The Electrician : the oldest weekly illustrated journal of electrical engineering, industry, science and finance, Vol. 139, No. 24 (3626)

E L E C T R I C I A N

4 \ .

three-core Im pregnated P ressure Cable, by tak in g th e place o f th ree single core cables, can effect considerable economies in first cost and in installation. T h e first 132 kV.

th ree-c o re I.P .C able in the W orld to be operated com ­ m ercially was m ade b y B .I.C a llen d er’s, and its suc­

cessful operation dem onstrates th e special advantages o f th is ty p e o f high voltage transm ission.

3 CORE

/. ^{P . C A B L E}

B R I T I S H I N S U L A T E D C A L L E N D E R ’ S C A B L E S L I M I T E D N O R F O L K H O U S E , N O R F O L K S T R E E T , L O N D O N , W . C .2

ivlETROPOLITAN-VICKERS ELECTRICAL CO. LTD • NUMBER ONE KINGSWAY ■ LONDON ■ WC. 2

I n t h e i r s h i p b u i l d i n g b e r t h a t S u n ­ d e r la n d t h e v i t a l w o r k g o e s o n e v e n w h e n d a y l i g h t f a d e s T h e h i g h ly e f f i c i e n t s y s t e m o f f l o o d l ig h t i n g r e c e n t l y d e s ig n e d b y M e t r o v i c k I l l u m i n a t i n g E n g in e e r s l i g h t s a s h i p b u i l d i n g b e r t h

88

f t . w id e a n d

110

f t . h ig h , c a p a b le o f d e a lin g w it h v e s s e ls u p t o

550

f t . in le n g t h

12 DECEM BER 1947

1673

T E L E P H O N E S : W A T F O R D 6626/7.— T E M P L E B A R 4294. T E L E G R A M S : “ T E M E L E C ” W A T F O R D .

12 D E C E M B E R 1947 T H E E L E C T R IC IA N

48482353232348532323

C A B L E S A L E S M A N N O W T H A T R E S T R I C T I O N S A R E O F F

Yes ! H e really has som ething to sing a b o u t—

J. & P. are su p p ly in g sta n d a rd V .I.R . Cables F R O M S T O C K .

T h e service fo r w h ich w e w ere fam ous before th e w ar is being re sto re d rap id ly — a p o in t w o rth re m em b erin g w hen n e x t h e skips into y o u r office.

* The one cloud in his sk y — lead-covered cables are still in short supply. F ortunately, we do hold stocks o f alternative types.

« J O H N S O N & P H I L L I P S L T D .

* C H A R L T O N . e L O N D O N S .Ê .7

hi inCdJc fh&f

m m í

m i W it

ik

M ¿k (paktu ,— .

1675

WHERE THEY USE BAKELITE LAMINATED

This special tm n -co il induction heater was b u ilt by Birlec L td . for ann ealin g th e rim s o f deep pressings. Special design difficulties were m et because o f the exceptional n u m b er of am pere turns in the coils. These coils, connected in series, were enclosed in an annular box b u ilt o f B A K E L l T E L am inated and filled w ith an in su latin g com ­ p o u n d . T he voltage on each coil is approxim ately 2,500 and th e frequency about 300 kc/s per second, cooling being supplied by w ater circulated in the copper tubes w hich form the coil conductors. B a k e l i t e L am inated was chosen because it was able not only to play its part in solving th e difficult insulation problem but to offer effective heat resistance w hen exposed to the tem perature of the pressings.

BAKELITE d> PLASTICS

REGD. TRADE MARKS

E sse n tia l M a te ria ls f o r E sse n tia l W ork

B A K E L I T E L I M I T E D • 1 8 G R O S V E N O R G A R D E N S • L O N D O N . S . W . I

1 2 D ECEM BER 19 4 7 THE E L E C T R IC IA N

F O U N T A I N S A B B E Y R IP O N

A m o n astic ruin, fo unded b y the C istercians in 1135. St. B e rn a rd se nt o n e o f his m o n k s to d ire ct b u ild in g op e ra tio n s

CRYSE

MADE IN ENGLAND

B I R M I N G H A M B U R Y S T E D M U N D S L E E D S L O N D O N

B R I G H T O N C A R D I F F L E I C E S T E R M A N C H E S T E R

B R I S T O L G L A S G O W L I V E R P O O L N E W C A S T L E

C R Y S E L C O L I M I T E D , K E M P S T O N W O R K S , B E D F O R D F I F T Y Y E A R S O F

f

1 2 DECEM BER 19 47

1677

W . Tv H E N L E Y ’S T E L E G R A P H

5 1 — 5 3 H A T T O N C A R D E N

W O R K S CO. LTD.

