TRANSMISSION SECTION: CHAIRMAN'S ADDRESSBy E. T. NORRIS, Member.*

"RELATIONS BETWEEN THE MANUFACTURER AND THE PURCHASEROF ELECTRICAL EQUIPMENT"

{Address delivered 17th October, 1945.)

We have the good fortune to commence this Session free fromthe demands and restrictions of war. We can now not onlyassume our pre-war activities but work vigorously on post-warproblems and the future development and progress of theSection's interests.

Our present membership is 1 894. It has increased steadilyand shows a healthy state of the Section, but I am sure this figureis much below what it ought to be. An indication of this occurredrecently when a local Transmission Group of the North-WesternCentre was formed. The interest aroused resulted in well over100 new members. All of these could, and should of course,have already joined the Section, since the only condition ofmembership is that they must be "actively engaged in one orother of those branches of the profession which come within thescope of the Section," and no cost is entailed. I feel sure theremust be many other potential members of this kind.

The Sections were instituted to cover certain prescribed fieldsof engineering which have become of sufficient importance andwidespread interest to justify such specialization. This impliesequality of status between Section and Ordinary Meetings, sincepapers come naturally before a Section because they are withinits scope and not because they are considered of minor im-portance. Ordinary Meetings take, in general, those papersdealing with subjects outside the scope of any of the Sections(Generation, for instance, is not covered by any Section), andon the other hand those papers of broader outlook which, whilstpossibly concerning one Section in particular, are of generalinterest to the membership as a whole.

Since the definitions of scope are deliberately broad, theboundaries are somewhat elastic and will allow frequent contactand, indeed, overlapping between Sections. These should beregarded not as causes for boundary disputes but as opportunitiesfor collaboration. On such occasions it is of mutual benefit tohold joint meetings, partly to attain a more comprehensive dis-cussion and partly to foster more intimate contact betweenSections on their common ground. For example, we in theTransmission Section share interests in common with the RadioSection in carrier-current communication and in some forms ofsupervisory control; with the Measurements Section in measure-ment generally, and particularly in connection with protectivegear and relays, etc.; with the Installations Section in particularsupply problems such as welding loads, and also because, ingeneral, the Installations Section represents our immediatecustomer. We have already had a number of these joint meetingsin the past, and I hope we shall have more in the future.

It has become the usual practice for Chairmen, in choosing thesubjects of their Addresses, either to discourse upon particularaspects in their own field of activity or else to give a broad reviewof progress within the scope of the Section concerned.

Many excellent Addresses of the latter type have been given inrecent years by Chairmen competent to survey the whole field ofengineering covered by the Transmission Section. A manu-facturing engineer's experience, whilst possibly detailed andextensive concerning the construction of apparatus, is only atsecond-hand in application and operation; I therefore rejectedthis alternative.

* Ferranti, Ltd.

My own experience, so far as the Transmission Section is con-cerned, lies 'chiefly in transformers, voltage regulators andassociated apparatus. But it so happens that there are twopapers coming before The Institution this winter dealing entirelywith transformers, one of them giving a broad and excellentsurvey of the whole field for standardization purposes. AnAddress on this subject would inevitably overlap or anticipatesome of this work. I therefore rejected that alternative.

In searching for a subject of which I might feel I have someexperience, and which might be interesting and to some extentoriginal to the Section, it occurred to me that I believe I am thefirst Chairman of the Section representing the manufacture ofmachinery and apparatus and particularly Transmission Sectionapparatus (as distinct from lines and cables). I propose to talkto you peculiarly as such and to discuss the relations betweenthe manufacturer and the user or purchaser. Many years' directexperience of these relations has resulted in analyses and con-clusions which I think will be helpful and which I hope will beinteresting to you.

