920 The lens gasket shall be a slotted circular neoprene ga sket specifically designed to exclude moisture, dust and road film. The optical unit shall be sealed to exclude moisture and dust. This may be accomplished in one of two ways:
i.If the open door contains the complete optical unit, the reflector/door and th e reflector/lampholder interfaces shall be equipped with specially designed neoprene seals to completely seal the optical unit. The section must not accumulate water. ii. If the reflector and lampholder remain in the section when the door is opened, the entire section shall be made watertight and dust tight by a weatherproof neoprene gasket contained in a gasket groove in the door. The gasket shall seal against a raised bead in the section to provide the proper seal. The lighted signal shall appear to be ill uminated over the entire visible lens surface without shadows when viewed from any angle up to 30 degrees each side of the optical axis horizontally and up to 45 degrees below the optical axis vertically. The required appearance, light distribution and candle power intensity from the complete assembled section shall meet latest revision of the ITE Specification. "A Standard for Adjustable Face Vehicle Traffic Control Signal Heads." Trunnions, Brackets and Suspensions: All trunnions, b rackets and suspensions used for assembling and mounting vehicle traffic control signal heads shall be entirely weathertight without the use of externally applied sealants or caulking. The trunnions, brackets and suspensions shall be the same manufacturer as the signal heads. All tubular parts shall be 1½ in ch IPS (DN40) pipe. When hollow cast brackets or trunnions are used, they shall be of sufficient strength to support the maximum load imposed by the signal heads under all normal wind conditions. The lower support or connection between signal heads in a spanwire or mast -arm mounted signal may be an aluminum casting or stamping of suitable strength. Wire raceway areas within brackets, trunnions and suspensions shall be of adequate size to carry all ne cessary wires without crowding, and raceway surfaces shall be free of sharp edges or protrusions which might damage insulation on wires. Suspensions for mast -arm or span -wire mounting shall include a device to permit adjustment for proper vertical alignme nt of the signal head. Non-metallic trunnions, brackets and suspension parts previously approved by the Division may be supplied. Such parts must be capable of mounting both metallic and non - metallic signal heads and must have metallic reinforcement at p oints of anticipated wear. Reinforcing metal must be compatible with aluminum, steel and galvanized steel. Backplates: All signal head assemblies so indicated on the Plans shall be provided with backplates designed to fit the combination of sections for each signal face. These backplates shall be fabricated from non -ferrous metal of gage to withstand distortion in 60 mph winds and shall be firmly attached to each signal face in such a manner as to withstand the above wind load and to permit the opening of any signal independent from the other doors in the signal face. Overhead signal heads shall have backplates with a five ( 5) inch border. Pedestal mounted signals shall have backplates with an eight (8) inch border. The backplates shall be finished wi th the best quality, oven -baked black enamel and shall comply with Federal Specifications TT -E-489. 921 715.42.6 .3-Metallic Signal Heads: Each head of this type shall be constructed primarily of aluminum and aluminum castings and stainless steel, and shall meet all requirements in subsection 715.42.6.2, and shall accept lenses and lamps as described in subsection 715.42.6.4. The section and door shall be one -piece, corrosion -resistant aluminum alloy die castings. Visors and reflectors shall be made from sh eet aluminum or die castings. All cast metal parts shall have a tensile strength of not less than 17,000 psi. All castings shall be clean, smooth and free from flaws, cracks, blowholes and other imperfections. The castings shall conform to ASTM B85 allo ys SC84A, SC84B, SG100A, SG100B, S12A or S12B. Sheet aluminum parts shall be manufactured from corrosion -resistant aluminum sheet having a tensile strength of at least 20,000 psi, except that reflectors shall be manufactured from the aluminum alloy sugges ted by the manufacturer. All hinge pins and latch parts shall be Type 304, stainless steel. Miscellaneous parts and hardware shall be made of non -corrosive materials. All parts shall have sufficient strength to show minimal damage under severe loading conditions. Visors shall be not less than 0.05 in ch thick. Reflectors shall be spun or drawn from aluminum not less than 0.025 inch thick.
