h is to ry ı erling hesla

One Strand at a Time

George Matto, Guest Author

I never perfected an invention thatI did not think about in terms ofthe service it might give others. Ifind out what the world needs,then I proceed to invent.

—Thomas Edison

Which company formed inthe last year will beoperating 100 yearsfrom now? Althoughevery company evolves

in some way, many go through variousstages of acquisition, merger, anddivestment and emerge as very differentbusinesses at the end of that period.One prominent exception that manyindustrial engineers know about is theOkonite Company. Okonite has focusedon a single product, insulated conduc-tors from 300 to 345,000 V, for 130years (Figure 1).

In 1979, in a publication titled‘‘The Okonite Company—Our One-Hundredth Year,’’ CEO Victor A.

Viggiano stated ‘‘ . . . that the successand longevity of Okonite is the resultof unusual efforts and exceptionalcontributions of many people.’’ Thisarticle will track the highlights ofthe history of both the people in-volved and the leaps in rubber insula-tion and cable-making technologyover 130 years. This history attemptsto show that this success comes fromthe founders’ decision to recognize aneed and then to fill it, rather thandevelop a product and try to sell it.

John Haven Cheever,EntrepreneurJohn Haven Cheever was an entrepre-neur and a businessman who investedin several companies in the Bostonarea, including Boston Belting andRoxbury Rubber. Roxbury Rubbermade domestic products from rubber,whereas Boston Belting manufacturedleather and woven fiber belts used aspower takeoffs from waterwheel lineshafts. One of the problems that Bos-ton Belting faced was that belts madeof traditional materials had a limitedlife expectancy; hence, there was aneed for alternative solutions thatoffered a longer service life.

Natural, uncured rubber is stickyand deforms easily. The rubber prod-ucts industry owes its creation toCharles Goodyear’s discovery of theprocess for stabilizing rubber, a processcalled vulcanizing because it entailsboth the heat and the addition of sul-fur. Goodyear was issued a patent forhis process in 1844. One of the earlyapplications was to make reinforcedrubber power takeoff belting; hence,Roxbury Rubber quickly acquired alicense to Goodyear’s process.

The legal counsel for RoxburyRubber was Henry F. Durant, wholater founded Wellesley College. In1856, Cheever, then at the age of 40,and Durant joined together to ac-quire half interest in New York Belt-ing and Packaging, another companythat employed rubber in its manufac-turing processes.

Dawn of the InsulatedConductors IndustrySamuel Morse invented the telegraphin 1837. Later, in 1875, AlexanderGraham Bell devised another formof electrical communications: the tele-phone. One year later, John Cheever’sson Charles Durant Cheever, togetherwith Captain William L. Candee,founded the first telephone companyin New York. John Cheever recognizedthat rubber-insulated wires would bebetter than the varnish-impregnatedcotton fabric insulation traditionallyused on telegraph wires. Therefore,together with Henry F. Durant, heestablished the New York InsulatedWire and Vulcanite Company to servethis emerging market.

The product offered by the newcompany employed an insulationtechnique based on natural rubbercalled Okonite. Two industry seg-ments are combined in the name: okwas the sign-off used by the telegra-phers, and nite was the end of the wordvulcanite. The name Okonite rubber iscredited to Captain Willard Candee,who sought to link the technologies ofrubber manufacturing with the emerg-ing electric and communications in-dustries. According to the companyrecords, Okonite insulation was for-mulated ‘‘to contain no less than 30%Digital Object Identifier 10.1109/MIAS.2008.929335

1Cable machinery in the 1920s.

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by weight of ‘wild, dry, up-river finepara rubber,’ with no admixtures oflow-grade rubber or rubber substitutes.’’

In September 1878, Thomas Edisonembarked on a project to light lowerManhattan from a centralized genera-tion plant with the still, yet to-be-per-fected, incandescent light bulb. Thiswas a major challenge heretofore, andonly individual homes or businesses ofwealthy businessmen had incandescentlight powered from local generators. Tolight all the homes and businesses in anarea was a grand plan and generated themarket for insulated conductors.

