HEVY MOVBLE TRUCTURE, INC. NINTH BlENNlL YIVIPOIUM "Preserving Trditionl Vlues with New Technologies" OCTOBER 22-25,22 ELIMINTING UBMRINE CBLE UE IN MOVBLE BRIDGE ELECTRICL YTEM Mitchell. Wisniewski HNTB Corportion ELECTRICLIELECTRONIC YTEM
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems by Mitchell. Wisniewski HNTB Corportion (973) 237-165 bstrct: ubmrine cbles hve trditionlly been used to crry power nd control signls cross the nvigble chnnel to relibly connect equipment on both sides of the chnnel. There re vriety of resons why lterntives to submrine cbles my be desirble. bridge electricl system cn be designed without the use of submrine cbles. The disdvntges of ny lterntive or combintion of lterntives must be considered s well s the potentil dvntges. Redundnt bckup systems should be included s well. n exmple of movble bridge electricl system designed without submrine cbles is the new Chelse treet Bridge which is verticl lift bridge which will replce the existing Chelse treet Bridge owned nd operted by the City of Boston. The Chelse treet Bridge will be instlled with electricl service on both sides of the chnnel nd smll number of extr flexible cbles drooped from the towers to the movble spn. These cbles will include opticl fibers for control, video nd udio communiction nd smll number of copper conductors for bckup control. Introduction: trditionl mens of crrying power, communiction nd control signls cross the nvigble chnnel spnned by ny type of movble bridge hs been through the use of one or more submrine cbles. These cbles re typiclly instlled through trenching, plowing or jetting or by lying on the top of the wterwy bottom. While these cbles re simple nd fmilir method of connecting the two sides of the chnnel together, there my be circumstnces in which use of n lterntive to submrine cbles could be desirble or even ncccssry. I hve explored lterntives to the use of submrine cbles during the design of n electricl system for the new Chelse treet Bridge. The new Chelse treet Bridge will be verticl lift with 45 foot long movble spn. This bridge will replce the existing Chelse treet Bridge owned nd operted by the City of Boston. ubmrine cbles will not be instlled on the new bridge becuse dredging of the nvigble chnnel is plnned to follow the instlltion of the new bridge electricl system. There re vriety of resons to consider lterntives to submrine cbles on other bridges. The disdvntges of ny lterntive or combintion of lterntives must be considered s well s the potentil dvntges. I m presenting some of my findings on these lterntives in this pper to inform the reder of these possibilities. HEVY MOVBLE TRUCTURE, INC. gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems Resons for lterntives to ubmrine Cbles: Effects of ubmrine Cble Instlltion on the Environment - ubmrine cbles re typiclly instlled into the bottom of the wterwy through mens such s jetting, plowing or trenching. These methods cn temporrily resuspend hrdous mterils which hd settled t the bottom of the wterwy bck into the wter where they cn become n incresed dnger to plnt nd mrine niml life. The ssocited environmentl permitting process cn be lengthy or prohibitive. Federl, stte nd locl requirements must be observed during the permitting process. Even if hrdous mteril is not fctor, the physicl disruption to the wterwy during cble instlltion my be concern for the fishing industry nd recretionl nd commercil boters. Effects of the Environment on ubmrine Cbles - ubmrine cbles re subject to dmge from misplced bot nchors, dredging efforts nd the nturl degrdtion due to exposure to the mrine environment. These fctors decrese the lift of the cbles necessitting replcement. Especilly if left on the top of the wterwy bottom rther thn under it, cbles cn be dmged by wter current induced motion nd brsion ginst rocks. Conflicting Instlltions or Work - The instlltion of bridge submrine cbles cn be hindered or restricted by prior instlltion of utility cbles nd pipes which my still be ctive. The instlltion cn lso be impcted by future utility instlltions or dredging. Product Ordering nd Instlltion Concerns - ubmrine cbles re expensive to procure nd expensive to instll. Led times for cble orders cn lso be long. Delys for the purchse of new cble cn be especilly troublesome if service must be quickly restored fter cble filure due to wer or dmge. Importnt Considertions in electing n lterntive: Cost - The cost of the lterntive must be considered nd weighed ginst other lterntives s well s the cost of proceeding with the instlltion of submrine cbles. This cost does not only include