715.42.6 4-Non-Metallic Signal Heads: Each head of this type shall be constructed
primarily of a non -metallic material, aluminum and stainless steel, shall meet all requirements of subsection 715.42.6.2 and shall accept lenses and lamps as described below. The non -metallic material used sha ll be durable and resistant to marring, scratching, discoloration, weather, temperature change, shock and color change from weather or photochemical action. The thickness of the non -metallic material shall be sufficient to provide at least the strength of the cast aluminum product of the same manufacturer at any location tested. In addition, the finished section shall pass the following test for strength: A completely wired three -section head without lamps or visors shall be securely fastened between two brackets. A one (1) pound weight with a spherical tip two ( 2) inches in diameter shall be impacted into the center section on any surface including the door with an impact of 70°ft-lb. No part of any section, except the lens, shall be dented, cracked, c razed, chipped, punctured or otherwise visibly damaged. The test shall be conducted at 0 F, 70F and 120F ambient temperatures after the head has been kept at the test temperature for 12 hours. Immediately after the test, lamps shall be installed and the head shall be shown to function normally. The non -metallic material, resin and reinforcement fibers, where used, shall be die -cast to produce a smooth glossy surface to which water, dirt and diesel oil will not readily adhere. Colors sh all be cast integrally in the material. The finished product shall be free from all visible casting defects, including color variances. All hinge pins and latch parts shall be Type 304 stainless steel. Miscellaneous parts and hardware shall be made of a non-corrosive material. Visors shall be at least as strong as aluminum sheet with a tensile strength of 20,000 psi and a thickness of 0.05 in ches. All parts shall have sufficient strength to show minimal damage under severe loading conditions. 922 Lamps a nd Lenses: Lamps: The lamps supplied with the traffic signal heads shall have the filament adequately supported to withstand the vibration induced from truck traffic and heavy winds. The light center length (LCL) is the dimension, in inches (mm), from t he center of the filament to the tip of the base. All traffic signal lamps shall have a brass, standard, medium screw base, a clear glass envelope and shall be in conformance with the following design requirements:
i.All eight ( 8) inch or twelve ( 12) inch traffic signal indications shall have a lamp rating of between 110 and 120 watts, a light center length (LCL) of 2 -7/16 in ch, with a minimum initial lumen value of 1,260 and a rated life of at least 6,000 hours. ii. All eight ( 8) inch or twelve ( 12) inch traffi c signal indications, used exclusively for flashing operation shall have a lamp rating of between 60 and 70 watts, a light center length (LCL) of 2 -7/16 in ch, with a minimum initial lumen value of 665 and a rated life of at least 6,000 hours. The glass e nvelope of the lamps shall be etched to show the manufacturers insignia or trademark, the voltage rating, the rated wattage and the rated life hours. Lenses: The lens shall be standard prismatic red, yellow or green and shall be durable on prolonged expo sure to weather. Each lens shall be of clear colored glass or polycarbonate resin, free from bubbles and flaws and shall be annealed to relieve internal stresses. Flashed lenses will not be accepted. Lenses shall conform to the ITE Specification, "A Sta ndard for Adjustable Face Vehicle Traffic Control Signal Heads," and any revisions to the latest edition. The luminous transmission for traffic signal lenses and the limits of chromaticity for traffic signal colors shall be as follows: Red The minimum relative luminous transmittance shall be 0.095; the value of y shall not be greater than 0.308 nor less than 0.998 minus x Yellow The minimum relative luminous transmittance shall be 0.440; the value of y shall not be less than 0.411 nor less than 0.995 minus x nor greater than 0.452 Green The minimum relative luminous transmittance shall be 0.200; the value of y shall not be less than 0.506 minus 0.519x nor less than 0.150 plus 1.068x nor greater than 0.730 minus x Each lens shall be furnished with a label which shall indicate that the lens meets the specifications of the Institute of Traffic Engineers, "A Standard for Adjustable Face Vehicle Traffic Control Signal Heads," latest edition . All lenses, except arrows, shall have pressed on its flange the word "TOP" to indicate the proper positioning of the lens in the door for obtaining the light distribution required, together with the diameter and other designations, including the name or trademark of the manufacturer needed fo r proper application and help in purchasing replacements. The nominal eight ( 8) inch lens shall have an outside diameter of from 8 -5/16 to 8 -3/8 inches. The nominal twelve ( 12) inch lens shall have an outside diameter of from 11 -15/16 to 12 -1/32 in ches (These dimensions do not apply to the visible indication area of the optically programmed head) . Each lens shall fit into a specifically designed slotted circular neoprene lens gasket designed to fit the housing door in such a manner so as to exclude moist ure, dust and road film. Arrow Lenses: Arrow lenses shall meet the ITE Specification, "A Standard for Adjustable Face Vehicle Traffic Control Signal Heads," latest edition , and all other specifications above. The lens shall be of approved color specified above. All lenses shall be covered, except for the arrow with the light from a 200 watt lamp placed behind it. The enamel shall be baked or fired into the lens. The enamel shall be hard and durable and shall not peel or flake when subjected to the heat of a signal lamp when the lens is in us e, or when the lens is washed. The arrow shall be the only illuminated portion of the lens.
