CN210416916U

CN210416916U - Unmanned ship sampling system

Info

Publication number: CN210416916U
Application number: CN201921269655.3U
Authority: CN
Inventors: 熊春洪; 邹雄伟; 李智; 彭云建
Original assignee: Lihero Technology Hunan Co ltd
Current assignee: Lihero Technology Hunan Co ltd
Priority date: 2019-08-06
Filing date: 2019-08-06
Publication date: 2020-04-28
Anticipated expiration: 2029-08-06

Abstract

The utility model discloses an unmanned ship sampling system, which comprises an unmanned ship and a floating dock for the unmanned ship to stop, wherein the floating dock is fixed at the water bank; a charging mechanism connected with the storage battery pack is arranged on the unmanned ship; the floating dock is provided with a berthing position for the unmanned ship to berth, the berthing position is provided with a charging pile connected with a station house power supply, the berthing position is provided with a charging pile connected with the station house power supply, the bottom end of the charging pile is fixed on the floating dock, the top end of the charging pile is suspended above the berthing position and can be electrically connected with a charging mechanism of the unmanned ship. The utility model discloses an unmanned ship sampling system is convenient for realize unmanned ship charging process's unmanned, and degree of automation improves greatly, has liberated the labour, has improved work efficiency.

Description

Unmanned ship sampling system

Technical Field

The utility model relates to an unmanned ship technical field especially relates to an unmanned ship sampling system.

Background

The monitoring of water quality of rivers and lakes is an important content of surface water environment protection, the monitoring data is an important basis for reflecting the water quality pollution degree, and the accuracy of the monitoring data has an important influence on the adopted environment protection measures. In the water quality monitoring of surface water bodies such as rivers, lakes and the like, sampling of offshore monitoring point positions of the surface water bodies is always a difficult problem which puzzles the environmental monitoring department. The unmanned ship water quality sampler is suitable for online monitoring of water quality of rivers, lakes and other water bodies and sample collection, and is widely applied to departments of environmental protection, water conservancy, fishery and the like. The system can completely replace the traditional field sampling which can be realized only by manually driving a ship to reach an offshore monitoring point. The existing unmanned ship sampling is to reach a sampling point by an onshore operator in a remote control manner, so that the multi-point sample can be continuously collected, the unmanned ship is remotely controlled by the operator to return after the sampling is finished, and a sampling bottle is taken out and is taken back to a laboratory for analysis.

The water quality sampler configured by the existing unmanned equipment has a complex structure, needs manual charging, is short in operation time, and needs manual intervention operation due to the fact that the water sample is transferred from the unmanned ship to the detection room and the unmanned ship is docked with the dock, so that automatic water quality monitoring operation is not convenient to realize.

SUMMERY OF THE UTILITY MODEL

The utility model provides an unmanned ship sampling system to solve unmanned sampling ship and charge inconvenient, need manual operation not be convenient for realize automatic technical problem.

According to one aspect of the utility model, the unmanned ship sampling system is provided, which comprises an unmanned ship and a floating dock for the unmanned ship to stop, wherein the floating dock is fixed at the water bank; a charging mechanism connected with a storage battery pack is arranged on the unmanned ship; the floating dock is provided with a berthing position for the unmanned ship to berth, the berthing position is provided with a charging pile connected with a station house power supply, the bottom end of the charging pile is fixed on the floating dock, and the top end of the charging pile is suspended above the berthing position and electrically connected with a charging mechanism of the unmanned ship.

Further, fill electric pile includes the mounting base and fixes the horizontal pole that charges on the mounting base, be equipped with the electric conductor on the horizontal pole that charges, the electric conductor is connected with the station room power, the mechanism that charges includes the elasticity portion that charges of vertical setting, the elasticity portion that charges passes through the mounting to be fixed on the unmanned ship, so that when the unmanned ship berths at the berth position, the elasticity portion that charges with the electric conductor electricity is connected.

Furthermore, both ends of the conductor are provided with insulating baffles, and the charging cross rod is an insulator.

Further, still be equipped with the sampling mechanism that is used for gathering the water sample on the unmanned ship and be used for with the water sample transfer mechanism of the water sample transfer that the sampling mechanism gathered, still be equipped with on the floating dock and store up appearance mechanism for be used for receiving and storing the water sample that water sample transfer mechanism carried, store up the detection mechanism that appearance mechanism passes through the water pump connection station room.