the cost of purchsing nd instlling the lterntive system hrdwre but in integrting the hrdwre into functionl system nd mintining it s well. Mintinbility - very importnt issue to consider is whether the new system will be mintined by the existing mintennce personnel nd whether these personnel will be willing nd ble to cquire ny dditionl trining nd eduction tht my be needed to keep the new system in working order. If mintennce will be provided by n outside orgnition, is tht orgnition locted nerby with work force tht cn respond s quickly s necessry to keep the bridge opertionl? Relibility - Modern rmored submrine cbles hve reputtion for being rugged nd ble to provide relible service. Concerns bout the lifespn of lterntives s well s dependble opertionl chrcteristics should be considered. bckup system should lwys be considered but this is especilly true when relibility of system is concern. fety - fety is the most importnt considertion. We must ensure tht bridge equipment will not strt operting by itself cusing personl injury or structurl ndlor mechnicl dmge. If our Emergency top hnction is not hrdwired to ll bridge equipment, there must be 1% fil sfe lterntive instlled in its plce. HEVY MOVBLE TRUCTURE, INC gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems Wired lterntives: Multiple Utility ervices (one per side of the chnnel) - This option will llow use of locl utility supplied electric service for powering of bridge mchinery without ny submrine cble to crry power fiom one side of the chnnel to the other. This works well for single or dul lef bscules nd tower drive verticl lift bridges. It cn be implemented on swing bridge if utility bridge is built to crry the service conduit bove wter level to the center pier. Use of such utility bridge would limit nvigtion to chnnel on only one side of the center pier. This strtegy cn be implemented on spn drive verticl lift bridge only in conjunction with n option such s droop cbles (described below) to crry power from one or both towers to the movble spn. Droop Cbles - Extr flexible cbles my be drooped between sttionry nd movble structures to crry power, communiction nd control signls. These cbles my consist of opticl fiber nd/or copper. Multiplexing of signls cn help minimie the number of conductors. Using this option, the emergency stop function my be hrdwired to keep this element of the system simple. The use of droop cbles is especilly useful for single nd dul lef bscules where the electricl mchinery moves with the bscule spn nd on the spn or tower drive verticl lift bridges. It is lso useful on swing bridge in conjunction with genertor nd/or direct engine drive lterntive s described under "Wireless lterntives", below. eril Cbles - Most often used between towers on verticl lift bridges, implementtion on other bridge types would require construction of foundtions nd towers to nchor the cbles. The towers nd/or the cbles themselves my be determined to be estheticlly objectionble nd my present hrd to ir trffic. Construction of foundtions for eril cble towers cn result in wterwy disruption. eril cbles my consist of opticl fiber nd/or copper. Multiplexing of signls cn help minimie the number of conductors. Directionl Drilling - Directionl drilling involves the use of globl positioning system (GP) to guide drill bit which tunnels below the wterwy. Generlly expensive, it llows circumventing ny environmentl concerns becuse use of this technology does not interfere with the wterwy or nd sediment on the bottom of the wterwy. During drilling, bentonite cly or polymer mteril is usully used during drilling to keep the drilled shft open. fter drilling, polyethylene duct is usully pulled through the drilled shft. Opticl nd/or copper cble my be pulled through the duct. Multiplexing of signls cn help minimie the number of conductors. dequte spce must be provided on both sides of the chnnel for setting up the directionl drilling equipment. The process of drilling the shft using the GP guidnce is extremely ccurte. This method my be implemented nywhere nd for ny type of bridge s long s enough room is vilble for the equipment. Hrdwired Cbles Run cross The Movble pn Terminted In Quick Connectors - This option consists of wiring power nd/or control cross the movble spn to the equipment on the opposite side of the chnnel. This wiring would be terminted in wether proof connectors which would be disconnected by bridge opertion personnel fter operting trffic signls, gtcs nd locks but before opening the spn. This works becuse during the time tht the movble spn is not fully closed, no other piece of bridge equipment