The subject put thus broadly could, of course, spread overmany lectures or even courses of lectures. For that reason, andalso to avoid extra-mural complications, I am going to bear inmint that we are essentially engineers, and exclude all political,financial and commercial aspects. I shall consider only en-gineering matters on the assumption that the whole subject liesbetween the manufacturer as an engineer and the customer as anengineer. So far as purely engineering or technical matters areconcerned this restriction of course presents no problem; theonly important difficulty arises from the fact that engineeringessentially includes consideration of cost, since it is the engineer'sbusiness to achieve the technical performance required aseconomically as possible.

I shall overcome this difficulty by distinguishing at the outsetbetween cost and price, and considering only the former. Thedifference between these two values includes not only legitimateprofit but also all political, financial and commercial considera-tions, whether under or over the counter. Commercially astuteengineers, and there are doubtless many present this evening,may consider that with these restrictions the discussion mustbecome somewhat ingenuous or even infantile, but I believethat, notwithstanding this handicap, the conclusions at which weshall arrive will be fundamentally arid practically sound, and evencommercially acceptable.

As a final point in this preamble, I should say that the Addresswill not attempt a complete and comprehensive study of thesubject, but purports to consider a selection of more or lessisolated problems of particular or topical interest. Lastly, theviews expressed and the conclusions drawn are my own as amember of The Institution and have no official significance,nor do they involve any of the firms with which I have beenassociated.

In order to give some sequence to this collection of remarks,I propose to discuss broadly the progress of the relations betweenmanufacturer and customer, and to consider, first, events up tothe placing of the order, and secondly events after delivery.The former will include the specification, quotation and dis-cussions relating thereto, whilst the latter will deal with installa-tion, operation and subsequent experience.

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NORRIS: TRANSMISSION SECTION: CHAIRMAN'S ADDRESS

THE PURCHASER'S SPECIFICATIONThe first step in this chain of events is the issue of an inquiry

wherein the customer tells the maker exactly what he wants or,in some cases, thinks he wants. That, at least, is the intention.This description is greatly simplified by the incorporation ofnational Standard Specifications. These serve a most usefulpurpose that is generally recognized, but to avoid confusionit is important to remember that they cover several different andindependent functions.

Primarily they fix standard definitions of tefms includingratings and technical characteristics, thus establishing a commonlanguage. Typical examples are Rated Voltage, Reactance,Regulation, Rupturing Capacity. In the second place theystandardize ratings and technical characteristics and also methodsand conditions of test and measurement. Examples here aredefinitions of efficiency and losses, the methods of measuringthem, and the determination of temperature rise under specifiedconditions. All of these objects are wholly good in that theypermit comparison of tenders, eliminate ambiguity of technicaldescription, and place no restriction upon invention or develop-ment. They do not, however, give a criterion of reliability orfactor of safety.

Hence the third function of the specifications is to standardizefactors of safety in the form of test values covering mechanical,electrical and thermal stresses. These include the establishmentof values of voltage tests, of limits of observable temperature riseunder the prescribed conditions. This function provides thecriterion of reliability. Everyone is aware of the repute ofBritish Standard Specifications in this respect. A guarantee ofBritish Standard Rating is an accepted criterion of reliable andassured performance.

The remaining objects are of more recent development and,whilst serving an excellent purpose, introduce certain limitationssuch that they are sometimes printed as appendices or separatefrom the main body of the specification. These objects includethe standardization of constructional features, chiefly thosewhich contribute towards the interchangeability of fittings orparts and the replacement of the whole apparatus.

More recent developments include Codes of Practice or Guiderto Operation giving advice and recommendations for the opera -tion and maintenance of. the apparatus. All of these latterobjects are liable, if care is not taken, to involve some restrictionin design and development. However, these risks can, and ofcourse should, be avoided.

The customer's specification will thus incorporate all theappropriate Standard Specifications, with the addition ofparticular data such as output rating, rupturing capacity, voltageand current ratings, etc. If that were all, there would be littleneed for this part of the Address. But the specification usuallyincludes special constructional features, some of which areessential to the individual case, but many of which are due to thepurchaser's endeavour to improve on or supplement the StandardSpecification, or to avoid what he regards as undesirable detailsof design or construction. These latter requirements usuallyresult in making the specification more onerous.

