JPH0240367Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a traction force adjustment device, and in particular, to a traction force adjustment device used when towing a submarine excavator by a work boat.

Pipes such as oil pipes, gas pipes, and water pipes laid on the seabed are protected by the following measures:
It must be buried under the sea. To bury this, a trench is excavated under the pipe, which is done using an underwater pipe trench excavation device (for example, Utility Model No. 50-36324, Utility Model No. 56
−17568, etc.) from a work boat at sea,
It is installed on the laid underwater pipe, the tow line is taken to a work boat on the sea, and the work boat moves to tow the drilling equipment along the pipe. This invention relates to a towing force adjustment device installed on a work boat during such towing.

[Prior Art] When towing the above-mentioned underwater pipe excavation equipment, conventionally, the work boat was moved by crawling an anchor wire. Therefore, the underwater pipe excavation equipment moves forward when the work boat winds up the anchor wire, and stops when the work boat stops winding the anchor wire, and it repeats forward movement and stopping, and the forward movement and stopping are sudden. In other words, the pulling force of the towline is not constant, and no device has conventionally been provided to make it constant.

[Problem that the invention attempts to solve]

As described above, in the conventional towing method, the towing force acting on the tow line is not constant, and the underwater pipe trench excavation equipment repeatedly advances rapidly and stops abruptly. There was a drawback. In addition, the movement of such underwater pipe excavation equipment on the seabed must be constantly monitored by a large number of divers.

This idea was created in view of the above drawbacks, and even though the work boat moves by winding or stopping the anchor wire, a constant pulling force is applied to the towline, and the underwater pipe trench excavation equipment is The purpose of this invention is to provide a traction force adjustment device that allows excavation to continue at a certain rate depending on the soil quality of the ocean floor, the depth of the pipe trench, etc.

[Means to solve the problem]

In order to achieve the above objectives, the traction force adjustment device of this invention is installed on a work boat, and includes a guide frame that guides the weight so that it can slide up and down, and a pair of guide frames installed at the upper end of this guide frame. A frame pulley, a weight pulley provided on the weight, and a weight pulley extending from the towed object and sequentially spanning over one of the frame pulley and the other of the weight pulley and the frame pulley. It is characterized by having a tow line whose end is fixed on the work boat.

[Effect]

The towing force adjustment device of this invention is constructed as described above, so that when the work boat winds up the anchor wire and moves forward, the weight slides on the guide frame and moves upward, so that the towed object is Move forward slowly and dig. Even when the anchor wire is stopped winding and the work boat stops, a constant pulling force is applied to the tow line due to the downward sliding action of the weight, and the towed object, that is, the underwater pipe excavation equipment, continues to dig. Continue. Appropriate required pulling force varies depending on the type of object to be towed, performance, seabed soil quality, etc., but soil quality etc. can be investigated by a diver before operation and the weight of the weight can be adjusted accordingly. .

〔Example〕

This invention will be described in detail with reference to the illustrated embodiment in which the towed object is an underwater pipe trench excavation device.

As shown in FIG. 1, the traction force adjustment device 1 according to this invention is installed at the front end of a work boat 2, suspended from the work boat 2 by a crane 3, etc., and set on an underwater pipe 5 laid on the seabed 4. Towing the pipe trench excavation device 6 7
It shall be used when towing by. The underwater pipe trench excavation device which is the towed object is, for example, the device described in the above-mentioned Japanese Utility Model Publication No. 50-36324 and Japanese Utility Model Publication No. 56-17568.
It is desirable to be towed along the pipe 5 at a constant rate in order to excavate the pipe.

As shown in detail in FIGS. 2 and 3, the traction force adjustment device 1 of this invention includes a steel turret-shaped guide frame 10 and a weight 11 provided vertically slidably within the guide frame 10. The guide frame 10 is composed mainly of
is appropriately fixed to the front end of the work boat 2 so as to stand upright. Further, a pair of frame pulleys 12 and 13 are provided at the upper end of the guide frame 10 with a distance maintained in the front and rear, and a weight pulley 14 is also provided on the weight 11. These pulleys are for hanging a tow rope 7, and as shown in FIG. , passes around the lower half of the weight upper pulley 14 , passes over the other pulley on the frame, that is, the rear pulley 13 , and is successively spanned over the pulleys so that the end can be fixed on the work boat 2 . . In order to stretch the towline 7 in this way, as shown in FIG. 2, a guide pulley 15,
Guide pulleys 16 are preferably provided at the lower ends of the guide frames 10, respectively. The towline 7 is first wound together by a winch, then stopped (adjustment is required if the water depth changes significantly) and, if necessary, restrained by a stopper (not shown).

To explain the operation, the work boat 2 is moved forward by winding the anchor wire 9. Since the end of the towline 7 is fixed on the workboat 2, the weight 11 is hoisted up along the guide frame 10 by the tension acting on the towline as the workboat moves. When the anchor wire is wound up and the work vessel stands still, the forward movement resistance is reduced by the operation of the underwater pipe excavation equipment (sludge suction and mud removal), and the tension acting on the towline due to the weight (weight of the weight) is reduced. (approximately 1/2 of Since the pulling force acting on the underwater pipe excavation device is generated by the weight, the pulling force can be adjusted by appropriately adjusting the weight of the weight.

[Effect of idea]

As described above, according to this invention, a traction force adjustment device is constructed by providing a vertically slidable weight within the guide frame and hooking the tow rope over the weight pulley so that the weight of the weight acts. Therefore, by using this, the underwater pipe trench excavation device can dig at a substantially uniform rate even when the work boat is moving forward or stopped, and has the effect of preventing unexcavated digging or over-digging. Additionally, the progress of the drilling rig can be visually checked on the work boat by the downward movement of the weight. There is also the effect that the amount of advance of the work boat can be determined by the amount of rise of the weight. Since the situation can be grasped on the work boat, the work of divers can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a side view showing a work boat equipped with a traction force adjustment device according to this invention in an underwater pipe trench excavation operation state, Fig. 2 is a side view showing an embodiment of the traction force adjustment device according to this invention, and Fig. 3 The figure is a front view seen in the direction of the arrow in FIG. 2. 1... Towing force adjustment device, 2... Work boat, 4... Seabed, 6... Towed object, that is, underwater pipe trench excavation device,
7... Towing line, 10... Guide frame, 11... Weight, 1
2, 13... Frame pulley, 14... Weight pulley.

Claims (1)

[Scope of utility model registration request] a guide frame that is installed on a work boat and guides a weight in a vertically slidable manner; a pair of frame pulleys provided at the upper end of the guide frame; and a weight pulley provided on the weight; A tow rope extends from the object to be towed, is sequentially strung over one of the frame pulleys, the weight pulley, and the other of the frame pulleys, and has an end fixed on the work boat. A traction force adjustment device.