needs to be operted (or needs to chnge stte s in the cse of red trffic light). Circuitry must be provided on ech side of the chnnel (with seprte utility power or bttery power) to mintin trffic lights nd gte rm lights during the spn opertion. This method is especilly useful for power nd/or control wiring on single lef bscules but my lso be used for control wiring on dul lef bscules, swing bridges (with control from the movble spn) nd on spn drive verticl lift bridges (with genertor nd/or direct engine drive nd control from the movble spn). HEVY MOVBLE TRUCTURE, INC. 91h Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems Dul ystems - single or dul lef bscule cn be equipped with seprte control house, control equipment, nd electricl service on ech side of the chnnel. One opertor per side would operte ll electricl equipment (including the movble lef) on their side of the chnnel. Bckup power cn be provided with seprte genertors on ech side of the chnnel. Opertor slries need to be weighed ginst the svings in submrine cble costs but this option my be especilly useful for single or dul lef bscule bridges with limited use or where circumstnces don't llow the use of other options. Telephone Lines - Wired telephone lines cn be used for control of equipment on single nd dul lef bscules. This is typiclly done with lesed line phone service with ssocited monthly chrges. Wireless lterntives: Generl - dvnces in technology in the communictions field hve provided vriety of low cost, sfe nd relible mens of wireless control. Wireless control lterntives re in use for sfe opertion of diesel locomotives, crnes nd hoists, ship loders nd people movers. Equipped with redundnt sfety circuits nd "wtchdog rely" hrdwre ndlor softwre which immeditely shuts down opertion of the system upon loss of communiction, it is not necessry to connect the emergency stop circuitry on one side of the chnnel with tht on the other with piece of wire. Wireless technologies provide vriety of significnt dvntges when compred to submrine cbles: Wireless technologies present no disruption to wterwys. Wireless communiction equipment cn be locted in res where protected from dmge. The instlltion of wireless communictions equipment llows flexibility which virtully elimintes the concern for conflict with other instlltions. Wireless communictions equipment is redily vilble nd cn be procured nd instlled quickly. Genertor Power nd/or Direct Drive Engine for pn Opertion - This option consists of instlling genertor ndlor direct drive engine so s to eliminte the need for power wiring to cross the chnnel. It is becuse of this lck of need to cross the chnnel with wiring tht I hve ctegoried this s "wireless" option. This option is especilly useful for the swing spn where nvigtion must be llowed on both sides of the center pier. In conjunction with droop cble, the genertor ndlor engine could be mounted on the center pier rther thn suspended on the structure bove the center pier. The weight of fuel nd the genertor ndlor engine must be considered in the structurl design. If direct drive engine is provided in ddition to the genertor, one cn ct s bckup to the other. This option is lso pplicble to the spn drive verticl lift bridge. On swing bridges, this option would be used long with multiple utility services (or dditionl gcncrtors) for opertion of bridge equipment mounted on the pproches. Mgneticlly ctivted witches - Mgneticlly ctivted switches cn provide simple option for use on single lef bscule or swing bridge. Mounted on the rest pier with corresponding clectromgnetic ctutors mounted on the movble spn, signls could be pssed for control of gtes nd trffic signls prior to opening the movble spn. Opening the spn would seprte the switches from the ctutors preventing use during the opening. s there is no need to operte ny equipment mounted on the pproches while the spn is open, this is not problem. HEVY MOVBLE TRUCTURE, INC. gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems Infrred - Infrred communiction technology is considered to be the fstest but the lest relible. There re four (4) types of infrred communiction technologies. The line of site technology is esily interrupted by obstcles. The sctter nd reflective technology is inexpensive nd cn provide firly relible communiction with some possibility of interruption due to wether conditions. The brodbnd opticl telepoint technology is relible but costs significntly more thn other infrred technologies. Lser Light - Lser light cn be used to provide relible communiction over long distnces. This communiction technology is more sensitive