Incorporating individual experience into a specificationfrequently results from a tendency to argue from the particularto the general. A common instance is the prohibition of par-ticular materials, due to the purchaser's experience of an indi-vidual failure or defect. Whilst this prohibition is natural, itignores the fact that the trouble may have been, and probablywas, due to faulty application or to defective material. Manu-facturers know how widespread is this practice. In my ownexperience, the aggregate of all these prohibitions would banevery known form of insulation in the construction of a trans-former and make its construction physically impossible. The

prohibition of wood, for example, is common and is due entirelyto instances of unsuitable use or treatment. Even paper andcotton have been excluded. An illogical result of this practiceis that it is the established materials of known composition thatare banned, whilst proprietary materials of unknown com-position, having impressive trade names, are as a class per-mitted.

The specification should therefore insist as little as possibleupon details of construction, and the manufacturer's ownpractice should be encouraged. This would avoid the implicationof asking the manufacturer to guarantee the purchaser's design.It is, of course, reasonable to exclude specific materials ormethods of construction, as distinct from general or classrestrictions. In many cases, the purchaser can allay any fears ofthis nature by a cautionary clause in the specification instead ofa prohibitive one, so that the manufacturer has in effect beenwarned.

With reputable manufacturers, the general design and con-struction will be sound, but each product will have its particulargood points. It is a temptation to wish for an apparatus in-corporating all the best individual features, as in the "ideal"motor-car. This may be attractive theoretically, but such aproduct is not practicable to buy or make. In support of thisand in explanation, I quote an extract from a recent report ofa Select Committee on National Expenditure:

The design of any piece of equipment if it is to be anything butmediocre must always be entrusted to some one individual, an artistwith a flair for design . . . it is no more possible for a Design Depart-ment as such to produce an efficient design than for a Committee topaint a picture.

The analogy is apt. Co-operation in artistic creation is, ingeneral, impossible, and a designer is as near to being an artistas an engineer ever gets.

The design of every apparatus involves a compromise ofseveral variables, usually interdependent and frequently mutuallycontradictory. The specification should therefore stipulate andfix no more of these variables than is essential for the particularcase, irrespective of the provisions of Standard Specifications.For example, the stipulation of a particular reactance value oftransformers may complicate the design, and is frequently atvariance with the desired efficiency and loss ratios. The exactvalue of reactance is usually only required for parallel operation,and in other cases, which are the majority, an approximate valuewith no tolerance limits should be allowed.

A common instance of a purchaser's modification to theStandard Specifications is in calling for more onerous tests,usually in the belief that this will result in more reliable per-formance. The design of any apparatus from this point of viewmust be such that it will withstand:

(a) Normal working conditions.(b) Abnormal working conditions, such as short-circuits and other

operation faults.(c) The specified tests.

If tests were perfect, they could be safely chosen to givesufficient factor of safety over (a) and (b). The more recentdevelopment of non-destructive testing is tending towards thisend, but is as yet very limited in application. The difficulty withall tests concerning satisfactory length of life is largely due to thefact that one cannot accelerate the flow of time. The only proofthat a switch insulation, for example, will last for 20 years isto work it for 20 years. Most standard tests endeavour tosimulate the acceleration of time by accentuation of stress. Forexample, a voltage test of three times normal for one minutemay be regarded as equivalent to normal stress for 25 years'operation.

MORRIS: TRANSMISSION SECTION: CHAIRMAN'S ADDRESS 39

These are approximate or even empirical assumptions, becausein general it is not possible to determine an equivalent of time instress. Moreover, ignoring this, the test shows only that theinsulation had 25 years' life before the test was applied. If it is aroutine test on every machine the subsequent life in service isstill unsure. For this reason such tests cannot be regarded in-trinsically as certain safeguards. It is, in fact, possible to designa transformer which could be guaranteed to withstand thestandard tests satisfactorily and could be equally guaranteed tobreak down in normal service within a year. What happens,then, in practice? The actual factor of safety is ultimately deter-mined not so much by the tests as by experience, and is ensuredby the determination and vital need of the manufacturer toavoid failures.

