GB2502993A

GB2502993A - Dockside bollard testing

Info

Publication number: GB2502993A
Application number: GB1210407.1A
Authority: GB
Inventors: Michael Harrison
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-06-13
Filing date: 2012-06-13
Publication date: 2013-12-18
Anticipated expiration: 2032-06-13
Also published as: GB201210407D0; GB2502993B; GB2502993C

Abstract

A device for testing a dockside bollard comprises a frame 12 adapted to rest on the dockside, means attached to the frame, such as a hydraulic ram 14, for applying a tensile force to the bollard 40 and a measuring device, such as a load cell or load shackle, for measuring the tensile force applied to the bollard. The frame includes at least one portion 26 which, in use, extends downwardly over the dockside edge for transferring force to the dockside during testing. The device may transfer force to the bollard at a range of angles in the horizontal and vertical plane, simulating the forces which a marine bollard may be expected to withstand in use. The tensile force may be applied via a rope or cable 18 and a pulley arrangement 16 and the frame may be of adjustable length and include a high friction surface to prevent the frame slipping during use.

Description

TESTING DEVICE

The present invention relates to a testing device and particularly but not exclusively to a testing device for testing a dockside bollard.

BACKGROUND TO THE INVENTION

Bollards are typically provided on docksides for mooring vessels. Single or multiple ropes or other lines are attached at one end to the vessel and at the other end to a dockside bollard. Several lines are typically attached between a vessel and the dockside, in an arrangement designed to minimise motion of the vessel. In one typical arrangement, bow line(s), stern line(s), breast line(s) and forward and aft spring lines extend at an angle to the side of the vessel, limiting movement of the vessel. Bow, stern and breast lines extend substantially perpendicular to the side of the vessel limiting movement away from the dockside caused by combinations of sway, yaw, roll and other motions.

A bollard provided on a dockside may be used throughout its lifetime to moor ships and boats of widely varying sizes and types, and each bollard may be used for attaching bow, stern, spring and breast lines. The bollards will therefore experience forces at any angle, from a direction substantially parallel to the edge of the dock, through a substantially perpendicular direction to a direction substantially parallel to the dockside in the opposite sense. The vertical component of the force may also vary substantially. For example, water levels may vary due to tides or other reasons, different types of ships may be moored, and ships may vary in draught due to changes in ballast or cargo weights. Also, the deck of a ship may move vertically with respect to the dockside, and may even move from a position below the dockside to a position above the dockside. The vessel may be urged away from the dock by wind, water current, tidal movement, or by water movement caused for example by a passing vessel. The forces experienced by the bollards are considerable, and may be up to 2000kN. Even larger bollards are used on occasion, for example as supplementary moorings used in storm conditions.

Bollards come in many shapes, types, sizes, capacities and materials. The characteristics of bollards have been developed over time but they arc anticipated to have a long life, and remain in service for many years. Bollards and theft fixings may suffer flx,m corrosion, fatigue and other effects which can weaken the bollard or the supporting structure over a period of time. Such damage may not be i".'u'ediately apparent, though it may have severe consequences on the ability of the bollard to withstand the required forces.

A bollard which fails to withstand the forces applied to it through mooring lines may cause a scrious or even fatal accident. It may also cause severe damage to dockside equipment A person attempting to embark or disembark flxm the vessel when the vessel breaks away flxm the dock may fill into the water between the side of the vessel and the dock with a risk of crushing or drowning. Injury may also be caused by the bollard itself as it breaks away, with steel, iron, concrete or other debris from the dockside being propelled at high speed. The mooring line itself may cause injuiy and where natural or synthetic fibre ropes or steel wire rope is used for moorin& the risk ofinjury caused by the high-tension rope snapping back is particularly great Even if no person is injured, bollards which fail typically cause damage to the dockside structure which may affect the integrity of adjacent bollards or other berthing, mooring, ship loadin& or access equipment which must be repaired before that part of the dock may be used again. Such repairs may take weeks or months, and have a substantial negative impact on the efficiency of a port.

