Common sense for the correct operation of crawler bulldozers

1. Speed change and advance/retreat

When shifting gears, first push the throttle handle forward to the low-speed idle position, then push the main clutch lever to the front to disengage the main clutch. Due to the effect of the small brake inside the main clutch, the power input shaft of the transmission stops rotating. At this point, the gearshift lever can be correctly moved to the desired gear, and then the advance and retreat rods can be placed in the forward or reverse position (when the bulldozer is moving forward, pull the advance and retreat rods backward; when it is reversing, push them forward). After shifting into gear, pull the throttle handle backward to increase the engine speed and smoothly connect the main clutch. The bulldozer then starts to move.

When the bulldozer is in motion, the main clutch lever should be pulled to the rear end and must not be placed in the semi-engaged position. The semi-engagement of the main clutch will accelerate the wear of the friction plates.

The transmission of a bulldozer usually has five forward gears and four reverse gears. The direction of the bulldozer's movement can be changed by using the advance and retreat rods.

When a bulldozer is in operation, it should run at the maximum speed as much as possible to enhance operational efficiency. However, drivers should always pay attention to whether the engine is running normally. When they find that the engine is overheating and black smoke is coming out of the exhaust, they should appropriately reduce the speed.

2. Steering

When turning while moving, the steering clutch lever on the steering side can be pulled backward to disengage the steering clutch. As a result, the speed of the tracks on the corresponding side slows down, and the bulldozer begins to turn. To make a sharp turn with a bulldozer, in addition to disengaging the steering clutch, the corresponding brake pedal should also be depressed. Generally, a sharp turn is only allowed when the bulldozer is in first gear. When the brake is not in use, the foot should not be placed on the brake pedal; otherwise, it will cause the brake band to wear out and increase fuel consumption.

When turning a bulldozer, the brake pedal should be pressed steadily to avoid jolting when turning. After the turn, you should first release the brake pedal and then the control lever. If the turning radius is large, there is no need to press the brake pedal. When there is no intention, it is strictly forbidden to make the bulldozer rotate at high speed in place to avoid the track derailing and causing an accident.

3. Driving on a slope

Bulldozers of different models have different climbing capabilities (generally 30°), and the slopes and terrains that bulldozers of the same structure can adapt to are also different. Drivers should be familiar with the climbing limit of the model they are using to avoid landslides due to insufficient ability to go up and down slopes.

Before going uphill, one should choose an appropriate speed gear based on the terrain, the size and length of the slope. It is not allowed to change gears during the climb. When going uphill, the bulldozer should run at a vertical Angle to the slope. It is not allowed to travel sideways on steep slopes. The shovel can be lowered appropriately to avoid obstructing the view and to enable it to touch the ground quickly in case of a landslide to assist the bulldozer in braking. If the engine stalls while going uphill, the fuel supply should be stopped immediately, the shovel lowered and emergency braking applied. When the machine cannot be stopped on a slope, shift to reverse gear and slide slowly to the bottom of the slope (while braking and sliding), then start the ground to persuade. If the fuel supply is not stopped and the vehicle slides down in the forward gear, the power will be transmitted back to the engine, causing it to reverse and catch fire, and the air filter will spray fuel outward. In case of a reverse rotation and fire, the accelerator should be quickly turned off and the bulldozer braked. Before restarting, check whether the gearshift lever is in neutral position.

When a bulldozer is going downhill, a low gear with a small throttle position should be selected and the brake pedal should be used.

4. Pass through cliffs or stony beaches

When a bulldozer needs to pass through large mounds of earth or cliffs and other obstacles, it should drive up slowly and at a low speed. At the moment when the machine body is about to tilt forward at the top, the clutch should be quickly disengaged to allow the front part of the bulldozer to touch the ground slowly, and then the clutch should be engaged to continue moving forward. Do not drive diagonally over obstacles. Do not pull the steering lever when driving over an obstacle.

When passing through a rocky beach, you should choose your route in advance and drive straight through it. Try to make as few turns as possible along the way. You should drive in low gear with a small throttle and must not drive in high gear with a large throttle or make sharp turns on the bumpy rocky beach.

5. Self-rescue when stuck in a vehicle

When bulldozers are operating in areas with extremely high water content or in muddy areas after rain, it is very likely that the vehicle will get stuck. There are two ways to save oneself after getting stuck in a car.

(1) If the bulldozer is pushing forward on flat ground and the vehicle does not get stuck too deeply, the bulldozer control lever can be operated, and the hydraulic blade can be lowered to lift the head of the machine, causing the tail to press down. Then, operate the bulldozer control lever to lift the hydraulic scraper, lower the head of the machine and reset the tail (the above process can be repeated multiple times depending on the situation of the stuck vehicle site). Next, shift the bulldozer into reverse gear I, appropriately increase the throttle, and engage the main clutch to reverse the bulldozer by a small distance (generally 5-10cm each time). Immediately, quickly press the brake pedal and disengage the main clutch lever. By repeating this many times, the trapped bulldozer can be smoothly driven backward.

(2) If the trapped bulldozer cannot be driven backward by the above method, one end of the steel rope can be fixed to a tree or stake, and the other end can be fixed to one or both tracks of the bulldozer (if only one track is trapped, the steel rope should be fixed to the trapped track; If both sides of the tracks are stuck and deeply stuck, two steel ropes should be fixed to both sides of the tracks. Then start the engine, shift into reverse gear I (or forward gear I), and slowly rotate the tracks to make the steel ropes wrap around the tracks and drag the bulldozer out.