John Cheever had gained extensiveexperience in developing rubber com-pounds and applying them to wire forcommunications applications by thetime Thomas Edison needed insulatedpower conductors. However, it wasthe commissioning of Edison’s PearlStreet Station in 1882 that providedthe stimulus that Cheever needed topromote his new product. Because itwas rubber based, Okonite insulationhad clear technical advantages overcompeting technologies: it was morewater resistant and resulted in lowerleakage and fewer electrical break-downs. As a result, rubber-based insu-lation soon dominated the market.

Cheever established a conductorinsulating plant on the property ofthe New York Belting Company inPassaic, New Jersey, and the incorpo-ration took place in 1884 (Figure 2).

Market-Back ProductDevelopmentThe historical strength of the Oko-nite Company has been its ability tostart with the target of creating anideal product to address a marketneed and then develop the process bywhich to produce that product.

John J.C. Smith was an inventorwho lived in nearby Passaic, New Jer-sey. Cheever acquired the rights to oneof Smith’s inventions that he couldapply to his wire insulating process.The process began by producing asperfect a rubber mix as possible andmilling to the correct thickness. Next,several layers were applied longitudi-nally to the conductor. Using Smith’sinvention, the last layer of the coveringwas first applied to a tin substrate thatwas slit to a precise width. After wrap-ping the rubber and tin compositestrip around the conductor lengthwise, the two edges were mechanically

closed. The uncured cable was thenplaced in a chamber where, under con-trolled heat, pressure, and humidity,the rubber insulation was vulcanized,as John Cheever had learned to do inhis previous businesses. This processbecame known as the strip process andwas characterized by the signature,patented ridge running the length ofthe cable. The resulting cable wasfree of known defects, and, moreimportantly, the uniform thicknessmore evenly distributed the electri-cal stress around the conductor andthrough the insulation. Together, thequality-controlled rubber, the uni-form application of insulation strips,and vulcanization within the tinsheath resulted in a vast improvementover all other methods of insulatingconductors at the time.

In 1885, the company’s name waschanged to the Okonite Company.The insulation name Okonite was sosynonymous with rubber that it evenappeared in Webster’s Dictionary.

The Middle Years: ManyTechnical AdvancementsIn 1931, Dr. Charles E. Bennettdeveloped high-pressure, fluid-filledcable for applications at 230 kV(today, 345 KV and higher). Theneed of utilities to move large mag-nitudes of power over greater distan-ces necessitated higher voltages, buthigher voltage would destroy con-ventional insulations. The premise ofBennett’s solution is that insulationunder pressure would be protectedfrom ionization. This revolutionary

development became the primaryelectrical infrastructure of the majorindustrialized cities of New York,Chicago, Boston, and Detroit.

At around the same time, DuPontintroduced DuPrene, later changedto neoprene. Okonite started utiliz-ing this material in 1933, when itwas known as Okoprene.

The Second World War brought aflurry of developmental activity. TheJapanese embargo of natural rubberimports to the United States drovethe development of alternative mate-rials. In 1937, butyl rubber was in-vented by Enjay as a substitute fornatural rubber, although it was notavailable for commercial applicationsuntil after the war. In 1940, thepolymerization of ethylene gas intothe polyethylene plastic was devel-oped and became available for wireand cable purposes in 1941–1942.

General Electric developed theorganic peroxide vulcanization ofpolyethylene in 1955. Like the vul-canization of rubber, this processimproved the thermal deformationcharacteristics of polyethylene andintroduced its use in wire and cable.On the basis of the developments byZiegler and Natta, in 1959, Exxonproduced the first laboratory samplesof polymerized ethylene propylene(EP) for prototyping. In 1962, thefirst ethylene propylene rubber(EPR) electrical insulation becameavailable from Okonite.

In 1963, Okonite made what lat-er proved to be a very significantchange in its manufacturing process:

2One of the early Okonite plants in Passaic, New Jersey. 9

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introduction of the continuous vulcaniz-ing (CV) in the North Brunswick, NewJersey, plant. In 1965, the last strip-process cables were produced for PublicService Electric and Gas Company.Sadly, this also meant the end of the‘‘Look for the Ridge’’ marketing slogan.

