3. Productivity Estimation of the Scraper

So, now, let us work on the first problem on productivity estimation of the scraper. So, a scraper with the assistance of the pusher is moving the dry earth soil having unit weight of 1660 kg per bank meter cube. So, you can see that this is a conventional pusher loaded scraper, here we are moving the material which is dry earth soil, its unit weight is given 1660 kg per bank meter cube.

In this chunk, we are introduced to the productivity estimation process for a scraper. The scraper, with help from a pusher, is designed to move dry earth soil, which has a specific weight that is given in the material description. This unit weight (1660 kg/m³) is crucial in calculating how much material the scraper can effectively move during operation. By understanding these parameters, we can estimate the scraper's productivity effectively.

Imagine you are using a wheelbarrow to move soil. If you know the weight of the soil you are carrying, you can determine how many trips you can make in an hour. Similarly, knowing the weight of the earth being moved helps businesses decide how many scrapers they need for a job.

So, the volume is given in volumetric measures is a bank state. So, that you have to clearly note it and the swell factor has given as 0.80. So, with the help of the swell factor you can do the conversion like from loose volume, you can convert it into bank volume or vice versa.

The swell factor plays a significant role in estimating productivity because it represents the ratio of loose material to compacted material. For example, if soil is disturbed, it can expand or swell, meaning when calculating how much fits in the scraper, you must adjust for this factor. Here, the swell factor is 0.80, indicating that for every cubic meter of loose material, it has a compacted volume of 0.8 cubic meters.

Think of fluffing up a pillow. If you fill a pillow with stuffing, it appears larger than it is when compressed. Similarly, soil expands when it is moved, and the swell factor helps us calculate how much space it will take once disturbed.

You should know that this swell factor will increase by 10 % due to pushing. Why is it particularly for the push loaded scrapers? Your swell factor increases by 10 % due to pushing. So, basically, you know that when the pusher is pushing the scraper. It offers more additional pressure to push more material into the bowl.

The swell factor for push-loaded scrapers increases due to the additional pressure exerted by the pusher on the material in the scraper bowl. This added pressure compresses the loose material more, making it denser and increasing its weight per cubic meter. As a result, we must adjust our calculations to account for this increased weight when estimating how much material the scraper can effectively carry.

Think of a suitcase that can only hold 20 pounds of clothes. If you sit on it and push down as you zip it up, you can fit more clothes than you could without applying that pressure. Similarly, the pusher allows the scraper to carry heavier loads.

So, assume the rolling resistance of 50 kg per ton for this particular haul route the rolling resistance is 50 kg per ton. So, if you want to convert it into equivalent gradient, you know that for 1% is a gradient equal to 10 kg per ton.

Rolling resistance is the force resisting the motion when a body (in this case, the scraper and pusher) rolls on a surface. Here, it's quantified as 50 kg per ton. This ensures we understand how much force is required to move the scraper. The conversion from the rolling resistance into gradient helps visualize how steep the incline would be, which is especially useful in planning the path of movement for the scraper.

When riding a bicycle uphill, you know it requires more effort than riding on flat ground. The rolling resistance helps us understand how much 'work' the scraper has to do against the ground to move forward.

Heaped capacity the scraper is given as 23.70 meter cube. They expect the load will be 95% of the heaped capacity. So, that means as we discussed earlier, we are not going to load the scraper to its fullest capacity.

The heaped capacity gives us the maximum volume the scraper can hold when fully loaded, which in this case is 23.70 cubic meters. However, practical considerations, such as efficiency and machine performance, recommend loading only up to 95% (approximately 22.52 m³). This accounts for diminishing returns, implying that overly full scrapers may not operate at optimal efficiency, leading to longer loading times.

Imagine filling a backpack with books. If you fill it to the brim, carrying it becomes much harder and awkward, slowing you down. However, if you leave a little space, the backpack is easier to carry and maneuver.

So, now we are going to analyze and find the probable scraper production and also find the cost to move a bank meter cube of material. So, you have to find the unit cost of production cost per bank meter cube.

Calculating the production costs involves determining how much it costs to move one cubic meter of material with the scraper. By analyzing factors like efficiency factors, operating costs, and cycle times, you can create a comprehensive assessment of how much money is spent for each volume of material moved. This is crucial for project planning and budgeting.

Consider a pizza shop calculating the cost per pizza. They total up ingredients, labor, and overhead costs to determine what each pizza costs to make, enabling them to price it profitably.

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