Further, sampling mechanism includes carousel, water pipe, sampling head, suction pump and first same water tank, the sampling head links firmly the first end of water pipe, first same water tank is connected the second end of water pipe, the water pipe is convoluteed on the carousel, through rotating the carousel is in order to realize the lift of sampling head, the suction pump sets up the carousel with on the water pipe pipeline between the first same water tank, in order to be used for extracting the water sample extremely first same water tank.

Further, the water sample transferring mechanism comprises a drainage pump and a drainage pipe, the drainage pump is connected with the first sample tank, the drainage pipe is connected with the drainage pump, and the drainage pipe is a pipeline which extends towards the outer side direction of the unmanned ship body and can be opened or recovered, so that when the unmanned ship transfers the water sample, an outlet of the drainage pipe is opposite to the sample storing mechanism, and the water sample in the first sample tank is transferred to the sample storing mechanism.

Further, store up kind mechanism and include second appearance water tank, the opening of second appearance water tank is the loudspeaker opening, the detection mechanism of station room is passed through the water pump connection to the bottom of second appearance water tank.

Furthermore, a limiting gate mechanism is arranged on the berthing position and used for limiting the berthed unmanned ship.

Furthermore, the limit gate mechanism comprises a limit gate rod and limit gate rod supporting bases located on two sides of the berth, one end of the limit gate rod is rotatably connected with the limit gate rod supporting base on the corresponding side, the limit gate rod is connected with a rotary driving mechanism to drive the limit gate rod to be lifted or put down, and a baffle used for limiting the unmanned ship is arranged in the middle of the limit gate rod.

Furthermore, two sides of the berth are provided with anti-collision strips.

Furthermore, a rain-proof shed is arranged above the berth.

The utility model discloses following beneficial effect has:

the utility model discloses an unmanned ship sampling system, including unmanned ship and the floating dock that is used for supplying unmanned ship to berth, floating dock fixes on the water bank, and unmanned ship is driven by electric drive system and is gone to the target position, and sampling mechanism gathers the water sample and stores, and the water sample has been gathered the back, and unmanned ship traveles to floating dock to berth on the berth position, the charging mechanism on the unmanned ship is connected with the electric connection of filling on the floating dock, realizes that unmanned ship's storage battery's automation charges. The utility model discloses an unmanned ship sampling system is convenient for realize unmanned and automatic of unmanned ship charging process, improves work efficiency.

In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be described in further detail with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. In the drawings:

fig. 1 is a schematic structural diagram of an unmanned ship sampling system according to a preferred embodiment of the present invention;

fig. 2 is a schematic structural diagram of another view angle of the unmanned ship sampling system according to the preferred embodiment of the present invention;

fig. 3 is a schematic structural diagram of another view angle of the unmanned ship sampling system according to the preferred embodiment of the present invention;

fig. 4 is a schematic structural view of the limit gate mechanism in fig. 1.

Illustration of the drawings:

1. an unmanned ship; 11. a charging mechanism; 111. a charging elastic part; 112. a fixing member; 12. a sampling mechanism; 121. a turntable; 122. a water pipe; 123. a sampling head; 124. a water pump; 125. a first sample water tank; 126. a support wheel; 13. a water sample transfer mechanism; 131. draining pump; 132. a drain pipe; 2. a floating dock; 21. a berth position; 211. a gate limiting mechanism; 2111. a limit brake lever; 2112. a limit brake lever support base; 2113. a rotation driving mechanism; 2114. a baffle plate; 212. an anti-collision strip; 22. charging piles; 221. mounting a base; 222. a charging rail; 2221. an electrical conductor; 2222. an insulating baffle; 223. a charging cable; 23. a sample storage mechanism; 231. a second sample water tank; 232. and (6) taking a water pipe.

Detailed Description

The embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered below.

Fig. 1 is a schematic structural diagram of an unmanned ship sampling system according to a preferred embodiment of the present invention; fig. 2 is a schematic structural diagram of another view angle of the unmanned ship sampling system according to the preferred embodiment of the present invention; fig. 3 is a schematic structural diagram of another view angle of the unmanned ship sampling system according to the preferred embodiment of the present invention; fig. 4 is a schematic structural view of the limit gate mechanism in fig. 1.

