‘Status of Cooperative Work on Joint Use of Poles * [By 366, MARTI end 1 TOMER, cag tts iil ella SESS Rat eyestrain cc rhe ot Ee eon hay sites th een ee a he * [PPLRLINONT sn ees fh a pees snes ec ste in thw same area ane ip eustomtre who are 10 a Tange exert sommes nisl thecetore necessary thas beh tps of ervive be carrie’ alony uve ane sree abd aighway TExpeience has shown that sfer sal mone saiiartaryconlcons car often fe eccuted she ye and] veep Tare crews srt erred fw tae sare pele, This fs dues pare un the fact that ciara nd Shmiing Sinem be more wily naistaiged where both esse © devise varied at Ls aeage goles vather than separate sles en The same die the eres Wace eparase linge ave alaced oa opp Siheiles of the sinecla aad ele, iis difiule to secure sed mata rer rarer fer acrice wires to RcLeags where these cross the Tine of the ntuer wisy Jeiet use o! pales Ly che panes and tleahone companies results ia ete uf foo y's na = oes al aighorass and Ketter appearance of serial lies. In ly theseloce, are deste oom the yb yi few. Tt conseives pole tnber ane a mary er ste wea to soth clases of ik than sesarare lines. Tiertne tieuluve atescioned advantages ‘oine we oF les Bye nore an ene cenipani hag boon widely aesmne No sotm plete dara ace avalable et the cstut nc a wae he pene Ting, bust iseetataced thar there ares lene Sve lion ple jt sed hy she power and islepone comocaies ia te Urseed Stat For of Yue clases af uli>e have bees rug rally fa the pt ‘oeeuly Foe sesraanal Ie devslapment.eeigr- and constrction of che Pica! yt of ash hae ene ace with the growth in tetitory an Tomb f ensonntessese Wie rrlor yolks a gla: wee uh th the possibilty of comity betyeen wees ef ae to ies umeher hava eal br satsfariurdy ave by pioperconszeucion meth, tere devi fe, 'nlerlevclopments have increased Pe ure sf Iypes al yer date Inetion eveuiee ragincing while yee Grequenlly aise a b> bow savsioesaa he properly mainta'med and exten or int'y sl es “Theor suriions have reese ane nee recsiving care consiera- iow fw the Joint Genezal Commitee ef the Nationa! Fett Lge Acoli anal Uell Teeptoue Systent, The eommitae hae secoat- nel evi principles and pccies forthe joint use of uod poles lehich are incended tvs ae hele spy ons nd commuricatin stony is stm wrk oat tick atv taal prodlents fd i der al iacyortat seeearl work in connection wth these Solis Hirnigh ie Joint Sukeommicee e= Uevelapment ane. Kee fein “The pisces sac ywootiets mentioned ee persented na espn ihe Ini Geral Comatice nader dace st brary 18, 1926, amd ‘eile Lesine she ope otis pepe: to conser chesepririples in Teta, the folowing secomnendations ae of interes fn thot inate che way iz wsiey this matter generally ein supe ‘Ezek party show fo He the igre of The cally and requivementa of ita own service, ievtuing ie character and design of sown facilites, both now seal in the fasuee, 19) Determine the sharaccer of 2 of cicuieswnd steucturee te be eel ov continuo i jeiat use, and determine che ekractes of Tignes ga xsuctures of ethecs with which tenes into ( Gooperate withthe other sany’so chat i eareying a the fonmgeing ities, soe cersiderasion wl be geven to the mutual pooh lea tick nay arb al thal rhe partes ean ‘lay deve rine ihe est enpineving solution “n sitmatons where the lia of both ar involve, 1 wil be olseived chat wile each oavey retains full responsibility ve fring an messing i evn problems. ic ie recomended thet bosh pestis eouperate iz working out mca ples rast tw na Ese of poe adn Frding che lint vera wagering wlan i rersaincction, ‘These a-eamong she meet inmwcteve ofthe princi ‘hist have een recomend se ne the Iesieapon which practi lcoopecstive work fe being raced forwand Witte parece of the Pllewing pasegsephe te eocribe whet ke teen lone sil wh sng dese bythe [nt Sabeummienee unt De ‘elmer an Reecar a reaction with te eaginee-ng ead evan Cate pruslen hie have Ine ennuneeied in jot use wat Cossrarertas Pascriss Jet me eons reins practises Reva undetzone slivs! eon:inual bagel en seen ue ese ont use eas Bist acopced and onesie! evelopment iy es be expected te te tune. However, ‘any nf he furdamental requ-ements or securing saisaetory con Fivia ajay wed pos weve secegnized at an eatly date and foray "ese fer prose dy pratie Tre tier slat ive Irv 3 ig hes seemed te nwo wines should far as pre ieee vse eigen testions Ty general thes aze larger and stranger Us the telephone wines. Thi Eluerently oo bmenrse of the fueeest cate capaeiey tequie Pliny pies wise in the upper sition on wnely eee pele avoids the norte tye telephore Bnenen climbing thor agh meee rete fesace namine and chacacteriton which they are no wey aii, wth CClarances