In 1967, an Okonite formulationof insulating rubber, today known asOkoguard, was developed and uti-lized to manufacture the company’sfirst 69-kV cable for PhiladelphiaElectric. By design, the original69-kV cables featured an all-EPRconstruction: strand and insulationsemiconducting shields along withthe insulation are compounds of thesame EPR formulation and werenonstrippable. This meant that theremoval of the outer semiconnectinglayer under the shield was accom-plished by the mechanical abrasion.This design was not practical for usein lower-voltage applications butresulted in a superior cable because ofthe absolute bonding of the insula-tion layers. Where many splices andterminations were required, a strip-pable, semiconducting insulation shieldwould be needed.

Here was the challenge: make anall-EPR cable, removing any questionof compatibility of layers, by utilizingthe same base rubber for each andachieve a homogeneity that wouldensure uniform thermal expansionand contraction and prevent waterincursion. However, a process had tobe developed to allow the semicon-ducting shield to be stripped from theinsulation. In a proprietary process,the bonding is impeded, which allowsthe semiconducting EPR insulationto be peeled away from the EPR insu-lation. The resulting insulation sys-tem has the same thermal, chemical,and mechanical characteristics through-out without resorting to dissimilarmaterials, which would compromisethe basic premise of an all-EPR cable.In 1974, the all-EPR, strippable insula-tion system was introduced to theelectrical industry for voltages between5 and 46 kV.

Another innovation is related tothe way peroxide is introduced intothe rubber. The traditional approachof adding peroxide directly into theBanbury mixer introduced the risk ofpremature vulcanization of the rub-ber and contamination. In 1983,Okonite was the first to apply the

peroxide absorption process to rub-ber products in which peroxide isabsorbed into the rubber rather thanmixed into the rubber. This allowedthe rubber accelerator to be accom-plished withoutthe addition of heatfrom a second Ban-bury pass.

This most recentstep in the evolu-tion of Okoguard isconsistent with thebasic tenant of thecompany. In fact,the 1923 Okonite In-sulated Wire and CableHandbook [2] includesthe following: ‘‘TheOkonite Company’stwo guiding policies,viz: first, ‘to make thebest product possi-ble’; second: ‘to standbehind the product,’were laid down byMr. Cheever and havenever been deviatedfrom.’’

By the end of the First WorldWar, management was changing atOkonite. H. Durant Cheever, son ofCharles H. Cheever and grandson ofJohn Cheever, had become presi-dent. The growing electrical mar-ket needed more and new productsthat had not yet been designed, andproduction would need to be in-creased. Most importantly, the meansof interfacing with customers was inneed of change.

The latter issue was solved byestablishing local sales offices withknowledgeable staff who could com-municate with customer engineerson a technical level. Okonite wasmanufacturing insulated cables foralmost every application that couldbe conceived: inside new efficient elec-tric motor-driven industrial plants,utility generating plants and theirdistribution systems, and under-ground, in the air, and under water.

The Recent Past:Electrifying ChangeEarly in the 1970s, Okonite acquired alicense from Kabelmatel of Hanover,Germany, for manufacturing a contin-uous metal sheathed cable. This metalsheath, called CLX for its character-istic sealed and longitudinal exterior,

eventually became an optional armorfor almost every cable design made bythe company. Originally, CLX wasmanufactured in the United States bythe Simplex cable company with a

steel sheath. Afteracquisition by Oko-nite, the design wasmodified to use acorrugated alumi-num sheath. Safetywas an overridingattribute because ofthe better con-ductivity of thealuminum sheathcompared with steel.

In the case ofcable for variablefrequency drives(VFDs), the appli-cation defined thecable as was dis-covered by Bentleyand Link of ABBin their quest tosolve the issue ofbearing wear inVFD motors. They

determined that the continuous, cor-rugated aluminum sheath both con-tained the high frequencies involvedwith the drives and provided a lowimpedance path for the damagingcommon mode current to be con-ducted away from the motor. Oko-nite agreed that an improved cablewould have distributed grounds inplace of a single ground wire.

In 1993, the company inaugurated astand-alone, highly automated, andcomputerized rubber mixing facility inOrangeburg, SC, which vastly improvedon the quality of the EPR material.Controlling the ethylene content of thebasic EPR insulation building blocklimited the degree of crystallinity ofthe final insulation compound and dra-matically increased the life of the cable.The earliest insulations were susceptibleto failure because of moisture, andunless the formulation of current insula-tions takes into account the crystallinityand other characteristics, insulationmoisture would still be a problem.

