 rear axles. While rear axles are almost always powered in the US, they are typically unpowered in Europe. The benefit of a powered axle is that it can be lowered to provide extra support for bigger loads. A powered axle would help to cushion some of the blow of the falling stone in this case.
A Better Way?
Is there a better way to load this huge stone than the dropping method this guy uses? One thing that may have helped would be to move the bucket as far to the other side of the rails as possible. Then instead of falling straight down, the side wall would absorb some of the impact first. Looking at the loading hinge and the front wheels, the loader probably could have gotten closer to the truck to do this, but maybe not. Another thing the loader driver could have done was put some pressure on the side rails to reduce rocking from the impact.
Dropping a stone this big from that height could ultimately damage the axle and suspension, but I guess that’s a risk these guys were willing to take. We get to see what the falling stone does to the dump truck, but it’s hard to say whether there was any significant damage done.
The Standard Dump Truck Loading Process
eHow has some guidelines for properly loading a dump truck, though they may not necessarily apply to this unique situation. The steps they recommend are:
1. Make sure the dump truck can handle the weight.
2. Park the truck on level ground and put on the parking brake.
3. Make sure the truck bed is all the way down.
4. After digging up the material to be loaded, lift it about 3 feet off the ground.
5. Drive the loader to the center of the dump truck.
6. Upon reaching the side of the dump truck, come to a complete stop.
7. Raise the bucket high over the dump truck wall.
8. Slowly move forward until the bucket is directly over the center of the width of the truck bed.
Look Out Below!
In this case, the stone actually does roll into the center of the dump truck bed, which is good. But an empty truck bed and a huge stone being dropped just isn’t a good combination, although it is definitely entertaining to watch. Tell me, do you think there would have been a better method to get the stone into the dump truck?