mut be provided stick give sueient space Leow the power wires so thas aoWer Hineaies wil not bave to cnate anc 2 telephone wes ste hey ane woukicg em post wines TW Movral space nat al prowl aubocinns searanne= above che tle Dna equips an tha: teephine Enesnes way etre cre teeptone Plast witheut dager of coming in souract with power eyeijmen (Csr etimbng sce pt lo 66 pid! so te tnennen mayen tuleswtcae having te le wstrmely civ to gwoid Eas cr sates ‘wath crete foam which they say receive physical inj, Fig 1 scum one muchos foe asaurirg eattaesory conditions om a ioiee'y usc pale earring circuits which both fie power and elephone s.0238 have ccogsized as seme sultan fo: ‘sin nse Tithe rater nl edge sgt sta as Ines te pee sthe woeeut iso nepara fies, Thai ctr rete soul e proved suc ae atand, nich vseeonstle acces of -alety urn conditions weies experience indizaes are likely #0 ozeur for, ae tea in any pats c, Wit ye 1 The alter ef foes: se etic stent, Ee aes mt these and tol cenwer sults ave folowed devel uevtsin Pre enor eld uf por eonetzseton, Wires to seco igs fusd undargeound concectians co aerial ple resine verily rim twee om ounly need pole, Tae cate, insulation aad meciaacl Protection of these bave receive pets! ender lin ste Ragauls tn woven Sule esrs aes heoveon vevticaly un cireuis of one type and he equipment of aaneher wily on joinely ied pules awe ae be tami i caren ; fours be ver ingntane fom 2h Hina te paras atl seep ose eevee Th the cass al elessrcal tens lishtning may ince high voller ox either supply or tenes isaties ies, The se aration late the supoly ard worezuviaros Gain fx ovt atest tay po there indted wage may bree done wit tl ar sel wee, the Ine ill ra Fig, 2.” Dasma pizar me, ofcourse, ssal, From figheg sem, Hraer, hn lighting has stetlisied a belweer the ower and oomneulins ills che nvcaal vellage a ndpuint ot aoiing terra the muply viva my maintain die are, This sess in che wansfer ‘ftaneer nt the elephne plant at weltages which may be well ove hat far which te nalts al mays ibe on bach the power And telepione system, This won uf altar belo to te general las that inchides insulator Pashovers stot Geuits on cables, Lee rounds aud similar power sysiern eoruerenems Thal alass cney the Dshabilisy of damage so the power evsten or serve, ‘While verily run attachments ‘wich improper elearances have layed a large part ia ccusing aueh occurrences, any situation where insufficient clearance berween power sm telephone facilities i pro ‘itm eee in similar ee Tmphasis hs, therefore, beer plein present cay tana on the nevewity of mainstinine proper tleastce ne well a strength of con resin ba present hi ind abvarmal. Fxperencelasshown ta mere Iie ceagnresareadserel this type alormal is kep oe Feaeonable nin, “The Joins General Corsaitte i avn care! cmnileation to the svaier of eonetucsion stendares om joist ase poles, Penny the fevetepmie uf nate e wer sang has Keay ean a at US See a ne isos wer wings nis, iy ave recommended the National Blecrial Safety Cove Ie ae gue to practise. Paoneciive Devices Boch telephone axl supndy sires ane equippes with ntertive stevices which are Gears ly Ce saat in pinciple. They may be Hive into too ger eral ens 1 These which pre yma ron abwirwal yagasemsit ng ‘protector blocs in the elehoue pce and lighting aevesters in the suppl ste 2, ‘These which sone sratecion fora shanna eu-sentnomeeing of heat exile and fates in the telephone plant and fuses aad ie ft breakers fa the supply system ‘hese protective deviow are vray defense aginst abormal conditions which #isimpracticale wo avai either by design or theoush fllerenne construetinn standard, Tara when all practicable preceusions with regard to claeranee, frength of construction and ingulation have been token, accidental Treks accu in bets power and telephone wires. In some eases cheve reget contacts between such wires. lier thar normal paeatia fre alo inteceere rte te eine sl power cient by Fghening fd other causes cis ocause of the liieations of ywutectve devices and other 2 ceccive mcweure tut it sew wi eer tyes of wii hae been inquestion Conskierabe diSerenres ut opinion exist betwten eng nocie ce tothe deste of hazard vols’ i juin use heten telephone Plane tnd ower siveils of vari types voltages, adams ower.