During the 1960s and early 1970s,Okonite had several owners, one ofwhom relinquished 100% of the com-pany’s stock as collateral on a loan onwhich he subsequently defaulted. Itseems fitting that in 1976, almost 100years after its formation, ownership of

OKONITE HASMANUFACTURING

PLANTS ONBOTH COASTSAND A SYSTEM

OF SERVICECENTERS

STRATEGICALLYLOCATED

ACROSS THECOUNTRY.

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the company would be transferred tothose who cared most about its prod-ucts and customers and future: itsemployees. The entire managementand each of the employees of thecompany have a shared ownershipthrough an employee stock ownershipplan (ESOP).

Today, Okonite has manufactur-ing plants on both coasts and a sys-tem of service centers strategicallylocated across the country. The Oko-nite Company operates close to its

roots, research-based rubber formula-tions, compounding its own rubberinsulation and equipping its plantswith machines designed to achieve aspecific end result: a wire and cableproduct with the highest acceptancein the electrical industry, supportedby a highly trained local sales force(Figure 3). The ESOP ownership en-sures a dedicated cadre of employeeswho subscribe to the founders’ prin-ciples of quality, excellence, andcustomer support.

Modern EPR insulation is a propri-etary mix containing a maximum of72% ethylene by weight to whichnumerous chemicals and compoundsare added and is the heart of the Oko-nite business today. Okoguard (EPR)is recognized as a long-life insulationproduct, but they don’t look foranother change in the name of thecompany. The name Okonite seemsto be serving just fine.

AcknowledgmentsThe author acknowledges the manyemployees of the Okonite Company,especially Victor A. Viggiano, AlfredC. Coppola, Wes Kegerise, and Rob-ert Seltsam, who have ensured thesuccess of the company and assistedin recounting our rich history.

References[1] A Brief History of the Okonite Company of

Passaic, NJ. John Royle & Sons, Mar. 1950.

[2] The Okonite Company Cable Handbook (Fore-

word), Passaic, NJ: Okonite. 1923.

[3] E. J. Houston, A Dictionary of ElectricalWords, Terms and Phrases.

[4] The Okonite Company 1878–1978 Our One-hundredth Year. Passaic, NJ: The Okonite

Company.

[5] J. M. Bentley and P. J. Link, Evolution ofMotor Power Cables for PWM SC Drives, IEEE

Standard 0-7803-3148-6-5/96, pp. 55–69.

[6] E. T. Bartolucci and G. R. Matto, Properand Installation Practices for ac Drives, IEEE

Standard 1-4244-0282-406.

IAS

le t te rs to the edi to r(continued from p. 4)

able to detect the approach of an arc-ing fault and send a signal to andopen the circuit within one-fourthcycle of a worker-initiated break-down of insulation in an electricalcircuit. We certainly encourage thedevelopment of fast response detec-tion systems. Such systems installedon equipment could also minimizethe risk of injury from non-worker-caused equipment failure. Other similarbenefits that we hope to see materializefrom the AF hazard project would bethings such as a device a worker couldwear while approaching electrical

equipment (prior to opening anydoors or removing panel covers),which would automatically show thevoltage involved and the incidentenergy at various distances from theenergized, exposed electrical conduc-tors or circuit parts.

We understand that if 100% effec-tive equipment were installed andprotective methodology implementedon all electrical equipment purchased inthe future, a transition to the newprotective scheme would require 30–50years. Until the transition is complete,existing equipment would continue to

be used and workers would continue tobe exposed to hazards generated in anarcing fault. We believe that the firstorder of business must be to protectworkers from injury when new or oldequipment is being used.

We wish to thank Mr. Lew Mer-melstein for his letter. His interest inpreventing electrical injury is appa-rent. We support his efforts to reducethe potential for electrical injury.

IEEE/NFPA Collaborationon Arc Flash HazardsSteering Committee

IAS

3Although the materials and manufacturing technology have evolved, Okonitestill makes the product that it was originally founded to produce 130 years ago:electrical cable.

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