715.42.6 5-Pedestrian Control Signal Heads (Incandescent): These Specifications
cover symbolic pedestrian signal assemblies to be illuminated by incandescent lamps mounted behind two lenses (one for each symbol), having translucent symbols. General Design Requirements: The nominal size of the lenses shall be twelve ( 12) by twelve ( 12) inches. Housing: The housing shall be constructed of cast or sheet corrosion resistant, non -ferrous metal or plastic, or of a combination of these materials. All cast metal parts shall have tensile strength of not less than 17, 000 psi. Sheet metal shall have a tensile strength of 27,000 psi. All parts shall be clean, smooth and free from flaws, cracks, blowholes and other imperfections. If the housing and doors of the signal heads are made of aluminum alloy, they shall have o ne of the following compositions:
i.If die castings are furnished, the alloys shall be in accordance with ASTM B85 60T or the latest revision thereof, and the physical characteristics and chemical content of the alloy used shall be within the combined limits established by allows S -12A, S -12B, SC-84A, SC -84B, SG -100A and SG -100B of the ASTM Specification. ii. If sand castings are furnished, the alloys shall be in accordance with ASTM B26 60T or the latest revision thereof, and physical characteristics and chemica l content of the alloy used shall be within the combined limits established by alloys S -5A and CS -72A of the ASTM Specification. iii. If permanent mold castings are furnished, the alloys shall be in accordance with ASTM B 108 60T or the latest revision thereof , and the physical characteristics and chemical content of the alloy used shall be within the combined limits established by alloys S -5A and CS -72A of the ASTM Specification. iv. If sheets are furnished, the alloys shall be in accordance with ASTM 209 58T or t he latest revision thereof, and the physical characteristics and chemical content of the alloy used shall be M1A of the ASTM Specification. When required, the successful bidder shall furnish satisfactory evidence that materials comply with the foregoing requirements. The housing shall be of unitized sectional construction and shall consist of as many sections as there may be optical unit levels. All sections shall be rigidly and securely fastened together into one weathertight signal face assembly. Each housing shall be arranged with round openings in the top and bottom so that it may be rotated between waterproof supporting brackets on trunnions and thus be capable of being directed at any angle to the horizontal plane. The openings shall be provided with 924 a serrated ring which shall permit indexing and locking of the signal head in five -degree increments throughout the entire 360 degrees of rotation possible. The portion of the housing adjacent to the bracket shall be properly reinforced so as to have sufficient strength against breakage from shock. The housing door of each signal section shall be a one -piece, corrosion resistant aluminum alloy die casting. Two hinge lugs shall be cast on the one side of the door and latch jaws shall be cast on the o pposite side of the door. The door shall be attached to the housing by means of two solid stainless steel hinge pins of not less than ¼ in ch diameter. A stainless steel latch screw, wing nut and washer on the latch jaw side of the housing shall provide f or opening and closing the signal door without the use of any special tools. A gasket groove on the inside of the door shall accommodate a weatherproof and dustproof seal. The outer face of the door shall have tapped holes equally spaced about the perimeter of the housing to accommodate screws for securing the signal head visors. Latch screws, hinge pins, wing nuts and washers shall be Type 304 stainless steel. The housing door shall be finished with the best quality, oven -baked yellow enamel and shall comply with Federal Specifications TT -E-489. The housing, when properly mounted using 1½ in ch (DN40) pipe brackets, shall be able to withstand a concentrated load of 50 lbs. placed six (6) inches from the centerline of the mounting brackets on eithe r side of the opening or on both sides of the opening simultaneously. Such loading shall not produce sufficient deformation to cause the material to fail or to take a permanent set that would interfere with opening the door, rotation about the brackets, o r loss of the weathertight integrity of the unit. Visors: Each signal head shall have a visor for each signal indication. The visor shall be designed to fit tightly against the door and shall not permit any perceptible filtration of light between door a nd the visor. The visor shall be eight ( 8) inches minimum in depth and inclined downward approximately 32 degrees with complete enclosure at the top and sides. The visor shall be of sheet construction and shall be of corrosion resistant, non - ferrous meta l not less than 0.05 in ch (No. 18 US gage) in thickness. The outside of the visor shall be of the same yellow enamel as the housing and door. The inside of the visors shall be painted a dull nonreflective black. Pedestrian Signal Lenses: Each lens shal l be clear colored glass or plastic free from bubbles and flaws, and shall be annealed to relieve internal stresses. Flashed lenses will not be accepted. Lenses shall conform to the ITE Specifications, "Adjustable Face Pedestrian Signal Standard," and re visions thereof, where applicable. The luminous transmission for pedestrian lenses and the limits of chromaticity for signal colors shall be as follows: Portland Orange -Don't Walk Symbol -The luminous transmittance shall be not less than 0.300; the value of y shall not be greater than 0.390 nor less than 0.997 minus x. Lunar White -Walk Symbol -The luminous transmittance shall not be less than 0.290; the value of x shall not be greater than 0.420 nor less than 0.329. The value of y shall not be greater tha n 0.510x plus 0.186 nor less than 0.510 plus 0.170. Each lens shall have pressed on its flange such designation and trademark of manufacturer to facilitate proper application and to help in purchase of replacements. 925 The nominal twelve ( 12) inch lens shal l have minimum overall dimensions of twelve