‘ prem las ivensed in iniportance as The use a higher strilucion vollagee and greater generaLng capacity have Leen ers Doge. “This matte is undes investization by the Joint Subcomnttes on Developaent and Research. Shdies ase now in progres in ove rural ven and in one sir aren corer he overenadvarages at Cisadvemiazes of she nse! higaesdisciution voltages and of join. nar nih these woltages under ree eantions he Ait experisital wor she hy the Joie? Subcommittee in comeccion with ae rotlens sus adele staly of Vee chavaebere SShcs of various types of vehi sty covered ll of the well Kener comercial Iypes of telephone fuses and a nusher a eaperi= ental models, Tae operating charactevistcn of thew Cunew were obtained ae volts of 250) 00, 750 and 15,200, The eusveat ‘ange wes fiom 16 to 1000 amperes,” ‘These tests were caried oa it 2 Iaboratory where 20,000 kya. of generating capi wow availble The tests showel the dependability that could be placed «yn he ‘varioun Fuser for interrupt voleage of the range from 2300 to 13.200, elt, "They shoe umler wha’ ponditons the fuses could be de ended upon and dhe ranges weve the availahle cype of fuses could mot Se depended un for safe operation “Anumber uf the experiwental models showed considerable promise nf impovenene over existing meslels al his werk will be cae ied ries tn selersine what improvements ca be made the operating choracteristia of fuse, “The est phase of the pavbler takes op jarladel stay af the vigeatias characteristics of various (pee of evervoltage pwctectors futabie lp wre om romsueation ceeuts, The experiments! work fevered! bres with dget eurens, 60 cycle aleerating earcent tr a complete study with » thmle ery oxeilegraph of the balvaie= finder sec gave ot for earl lace prions, ae warn tubes, hese tete showed that ehe carbon blcleprutecor has breakfosn point with all eypee of applied wave trons which is sufiient'y fast Felli to poorer the insti thas Seca use the ensmniea Ten plant, ae shown by simile tests om conderseraeé caste pwr. The sori of shes back fief the= teal hy pretest pul thecirvait when saying current foe ea: ppretiae Tegt of "The tests Wits steep wave foncs were ued 19 a rae of rise of 6,500 alts pot niesstcand, nl it yee ecard Ly tee af Propagacen of steep uve front vatagee txough telephone cable hat {was practically impli Lo subject the pla to v.t2ges wth any lancer ras of ree than those wed in sh poaeerer ata Ihe pnlies of aden poonection ol the ete pla ise tee, olive, cannot Se solved hy Ie devel of Th teghone fretective devises lone. ‘The provative device in che power sytem, bie enullyimporsaet “One of the portent fusions of she peaeesevatem peotesive de sows is shat of wearing power system aula ina reasonable tine inter Sal. Obviously, telephone proteetive equipuent cannot be expected te prevent damage ‘0 eeephone plant in case of contact between the tree cleus of the two tities when per tem protertive devi. Fai cnnpesate i the physi! cone of the ceeuis ie inlael uve sn leit period of time ‘One problem in the development and seseavch work is the dsing uf the part thatthe protectivedieieesom ea system wit playin abner nol conditions. Tis necessary thut the versal protective mipment bye arkjuate anc that the burden wf peerenring weakbeses ia the protective mquipment af one sestem be not threwn on the prutectve souipmeat of the other. There are iaevent Limitations in bork classes ‘f peoective equim Nha! mul be deine ‘Thereiory the next step in this investigation ie determination of the overall eharacterstns u! poswercicuit and telephone ccc pro- ‘ection under oypieal conditions of euntact hetweea the tvo plants. While prolertive devices age sm important element in connection with joint use invlving retain types of power czeuts empioving the Tighter disibucion wolty, there are also other important considera- tions. Ihe general inslaton of the telephone plat mst ns be considered, cereily ir connection with dsop loos tech to ae fneeiing ubeeberé’ yremices, "These matters are alo being sued by the Joint Scboomnstee ‘All the problems, ae is the eve of bers being studied by the Joint General Comite, eco beng approached oa the bees of dece= mining tie bet over-alloeveuriry oclation such that beth systeme cen [ravi the’ servces ia she mew! convenient and economical manne Tsnmoren Ceonastion In che early story of joint ave, cose induction probleme involving stucce lighting virvuitn spueaieds Otsec intersting probleme were fncoustersl sul, for example, oe the aceicenta grounding of ne ‘corner of an sla lia parce system wh its resulting umlsces] ‘oltoge inuctive effets 01 operswie reentone circus, Which type (F cekeplume coustuetinn then predominate! Sx thew prublonis acase chy reel erful study’ ard with The leven sul eqterded 3 of relehone cables and che ae 0 iinorowed opecsting meituxls iv ywncer avd cclephone distribction severally, inductive coord-tien of uncer and telephone esteibution Shsteae in the urfion enmmunities ecame Hess treble al dil fot fora time rive any luge anoups ef eanileraton