As shown in fig. 1 to 3, the unmanned ship sampling system of the present embodiment includes an unmanned ship 1 and a floating dock 2 for the unmanned ship 1 to stop, where the floating dock 2 is fixed at a water bank; the unmanned ship 1 is provided with a charging mechanism 11 connected with a storage battery pack; the floating dock 2 is provided with a berth 21 for the unmanned ship 1 to berth, the berth 21 is provided with a charging pile 22 connected with a station house power supply, the bottom end of the charging pile 22 is fixed on the floating dock 2, the top end of the charging pile 22 is suspended above the berth 21, and the charging pile 11 is electrically connected with the charging mechanism 11 of the unmanned ship 1, and when the unmanned ship 1 berths, the charging mechanism 11 is electrically connected with the charging pile 22 to finish the automatic charging of the unmanned ship 1. It should be noted that the electrical energy in the station house power supply may originate from the conversion of solar energy, wind energy, tidal energy, etc. Fill electric pile 22 can be various suitable mechanisms in the utility model discloses in the preferred embodiment, in order to ensure can be convenient realize the electricity with unmanned ship 1 and be connected, fill electric pile 22's bottom mounting on floating dock 2, its top suspension is in the top of berth 21, and with the detachable connection of charging mechanism 11 of unmanned ship 1. Of course, the charging pile 22 may be in non-contact communication with the charging mechanism 11 of the unmanned ship 1, for example, by wireless induction, so as to realize wireless charging with the unmanned ship 1.

The unmanned ship sampling system comprises an unmanned ship 1 and a floating dock 2 for the unmanned ship 1 to stop, wherein the floating dock 2 is fixed on the water bank, the unmanned ship 1 is driven by an electric drive system to run to a target position, and after water sample collection is finished, the unmanned ship 1 runs to the floating dock 2 and stops in a berth 21. When the unmanned ship 1 stops at the berthing position 21, the charging mechanism 11 on the unmanned ship 1 is electrically connected with the charging pile 22 on the floating dock 2, so that the automatic charging of the storage battery pack of the unmanned ship 1 is realized, the unmanned and automatic charging process of the unmanned ship is realized, and the working efficiency is improved.

The unmanned ship sampling system of this embodiment is equipped with camera (not shown) on unmanned ship 1, can monitor the condition around unmanned ship 1, and unmanned ship 1 is connected with the control system electricity, and control system controls the route of marcing of unmanned ship 1, and control system belongs to prior art to the control of the route of marcing of unmanned ship, the utility model discloses do not describe here any longer.

In this embodiment, the charging pile 22 includes an installation base 221 and a charging cross bar 222 fixed on the installation base 221, a conductor 2221 is arranged on the charging cross bar 222, and the conductor 2221 is connected with a station power supply; the charging mechanism 11 includes a vertically arranged charging elastic part 111, the charging elastic part 111 is fixed on the unmanned ship 1 through a fixing part 112, so that when the unmanned ship 1 is parked at the parking position 21, the charging elastic part 111 is electrically connected with the electric conductor 2221, and thus, by setting the charging part to be elastic, the electric conductor can be stably contacted with the charging part while the unmanned ship can be parked well, and the stability and the safety in the charging process can be ensured. Alternatively, a mounting base 221 is provided only at one side of the berth 21, and one end of the charging crossbar 222 is fixed by the mounting base 221 and the other end is suspended. In another alternative, mounting bases 221 are provided on both sides of the berth 21, and both ends of the charging crossbar 222 are fixed by the mounting bases 221. Conductor 2221 is arranged on charging cross bar 222, and conductor 2221 is connected with the station power supply through charging cable 223. The elastic part 111 that charges is vertical to be fixed on unmanned ship 1, and be connected with unmanned ship 1's storage battery through charging cable 223, when unmanned ship 1 berths into berth position 21, the electric connection is realized with the electric conductor 2221 contact of horizontal setting on the horizontal pole 222 of charging to vertical elastic part 111 that charges, thereby realize unmanned ship's automatic charging, the elastic force of the elastic part 111 that charges provides the cushion force when charging the mechanism and charging the horizontal pole initial contact, prevent that charging mechanism 11 and charging pile 22 from being bumped badly, the elastic part 111 that charges is preferred is the spring that charges, during charging, the spring that charges can crooked buffering when the contact. Preferably, the control system includes a power detection device, the power detection device is electrically connected to the storage battery pack of the unmanned ship 1, when the power detection device detects that the storage battery pack is insufficient in power, the detection signal is transmitted to the control system, and the control system controls the station power supply connected to the charging pile 22 to be powered on to start charging the storage battery pack. When the power detection device detects that the storage battery pack is full of power, the detection signal is transmitted to the control system, and the control system controls the station power supply connected with the charging pile 22 to be powered off.