L O N D O N . E C - 1

1 2 D ECEM BER 19 4 7 THE E L E C T R IC IA N

T h e s e b o x e s h a v e s o l v e d t h e p r o b l e m o f t e r m ­ i n a t i n g o v e r h e a d l o w t e n s i o n l i n e s a r r a n g e d in v e r t i c a l f o r m a t i o n . J o i n t i n g i s e a s y , t h e c o n d u c t o r s l o o p d i r e c t t o t h e c o n d u c t o r f i t t i n g s , a n d t h e b o x i t s e l f fits s n u g l y a l o n g s i d e t h e p o l e . A v a i l a b l e f o r m u l t i c o r e c a b l e s u p t o 6 6 0 v o l t s w o r k i n g p r e s ­ s u r e . F u l l d e t a i l s a r e g i v e n i n c a t a l o g u e U . E . l l .

H E N L E Y

ELECTRICAL DISTRIBUTION

EQUIPMENT

G A L V A N / S E D 5 E C T / O N A L S T E E L L I G H T I N G S T A N D A R D S

H E X A G O N A L

□ » C I R C U L A R

H O T S P E L T E R G A L V A N I S E D

A F T E R M A N U F A C T U R E

S u p p lie d to N O RTH A M PTO N LIG HT A N D P O W E R C O . LTD.

!

.Supplied to

SH EFF IELD CORPORATION L IG H T IN G D E P A R T M E N T

SEND FOR CATALOGUE EN

/2 4 0

T Y B U R N R5 E R D I N C T O N

B I R M I N G H A M 2 4

T E L E G R A M S & C A B L E S / P O L E S B I R M I N G H A M ' C O D E S I B E N T L E Y S 2?.° A . B . C . 5 ™

P ^{o l e s} Lt£

1679

C O O K E R T H E

( N H D A P P R O V E D )

Light to handle and

install

EDA interchange

ability

Impervious

to rust

Instantly removable hobs

oven interior sub circuits

separately fused

Simmering device if required Thermostatic

oven control

P A R N A L L ( Y A T E ) L I M I T E D • 4 3 P A R K S T R E E T ' L O N D O N - W l

12 D ECEM BER 19 4 7 THE E L E C T R IC IA N

D o y o u w a n t t o s a v e c o s t s , l a b o u r a n d t r o u b l e ?

ST A N D A R D R O A D , N O R TH A C T O N , L O N D O N , N .W .10. Tel

:

ELGar 6601

Bring your electricity to the machine and not your machine to the electricity. Our B.B.T. Trunking System is the

modern method o f supplying electric power to motorised

machinery.

0 B .B .T . T r u n k in g is to ta lly e n c lo s e d , steel clad, fire r esistin g .

0 B .B .T . T r u n k in g is adaptable to any m a ch in e area and p r o v id e s elec tric p o w e r e v e r y tw o fe e t.

0 E L E C T R IC S U P P L Y is b r o u g h t to an y d esired p o s itio n th r o u g h e n c lo s e d B u s-B ars and fu s e d ta p p in g -b o x e s.

e *t. mo®

?

M O T O R I S E D M A C H I N E R Y d fr o m B .B .T . can b e re-arranged at w ill to su it p r e v a ilin g p r o d u c tio n

req u irem en ts. L o a d in g up to 300 am ps.

0 B .B .T . T r u n k in g is b u ilt o n th e u n it p rin cip le and can b e e x te n d e d readily.

0 B .B .T . T r u n k i n g c a n b e in sta lle d w e ll ahead o f m o to r ise d m a c h i n e r y s i n c e t h e p r e c i s e p o s itio n o f m a ch in ery n eed n o t be k n o w n in a d v a n ce.

0 B .B .T . T ru n k in g is standardised in 12 ft. le n g th s : Overall

3 P h . 3 w ire . ; . 9 !" x 3I"

3 P h . 4 w ire . . . 11" x 3 !"

f B .B .T . T r u n k in g is a p p ro v ed and u sed b y G o v e r n m e n t

D e p a r tm e n ts .

Export Enquiries Invited

THE E L E C T R IC IA N

1631

B R A N C H S E R V I C E

O U R O R G A N I S A T I O N H A S B R A N C H O F F I C E S A N D S T O R E S , A T T H E U N D E R M E N T I O N E D A D D R E S S E S , W H E R E Y O U R N E E D S W I L L R E C E I V E C A R E F U L

A T T E N T I O N

T H E L O N D O N E L E C T R I C W I R E C O M P A N Y A N D S M I T H S L I M I T E D C H U R C H R O A D, LEYT O N , L O N D O N , E.IO

F R E D E R I C K S M I T H & C O M P A N Y A N A C O N D A W O R K S , SALFO RD 3, Lancs.