awever, during erst year the intwoducsion and extended wse of ‘orions types mulligrouiaded dleibution spent derived ie Ue Teper by Mess. Harton at] Siver andthe sine of certain type CF Signaling en Iocal ceksphoae cuits hve coacribuced tower mth fg imorcant the copederntion of ite alueive eects fn eornection with joint use, This mater i eect wore uly in the paper by Mere, Hasina and Silver “The sechniee! fectirs involv in inductive coordinasion problenst tuader joine ure condi are vompliested, The details regarding these factors sd the rel of the estenive studies of Use mates by tre Join Subomaitie on Develapment rel Research are described in the pape: by Messrs, Wills and Reine! The vatious operating problems whic lave arizen almost ince the birth of the jonor aed veephine industies ana the investigations flucted by the Joint Subeirimaiice 47 Development and Reseszch seats the importante af i= careful cos aidevecin tothe indnrive oovdinetion feature jiu use am’ a neuen this factor in ettos Mf the relative advansagts ad disadvantages a joint uae as compared Jwithsesmite fines Tie fsetor shold, of murae, be eoasicered from, Toth its technical gd eee apes ‘Much ean be accomplished i. the iduetive eootdinasion of the rv isribucing. systems by wooperuive advanoe planning Un urbar ltcae wher the telephone ecuits are largely in rable there is about 2 two to one ration he inductive effect Between joint line ade rate lines acioss the street Ty rural area where che telephone cre re largely open sre, the ratio ofthe induetiveefeces on jine lines SSommpared with separaee lines crise the Ty, i much greater ther things being eal Th urban areas the power anil ‘elephone companies can through cooperative pnnrng requantly asvange to establish important power fenders sd tieuone cenie an separate sere ane Uerely avoid Tange iuctive e=ecte and permit ire exvensive aint wae ef branch, Toes, Vela review of che equipment ihe power ard tle home cteuis ad the inceodueiom of operating practises designed 0 Temit tie ieduetive evsceptiventey of the teleyuone circus and the inaucsive intuesce of power crevile Toman iemportant pect of ad ance placing and conperaten Ae described in che pur ly Mewes, Wills and Blackwell, these lnirerFaetorefneele tl ena ae Tmizasion of the odd tiple fre fideney sesie arising in V-commmtnd yoru feeling ively othe line and i single-phase cervive lenclormers, Suitable limitations ‘ol che unbulances existing among. the Tosds connect between the thieesphase concise! the neutral, Hat the ground recura com ‘Grousding of aerial telephone cab sheath ro provide for increased hileing and the wre! central ice ad sation equiprien: providing Ur higher degre of ue wit yeapect eo ground are helpful ‘The master of joie ese may inv ve beh oral aad url. comma ties” It ie mince generally sesecarel with the latter because of the feveie limtetions in physical qa availabe for uitty use. Li: the ‘ae of rural bes whe tr telephone szests are lagely in pe wie 20 PBL SESE LHCRNICAL JOURNAL and the esponurts hesweea pertcular cicuit are Tkely to be long, joins tse i wot eiways practice, I= these cases locations for separate Tines are usually evailable Purchermor, ec ume in wal pref no aly eum fom ‘ pavely cometiuction sendin deco the fact that relatively longer ans ean often be used on the power nes and bath utlices sce abe in mary instances wo wee share and lighter poles thea wou:d be oractcable in joint ase. Joint wee wich telephone ‘all cicuits or vower sranenision nes Aas not, in general, bees found desieale TTypee of conetraetion vary oo see ssl sevine reqicements An inductive efecrs are sue il 5 Letmie aerenonmiesl ea eaery Ot sch construction Joint use of poles by power and telephone companies has siany advantages, both (com the standpoine of the public ard from the andpeiat of the wive using compenics, ‘This is especially tue ia Dullt-up commits TImportae problems brwighs abot by developments in practises, pstievlarly inthe we of high vole distboun, remain to bes ved, Cari talhereuce to yeumraly amped practons wit regant 1 legrancin, x reg: ctntrucion.inleton ad intive ple ‘lin i noteetry facade tat the advantages of joie uae can be seeued In consisting specie cases propesed fo: jit us, advisable that all of ease tasorn he etdiod conpevatively fy the companies con ‘eunedl, to the end shat good service, ser antl ecomomy by eth cases al uilcy may be pronased, Itc important thor eversthing pratiraltle sould be dane to fst tate jane uve siostruction an eaten is isefulss, ‘The Joint Geveral Committee of the Nationa Hlsisie Light Awecalion aa ull Telephone Systeme continuing its effort in this connection