SPECIAL SPECIFICATION 5273 Dragnet Vehicle Arresting Barrier

Transcription

1 2004 Specifications CSJ , etc. SPECIAL SPECIFICATION 5273 Dragnet Vehicle Arresting Barrier 1. Description. This Item governs for the furnishing and installation of Dragnet Vehicle Arresting Barriers in designated field locations as shown on the plans and as detailed in the Specifications. 2. Materials. A. General Requirements. All materials furnished, assembled, fabricated, or installed under this Item must be new, corrosion resistant, and in strict accordance with the details shown on the plans and in the Specifications. The Dragnet Vehicle Arresting Barrier is used to prohibit motor vehicles from entering a closed highway. The Dragnet must safely decelerate and stop a vehicle in accordance with NCHRP 350 guidelines, Test Level 3. The Dragnet Vehicle Arresting Barrier includes, but is not limited to the following: B. Functional Requirements. - Vehicle restraining mechanism - Structural frame - Lifting mechanism - Local controls The Dragnet Vehicle Arresting Barrier includes a vehicle restraining mechanism to decelerate and stop errant vehicles. The restraining mechanisms consist of, as a minimum, one energy-absorbing device on either side of a restraining net. The devices travel with the lifting-lowering mechanism to open or close a road and have bi-directional vehicle stopping ability. The restraining net has high strength impact capacity and has reflective stop sign attached. The net entraps the vehicle and transfers the force of the impact to the energyabsorbing device. The structure used to support the restraining and lifting-lowering mechanisms must be capable of withstanding all operating loads placed upon them, to include load transferred by the impact and deceleration of the vehicle, by the lifting-lowering mechanism, and by loads generated by environmental conditions. Each structure is secured at its base to a reinforced concrete foundation. This structure must be high enough to allow for a minimum of 17'-10" of space between the bottom of the net and the roadway when the net is in the up position. The lifting-lowering mechanism is an electro-mechanical device used to lift and lower the restraining mechanism. This mechanism consists of two carriages, one on each side of the

2 support structure, two drive sprockets, and other necessary appurtenances required to achieve a fully operational system. When lowered the carriage transfers the kintetic energy from the restraining device to the energy absorber and subsequently into the base plate of the structural frame. The barrier must be capable of both remote and local control. Manual controls are provided to locally position the restraining net during failure of remote control, or in maintenance or emergency conditions. Controls consist of raise, stop and lower functions. Failure of Power Supply requires use of a manual hand crank. C. Electrical Requirements. 1. Drive Motor. The motor must be totally enclosed, non-ventilated, ball-bearing, and instant-reversing type. It operates from three phase 480 VAC at 60 Hz. 2. Local Control Panel. The Contractor provides a local control panel, specified below. The local control panel is installed in the surveillance cabinet as shown on the plans. The panel of the dragnet controller has the following clearly labeled waterproof switches. Dragnet Up - Push button switch to control raising of the barrier. Dragnet Down - Push button switch to control lowering of the barrier. Operations Mode Select - Rotary switch used in conjunction with HOV Lane Control panel to determine mode of operation of the barrier. The mode of operation is controlled as follows: Local Control Panel HOV Lane Control Panel Mode of Mode Switch Mode Switch Operation Local HOV Lane HOV Lane Remote HOV Lane HOV Lane Local Remote Local Remote Remote Remote Commands and confirms are as follows: COMMANDS CONFIRMS 1. Up 1. Up 2. Down 2. Down 3. Local Control A true "local control confirm" indicates that the operations mode select switch is in the local position. A true "up confirm" indicates that the barrier is fully up. A true "down confirm" indicates that the barrier is fully down. Both "up confirm" and "down confirm" are false when the barrier is not fully up or fully down

3 A true "up command" (0 VDC) from the local control unit to the local control panel for greater than.5 to 5 seconds adjustable in.5 second intervals simultaneous with a false "down command" causes the local control panel to send a 120 VAC "up" signal to the barrier. A true "down command" (0 VDC) from the local control unit to the local control panel for greater than.5 to 5 seconds adjustable in.5 second intervals simultaneous with a false "up command" causes the local control panel to send a 120 VAC "down" signal to the barrier. Invalid conditions are not acted upon by the local control panel, including: - Valid command of less than.5 seconds in duration. - Simultaneous true "up command" and "down command". - Simultaneous false "up command" and "down command". 3. HOV Lane Control Panel. An HOV Lane control panel is provided and installed in satellite number 4 as shown on the plans. The front panel of the HOV Lane Control Panel has the following clearly labeled waterproof switches: Dragnet Up - Push button switch to control raising of the barrier. Dragnet Down Push button switch to control lowering of the barrier. Operations Mode Select - Two position switch used in conjunction with local control panel as described in Section to determine mode of operation. 4. LOAD SWITCHES. The load switches required to operate the Dragnet Vehicle Arresting Barrier are included as part of this Item. Load switches are solid state and have no moving parts. The load switches must meet the requirements set forth in Section 5 of NEMA Standard TS1-1989, latest revision, and must be "triple signals load switch" type. An indicator light for each circuit is provided on each load switch. The indicator light is on when a true input to the load switch is present. The load switches are capable of operation at 10 amperes of tungsten lamp load over the specified temperature range. 5. Wiring. Wires exiting and entering the barrier housing is via terminal blocks in the housing and through openings in the concrete foundation or pedestal. Barrier housing must be properly grounded. All wiring must meet the requirements of the National Electric Code. All wires are cut to proper length before assembled. No wire is doubled back to take up slack. Wires are neatly laced into cables with nylon lacing or plastic straps. Cables are secured with clamps. Service loops are provided to facilitate the removal and replacement of assemblies, panels, and modules for maintenance

