1. Field of the Invention
The present invention relates generally to a security barrier for use at a port or the entrance to an inland waterway which receives ships laden with cargo or military watercraft. More specifically, the present invention relates to a port security barrier which is economical, easy to transport and assemble and provides sufficient strength to stop, delay and discourage attacks by boats of 65 feet or less in length on high valued waterfront assets.
2. Description of the Prior Art
There is currently a need within the Department of the Navy to provide protection for military watercraft which are moored at ports or inland waterways. In particular, there is a need to provide protection for military watercraft against explosive laden boats while the watercraft are moored at a port or an inland waterway.
There is also need to keep initial cost as low as possible and also meet military security requirements by (1) making the barrier as light as practical; (2) using low-cost standard materials where ever practical; (3) making the system as simple as possible; and (4) making the barrier easy to assemble and deploy.
Maintenance cost of the port security barrier are also a consideration. Low maintenance cost are generally achieved by using composite materials and keeping the port security barrier simple and minimizing the number parts required to keep the barrier operational.
Further operational cost need to be kept at low levels. Low operational cost can be achieved by the port security barrier light weight and keeping wind, current and wave loading on the barrier as low as practical so that operators can easily open and close barrier gates.
The present invention overcomes some of the difficulties of the past including those mentioned above in that it comprises a relatively simple in design, light weight and easy to relocate port security barrier which is designed to protect watercraft and ocean going vessels from attack by explosive laden boats which are generally 65 feet or less in length and travel at speeds of 50 knots or greater.
The port security barrier includes multiple barrier float assemblies connected to one another to form the barrier. Each barrier float assembly is approximately 40 feet in length and includes two pontoons which are located near each end of the assembly. The barrier float assembly also has a main longitudinal net support beam which includes a pair of net fence post located near each end of the longitudinal net support beam. The fence post provide support for a horizontal line or wire to which is attached a nylon barrier net, which functions as a capture net. The nylon barrier net operates as the capture mechanism for the port security barrier preventing a high speed boat from entering a restricted port area.
A pair of identical saddle and belly band assemblies secure each of the pontoons to the main longitudinal net support beam. A flanged sleeve connector is used to secure adjacent barrier float assemblies to each other.
One end of the barrier float assembly is designed to accommodate a latching mechanism that is used to couple the barrier float assembly to a mooring buoy. The latching mechanism allows the barrier float assembly to be swung open and then closed acting as a gate for vessel traffic which passes through the assembly into and out of a port facility.
Referring to
The port security barrier 20 is designed to protect ocean going vessels and watercraft and stop approximately 99.9% of United States commercial boats with a minimum working stopping capacity of approximately 1.8 million foot-pounds of kinetic energy. The barrier 20 also has a factor of safety to increase net replacement time, thus, the net boat stopping capacity is approximately 3.6 million foot-pounds.
The nylon net 22 has five horizontal members 30 of ¾ inch diameter nylon with a spacing of 15 inches and 21 vertical members/nylon ropes 32 of ⅝-inch diameter nylon with a spacing of 24 inches. The nylon net 22 generally has a length of 42 feet which is the approximate length of each barrier float assembly.
Net 22 in another embodiment comprises a mesh in which there is 13¾″ spacing between horizontal ropes 30 and 18″ spacing between vertical ropes 32. The height of net 22 is five feet. In this embodiment the horizontal ropes 30 are ¾″ 12-strand braided nylon, with a minimum breaking strength of 17,900-LBS. The vertical ropes are ⅝″ or ¾″ 12-plait nylon, with a minimum breaking strength of 13.900-LBS. Each rope 30 and 32 of nylon net 22 is pre-shrunk or stabilized against water shrinkage.
The capture net's horizontal members/ropes 30 and vertical members/ropes 32 that are integrally connected to one another such that tensile loads introduced into the capture net are distributed throughout the horizontal members 30 and the vertical members 32 of the capture net 22.