In this embodiment, the two ends of the conductor 2221 are both provided with the insulating barriers 2222, and the charging crossbar 222 is an insulator. Two ends of the conductor 2221 are isolated by the insulating baffles 2222, and the charging cross bar 222 is an insulator to prevent safety accidents caused by electric leakage.

In this embodiment, unmanned ship 1 is further provided with sampling mechanism 12 for collecting a water sample and water sample transfer mechanism 13 for transferring the water sample collected by sampling mechanism 12, floating dock 2 is further provided with sample storage mechanism 23 for receiving and storing the water sample transferred by water sample transfer mechanism 13, and sample storage mechanism 23 is connected with the detection mechanism of the station room through the water pump. After the unmanned ship 1 is driven by the electric drive system to travel to a target position, the sampling mechanism 12 collects and stores a water sample, after the water sample is collected, the unmanned ship 1 travels to the floating dock 2 and stops in the berth 21, and the water sample transfer mechanism 13 transfers and conveys the water sample collected by the sampling mechanism 12 to the sample storage mechanism 23 on the floating dock 2 to complete the water sample collection operation. Then the sample storage mechanism 23 conveys the sample water to the station room detection mechanism for detection through a water pump and a water pipe. The unmanned ship sampling system of the embodiment can realize unmanned and automatic sampling-sample transfer-sample detection whole process only by electrically connecting the control system with the related part mechanism and electrically connecting the control system, thereby liberating labor force and improving working efficiency.

In this embodiment, the sampling mechanism 12 includes a rotating disk 121, a water pipe 122, a sampling head 123, a water pump 124 and a first sample water tank 125, the sampling head 123 is fixedly connected to a first end of the water pipe 122, the first sample water tank 125 is connected to a second end of the water pipe 122, the water pipe 122 is wound on the rotating disk 121, the rotating disk 121 is rotated to lift the sampling head 123, and the water pump 124 is disposed on the water pipe between the rotating disk 121 and the first sample water tank 125 to be used for pumping a water sample to the first sample water tank 125. Carousel 121 is connected with rotation actuating mechanism, and water pipe 122 convolutes on carousel 121, and the first end fixedly connected with sampling head 123 of water pipe 122, the first end of water pipe 122 support through supporting wheel 126 and hang in the outside of unmanned ship 1, rotates carousel 121, can realize the lift of sampling head 123 to can gather the water sample of different water depths. The turntable 121 and the water pump 124 are both electrically connected with the control system, when the unmanned ship 1 moves to a target position, the turntable 121 is controlled to rotate to lower the sampling head 123 to a target depth under a control instruction, then the water pump 124 is controlled to start to automatically collect a water sample, and the water sample is stored in the first water sample tank 125. After the water sample collection is completed, the turntable 121 rotates to withdraw the sampling head 123, and the water pump 124 is turned off.

In this embodiment, the water sample transfer mechanism 13 includes a drainage pump 131 and a drainage pipe 132, the drainage pump 131 is connected to the first sample tank 125, the drainage pipe 132 is connected to the drainage pump 131, the drainage pipe 132 is a pipe that extends toward the outer side of the hull of the unmanned ship 1 and can be opened or recovered, so that when the unmanned ship 1 stops at the berth 21, the outlet of the drainage pipe 132 faces the sample storage mechanism 23, so as to transfer the water sample in the first sample tank 125 to the sample storage mechanism 23; further, the drain pipe 132 is provided at one end on the unmanned ship 1, and at the opposite end, is provided extending toward the outside of the hull of the unmanned ship 1 so as to be openable and retractable.

