1.2. Maneuver Time

So, this cutting and pushing will go together. So, the time required to push, backtrack and maneuver into position, so that is called as a cycle time of the bulldozer. So, you are going to cut the earth, push the earth, dump it at the required place, then backtrack, backtrack in the sense you are going to return, return back to the original position where you want to do the dosing operation again.

In construction and earthmoving tasks, understanding cycle time is crucial. Cycle time refers to the complete operation involving cutting the ground, pushing the material, dumping it, and then returning to the starting point to repeat the process. This entire sequence from start to finish is essential for determining how efficiently a bulldozer can operate on a task.

Think of a bulldozer as a chef preparing a dish. The cycle time is like the process where the chef first gathers ingredients (cutting), prepares and cooks them (pushing), serves the dish (dumping), and then returns to gather more ingredients (backtracking). Each step must be done efficiently to complete a meal quickly.

So, other things are maneuvering, maneuvering in the sense whatever adjustments you do, like for increasing the speed, accelerating or decreasing the speed, changing the gear, so the time needed for changing the gear, all those things comes under the maneuvering. So, we call this as fixed time, this is fixed time and this one is variable time, your push and backtrack it is called this variable time.

Maneuvering time includes all adjustments the operator must make during operation, such as changing gears or altering speed. This can be categorized into fixed time (related to machine design and condition) and variable time (which depends on operational choices like the speed or push distance). Fixed time remains constant regardless of how much material is being moved, while variable time can change based on conditions like load and distance.

Imagine a car driver adjusting speeds as they drive. The time taken to shift gears and speed up or slow down represents the maneuvering time. If the driver faces traffic (variable time), their time on the road changes, whereas a straight, easy path (fixed time) remains constant regardless.

Why do we call this push time and backtrack time as variable time? Because it is variable depending upon your haul distance. So, greater your haul distance greater will be a push time and return time or backtrack time. So, this is solely dependent upon your haul distance, so this is dependent upon your haul distance, so that is why we call it as variable obviously it depends upon the speed also.

Push time refers to the duration taken to move material forward, and backtrack time is the return to starting position. Both are categorized as variable time since they depend on haul distances – the longer the distance, the longer the push and backtrack times will be. This variability also links to operational speed; faster speeds can reduce these times.

Consider a courier delivering packages. If they need to travel far (haul distance), it will take longer to deliver and return. However, if they have a bike (speed), they can reduce their travel time, just like a bulldozer might with an optimal speed setup.

To know the push time and the backtrack time, I need to know the travel distance or the dozing distance or the haul distance. I need to know the travel distance and I also need to know the speed. So, you very well know how to determine the speed. So, in the earlier lecture, I discussed about how to determine the speed from the performance chart.

In order to calculate how long it takes to push or backtrack, we need to know two key factors: the distance the bulldozer has to travel and its speed. The speed can often be determined using a performance chart, which provides information relevant to specific working conditions and the associated capabilities of the machine.

Think of calculating how long it takes to drive to a friend's house. If you know the distance and how fast you can drive (speed), you can easily estimate if you'll arrive in 15 minutes or closer to an hour.

So, now let us see what is this maneuver time? So, already I told you maneuver time is nothing, but the time needed for changing your speed accelerating, changing the gears, or reducing the speed, so that is what is called as maneuver time. So, this maneuver time will depend upon the type of transmission.

Maneuver time, as mentioned before, refers specifically to the alterations in speed and gear changes necessary during bulldozer operation. The type of transmission system installed in the bulldozer greatly affects how long these adjustments take. For example, automatic transmissions change gears faster than manual (direct) systems, which require the operator’s intervention.

Consider driving a car with an automatic versus a manual transmission. An automatic car shifts gears on its own, allowing for quicker adjustments in speed, while a manual car requires the driver to manually shift gears, taking slightly longer.

Depending upon this transmission mode, your maneuver time will change. Say if you are going to go for power shift that is automatic gear change, the maneuver time is 0.05-minute, 0.05 minute in the sense 3 seconds. But your manual gear change that is direct transmission if you go for it will be 0.1 minute, say 6 seconds. So, you need to know that based upon the mode of transmission whether manual gear change vehicles or automatic gear change vehicles depending upon the time taken for the maneuvering also will vary.

The mode of transmission directly influences how quickly a bulldozer can adjust its operational settings. For example, using a power shift (automatic) means quicker adjustments at only approximately 3 seconds, while manual gear changes take about twice as long (6 seconds). This means when estimating cycle time, recognizing which type of transmission is in use is essential for accuracy.

Think of a racing car. If it has an automatic shifting system, it might accelerate faster around corners. But if it’s a stick-shift car, while it can be thrilling, it takes the driver longer to change gears, meaning speed can be affected.

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