Barrier float assembly 40 has a netting support structure consisting of a netting termination post 42 located near one end of the main longitudinal net support beam 44, a fence post 46 located on net support beam 44 approximately 66-⅝″ from termination post 42, and a fence post 48 located near the other end of net support beam 44.
The excess netting portion 50 located at the left end of net 22 is secured to netting termination post 42 by five anchor shackles 52 attached to termination post 42. Each of the five horizontal ropes 30 has an eye loop 54 at the left end of the rope 30. The eye loop 54 at the left end of each of the five horizontal ropes 30 of net 22 secures the left end of the rope 30 to one of the anchor shackles 52 attached to termination post 42.
There is a lanyard 53 in proximity to each termination post 42. Lanyard 53 has a minimum breaking strength of 90,000 pounds.
At this time it should be noted that the barrier float assemblies which are at the end of a chain of barrier float assemblies, such as barrier float assembly 40 are the only assemblies which include a netting termination post.
Wire ties 56 are used to secure the five horizontal ropes 30 of net 22 to fence post 46. In a like manner, wire ties 58 are used to secure the eye loop 55 at the right end of each horizontal rope 30 to the fence post 48. Five anchor shackles 60 are attached to fence post 48 which are also used to secure the five horizontal ropes 30 of net 22 to fence post 48. The eye loops 54 and 55 are 9-inch inside length at each end of the rope 30 with a 4-3-2 plated rope splice.
Nylon net 122 is the section of the barrier net 124 positioned between adjacent barrier float assemblies 40 and 120 The five anchor shackles 60 secure the left end of nylon net 122 to net post 48. The right end of nylon net 122 is secured to fence post 126 by five wire ties 128.
At this time it should be noted that a portion of the nylon capture net at one of each of the barrier float assemblies overlaps the adjacent barrier float assembly and is attached to one of the fence post of the adjacent barrier float assembly. For example, nylon net 122 is the portion of nylon capture net 124 for barrier float assembly 120 which is attached the right fence post 48 of barrier float assembly 40,
At this time it should also be noted that the vertical and horizontal ropes used to assemble the barrier net 22 are coated with a marine grade finish (various colors) at the time of manufacture to minimize nylon shrinkage caused by exposure to water. A polyurethane water base coating (maximum allowable dilution rate =2 parts water to 1 part polyurethane) is applied as a final UV protection to each rope 30 and 32 of nylon net 22.
Positioned a top fence post 46 is an aid to navigation light 62 which is set to various flash patterns. The flashing navigation lights are installed on every other barrier float.
A horizontal galvanized or stainless steel wire rope 66 is supported above the upper horizontal rope 30 of nylon net 22. Steel wire rope 66 is secured at one end to fence post 46 by a turnbuckle and sleeve compression assembly 70. Steel wire rope 66 is secured at the opposite end to fence post 48 by a sleeve compression assembly 72. The turnbuckle of turnbuckle and sleeve compression assembly 70 allows a user to adjust steel wire rope 66 such that rope 66 drops no more than six inches between fence post 66 and 68 with nylon net 22 installed.
Between fence post of the port security barrier 20, the upper horizontal net rope 30 is secured to the wire rope 66 with wire ties 64 spaced approximately 18-inches apart. The tail end of the wire ties 64 also serve as a bird deterrent.
Similarly, a horizontal galvanized or stainless steel wire rope 74 is supported above the upper horizontal rope 30 within the excess netting portion 50 of nylon net 22. Steel wire rope 74 is secured at one end to netting termination post 42 by a turnbuckle and sleeve compression assembly 76. Steel wire rope 74 is secured at the opposite end to fence post 46 by a sleeve compression assembly 78.
A warning sign 80 which warns an intruder that access to the area beyond barrier 20 is restricted is affixed to the nylon net 22. Warning sign 80 is an etched metal sign inscribed in 3-inch high letters and is hung on nylon net 22 from the threat side of the netting clear of the net support structure. One warning sign is hung on every second barrier float.