12.by twelve ( 12) inches with a visible area of eleven ( 11) by eleven ( 11) inches. Message: The Walk -Don't Walk symbols shall be according to the Standard Highway Signs Booklet, published by the Federal Highway Administration. The surface of the lens, except for the symbol, shall be covered by opaque enamel of sufficient thickness to totally obscure the light of a 150 -watt lamp when placed twelve ( 12) inches behind the lens. The enamel shall be baked or fired into the glass and shall not peel or flake during normal use. Reflectors: Reflectors shall be specular Alzak finished aluminum and be designed for a 10 year service life. Reflectors shall be mounted in a cast aluminum reflector support attached t o the housing, or shall be an integral reflector and support of formed sheet aluminum. The reflector assembly shall be pivoted to the housing and shall be designed so that it can be swung out or easily removed without the use of any tools. The method of mounting and fastening reflectors shall be sufficiently rigid to secure proper alignment between the lens and reflector when the door is closed. The construction of the signal head and its components shall be such that the fit between the reflector and th e lens will eliminate all possibility of false indications. Reflectors shall have an opening in the back for the lamp socket. Pedestrian signal reflectors shall be of specular aluminum, the thickness of the anodic coating shall be a minimum of 0.0001 in ch or its equivalent, spun or drawn from metal not less than 0.025 in ch thick, equipped with a bead or flange on the outer edge to stiffen the reflector and insure its being held true to shape. The reflecting surface shall be totally free of flaw s, scratches, defacements or mechanical distortion. Light Distribution: The lighted signal shall appear to be uniformly illuminated over the entire message surface, without shadows when viewed from usual angles encountered in service. Distribution of li ght through the letters shall be uniform and free from halation or other uncontrolled scattering which may reduce legibility of the message. The pedestrian indications should attract the attention of, and be readable to, the pedestrian (both day and night ) at all distances from ten (10) feet to the full width of the area to be crossed. When not illuminated, the WALK and DON'T WALK symbols shall not appear to be illuminated by external light sources when viewed from the far end of the crosswalk they contr ol. Lamps: Lamps supplied with the pedestrian signal heads shall have the filament adequately supported to withstand the vibration induced from truck traffic and heavy winds. All pedestrian signal lamps shall have a brass, standard, medium screw base an d clear glass envelope. The light center length (LCL), or the dimension, in inches (mm), from the center of the filament to the top of the base, shall be in conformance with the following design requirements: All pedestrian signal lamps for use in twelve (12) inch pedestrian signal heads shall have a light center length of three ( 3) inches. Pedestrian signal lamps shall conform to the following standards: Twelve -Inch Pedestrian Signal Nominal Wattage Rated Life Hours Min. Initial Lumens 150 watt series 6,000 1,950 The glass envelope of the lamps shall be etched to show the manufacturer's insignia or trademark, the voltage rating, the rated wattage, and the rated life hours. Lamp Receptacle: The lamp receptacle shall be heat resisting material designed to properly position a medium screw base pedestrian signal lamp with means to accommodate a lamp having light center three ( 3) inches in length for the 150 -watt series. The receptacle shall be provided with a lamp grip to prevent the lamp from working loose due to vibration. Provision shall be made on either the lamp receptacle or the reflector holder to permit rotation of the lamp so that the lead -in wires are up, and a secure fastening for th e retention of the lamp in that position, but shall not permit any change in position of the socket with respect to the optical center of the reflector. The metal portion of the lamp receptacle shall be compatible with brass or copper. Wiring: Each lamp receptacle shall be provided with two coded No. 18 or larger lead wires, Type TEW, 600 volt, AWM fixture wire with 1/32 in ch, 221ºF rating thermoplastic insulation, securely fastened to the socket, and with sufficient length to reach the terminal block wi th the reflector fully open. The thermoplastic insulation shall at minus 30 F be capable of being bent six times around a one ( 1) inch mandrel without damage to its insulating properties at rated voltage. A suitable terminal block signal housing shall be provided. Trunnions, Brackets and Suspensions: All trunnions, brackets and suspensions used for assembling and mounting vehicle traf fic control sign heads shall be entirely weather -tight without the use of externally applied sealants or caulking. The trunnions, brackets and suspensions shall be the same manufacturer as the signal heads. All tubular parts shall be 1½ in ch IPS (DN40) p ipe. When hollow cast brackets or trunnions are used, they shall be of sufficient strength to support the maximum load imposed by the signal heads under all normal wind conditions. Wire raceway areas within brackets, trunnions and suspensions shall be of adequate size to carry all necessary wires without crowding, and raceway surfaces shall be free of sharp edges or protrusions which might damage insulation on wires.