Due to the above mentioned dangers, it is prudent to test dockside bollauls at regular intervals. To do this, the maximum force expected to be applied by a moored ship must be simulated. The expected forces due to spring lines may be replicated and tested using lines connected to adjacent bollards. Howevei expected forces due to bow, stem and breast lines are difficult to replicate and measure, particularly in the fall range of vertical angles. Various testing methods are available for checking the body of the bollard for cracks and defects. Other tests can apply vertical tension to anchor or fixing bolts. However, such tests cannot guarantee the performance of the bollard under realistic loading conditions which combine shear forces, tensile forces and overturning moments, and cannot verifr the integrity of the fall mooring assembly comprising of bollard body, anchors or bolts and concrete or other supporting structure.

It is an object of the present invention to reduce or substantially obviate the above mentioned problems.

STATEMENT OF INVENTION

According to a first aspect of the present invention, there is provided a device for testing a dockside bollard comprising a frame having a base adapted to rest on the dockside, means attached to the frame for applying a force to the bollard and a measuring device for measuring the force applied to the bollard, the frame including at least one portion extending downwardly from the base which, in use, extends downwardly over the dockside edge for transferring force to the dockside during testing.

The testing device is advantageous, since it allows testing of bollards by replicating the various forces and moments which they may experience when used to moor a vessel. The applied force may be in a horizontal direction substantially perpendicular to, and away from, the dockside, so as to simulate the force experienced by a bollard with a head, stern or breast line attached.

The angle between the direction of the applied force and the horizontal may be adjustable. By adjusting the vertical component of the applied force, the changing direction of force which will be experienced due to different vessel types, and due to variations in water level, ballast condition or loaded cargo may be replicated.

A second frame may be induded, and may be pivotally mounted to the first frame.

Means for applying a force, particularly tensioning means, may be attached to the second frame. The tensioning means may conveniently be located on a landward side of the device, so that the means may be operated by a user on dry land.

A pulley or drum may be provided, and may be supported on an upwardly extending portion of the frame. The pulley or drum allows the tensioning means to be located on the landward side of the device, whilst applying tensile force to the bollard from a seaward direction. This allows the force of a moored vessel to be accurately replicated, and protects the user since any failure caused by testing will cause the bollard and/or parts of the dock structure to be projected towards the water, away from the user.

The tensioning means may be a hydraulic ram, and the measuring device may measure the hydraulic pressure in the ram. A hydraulic ram is capable of producing the very large forces which may be experienced by a bollard when used for mooring a large vessel.

The tensioning means may alternatively be a winch, pulley blocks, a screw jack, or any other suitable means.

The measuring device may alternatively be a load cell, a load shackle, or any other means of measuring applied forces.

The downwardly extending frame portion may be provided with a high friction surface, for example rubber or polyurethane. The high-friction surface prevents the device from lifting when the tensioner is activated.

The frame may include feet or other supports for raising the frame from the surface of the dockside. Supports are advantageous where the dockside is not level, or is obstructed by for example a curb.

The base portion of the frame may be adjustable in length, to accommodate varying distances between bollards and dock edges.

A cage may be provided which substantially encloses the bollard whilst testing is in progress. The cage provides for safe operation since any debris generated by a bollard failure during testing will be contained and will not injure the tester or other persons.

A rope or other flexible line may be provided for transmitting force from the tensioner to the bollard. A rope or flexible line is advantageous since it allows for the use of a pulley, with the above mentioned advantages.

Transmitting the force via a rope or line most closely replicates the operating conditions of thc bollard in normal use. Since bollards are designed for mooring vessels via ropes or lines, all bollards will be compatible with a testing device which applies a force to a bollard in this way.

A rope or flexible line can be of similar material, size and constniction to thc mooring lines of ships and thereby attach to the bollard in a manner which closely simulates actual working conditions.

The rope or line may be made from steel wire, manila fibre, high modulus polyethylene such as Dyneema (1CM), nylon, polyester such as Dacron (RIM), polyaramid such as Kevlar (RTM), or any other suitable synthetic or natural material of adequate working load and minimum breaking strength.