4 6. Power Requirements. The Dragnet Vehicle Arresting Barrier and the associated equipment operate from 480 plus or minus 50 VAC, 60 Hz plus or minus 3 Hz. The equipment operation is not affected by transient voltages, surges, and sags normally experienced on commercial power lines. The Contractor checks the local power service to determine if any special design is needed for the equipment. The extra cost, if required, is included in the bid price of the dragnet vehicle arresting barrier. 7. Transient Suppression. All DC relays, solenoids and holding coils have diodes across the coils for transient suppression. All AC contractors have snubbers. 8. Protection. The equipment contains readily accessible, manually resettable, or replaceable circuit protection devices (such as circuit breakers or fuses) for equipment and power source protection. Circuit breakers or fuses is provided and sized such that no wire, component, connector, PC board or assembly is subject to sustained current in excess of their respective design limits upon the failure of any single circuit element or wiring. 9. Fail Safe. The equipment is designed such that the failure of the equipment does not cause the failure of any other unit of equipment. D. Mechanical Requirements. 1. Barrier Construction. All external shafts and fasteners must be corrosion resistant. All contractors and limit switch contacts are of silver alloy. Barrier transmission is gear-driven, with no belts or chains. The transmission mechanism is removable as a single unit. All shafts protruding from gear boxes containing oil are equipped with dual oil seals. Each transmission sub-assembly is interchangeable with all other such units. All bearings are designed for one million cycles of operation. Lubrication is not required at any point more often than once every 12 months. E. Environmental Design Requirements. The barrier and its associated equipment must meet all of its specified requirements during and after subjecting to any combination of the following conditions: 3. Construction. - Ambient temperature range of 0ºF to 140ºF - Temperature shock not to exceed 30ºF per hour, during which the relative humidity does not exceed 95%. - Relative humidity range not to exceed 95% over the temperature range of 40ºF to 110ºF. - Moisture condensation on all surfaces caused by temperature changes

5 A. General. The Dragnet Vehicle Arresting Barrier design and construction must utilize the latest available techniques with a minimum number of parts, subassemblies, circuits, cards, and modules to maximize standardization and commonality. The equipment is designed for ease of maintenance. All component parts are readily accessible for inspection and maintenance. Test points are provided for checking essential voltages and waveforms. B. Electronic Components. All electronic components must comply with Special Specification, "Electronic Components" included. C. Mechanical Components. All external screws, nuts, and locking washers must be corrosion resistant; no self-tapping screws shall be used unless specifically approved by the Engineer. All parts are made of corrosion resistant material, such as plastic, stainless steel, anodized aluminum or brass. All materials used in construction are protected from fungus growth and moisture deterioration. Dissimilar metals are separated by an inert dielectric material. D. Testing, Training, Documentation, Final Acceptance and Warranty. Testing of the Dragnet Vehicle Arresting Barrier must comply with Section 2.3, 2.4, 2.5 and 2.6 of Special Training of the Dragnet Vehicle Arresting Barrier must comply with Section 3.0 of Special Documentation for the Dragnet Vehicle Arresting Barrier must comply with Section 4.0 of Special Final Acceptance of the Dragnet Vehicle Arresting Barrier must comply with Section 5.0 of Special Warranty for the Dragnet Vehicle Arresting Barrier must comply with Section 6.0 of Special 4. Measurement. This Item will be measured as each unit furnished, installed, made fully operational and tested in accordance with these Special Specifications. 5. Payment. The work performed and materials furnished in accordance with this Item and measured as provided under "Measurement" are paid for at the unit price bid for "Dragnet Vehicle Arresting Barrier". This price is full compensation for all equipment described under this Item with all cables and connectors; all documentation and testing, and furnishing all labor, materials, training, equipment, and incidentals