JPS5931326A - Submarine cable burying machine - Google Patents

Abstract

PURPOSE:To raise the burying speed of submarine cables by providing a jet nozzle to jet air-bubbled water onto the front and both sides of the plow blade. CONSTITUTION:A plow blade 24 is attached to the lower part of the machine body 11 having sledges 12 provided to both ends of its lower part, an air supply pump 18, a water supply pump 22, and an air mixer 23, and a front jet nozzle 25 is provided to the front of the machine 11 and also side jet nozzles 26 are provided to both sides of the body 11. The pumps 18 and 22 are operated by a power control line 10 inside a rope 13 to drag the machine body 11 from the upside of a tug boat (not illustrated), and the excavation of the sea bottom and the moving of soil are performed with the plow blade 24 while jetting water and air mixed by the device 23 in the form of an air-bubbled jet from nozzles 25 and 26. In this case, a hood 27 serves to exactly settle the excavated soil flying high into the excavated trench where a submarine cable 14 is dropped, thus permitting the cable to be buried.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a burying machine for burying submarine cables laid in the sea, lakes, etc. in underwater ground.

Conventional submarine cable burying machines of this type include, as shown in Fig. 1, a movable submarine cable burying machine in which a plow blade 2 is provided between the sleds 1 on both sides, and a movable submarine cable burying machine in which a plow blade 2 is provided between the sleds 1 on both sides, as shown in Fig. 2. A water jet submarine cable burying machine equipped with a water jet spout 3 at the bottom of the tunnel excavates the underwater ground while being towed by a towing vessel, and drops the cable into the excavated trench. It is. In the former method, the underwater ground is mechanically excavated by the plow blade 2, so the digging resistance is very large.During mobile excavation, the frictional resistance due to the accumulation and adhesion of earth and sand on the front and side parts of the plow blade 2 is This has the disadvantage that the towing vessel that pulls the burial machine becomes large because it acts as an extra resistance force.

In addition, since the latter uses a water jet underwater, the friction between the water jet and the surrounding water causes large water jet attenuation, resulting in poor excavation efficiency and limited to work in areas where the excavation ground is relatively soft. was. Furthermore, the removal of earth and sand after ground excavation is limited by the discharge water capacity and is not sufficiently removed, resulting in the drawback that the excavation depth and excavation speed are small.

In view of the above-mentioned points, the present invention provides a submarine cable burying machine equipped with a groove and a plow blade, which reduces digging resistance and improves the soil removal effect, thereby increasing the digging speed and therefore the cable burying speed. A submarine cable burying machine is provided, and the drawings will be explained in detail below.

Figures 3 to 5 show an embodiment of the submarine cable burying machine of the present invention, where 11 is the fuselage body, 12 is the lower part of the fuselage body 11 on both sides. 14 is a submarine cable,
15 is a cable passage, 16 is a cable presser, and 18 is an air supply pump, and this pump 18 takes in air through an air supply hose 21 from a snorkel 20 attached to a buoy 19 floating on the water surface. 22 is a water supply pump designed to take in water from the surrounding area, 23
2 is an air mixing device for mixing air supplied from the air supply pump 18 and water supplied from the water supply pump 22, 24 is a plow blade, and a front jet nozzle is provided in front of the plow blade 24. 25 is provided, and side jet nozzles 26 are provided on both sides thereof, and these front jet nozzles 25 and side jet nozzles 2
6, the water and air mixed by the air mixing device 23 are jetted as an air bubble jet. An air bubble jet is ejected from the front nozzle 25 as shown in FIG. 5(a), and from the side nozzle 26 as shown in FIG. 5(b). 27 is a hood for soil removal.

Note that the air supply pump 18 and the water supply pump 1
9 can be controlled on board the towing vessel by means of a power control line in the tow rope 12.

In normal operation, excavation and removal is carried out together with the plow blade 24 while injecting an air bubble jet, but the water bottom ground in front of the plow blade 24 is turned into soft ground by the air bubble water jet jetted by the front jet nozzle 25. At the same time, the air bubbles form an air layer on the front surface of the plow blade 24, which reduces the frictional force between the excavated ground and the surface of the plow blade 24, thereby reducing digging resistance. In addition, the dirt and sand remaining on the front surface of the plow blade 24 is efficiently discharged by the air lift effect caused by air bubbles. On the other hand, the air bubble water jet injected from the jet nozzle 26 removes the dirt adhering to the side surface of the plow blade 24, and also forms an air layer by air bubbles on the surface of the side surface of the plow blade 24 in the same manner as described above. Significantly reduces the frictional resistance of 24. Additionally, a front jet nozzle 25 and a side jet nozzle 26
The sinking speed of the excavated earth and sand is reduced by the air bubbles that are injected. Therefore, when the cable is buried, the submarine cable 14 is not subjected to sudden soil stress, and the residual tension of the cable during burial is sufficiently alleviated.

In addition, the soil removal hood 2 that covers between the sleds 12 and 12 on both sides
7, the cable is buried by ensuring that the earth thrown up by the excavation sinks into the excavated trench into which the submarine cable 14 has been dropped.

In addition, when the water depth is shallow, air and water may be supplied to the tank for producing air bubble water by a pump boat from the water.

As described above, according to the present invention, air bubble water is jetted from the jet nozzles provided on the front surface and both side surfaces of the plow blade, thereby reducing the frictional resistance on the front surface and both side surfaces of the plow blade. In addition, the air bubbles injected from the front nozzle efficiently discharge dirt stuck in the front of the plow blade by the air lift effect, increasing cable burying speed, downsizing the towing vessel, Furthermore, it is possible to improve the adaptive excavation depth. On the other hand, the air bubbles also have the effect of reducing the settling speed of the excavated earth and sand, and relieving the residual tension of the buried cable.

[Brief explanation of drawings]

1 and 2 are side views of a conventional submarine cable burying machine, FIG. 6 is a front view of an embodiment of the present invention, FIG. 4 is a side view of the same, and FIG. 5 is a side view of a conventional submarine cable burying machine. The explanatory diagram of the injection state of air bubble water is shown. 12... soshi, 14... submarine cable, 24...
・Plow blade, 25...Front jet nozzle, 26...Side jet nozzle 5 times (2) (1)

Claims (1)

[Claims] In a submarine cable burying machine equipped with a shaft and a plow blade,
A submarine cable burying machine characterized by a jet nozzle that sprays air bubble water on the front and both sides of the plow blade.