The assurance provided by experience is illustrated by recentdiscussions in this country and in America on proposed surgetests for transformers. In these tests it is not yet possible to besure of detecting failure, and apprehension is generally expressedlest partial damage should be done during the tests which wouldnot be detected and would result in a weakened transformer goinginto service. In consequence, a variety of precautions, safeguardsand complications have been suggested to allay these fears.Now exactly the same risk has existed, and still exists, in theordinary standard 50-c/s voltage tests which nobody nowcriticizes or worries about—owing to the assurance and con-fidence which lengthy experience and practice have established.These remarks imply that, in general, severe tests may notprovide the assurance expected and, in fact, may well meanthat the design becomes a matter of providing sufficient strengthto pass the test and yet leaving enough remaining strength fornormal working conditions.

The foregoing considerations of the purchaser's specificationcover normal conditions. The possibilities of the specificationare carried to excess if the purchaser exploits competition orcustomer value in order to exert technical pressure on themanufacturer. The limit of pressure in this respect has probablygiven rise to the somewhat cynical statement that an astutepurchasing department should be able to buy below cost if thereare live or more suppliers.

Apart from deliberate exploitation of this kind, which Ispecifically excluded from consideration in this Address, it maywell happen that a purchaser, in his endeavour to satisfy hisengineering requirements, calls for a combination of technicalor constructional features which, in the view of the manu-facturer's designers, would result, due to complication, in aproduct of engineering, standard below the reputable level. Forexample, in a transformer, series-parallel connections, extensivetappings, dual voltage ratings, though satisfactory individually,may in combination preclude sufficient mechanical and electricalstrength. The manufacturer may then find himself in the positionof hesitating to express this view to the customer for fear ofcompetitors' assurances and ready acceptance of the demands.

These remarks may be summarized by saying that the specifica-tion should essentially stipulate what the customer wants but nothow it should be done, and should leave design and constructionaldetails to the manufacturer as far as possible. The commonpurpose of a specification, that it should enable the customer topurchase from any manufacturer regardless of reputation, withassurance of equally satisfactory operating performance, doesnot apply in general to engineering apparatus of interest to theTransmission Section, and a specification should not be regardedby the purchaser in this light. For example, in some work it ispracticable for the purchaser's engineers to prepare a specifica-tion and hand it over to the purchasing department with technicalfreedom to accept any offer, knowing that the prescribed testsand inspection will ensure satisfactory performance.

THE MANUFACTURER'S TENDERHaving received the inquiry and specification, the manu-

facturer prepares a tender describing his proposition and giving,of course, the price and the required dimensional and other data.The chief among these are technical performance values, such asefficiencies and other characteristics affecting the economy andoperation of the plant. Since in most cases these values are notfixed but are related to cost and size so that economy of operationvaries with cost, it is usual to give guarantees of the more im-portant values. This practice ensures responsibility on themanufacturer's part for the relation between promise andfulfilment. The chief objects of the guarantees are:

(a) As technical information to the customer concerning the per-formance.

(b) To permit comparison of tenders on a common basis.

It is also usual to subject the guarantees to tolerance allowances.Tolerances have arisen because it is not possible to predeterminewith exactness the technical performance of most machinery andapparatus, owing to disturbing factors over which the designerhas no control, such as variation in the quality of materials usedand irregularities in construction and assembly. The ideal systemwould be a statement of the mean expected value together withthe standard deviation. No method, however, has yet beensuggested of achieving this end in a satisfactory manner.