According to a second aspect of the present invention there is provided a method of testing a dockside bollard comprising applying a force to the bollard and measuring the applied force using a testing device in accordance with the first aspect of the invention.

According to a third aspect of the invention there is provided a method of testing a bollard comprising applying a plurality of measured forces from different directions to a bollard, to determine if the bollard can withstand the applied forces.

DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which: Figure 1 shows a side view of a bollard testing device, in which the angle of force has bccn adjusted to around 300; and Figure 2 shows a plan view of the bollard testing device of Figure 1 with the hydraulic cylinder omitted to more clearly show the positioning of a bollard under test.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring to Figures 1 and 2, a testing device for a dockside bollard is indicated generally at 10. The testing device 10 comprises a first frame 12 and a second framc 13, a hydraulic ram 14, a pulley 16 and a rope or cable 18.

The first frame 12 is made from steel plates and section, and includes a base portion 20, a hinge portion 22, a first vertical portion 24, a second vertical portion 26, a first brace portion 28 and a second brace portion 30. The base portion 20 is substantially rectangular, having two ends and two sides, with an open centre. In use, the base portion 20 may rest horizontally on a dockside 32 on feet 21, with a bollard 40, held in position with ground anchors 42, extending upwardly through the open centre. This is best seen in Figure 2. In this position, ends of the base portion 20 lie parallel to the edge of the dockside 32 and the sides of the base portion 20 lie perpendicular to the edge of the dockside 32. The feet may have a high friction coating to help resist slipping.

The hinge portion 22 extends from one end of the horizontal base portion 20 and comprises two steel plates secured to longitudinal struts of the base portion 20 and the first brace portion 28. The first brace portion 28 comprises two steel struts extending from the base portion 20 and hinge portion 22, at an angle of approximately 30° from the base portion, meeting the first vertical portion 24 at its upper end. The first vertical portion 24 extends upwardly from the horizontal base at a position approximately three quarters of the distance between the hinge portion and the other end of the base portion. The first vertical portion 24 comprises two vertical struts substantially at either side of the base portion.

The second vertical portion 26 extends downwardly from the same position on the horizontal basc portion 20 as the first vertical portion 24 and comprises two vertical struts at either side of the base portion, the two vertical struts of the first vertical portion 24 being integrally formed with the two vertical struts of the third vertical portion 26. The second vertical portion 26 is provided with a high-friction surface, for example rubber, provided on bumper elements or feet 23, which rcst against thc dockside 32 in use.

A second brace portion 30 is provided between the bottom end of the second vertical portion 26 and thc seaward end of the base portion 20.

The length of the base portion 20 is adjustable to accommodate varying distances from dock face to bollard. To accommodate adjustment of the base portion 20, the first brace portion 28 may be detachable or adjustable. The adjustment means may be telescopic members, or detachable additional sections.

One or both end sections of the base portion 20 may be removable to allow the testing device to be slid over a bollard, avoiding the need for lifting. The end section may be replaced before the testing device is operated, and removed again after operation to facilitate easy removal of the testing device from the bollard.

The second frame 32 comprises two sides 34, a first (landward) end section 36 and a second (seaward) end section 38. The second frame 32 is pivotally mounted to the hinge portion 22 of the main frame 12 at the first end 36, and at the second end 38 clamps to the first vertical portion 24 at and position between the bottom and the top of the first vertical portion.

The hydraulic ram 14 is mounted to the second frame 32 at a substantially central location between the sides 34 of the second frame 32.

A pulley 16 is provided at the second end 38 of the second frame 32, at a substantially central location between the sides 34. The pulley may freely rotate. A rope, wire or other line 18 is attached at one end to the hydraulic ram 14, passes around the pulley 16 and is attached to the bollard 40 by a soft eye or other suitable connection.

The pulley 16 is provided with a number of grooves so that various diameters of rope may be used with the testing device.

The angle between the rope 18 and the horizontal may be adjusted by raising or lowering the second end 38 of the second frame 32. This is done by pivoting the second frame 32 where itis mounted to the hinge portion 22 of the first frame at the firstend36.

