1.3. Load Ratio

The load ratio indicates the pushing ability of the material. It is nothing but the horsepower per loose meter cube of material retained in front of the blade. Here, the volume of the material is indicated as loose meter cube, meaning the material is in a loosened state. After the material is cut, it has already been excavated, and the load ratio measures the blade's ability to push this loose material.

The load ratio is essentially a measure of the bulldozer's effectiveness at pushing material that has been loosened. It is calculated by taking the horsepower available at the blade and dividing it by the volume of the material in a loose state, which is measured in cubic meters. This ratio helps to indicate how much material the bulldozer can effectively push with its available power.

Imagine you are pushing a shopping cart. If the cart is full and heavy, it will require more effort (or horsepower) to push it. Now, if you have a cart that is only carrying loose, lightweight items like bags of chips (loose material), you can push it with much less effort. Similarly, the load ratio helps us understand how easy or difficult it is for the bulldozer to push the material in front of it.

The load ratio measures the blade's ability to push the load once the blade is loaded. If the soil is highly dense, the blade will struggle to push it. Conversely, if the soil is less dense, it will be easier to push. Therefore, a higher load ratio means the dozer can push the load at a greater speed. This ratio is dependent on both the type of material being pushed and the design of the blade itself.

Various factors affect the load ratio, especially the density of the material. When the material is dense, like clay, it requires more power to push, resulting in a lower load ratio. On the other hand, lighter materials, such as loose soil or sand, allow for a higher load ratio since they can be pushed more easily. The design of the blade also plays a critical role; smaller blades typically achieve higher load ratios due to better concentration of power.

Think about trying to push a car (dense material) versus pushing a bicycle (light material). Pushing the car requires a significant amount of strength because of its weight, and you can't go very fast. However, pushing a bicycle is much easier and you can move quickly. The load ratio for the bulldozer works similarly; it tells us how easily the machine can push various types of materials based on their density.

Smaller blades generally have higher cutting and load ratios. This is due to the higher concentration of power per meter cube of material in front of the blade. Blades that are smaller can push the material more effectively due to this power concentration.

The size of the blade affects its performance significantly. A smaller blade has a more concentrated force acting on a smaller surface area, which translates into higher efficiency when pushing the same amount of loose material. This is because power (horsepower) is more effectively utilized on a smaller area, making the push more effective. Hence, for applications where precision and efficiency are vital, smaller blades are often preferred.

Consider a person trying to push a heavy box over a carpet. If they use a small, focused point of contact (like a small furniture dolly), they can move it more easily than if they tried to push the same box with their bare hands across the same carpet. The focused force and efficiency in weight distribution allow for easier movement, similar to how smaller blades on bulldozers work under load.

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