Tolerances have always been, and still are, a vexed questionbetween manufacturers and purchasers, partly because thepurchaser naturally prefers a definite guarantee, and partlybecause tolerances are often associated with commercial astute-ness or incompetence in manufacture. There is much sophistryin these discussions. Many manufacturers are in the anomalousposition of insisting on tolerances through their standardizationcommittees, and trade Associations, and at the same timeassuring their customers that they always design well withintheir guarantees. I suggest that these attitudes are not onlytechnically incorrect but logically unsound and commerciallyunnecessary.

A tolerance naturally affects the risk of rejection and, in thecase of losses, for example, will permit a lower guaranteed value.In fact, if properly utilized, a tolerance will permit a guaranteegiving the purchaser a truer indication of the actual performance,a result in many ways fairer to the manufacturer and of morevalue to the customer. This is the chief justification of toleranceallowances on efficiency or loss guarantees. Since, however,their proper use cannot be controlled, they permit more latitudeto the maker and are open to improper use.

A guarantee generally involves some risk to the manufacturer,even with tolerance allowances. It is, in fact, this risk whichdetermines the actual value of the guarantee. The purchaser,by imposing penalties, introduces a commercial element so thatthe risk has two aspects, technical and commercial. It is oftenassumed by the purchaser that a guarantee has been given as atechnical risk which has actually been treated by the manu-facturer, or the manufacturer's Association, as a commercialrisk, the difference being that in the latter case the considerationis not so much the technical possibility of a value being outsidethe guarantee as the commercial risk of incidence combined withdetection and the consequent resultant cost of correction.

These conditions apply not so much to efficiencies and losseswhich are accurately measured as a routine test, but to otherguarantees of performance which may only seldom be incurred.Typical examples are the behaviour of plant under abnormalconditions such as short-circuits, lightning stresses, etc. A makermay not know as a technical fact that his product is surgeproof;he may even know that it is not surgeproof. The chances of itsbeing called upon to withstand a severe lightning surge are so

40 NORRIS: TRANSMISSION SECTION: CHAIRMAN'S ADDRESS

small that, combined with the chance of its failure, the total riskmay well be acceptable commercially, and a guarantee offeredwhich may be misinterpreted by the purchaser.

An important application of loss guarantees is in the capitaliza-tion of running and operating costs to determine the mosteconomical relation between first cost and technical performance.From a series of designs having different proportions of cost andperformance, the alternative giving the lowest total capitalizedcost is chosen. If the appropriate capitalization data are givenby the purchaser in his specification, then the manufacturer canput forward the most economical design for the particular con-ditions. A number of papers have been read before The Institu-tion within recent years dealing with this capitalization, or theeconomics of engineering. These brought forth considerablediscussion and criticism, not only of the details of application,but also of the basic principles themselves.

Whilst the importance of capitalization is generally appre-ciated, the practical application seldom seems to induce aninitial expenditure exceeding the lowest offer. It seems im-portant, therefore, to consider not merely capitalization valuesbut the limitations of their application. The most generalcriticism is that capitalization essentially involves expression ofthe future in terms of the present, and that this prognosticationcould never be done with certainty or even with assurance sincethe future is always unknown. Owing to these conditions, it issuggested that capitalization be regarded as of broad and generalsignificance rather than as a matter of specific and detailedcalculation. It calls for shrewd judgment and even politicalanticipation in the final choice.

INSTALLATION AND OPERATIONWhen the apparatus has been delivered and installed, the major

interest in it is rapidly transferred from the manufacturer to theuser. So much is this so, that under present conditions themanufacturer usually regards the transaction as highly satis-factory if he hears no more about the apparatus thereafter.It should, however, be more widely appreciated that manu-facturers are entirely dependent upon operating data forexperience and confirmation of their design and constructionalstandards. For this purpose, operating experience, both goodand bad, is essential, the good, in this case, including Jackof bad. It is desirable that the user should neither sufferin silence nor benefit in silence. This detailed reportingof operating experience is considered here entirely from thetechnical or engineering point of view; it would take the formof a private communication between the user and the particularmanufacturer concerned. There are, of course, other aspectsconcerning commercial advertisement and publication in theform of testimonials.

