3.2. Lifting Capacity and Operating Radius

They have poor mobility. So, that is why it is preferable to place a truck very close to the excavator. So, very commonly you can see that the truck is placed at 90 degree. So, the truck is placed at 90 degree, this will be 90 to the bucket position. So, this is a common position.

This chunk discusses the mobility of heavy equipment such as excavators and the optimal positioning of trucks in relation to them. Due to the limited mobility of excavators, positioning trucks close to the equipment is crucial for effective operation. It is common practice to place the truck at a right angle (90 degrees) to the excavator, which allows for efficient loading without requiring the excavator to swing excessively.

Imagine trying to fill a bucket from a well. If you stand too far back, it takes longer to pour the water in—this is similar to an excavator and truck relationship. The closer the truck (or person) is, the quicker and easier it is to load the material, leading to increased efficiency and reduced effort.

So, basically angle of swing is nothing but the horizontal angle between the digging and the dumping position between the loading and the dumping position. As the truck moves further away, your angle of swing would increase. As the angle of swing increases, your cycle time will increase, and productivity will decrease.

The angle of swing refers to how far the excavator must turn to move its load from the digging position to the dumping position. If the truck is farther away, the excavator has to swing more, which increases the 'cycle time'—the time it takes to complete a load. This increase in cycle time means that less material is moved over a given period, thereby reducing productivity.

Think about swinging a ball on a string. If you need to swing it 90 degrees (like the excavator loading a truck nearby), it’s fast. But if you have to swing it all the way around (like swinging to a truck placed far away), it takes much longer and requires more effort, slowing down the overall process.

So, ideal condition ideal production of shovel is based on 90 degrees swing that is what I told you, the truck will replace it 90 degree is ideal condition and the actual height of cut in your project site should be the same as optimum height of cut.

The ideal condition for productivity occurs when the angle of swing is at 90 degrees and the height of cut matches the optimum height for the machine. Achieving these conditions allows the excavator to operate at maximum efficiency. If either of these conditions is not met, productivity can suffer.

Consider an archer aiming at a target. If the archer stands too far away or at an awkward angle, hitting the bullseye becomes difficult. Similarly, maintaining optimal conditions for excavators ensures they can hit their productivity targets effectively.

Now, let us see what are all the adjustment factors, we have to apply while doing the productivity estimation based upon the height of the cut of material actual height of cut of material in your project site and based upon the angle of swing that is going to depend upon the position of your truck relative to the position of your excavator.

When estimating productivity, certain adjustment factors must be applied based on the actual height of cut and the angle of swing. For example, if the actual height of the cut is lower than the optimum height, a correction factor will need to be applied to account for decreased productivity. Similarly, if the angle of swing deviates from 90 degrees, this also affects productivity and necessitates a correction.

Imagine cooking and you need ingredients. If you’re shorter than the counter (lower height) or if you’re standing too far back (different angle), it takes longer to prepare the meal. Similarly, in construction, deviations from ideal conditions require adjustments to maintain productivity.

Another thing to be noted is truck spotting clearance. That means, as I told you, it is preferable to place a truck closer to the excavator. But at the same time, note that there should be some space left for the tail swing of the shovel.

While it is important to place the truck close to the excavator for efficiency, there must also be enough clearance for the excavator's tail to swing without hitting the truck. This prevents any potential collisions, ensuring safety and operational efficiency.

Think of a dancer performing in a tight space. They need enough room to move their arms without knocking over something next to them. Similarly, equipment needs sufficient space to operate safely and effectively.

Other important factor is haul unit exchange time. That means the time needed for the loaded truck to leave its position and for a new truck that is an empty truck to take the position.

Haul unit exchange time refers to the time required for a loaded truck to clear the loading area and for an empty truck to take its place. Minimizing this exchange time is crucial for maintaining productivity, as any delay can increase cycle time and hinder overall operations.

Imagine a busy restaurant where one waiter has to clear a table before the next customer can be seated. The quicker they can do this, the faster the restaurant serves customers, similar to how quick truck exchanges keep construction projects on schedule.

Now let us see how to estimate the productivity of the shovel. So, for all these machines, the principle is going to be the same, you can see the formula everything is going to be similar only.

Estimating the productivity of a shovel involves understanding several factors, including the heaped bucket volume, bucket fill factor, and cycle time. The basic formula includes these elements and allows for the calculation of productivity per hour based on corrected factors relevant to the working conditions.

Calculating productivity is like figuring out how much lemonade you can sell at a stand. You need to know how big your pitcher is (bucket volume), how much lemonade you usually fill it with (fill factor), and how long it takes to serve each cup (cycle time) to understand how many cups you can serve efficiently.

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