Amphibious excavator is a special engineering machinery that can operate on land and in water.
1、 Structural characteristics
chassis Design
The chassis of amphibious excavators is a key component. It usually adopts a floating box structure, which is like installing several large sealed floating boxes at the bottom of an excavator. The floating box can provide sufficient buoyancy to allow the excavator to float in the water. For example, some large amphibious excavators have larger floating boxes that can withstand the weight of the excavator itself and a certain amount of load weight, ensuring stability on the water surface.
In order to adapt to different underwater terrains, the chassis will also be equipped with special tracks. This type of track is wider than the tracks of ordinary excavators, and the pattern design of the track is also helpful for walking on muddy water or soft shores. It can increase the contact area with the ground or water bottom, reduce the pressure per unit area, and prevent the excavator from sinking.
Sealing and waterproofing system
The sealing of the excavator body is crucial for working in water. There is a good sealing design at the connection between the cab and various mechanical components. The cab is generally in the form of a sealed cabin, with rubber sealing strips on doors, windows, and other parts to ensure that water does not enter the cab and provide a dry working environment for operators.
For key components such as engines and hydraulic systems, there will be specialized waterproof covers and sealing devices. For example, waterproof barriers will be installed around the engine compartment, and sealing gaskets will be used at critical interfaces such as oil pipes, wire entrances, etc. to prevent water from entering and causing component damage.
Working device
The working devices of amphibious excavators, such as boom, boom, and bucket, are structurally similar to ordinary excavators, but may place more emphasis on corrosion resistance in material selection. Because when working in water, the working device is more likely to come into contact with water containing various chemicals, such as seawater, which can accelerate the corrosion of metal components. So, these components may be made of special alloy steel or undergo anti-corrosion treatment to extend their service life.
The action control of the working device is still completed through the hydraulic system, which also has some special designs. For example, in order to prevent hydraulic oil from malfunctioning due to temperature changes when working in water, the hydraulic system will be equipped with better heat dissipation devices to ensure stable performance of the hydraulic oil and normal operation of the working device.
2、 Working principle
Land operations
On land, the working principle of amphibious excavators is basically the same as that of ordinary excavators. It drives the hydraulic pump through the engine, which delivers hydraulic oil to various hydraulic cylinders, controlling the movements of the boom, arm, and bucket. The operator operates the control lever in the cab and carries out excavation, loading, and other operations according to the job requirements. For example, when excavating soil on a construction site, it can dig the foundation and move the soil like a regular excavator.
Working in water
When working in water, the float box provides buoyancy to keep the excavator floating on the surface of the water. The operator controls the rotation of the tracks to achieve the movement of the excavator in water. During the excavation process, the movement of the working device is similar to that on land, but due to the resistance of water, the movement may be slightly delayed. Meanwhile, due to buoyancy, the force exerted on the bucket during excavation differs from that on land. For example, during river dredging operations, the bucket cuts into the sediment at the bottom of the water, then excavates and lifts the sediment, and unloads it onto the transportation equipment on the shore by rotating the machine body.
3、 Application Fields
water conservancy project
Used for river dredging, clearing silt and debris in the river, and maintaining the smoothness of the river. It can operate in water areas that are difficult for ordinary excavators to reach, such as the central area of some deeper rivers. In reservoir maintenance and construction, amphibious excavators can also be used to clean sediment at the bottom of the reservoir, as well as for earthwork excavation around the reservoir.
Wetland development and protection
When constructing necessary infrastructure in wetlands, such as building boardwalks and digging small ditches, amphibious excavators can avoid causing excessive damage to wetland ecosystems. At the same time, in wetland ecological restoration projects, it can also be used to remove invasive alien species, such as cleaning up overexploited aquatic plants in wetlands.
combat a flood and go to the rescue hurriedly
During floods, amphibious excavators can carry out rescue work in flooded areas. It can clear obstacles on the road, such as collapsed trees, muddy sections, etc., and open up channels for rescue vehicles. It can also be used to reinforce dams, such as filling and compacting soil on the upstream or downstream surface of dams, to enhance their flood resistance.
4、 Advantages and limitations
advantage
Multi functionality is one of the main advantages of amphibious excavators. It can cross two different working environments, land and water, reducing the trouble of frequent equipment replacement in some complex projects. For example, in a project that involves both land earthworks and adjacent water dredging, a single amphibious excavator can complete all the work.
Its maneuverability is relatively good. In some shallow waters and coastal areas, amphibious excavators can freely shuttle and quickly reach the work site. Compared with some traditional water-based equipment such as dredging ships, it has higher operational flexibility in nearshore and shallow water areas.
limitations
The cost of amphibious excavators is relatively high. Its complex chassis structure, sealing system, and special working devices all increase manufacturing costs, and due to relatively low market demand, its price will also be relatively expensive.
When working in water, the depth of operation is limited. Generally speaking, it is suitable for operation in shallower waters because as the water depth increases, the water pressure also increases, and higher requirements are placed on the sealing of the fuselage and the buoyancy of the chassis. Moreover, the operation of its working device in deep water will be more restricted.
