Laying plow
A laying plow is an attachment or an independent special device or device combination for laying cables and pipes in the ground. The cables and pipelines to be laid are brought into the ground with the help of a suitable cutting and laying device, without digging the ground and without mixing the soil layers. This creates a narrow cut in the ground that collapses again by itself or by driving over the soil scar.
All kinds of partially flexible lines can be plowed in - gas, sewage, drinking water, electricity, communication lines or conduits into which fiber optic cables and power cables can later be blown, for example . With a laying plow, several cables or pipes can be pulled in at the same time. Route warning tapes and earth conductors can also be inserted in the same work step. Some of the lines that have been laid can also be surrounded by a bed of sand. A line to be plowed in is guided stress-free by a roller into a guide device behind the plow blade.
Special plows allow cables to be laid behind guardrails and under the river bed of bodies of water. When laying submarine cables , special cable plows for underwater use are used. The submarine cable laid by the cable ship is plowed or washed into the seabed by the cable plow that has been pulled. In this way, the submarine cable is better protected against damage from anchors, trawls and other things.
Functional structure
Self-propelled laying devices
Self-propelled laying devices are specially developed vehicles or excavators, tractors, bulldozers or the like. as a basic vehicle with installed laying tools.
Static laying plow
These special tools with mechanical or hydraulic functionality are attached to a basic vehicle such as B. Mounted caterpillar. They allow ducts for cables or hoses to be drawn in the ground, optionally with simultaneous laying of cables or hoses, but also accessories such as marking tapes. Laying depths of up to 80-100 cm are possible in the floors with floor classes 1 to 4, with additional support from a towing vehicle, floor class 5 is possible. These machines are suitable for smaller laying material. Combining cables, pipes, etc. is usually not possible.
Dynamic laying plow
Like static plows, dynamic laying plows are either conversions of a basic vehicle or specially developed vehicles. Vibration devices are used here to reduce cutting forces and soil breakage.
They are mostly used on floors with floor classes 1 to 4 and reach a laying depth of up to 1.5 m. The size of the laying material is usually limited to a diameter of 20 cm.
The attachments on the basic vehicle work in the rear or on the booms and usually have shorter cutting tools. That makes them mobile, but less stable against soil influences. The attachments must actively compensate for pitching movements of the base vehicle, which is why control devices are necessary.
In order to generate the necessary tensile forces in unfavorable soil conditions and to avoid major soil damage, machines with large-area drives and special plates are used to compact the soil.
These laying plows are often additionally supported by a towing vehicle or winch. They usually have a higher laying performance than static laying plows, but the laying depths and the possibility of combining the laying material remain rather limited.
Pulled static laying devices
Pulled laying devices are part of the laying system that has a towing vehicle or winch as a second component. Pulled laying devices are special carrier vehicles that can drive independently, but are pulled by the towing vehicle or winch during the laying operation.
The separate generation of the propulsive force by a special towing vehicle provides very high forces for the ground breaking and laying. This enables higher laying performance, which is characterized by greater laying depth (up to 2.5 m), larger (up to 60 cm diameter) and complicated laying material (lines in triangular formation or at a specified distance) and high laying speed even in rocky soil of class 6.
Another advantage of towed laying devices is a narrow and constant course of the plow path. Self-propelled laying devices usually require a larger working strip than the actual width of the vehicle because possible lateral shifts can occur due to plowing forces and soil properties. They can hardly or not at all adapt to the terrain. In addition, towed laying devices and towing vehicles usually cause less damage to the ground than self-propelled laying devices.
Procedure
There are two methods of plowing in the cables and / or pipes: the insertion method and the pull-in method. During the insertion process, the floor is cut open with the cutting device, the laying material is passed through the laying device, which works like a drawn shuttering, and placed on the bottom of the floor slot. This happens in one step. The laying slot closes over the laid laying material, depending on the nature of the floor and the size of the laying material, either by itself or after minor reworking, e.g. B. Driving over the soil scar.
With the pull-in method, the laying material is attached directly to the cutting device of the plow and pulled into the ground. Due to the resulting tensile forces on the laying material, this method is less gentle, but allows the laying of large and stiff laying material such. B. large steel pipes.
Laying material
With a laying plow, cables and pipes made of flexible material are generally incorporated. Their size, number, arrangement and laying depth vary depending on the laying device or system. As already mentioned, laying rigid laying material such as B. Steel pipes in the pull-in process possible. Today's laying plow and systems are equipped with monitoring functions that document the tensile forces that occur on the laying elements, as well as the position and depth of the laid cables and / or pipes. As a result, the laying also meets the particularly high demands on the laying material and the laying quality.
environment
The laying of cables and pipes with the plowing method takes place without serious incisions in nature: humus removal or removal of trees and bushes is usually not necessary, the soil layers do not mix. Several cables and / or pipes can be laid at the same time (with pulled laying devices) in one work step with high daily output. The resulting slot in the floor collapses by itself or is closed when the throw-up is rolled in. There is hardly any damage to the floor (with pulled laying devices).