715.42.6 6-Optically Programmed Traffic Signal Heads: The purpose of this
section is t o set forth the minimum specifications for all optically programmed traffic signal heads and associated equipment. Signal Heads: All signal heads shall be the nominal twelve ( 12) inch type and shall be adjustable through 360 degrees about a vertical axis , with each individual section being 927 adjustable plus or minus nine degrees about a horizontal axis, maintaining a vertical centerline through couplers and conduit. Each section shall be equipped with a sun visor. All die cast aluminum parts shall conform to the following specifications or the latest revision thereof; Die casting SC -84A, SC -84B, SG -100A, SG -100B or S -12B of ASTM Specifications B85. All stainless steel shall be of Type 304. All surfaces outside of the signal heads (except the underside of the visors) shall be finished with the best quality, oven -baked yellow enamel and shall comply with Federal Specifications TT -E-489. The signal head housing shall consist of an assembly of separate interchangeable sections, expansible type for vertical m ounting without tie rods, substantially secured together in a watertight manner to form a unit. Each section shall house an individual optical unit. The top and bottom of the signal housing shall have an opening to accommodate standard twelve ( 12) inch (DN40) pipe brackets. The optical system shall consist of a lamp, a circlet reflector, an optical limiter -diffuser combination and an objective lens. The lamp shall be nominal 150 watt, 120 volt AC, three prong, sealed beam having an integral reflector an d an average rated life of 6,000 hours. A circlet reflector with a specular inter surface shall mate the lamp to the diffusing element. The optical limiter -diffuser combination shall provide an imaging surface, at focus on the optical axis for objects 90 0 to 1,200 f oot distance and permit an effective veiling system to be variously applied as determined by the desired visibility zone. The optical limiter - diffuser shall be provided with positive indexing means and composed of heat resistant glass. The ob jective lens shall be a high resolution planar incremental lens hermetically sealed with a flat laminate of weather -resistant acrylic. The lens shall be symmetrical in outline and may be rotated to any 90 degree orientation about the optical axis. Lens c olors shall conform to the specifications of the Institute of Traffic Engineers, latest edition . Each signal head shall be equipped with a dimming mechanism that will gradually reduce the candlepower for nighttime operation to approximately 15 percent (15%) of that for daytime operation. The lamp fixture shall comprise a separately accessible housing and integral lamp support, ceramic socket and self -aligning, quick release lamp retainer. Electrical connection between case and lampholder shall be accompl ished with an interlock assembly which disconnects the lampholder when open. Coded No. 16 lead wires shall be used of a length sufficient to permit solderless connection to line wires external to the signal. All signal indications shall be in a straight line and shall be in the following order, although all indications shown need not be included in all cases. In vertical signals, Position 1 shall be at the top, and Position 8 at the bottom. In horizontal signals, position 1 shall be at the left (facing the signal), and Position 6 at the right. Position Signal Indication Vertical Horizontal 1 1 Red 2 2 Yellow 3 4 Green 4 5 Straight Thru Arrow 5 3 Left Turn Arrow 6 6 Right Turn Arrow 7 Don't Walk Symbol 8 Walk Symbol Each signal head shall be equipped with a suitably designed visor. The underside of the visor shall be flat black paint. Hardware: All trunnions, brackets and suspensions used for assembling and mounting vehicle traffic control signal faces shall be entirely weathertight. All tubular parts shall be 1½ in ch IPS (DN40) pipe. When hollow cast brackets or trunnions are used, they shall be of sufficient strength to support the maximum load imposed by the signal heads under design wind conditions. The lo wer support or connection between signal heads in multi -way span wire or mast arm mounted signals may be an aluminum casting or stamping of suitable strength. Wire raceway areas within brackets, trunnions and suspensions shall be of adequate size to carry all necessary wires without crowding, and raceway surfaces shall be free of sharp edges or protrusions which might damage insulation on wires. Suspensions for mast arm or span wire mounting shall include a device to permit adjustment for proper vertical alignment of the signal head.
715.42.6 7-Lane Control Signal Heads (Single Lamp):
General Design Requirements: Each signal head shall be of the adjustable, colored -light type with the number and type of sections described and as shown on the Plans. Si ngle indication heads shall be mounted on a vertical axis. Each head shall have an indication in one direction only and shall be adjustable through 360 degrees about a vertical axis for single indication heads, or about a horizontal axis for multi -indicat ion heads. All lane control signal heads at any one intersection shall be of the same make and type. Position of Signal Indications: All signal indications shall be in a straight horizontal line and shall be in the following order although all indicatio ns shown need not be included in all cases. Position 1 shall be at the left (facing the signal), and Position 3 at the right. Position Signal Indication 1 Red X 2 Yellow X 3 Green Arrow Assembly: Each head shall consist of an assembly of individual interchangeable sections securely bolted together to form a unit. Sections shall be capable of being oriented horizontally or vertically without the use of additional parts. There shall be no tie rods used in the assembly. The finished assemb ly shall present a clean, neat appearance. Each individual section shall house a complete optical unit. The ends of each section shall have an opening to accommodate standard 1½ in ch (DN40) pipe brackets. The openings shall be in line. The assembly sha ll be capable of being rotated between standard waterproof supporting brackets or trunnions and thus aimed in any direction in the specified plane. The portion of each section adjacent to the bracket openings and the portion used for connecting sections s hall be properly reinforced to provide sufficient strength to resist shock, vibration and impact damage. Each section shall have lugs for the mounting of at least one six -position, twelve - terminal, barrier -type terminal block. 