thn the infrred technology nd is limited to line of site usge. Obstcles such s bots cn interrupt the signl. s there is no need, however, to operte ny bridge equipment while the bot is pssing, this my not be criticl flw. Rdio - Rdio hs evolved into very sfe nd relible mens of control. Of the vrious rdio technologies, the pred pectrum technology hs the reputtion of being the most relible nd the most populr. This technology ws originlly developed for militry usge for communictions which required relibility nd security. t lest one mnufcturer offers rdio interfce hrdwre tht cn be directly instlled into PLC (progrmmble logic controller) rck. Conclusion: Movble bridge electricl systems cn be successfully instlled nd operted without submrine cbles. The vrious technologies described bove hve history of successful implementtions in pplictions where security, relibility nd sfety re importnt. These technologies re eqully pplicble to movble bridge pplictions. The electricl system developed for the Chelse treet Bridge, used reltively conservtive pproch to system without submrine cbles. The Chelse treet Bridge will be instlled with seprte electricl services on both sides of the chnnel. Video, intercom nd control signls will be multiplexed nd trnsferred cross redundnt droop cbles using highly flexible fiber optic cbles. Bckup control utiliing n uxiliry drive motor ws providcd with redundnt flexible copper cbles. The combining of the two pproches (fiber optics nd copper) llowed for gret reduction in the mount of cbling required cross the spn. The unique chrcteristics nd requirements of ny spccific ppliction must be considered in choosing n lterntive to submrine cbles. ome options re limited to or re prticulrly suited for use on specific movble bridge types. Combining of options cn be vluble in tht the drwbcks of one option cn be blnced by the strengths of nother. For some pplictions, the best choice my be combintion of options or temporry use of one or more options. HEVY MOVBLE TRUCTURE, INC. gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems CONTROL PPLICTION Movble Bridge Type vs. ubmrine Cble lterntive Type VERTICL LIFT - PN VERTICL LIFT - TOWER WING - I NVIGBLE CHNNEL WING - 2 NVIGBLE CHNNEL BCULE - INGLE LEF BCULE - DUL LEF nu 1 om! no 'w J wm w o GK nn --- " 1 Z I-' LU wd -I -I -I f~ I- * o 3 o w g g w 11- m _I 3). w I- om -3 -I -2 2 s KEY: - pproch equipment (gtes nd signls). - pn drive equipment. I - Requires droop cble in conjunction. 2 - Requires directionl drilling in conjunction. 3 - Requires droop cble or wireless option in conjunction. Note: Chrt bove depicts potentil pplicbility of vrious pproches to vrious movble bridge types. HEVY MOVBLE TRUCTURE, INC gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems POWER PPLICTION Movble Bridge Type vs. ubmrine Cble lterntive Type VERTICL LIFT - PN VERTICL LIFT - TOWER WING - 1 NVIGBLE CHNNEL WING - 2 NVIGBLE CHNNEL BCULE - INGLE LEF BCULE - DUL LEF Y, $3 3 w ecn -I -2 Y 5 8 g W -1 m 3-1 w -I -3-3 < FZ -1 w d Eg nn -I LY W rlr g cd ow w g w no I KEY: - pproch equipment (gtes nd signls). - pn drive equipment. 1 - Requires droop cble in conjunction. 2 - Requires conduit long wlkwy to center pier (spn opens in only one direction) or slip ring ssembly t center of spn. 3 - Requires slip ring ssembly t center of spn. Note: Chrt bove depicts potentil pplicbility of vrious pproches to vrious movble bridge types. HEVY MOVBLE TRUCTURE, INC gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems COMMUNICTION (INTERCOM, CCTV, PLC, ETC.) PPLICTION Movble Bridge Type vs. ubmrine Cble lterntive Type VERTICL LIFT - PN VERTICL LIFT - TOWER WING - 1 NVIGBLE CHNNEL WING - 2 NVIGBLE CHNNEL BCULE - INGLE LEF BCULE - DUL LEF 89 o m no Jw m w " -2-2 J F OJ - nn -I F Y O 3 o w 8 w n m t w nu, g ~ i w w o J ~ l 2 - s KEY: 1 - Requires droop cble in conjunction. 2 - Requires slip ring ssembly t center of spn. Note: Chrt bove depicts potentil pplicbility of vrious pproches to vrious movble bridge types. HEVY MOVBLE TRUCTURE, INC. gth Biennil Movble Bridge ymposium
Eliminting ubmrine Cble Use in Movble Bridge Electricl ystems TRFFIC IGNL ', UTILITY POLE, TRNFORMER -, ND METER UTILITY POLE. TRNFORMER ND METER xg LBL%~P~~ Cb&K8E DUii% BCVLE - ELEVLITIO Not to scle -- FZ%2&PLE @TE9: I. DUL INCOMING ELECTRICL ERVICE. ECH ERVICE ERVE EQUIPMENT ON THE ME lde OF THE CHNNEL 2. GENERTOR ON ECH lde OF THE CHNNEL (IN CONTROL HOUE) FOR BCKUP POWER. 3, MOTOR CONTROL EQUIPMENT ON ECH lde OF THE CHNNEL ERVING BRIDGE EQUIPMENT ON THT IDE. 4. NO UBMRINE CBLE. HEVY MOVBLE TRUCTURE, INC. gth Biennil Movble Bridge ymposium