After the unmanned ship 1 collects the water sample, the control system controls the unmanned ship 1 to return and stop to the berth 21, the drain pipe 132 of the water sample transfer mechanism 13 is a vertical rigid pipe, after the unmanned ship stops in place, the drain pipe 132 can be opened and suspended above the sample storage mechanism 23, the outlet of the sample storage mechanism 23 is just opposite to the outlet of the drain pipe 132, and the control system controls the drainage pump 131 to start and transfer the water sample in the first sample water tank 125 to the sample storage mechanism 23.

In this embodiment, the sample storage mechanism 23 includes a second sample water tank 231, an opening of the second sample water tank 231 is a horn opening, and the bottom of the second sample water tank 231 is connected to the detection mechanism of the station room through a water pump. Second appearance water tank 231 is used for collecting the water sample of being transported by first appearance water tank 125 transfer, and the water sample flows to second appearance water tank 231 through unsettled drain pipe 132, and second appearance water tank 231 sets up to the loudspeaker opening, can increase the area of receiving the water sample, prevents that the water sample splash from going out. The bottom of second appearance water tank 231 is connected with intake pipe 232, and intake pipe 232 intercommunication water pump can carry the detection mechanism of standing the room with the water sample in the second appearance water tank 231, and detection mechanism accomplishes the detection to each item index of water sample.

In this embodiment, the berth 21 is provided with a limit gate mechanism 211 for limiting the parked unmanned ship 1. After the unmanned ship 1 is parked at the berth 21, if the unmanned ship is not fixed and limited, the unmanned ship is easy to rock and even drift under the action of water surface waves and storms. Unmanned ship waves to be unfavorable to charging, leads to easily that charging mechanism, charging pile striking damage lead to, consequently, sets up spacing gate mechanism 211 at berth position 21, and after unmanned ship 1 berthed and got into berth position 21, spacing gate mechanism 211 was about to unmanned ship 1 fixed the assigned position in berth position 21.

In this embodiment, the limit gate mechanism 211 includes a limit gate bar 2111 and limit gate bar support bases 2112 located at two sides of the berth 21, one end of the limit gate bar 2111 is rotatably connected with the limit gate bar support base 2112 at the corresponding side, the limit gate bar 2111 is connected with a rotation driving mechanism 2113 for driving the limit gate bar 2111 to be lifted or put down, and a baffle 2114 for limiting the unmanned ship is arranged in the middle of the limit gate bar 2111. Before the unmanned ship 1 enters the berth 21, the limit lock rod 2111 is opened, when the tail of the unmanned ship 1 is detected to enter the berth designated position, the rotary driving mechanism 2113 drives the limit lock rod 2111 to rotate, the limit lock rod 2111 is closed, the baffle 2114 is abutted against the stern of the unmanned ship 1, and the unmanned ship 1 cannot exit from the lower part of the limit lock rod 2111. The limit brake lever support base 2112 is provided with a position detection mechanism for detecting whether the stern of the unmanned ship 1 enters a designated position of the berthing position. The limiting gate mechanism 211 is electrically connected with the control system and used for automatically controlling the starting of the limiting gate mechanism 211.

In this embodiment, two sides of the berth 21 are provided with bumper strips 212. The unmanned ship 1 is driven into a designated position from an opening of the berth 21, and the anti-collision strips 212 are arranged on two sides of the berth 21, so that the impact between the hull of the unmanned ship 1 and the floating dock 2 can be buffered, and the unmanned ship 1 and the floating dock 2 are prevented from being damaged. In this embodiment the floating dock 2 is formed of rubber sheets of a certain thickness spliced together, which can float on the water. In other embodiments, wood or other materials may be used.