Located near each end of the main longitudinal net support beam 44 of barrier float assembly 40, are two 14-foot long 24-inch OD pontoons 82 and 84. Pontoons 82 and 84 are either foam filled or have an interior which hollow, i.e. not filled with foam. The pontoons 82 and 84 of barrier float assembly 40 are generally perpendicular to the main net support beam 44 of barrier float assembly and are spaced approximately 26 feet apart center line to center line.
The main longitudinal beam 44 used in the preferred embodiment is a 12×8×¼ inch structural steel beam, which is chemical and corrosion resistant. A pair of identical saddle and belly band assemblies 86 secure each of the foam filled pontoons 82 and 84 to the main longitudinal net support beam 44.
It should be noted that other types of beams could be used as the main longitudinal support beam. For example, a 12.75-inch OD HDPE (high density polyethylene) beam could be used as the main longitudinal beam for port security barrier 20. This type of beam is extremely chemical and corrosion resistant and would provide more than adequate protection from the corrosive effects of seawater.
Similarly barrier float assembly 120 has a main net support beam 140 and a pair of foam filled pontoons 142 and also a nylon net 124 which operates as a capture net to deter high speed watercraft from entering a restricted area such as a military ship docking facility.
The overall length of each of each barrier float assembly 40 and 120 is approximately 40 feet.
Referring to
Attached to longitudinal net support beam 44 is a tow bracket 148 which is positioned inward from flange 138 of support beam 44. Attached to longitudinal net support beam 129 is a tow bracket 150 which is positioned inward from flange 136 of support beam 129. The tow brackets 148 and 150 are used to secure a safety chain 152 to each of longitudinal net support beams 44 and 129 when the support beams 44 and 129 are connected as shown in
The safety chain assemblies 152 are 11 chain links long plus two end links or two detachable links suitable for assembly to shackles 149 at each end of chain 152. The shackles 149 are secured to tow brackets 148 and 152.
Each tow bracket 148 and 150 also has a kayak wire support bracket 154. Attached to kayak wire support bracket 154 is a turnbuckle 156 for one end of a kayak guard wire 158. The other end of kayak guard wire 158 is secured to a kayak wire support bracket 160 attached to support beam 44 adjacent pontoon 82. Kayak guard wires 158, 162 and 164 run the length of support beam 44 to prevent kayak and canoes from passing underneath the port security barrier into restricted waters.
Referring to
A tension element 184 is centrally located in the latch connector spear 174. A pin 186 is used to secure one end of tension element 184. The opposite end of tension element 184 is connected to a lanyard 188. Lanyard 188 engages a pair of sheaves 190 and 192 mounted on buoy 72 has its opposite connected to a tug boat (not illustrated). When it is desired to close the latch connector assembly 170, the tug boat pulls the lanyard 188 around the sheaves 190 and 192 in a clockwise direction, which pulls the tension element 184 and connector spear 174 into the interior of latch connector receiver 178.
The latch connector receiver 178 has a locking element 194 in its interior which engages either tension element 184 or another component of the connector spear 174 in the manner illustrated in
A hand winch 198 mounted on buoy 172 can also be used to secure barrier float assembly 40 to buoy 172. One end of lanyard 188 is rotatably connected to the hand winch 198 while the other end of lanyard 188 is connected to tension element 184. By rotating the winch 198 in a counter-clockwise direction the user draws the latch connector spear 174 into the latch connector receiver 178 securing the main longitudinal net support beam 44 of barrier float assembly 40 to buoy 172.
Other connectors could be used to secure the main longitudinal net support beam 44 for barrier float assembly 40 to a buoy 172. For example, the connector could be a high strength flexible wire rope or a nylon rope have similar characteristics.
A safety line 200 (
There is also a ½-inch diameter support rope 202 (
Referring to
From the foregoing, it is readily apparent that the present invention comprises a new, unique, and exceedingly useful low cost port security barrier for preventing attack watercraft from entering a restricted port area, which constitutes a considerable improvement over the known prior art. Many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.
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Number | Date | Country | |
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20080105184 A1 | May 2008 | US |