929 The housing door shall be a one-piece casting having two hinge locations and at least one latch location. The hinges shall have stainless steel pins at least 3/16 in ch diameter. The latch shall consist of : (1) a latch jaw on the door and a stainless steel latch screw, wing nut and washer securely affixed to the housing; or (2) a captive wing nut, washer and screw assembly on the door and a captive nut in the housing. It shall be possible to open and remove the door without the use of any tools. The door shall have a gasketed open ing that shall provide a visible lens area of 120 sq. inches for a nominal twelve ( 12) inch lens and 289 sq. in ches for a nominal 18 in ch lens. All lenses shall be as described in 715.42.6.7.1. The door shall have a gasketed opening that shall provide a visible lens area of 120 sq. inches for a nominal twelve ( 12) inch lens and 289 sq. in ches for a nominal eighteen ( 18) inch lens. All lenses shall be as described in subsection 715.42.6.7.1. The door shall have four equally spaced visor attachment points around the lens opening. Visors shall be at least ten ( 10) inches long for a twelve ( 12) inch lens and at least twelve ( 12) inches long for an eighteen ( 18) inch lens. Heads shall be supplied with standard visors, unless otherwise noted on the Plans. All new signal heads at any one intersection shall have the same type visors supplied, unless otherwise specified on the Plans. Visors shall be designed with a dow nward tilt between 3½ degrees and 5 degrees, shall eliminate the escape of light from one indication to another and, with the optical unit, shall eliminate the return of outside rays entering the unit from above the horizontal (known as sun phantom). The section and all brackets, trunnions and suspensions shall be finished with yellow enamel. The door and the outside of the visor shall be finished with either yellow or black enamel. The inside of the visor shall be finished with a flat black enamel. All enamel shall be best quality, oven -baked meeting Federal Specifications TT -E-489. The optical unit shall consist of the lamp, lampholder, reflector, lens gasket and lens, and shall be so designed that all light emitted by the unit passes through the lens and so that any possibility of false indications is eliminated. The lampholder shall be of heat resisting material designed to properly position a medium screw base traffic signal lamp, with means to accommodate a lamp having light center three ( 3) inche s in length for the 116 -watt series and six (6) inches in length for the 200-watt series. The lampholder shall be provided with a lamp grip to prevent the lamp from working loose due to vibration. Provision shall be made on either the lampholder or the reflector holder to permit rotation of the lamp so that the lead -in wires are up, and the lamp shall be retained securely in that position, but no change in position of the socket with respect to the optical center of the reflector shall occur. The metal p ortion of the lampholder shall be compatible with brass or copper. Each lampholder shall be provided with two coded No. 18 AWG or larger lead wire, Type TEW 600 -watt fixture wire 2/64 in ch, 105C rating thermoplastic insulation, securely fastened to the s ocket, and with sufficient length to reach the terminal block with the holder or door fully open. The thermoplastic insulation shall be at minus 30 F capable of being bent six times around a one ( 1) inch mandrel without damage to its insulating properties at rated voltage. A suitable terminal block or blocks shall be provided in the second section from the left or in each section of one -section heads. The terminal block shall have at least 930 one section for each signal head section plus at least two additio nal sections per block. Terminal blocks shall be standard commercially available units. Reflectors shall be specular aluminum in accordance with the latest ITE Specifications and shall be mounted in a reflector holder. The reflector holder shall provide a rigid reflector mounting to assure proper alignment between the lens and the reflector with the door closed. The reflector shall have a lampholder opening in the back. The reflector shall have a head or flange on the outer edge to stiffen the reflecto r and insure its dimensional stability. The reflecting surface shall be totally free from flaws, scratches, defacements and mechanical distortion. The lens gasket shall be a slotted neoprene gasket specifically designed to exclude moisture, dust and roa d film. The optical unit shall be sealed to exclude moisture and dust. This may be accomplished in one of two ways:
i.If the door contains the complete optical unit, the reflector/door and the reflector/lampholder interfaces shall be equipped with speciall y designed neoprene seals to completely seal the optical unit. The section must not accumulate water. ii. If the reflector and lampholder remain in the section when the door is open, the entire section shall be made watertight and dusttight by a weatherproof neoprene gasket contained in a gasket groove in the door. The gasket shall seal against a raised bead in the section to provide the proper seal. The lighted signal shall appear to be illuminated over the entire visible lens surface without shadows when viewed from any angle up to 39 degrees each side of the optical axis horizontally and up to 45 degrees below the optical axis vertically. The required appearance, light distribution and candlepower intensity from the complete assembled section shall meet latest revision of the specifications of the Institute of Traffic Engineers, "A Standard for Adjustable Face Vehicle Traffic Control Signal Heads." Trunnions, Brackets and Suspensions: All trunnions, brackets and suspensions used for pedestrian signal heads shall be entirely weathertight without the use of externally applied sealants or caulking. The trunnions, brackets and suspensions shall be of the same manufacturer as the signal heads. All tubular parts shall be 1½ in ch IPS (DN40) pipe. Wh en hollow cast brackets or trunnions are used, they shall be of sufficient strength to support the maximum load imposed by the signal heads under all normal wind conditions. The lower support or connection between signal heads in a span -wire or mast -arm mounted signal may be an aluminum casting or stamping of suitable strength. Wire raceway areas within brackets, trunnions and suspensions shall be of adequate size to carry all necessary wires without crowding, and raceway surfaces shall be free of sharp e dges or protrusions which might damage insulation on wires. Suspensions for mast -arm or span -wire mounting shall include a device to permit adjustment for proper vertical alignment of the signal head. Non-metallic trunnions, brackets and suspension parts previously approved by the Division may be supplied. Such parts must be capable of mounting both metallic and non - metallic signal heads and must be compatible with aluminum, steel and galvanized steel. Metallic Lane Control Signal Heads: Each head of t his type shall be constructed primarily of aluminum and aluminum castings and stainless steel, shall meet all 931 requirements of 715.42.6.7 and shall accept lenses and lamps as described in subsection
715.41.6 7.1.