So far as breakdowns or failures are concerned, it has recentlybeen suggested that a national clearing house should be establishedwhich would collect all information of this kind, classify andanalyse it. Periodically, reports would be disseminated amongboth manufacturers and users, thus making generally availablethe experience and operating data resulting from the relativelyfew or isolated incidents of trouble. It is not usually easy toexpress such analyses or post-mortems in an intelligible formenabling the correct assessment of contributing characteristics tobe realized without much detailed and circumstantial information.Nevertheless, the suggestion is commendable, and I hope it willmature.

Apart from the details of correction or replacement in eachparticular case, the major difficulty with failures or breakdownsis that the user has little means of assessing the significance of thefailure and its justifiable effect upon future practice or specifica-tions. In other words, the user has seldom a sufficiently broad

knowledge to apply a sense of proportion to the symptoms,A breakdown in a particular apparatus may be, and often is,a 100 % failure to the user in that it is a failure of the first or onlyapparatus of that particular size or type. On the other hand,the manufacturer has evidence of the integrated operatingexperience of the whole production of that apparatus, and tohim such a failure may be one in ten or one in ten thousand.In the latter case, the manufacturer would be justified in tech-nically ignoring the particular failure, but such an indifferencewould naturally not impress the user. The assertion by themanufacturer that he has never had a failure like that before,seldom fills the operating engineer with tranquillity.

A typical example occurred recently of three automaticregulators sent overseas, two of which arrived on site with themotor frames cracked. Some thousands of similar regulatorshad been sent to all parts of the world quite safely, and it wasevident from other incidents that this particular consignmenthad received quite abnormal treatment in transit. To thecustomer, however, the failure was two in three, or 67 %. Theframes were accordingly altered at some expense, for politicalreasons, although the manufacturer would have been quitejustified from the technical or engineering point of view inignoring the incident.

Although the will to appraise accurately all the indicationsand evidence of a breakdown is usually present, experience hasshown that this end is often not achieved. From the technicalor engineering point of view such post-mortems are difficultbecause, in the event, the efforts of the engineering staff areconcentrated upon correction rather than upon analysis, andoriginal symptoms may be obscured by subsequent and moredevastating events. It is usually at a late stage that the eventscan be considered retrospectively. It frequently happens thenthat the first symptom observed stands out in the mind of theoperating staff and may be misleading as to the cause. As anexample, it has happened that the first symptom noticed was theoperation of one particular item of the protective gear, whichimplied, of course, a fault corresponding to its particular signifi-cance. Due to inductive interference in the protective-gearcabling circuit, this operation had actually been causederroneously by later events and thus gave quite misleadingresults.

It is commonly supposed that freedom from failure or troubleof any kind is the desirable and attainable ideal. It is certainlyin most cases attainable, the degree depending upon cost,assuming skilled design and manufacture, but in general a productwhich never gives any trouble—and I use.the word "never" herein its absolute sense—has in consequence an unknown marginof strength, and is to this unknown extent unnecessarily expensiveand therefore wasteful. Further, even when attainable, the costof ensuring this absolute immunity from trouble is usually soexcessive in comparison with an entirely satisfactory practicalperformance that this realization is seldom justifiable as atechnical achievement. Such a practical service would justify allbut absolute commercial claims.

In this Address I have discussed within the scope of theTransmission Section some of the relations between the manu-facturer and the user or operating engineer which seem to meworthy of consideration. I have done this in the hope that itmight lead in some small degree to a better understanding and,in consequence, a better co-ordination of mutual problems andinterests. These two parties, the maker and the user, are,however, in themselves of secondary importance. The under-standing and co-ordination which are emphasized are not merelyfor their individual or mutual benefit, but to assist and enableboth to be of better service to the community.