In this embodiment, a rain-proof shed is arranged above the berth 21. Set up the weather enclosure in the top of berth 21, unmanned ship berths when berthing at berth 21, and whole unmanned ship hull all is in inside the weather enclosure, no matter charge the mechanism and charge or the sample shifts and all goes on inside the weather enclosure, has avoided the dangerous condition and the pollution of rainwater to the water sample that the rainy day probably brought.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An unmanned ship sampling system is characterized in that,

the unmanned ship comprises an unmanned ship (1) and a floating dock (2) for the unmanned ship (1) to dock, wherein the floating dock (2) is fixed on a water bank;

the unmanned ship (1) is provided with a charging mechanism (11) connected with a storage battery pack;

the unmanned ship is characterized in that the floating dock (2) is provided with a ship berth (21) for the unmanned ship (1) to berth, the ship berth (21) is provided with a charging pile (22) connected with a station house power supply, the bottom end of the charging pile (22) is fixed on the floating dock (2), and the top end of the charging pile (22) is suspended above the ship berth (21) and electrically connected with a charging mechanism (11) of the unmanned ship (1).

2. The unmanned marine sampling system of claim 1,

the charging pile (22) comprises a mounting base (221) and a charging cross bar (222) fixed on the mounting base (221), a conductor (2221) is arranged on the charging cross bar (222), the conductor (2221) is connected with a station power supply,

the charging mechanism (11) comprises a charging elastic part (111) which is vertically arranged, the charging elastic part (111) is fixed on the unmanned ship (1) through a fixing part (112), so that when the unmanned ship (1) stops at the ship berth (21), the charging elastic part (111) is electrically connected with the electric conductor (2221).

3. The unmanned marine sampling system of claim 2,

insulating baffles (2222) are arranged at two ends of the conductor (2221), and the charging cross rod (222) is an insulator.

4. The unmanned marine sampling system of claim 1,

the unmanned ship (1) is also provided with a sampling mechanism (12) for collecting water samples and a water sample transferring mechanism (13) for transferring the water samples collected by the sampling mechanism (12),

the floating dock (2) is also provided with a sample storage mechanism (23) for receiving and storing the water sample conveyed by the water sample transfer mechanism (13), and the sample storage mechanism (23) is connected with the detection mechanism of the station room through a water pump.

5. The unmanned marine sampling system of claim 4,

sampling mechanism (12) are including carousel (121), water pipe (122), sampling head (123), suction pump (124) and first same water tank (125), sampling head (123) link firmly the first end of water pipe (122), first same water tank (125) are connected the second end of water pipe (122), water pipe (122) are convoluteed on carousel (121), through rotating carousel (121) are in order to realize the lift of sampling head (123), suction pump (124) set up carousel (121) with on the water pipe between first same water tank (125) the pipeline, in order to be used for extracting the water sample extremely first same water tank (125).

6. The unmanned marine sampling system of claim 5,

the water sample transferring mechanism (13) comprises a drainage pump (131) and a drainage pipe (132), the drainage pump (131) is connected with the first water sample tank (125), the drainage pipe (132) is connected with the drainage pump (131), the drainage pipe (132) is a pipeline which extends towards the outer side of the unmanned ship (1) body and can be opened or recycled, so that when the unmanned ship (1) transfers water samples, an outlet of the drainage pipe (132) is opposite to the sample storing mechanism (23), and the water samples in the first water sample tank (125) are transferred to the sample storing mechanism (23).

7. The unmanned marine sampling system of claim 6,

store up appearance mechanism (23) and include second appearance water tank (231), the opening of second appearance water tank (231) is the loudspeaker opening, the detection mechanism of standing the room is connected through the water pump in the bottom of second appearance water tank (231).

8. The unmanned marine sampling system of claim 1,

and a limiting gate mechanism (211) is arranged on the berthing position (21) and used for limiting the berthed unmanned ship (1).

9. The unmanned marine sampling system of claim 8,

the limiting gate mechanism (211) comprises limiting gate rods (2111) and limiting gate rod supporting bases (2112) located on two sides of the ship berth (21), one end of each limiting gate rod (2111) is rotatably connected with the corresponding limiting gate rod supporting base (2112), the limiting gate rods (2111) are connected with a rotary driving mechanism (2113) to drive the limiting gate rods (2111) to be lifted or put down, and baffles (2114) used for limiting the unmanned ship are arranged in the middle of the limiting gate rods (2111).

10. The unmanned marine sampling system of any one of claims 1 to 9,

and anti-collision strips (212) are arranged on two sides of the berth (21).