The section and door shall be one-piece, corrosion -resistant aluminum alloy die castings. Visors and deflectors shall be made from sheet aluminum or die castings. All cast metal parts shall have a tensile strength of not less than 17,00 0- psi. (117 MPa). All castings shall be clean, smooth and free from flaws, cracks, blowholes and other imperfections. The castings shall conform to ASTM B85 alloys SC -84A, SC -84B, SG - 100A, SG -100B, S -12A or S -12B. Sheet aluminum parts shall be manufactured from corrosion -resistant aluminum sheet having a tensile strength of at least 20,000 psi, except that reflectors shall be manufactured from the aluminum alloy suggested by the manufacturer. All hinge pins and latch parts shall be Type 304, stainless steel. Miscellaneous parts and hardware shall b e made of non -corrosive materials. All parts shall have sufficient strength to show minimal damage under severe loading conditions. Visors shall be not less than 0.05 in ch thick. Reflectors shall be spun or drawn from aluminum not less than 0.025 in ch thick.
715.42.6 7.1-Lamps and Lenses for Lane Control Signal Heads:
Lamps: Lamps supplied with the lane control signal heads shall have the filament adequately supported to withstand the vibration induced from truck traffic and heavy winds. The light ce nter length (LCL), is the dimension, in inches, from the center of the filament to the tip of the base. All lane control signal lamps shall have a brass, standard, medium screw base and a clear glass envelope and shall be in conformance with the following design requirements: Head Size Wattage Series LCL Minimum Rated Life Minimum Initial Lumens 12 116 3 in. (75 mm) 6,000 hours 1,260 18 200 6 in. (150 mm) 6,000 hours The glass envelope of the lamps shall be etched to show: the manufacturer's insignia or trademark, the voltage rating, the rated wattage and the rated life hours. Lenses: The lens shall be standard prismatic red, yellow or green and shall be durable on prolonged exposure to weather. Each lens shall be of clear co lored glass or polycarbonate resin free from bubbles and flaws and shall be annealed to relieve internal stresses. Flashed lenses will be accepted. Lenses shall conform to the specifications of the Institute of Traffic Engineers, "A Standard for Adjustab le Face Vehicle Traffic Control Signal Heads," January 22, 1966, and any revisions thereof. The luminous transmission for traffic signal lenses and the limits of chromaticity for traffic signal colors shall be as follows: 932 Red The minimum relative luminous transmittance shall be 0.095; the value of y shall not be greater than 0.308 nor less than 0.998 minus x Yellow The minimum relative luminous transmittance shall be 0.440; the value of y shall not be less than 0.411 nor less than 0.99 5 minus x nor greater than 0.452 Green The minimum relative luminous transmittance shall be 0.200; the value of y shall not be less than 0.506 minus 0.519x nor less than 0.150 plus 1.068x nor greater than 0.730 minus x Each lens shall be furnished with a label which shall indicate that the lens meets the latest revision of the specifications of the Institute of Traffic Engineers, "A Standard for Adjustable face Vehicle Traffic Control Signal Heads." All lenses shall have pressed on the fl ange the work "TOP" to indicate the proper positioning of the lens in the door for obtaining the light distribution required, together with the size and other designations, including the name or trademark of the manufacturer needed for proper application a nd help in purchasing replacements. Each lens shall fit the housing door in such a manner so as to exclude moisture, dust and road film. All lenses shall be covered except for the X or the arrow with a dull or dark gray enamel of thickness sufficient to totally hide the light from a 200 -watt lamp placed behind it. The enamel shall be baked or fired into the lens. The enamel shall be hard and durable and shall not peel or flake when subjected to the heat of a signal lamp when the lens is in use, or when the lens is washed. The X or the arrow shall be the only illuminated portion of the lens.
715.42.7 Auxiliary Traffic Signal Equipment: The purpose of this section is to set forth
the minimum design and functional requirements for all types of optional auxiliary equipment which are described in this section. All auxiliary equipment shall operate on 120 volts, 60Hz, AC power supply. The equipment operation shall not be affected by supply voltage variations between the limits of 10 percent (10% ) above and 10 percent (10%) below 120 volts standard service. Similarly, the equipment operation shall not be affected by any change in temperature between the limits of plus 122 F and minus 30 F without the necessity of any heater element. The Contractor shall furnish manufacturer's instructions for installing, maintaining and placing into operation the auxiliary equipment, along with engineering data, diagrams, etc. or any later changes or improvements which may increase the performance of the equipment purchased. The Contractor is required to turn over to the Division any guarantees or warranties which are given by a manufacturer. The Division reserves the right to withhold any payment which may be due for equipment which does not meet Spec ifications. Solid state flashers meeting current NEMA TS standards and capable of the above specified outputs and circuit ratings are an acceptable alternate to motor driven units.
715.42.7 1-Flasher Units: The purpose of this subsection is to set for th minimum
specifications and design requirements for flasher units to perform the flashing combinations as specified on the Plans. The signal flasher unit shall be a motor -driven switching device for flashing beacons or traffic signal indications at sign alized intersections. It shall be designed for back -panel 933 mounting in a flasher or traffic signal controller cabinet and shall be complete with jack - mounting subbase. The unit shall be capable of flashing two non -simultaneous signal circuits at a rate of not less than 50 nor more than 60 flashes per minute per circuit, with approximately 50 percent (50%) on and 50 percent (50%) off periods. Each flashing circuit contact shall be rated at 15 amperes, 120 VAC, 60 Hz under continuous make and break duty. T he closing and opening of the flashing circuit contacts shall be accomplished in such a manner as to avoid undue pitting and burning. The flasher contacts shall be equipped with adequate integral radio interference filters. The flasher motor shall be dura ble and provide a constant flash rate. It shall be designed for synchronous operation on 120 VAC, 60 Hz and shall have lifetime lubrication.