The second frame 32 may be pivoted without mechanical assistance. Alternatively, supplementary pulleys, winches, rams or other devices may be provided, especially in larger embodiments of the testing device, to assist with pivoting the second frame, which may then be locked in position at the desired angle using bolts, clips or other devices.

When the testing device 10 is in operation, the hydraulic cylinder 14 is actuated, which applies a tensile force to the rope 18 and to the bollard 40 through the soft eye.

The frame 20 does not move, because the frame exerts a force on the dockside through the base portion 20 and the second vertical portion 26. The force exerted will be substantially inland and downwards, and the testing device 10 will theitibre not move. Where the force is being applied to the bollard at an angle where there is an upwards vertical component of fbrcc being exerted on the dockside, the high-friction surfice of the second vertical portion 26 of the frame 12 will provide a reaction, preventing movement of the testing device. Ballast or securing lines may also be provided to resist upward vertical forces and to ensure that the testing device remains stationary whilst in operation.

The tension applied to the bollard 40 via the rope is measured by a load cell or other measuring device and the tension will depend on the type of bollard being tested, and the anticipated load that the bollard is expected to withstand. By repeated testing with the second frame 13 positioned at different angular positions to the base of the first frame, different loadings can be simulated. A cage, not shown, may surround the bollard 40 being tested, in case of a failure.

Testing devices may be produced in different sizes, in order to suit different sizes of bollard. It will be appreciated that the testing device is portable, does not require alternations to the ship berthing structure, is suitable for testing all types of bollard and provides repeatable tests with controlled loads. Remote operation is also possible with remote control means for the hydraulic cylinder 14.

Claims

CLAIMS1. A device for testing a dockside bollard comprising a frame having a base adapted to rest on the dockside, means attached to the frame for applying a force to the bollard and a measuring device for measuring the force applied to the bollard, the frame including at least one portion extending downwardly from the base which, in use, extends downwardly over the dockside edge for transferring force to the dockside during testing.
2. A testing device as claimed in claim 1, in which the angle between the direction of the applied force and the horizontal is adjustable.
3. A testing device as claimed in claim I, in which a second frame is included, pivotally mounted to the first frame.
4. A testing device as claimed in claim 3, in which the means for applying a force is attached to the second frame.
5. A testing device as claimed in claim 3 or 4, further comprising a pulley or drum, the pulley or drum being supported on the second frame.
6. A testing device as claimed in any of the preceding claims, in which the means for applying a force is provided by a hydraulic ram.
7. A testing device as claimed in claim 6, in which the measuring device measures the hydraulic pressure in the ram.
8. A testing device as claimed in any of the preceding claims, in which the measuring device is a load cell.
9. A testing device as claimed in any of the preceding claims, in which the measuring device is a load shackle.
10. A testing device as claimed in any of the preceding claims, in which the downwardly extending frame portion is provided with a high-friction surface.
11. A testing device as claimed in claim 10, in which the high-friction surface is made from rubber.
12. A testing device as claimed in claim 10, in which the high-friction surface is made from polyurethane.
13. A testing device as claimed in any of the preceding claims, in which the frame includes feet or other supports for raising the frame from the surface of the dockside.
14. A testing device as claimed in any of the preceding claims, in which the base portion of the frame is adjustable in length.
15. A testing device as claimed in any of the preceding claims, in which the frame comprises a cage in which a bollard is substantially enclosed whilst undergoing testing.
16. A testing device as claimed in any of the preceding claims, further comprising a rope or other line for transmitting tension provided by the means for applying a force to the bollard.
17. A method of testing a dockside bollard comprising applying a force to the bollard and measuring the applied force using a testing device as claimed in any one of claims Ito 16.
18. A method of testing a bollard comprising applying a plurality of measured forces from different directions to a bollard, to determine if the bollard can withstand the applied forces.
19. A testing device substantially as described herein with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.
20. A mcthod of testing a bollard including a dockside bollard substantially as described herein with reference to and as illustrated in Figures! and 2 of the accompanying drawings.