715.42.7 2-Time Clocks: The purpose of this subsection is to describe the 24 -hour
electric programmable time cl ocks to be used in pretimed and traffic -actuated signal controllers. The clock motors shall be designed for synchronous operation on 120 volts, 60 Hz, single phase alternating current. The clocks shall be programmable for circuit on -off operation at 15 -minute intervals of the day. In addition, the clocks must be capable of skip - a-day operation. Each clock dial shall provide from one to 48 on -off operations per day minimum in 15 -minute settings. Each clock shall be capable of operating in a "power -off" condition for a minimum of ten hours. Drive for the clock when electric power is off shall be provided by a reserve spring which is wound automatically during "power -on" periods. All time clocks must be easily accessible and demountable and fit within th e controller cabinet.
715.42.7 3-Offset Interrupter: The purpose of this subsection is to set forth functional
specifications and design requirements for a system offset interrupter. The offset interrupter shall provide system offset interruption in th e range of at least 0 to 40 seconds in one -second increments. No tools or additional timing gears shall be required to change the interruption interval. The interval shall be set by use of a calibrated dial on the front of the unit. The interruption per iod shall be of sufficient duration to release all dial or coordination units in the system, or both. A switch shall be provided to eliminate the function of the offset interruption.
715.42.7 4-Preemption: Preemption equipment shall be constructed and wired so as
to transfer control of the signals from the controller to the preemption unit when actuated by the method specified and shall provide the color sequence specified. The preemption shall cause a clearance interval to be timed prior to the preemp tion sequence if actuated during a "green" or "flashing yellow" interval, unless otherwise specified. Pedestrian WALK -DON'T WALK signals shall be placed on DON'T WALK during the preemption clearance interval and shall be turned off during the preemption s equence, unless otherwise specified. Installation of the preemption equipment shall not alter the internal wiring of the controller unit normally furnished by the manufacturer. After release of the preemption, normal controller operation shall be automatically resumed at the beginning of the "green" interval specified on the Plans and on actuated controllers, calls shall be placed on all phase in order for the controller to complete one cycle before resuming normal actuated operation. 934 Two sets of complete wiring diagrams shall be provided showing the physical layout of all relays and other components of the preemption unit.
715.42.7 4.1 -Implementation : When included in the plans, the priority control system
shall provide advance signal control p er intersection approach. The systems consist of an emitter, detector, confirmation light and a card rack mounted signal interface unit. Priority control shall be measured as a complete unit in place per intersection or control location. This item shall consist of a complete electrical mechanism and all intrinsic items necessary for controlling preemptive functions at each intersection. When accepted as complete, the quantities determined and as provided below will be paid for at the contract unit price compensation for furnishing all materials and doing all work prescribed in a workmanlike manner and for furnishing all labor, equipment, tools and incidentals to complete the necessary work per intersection. The emitter shall be mounted on the priority v ehicle and transmit a shaped, optical pattern of infrared light to a detector at the prioritized intersection approach. The interface unit will then input a call to the controller for a pre -programmed preemption routine. The transmit/receive distance for each intersection approach must be user programmable and will be the responsibility of the Division of Highways to determine and set. A means of adjustment for the transmit/receive distance per approach must be provided with the system. See I/S phasing and estimate of quantities.
715.42.7 4.1.1 -Optical Emitter : The Optical Emitter (OE) must be a single pulsed
infrared light source capable of delivering sufficient optical energy to activate compatible
O.C.S. detectors up to 2500 feet. Emissions must b e precisely timed pulses of high intensity light. The O.E. must be available in 10HZ and 14HZ (+/ - 1 HZ) modules for use as low and high priority vehicles. The range of activation of preemption at signalized intersections must be a function of the P.C.S. hardware.
715.42.7 4.1.2 -Detector : The Detector unit must be responsive to the optical emitter
at a distance of up to 2500 feet. The unit must be totally compatible with all features of the emitter and be capable of priority distinction without the ad dition of special detectors. The Detector shall have a minimum reception angle of 35 degrees.
715.42.7 4.1.3 -Card Rack Mounted Interface Unit : Each interface card must
provide a two (2) to four (4) channels per card for a total of (8) eight pre -empt ou tputs for use by the local traffic signal controller.
715.42.7 4.1.4 -Control Equipment : Preemption control must be applicable to NEMA
TS1 standards.
715.42.7 4.1.5 -System Requirements : Preemption control equipment must be
compatible and completely in terchangeable with existing preemption systems (as it relates to these special revisions and the WVDOH APL). All P.C.S. equipment for this system must be on the WVDOH Approved Products List (APL). Fixed card racks with integral power supplies and capacit ies to accommodate required P.C.S. features must be in the controller cabinet with priority control.
Source: West Virginia Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 942–956 of 1,006.