A ssocia ted w ith

B I R M I N G H A M

" L e w c o s H o u s e ” , 47, C o r n w a l l St., 3. C e ntra l 3941

B R I G H T O N

16, M a r k e t S tre e t. B righ ton 4 8 5 0

B R IS T O L

4 , R o s e m a r y S t r e e t, B ro a d m e a d . B ristol 2 3 7 5 3

C A R D I F F

W e s t C a n a l W h a r f .

G L A S G O W

75 , R o b e r t s o n S tre e t, C .2.

L E E D S

44/45, Y o r k Place.

L E IC E S T E R

L e w c o s H o u s e ” , Q u e e n S tre e t. L e ic e ste r 2 0 0 2 2

L I V E R P O O L

Im p e r ia l C h a m b e r s , 62 , D a le Stre e t. C e n tra l 6 8 0 8

L O N D O N

3 1 -3 3 , S p e n s e r S t r e e t, S . W . I . Victoria 0 5 0 4 C a rd if f 12 80

C e n tra l 9 0 0 2

L eeds 21991

T H E L I V E R P O O L E L E C T R I C C A B L E C O M P A N Y L I M I T E D

L I N A C R E L A N E , B O O T L E , L I V E R P O O L 20 a n d

V A C T I T E W I R E C O M P A N Y L T D 7S. ST. S I M O N S T R E E T , S A L F O R D 3, Lancs

M I D D L E S B O R O U G H

54, J o h n s o n S t r e e t. M ld d lesb orou gh 2 5 2 4

N E W C A S T L E - O N - T Y N E

61, B la n d f o rd S t r e e t. N e w ca stle 2 7 7 3 7

N O T T I N G H A M

26, St. M a r y ’s G a t e . N o ttin g h a m 4 3 3 2 8

P L Y M O U T H

2, M il t o n S tre e t. Plym outh 6 1 9 7 5

M A N C H E S T E R

4, C h a t h a m S t r e e t, I. C e n tra l 2 9 6 6

1 2 D ECEM BER 19 4 7

1683

>00 1000 100

I k i l o w a t t h o u r s

S IE M E N S SINGLE-PHASE

A L L - I N S U L A T E D

E L E C T R I C I T Y M E T E R S

T Y P I 21

Adrl. oI SIEMENS ELECTRIC LAMPS AND SUPPLIES LIMITED, 38/39 Upper Thame» Street, London, E.C.4

Branches al-BellasI, Birmingham, Bristol, Cardiff, Dublin, Glasgow, Leeds, Liverpool, Mamhesler, Newcaslle-on-Tyne, Noliingham, Sheffield,

1 2 D ECEM BER 19 4 7 THE E L E C T R IC IA N

M P A L L T S L T D S O I T H I H R Y I I D E N F I E L D , M I D D X

"SCVTMSW^L

D ECEM BER

1685

O f robust, durable construc­

tion and guaranteed to be within the limits of First Grade Accuracy to B.S.S.89.

Further particulars gladly sent on request.

DELIVERY FROM S T O C K

THE GENERAL ELECTRIC CO. LTD., MAGNET HOUSE, KINGSWAY, LONDON, W.C.2

1 2 DECEM BER 19 47 THE E L E C T R IC IA N

INSULATORS

T U B E S

TEXOLEX LAMINATED PLA STICS COMBINE MECHANICAL STRENGTH AND HIGH ELECTRICAL INSULATION PROPERTIES

T H E B U S H I N G C O . L T D .

H E B B U R N - O N - T Y N E

LONDON OFFICE ! IMPERIAL HOUSE Kl NG SW A Y , W. C.2. Tel.-TEM. BAR 9 5 8 4

Oar Boar

Op©n m a rin e.typ e sw itch b oard controlling three 200 kW generators and circuits and incorporating Dorman XL air- break circuit breakers and Dorman " F " type sw itches as in stalled on the L.N.E. R ailw ay's n ew cargo liner S.S. Arnhem

(John Brown & Co., Ltd.)

D O R M A N & S M I T H LTD. • M A N C H E S T E R • L O N D O N ■ G L A S G O W

THE E L E C T R IC IA N

E 2 I 4 7

1 2 D ECEM BER 19 4 7

W h o

ran an underground movement in London in the ’Eighties?

Im possible to keep that dark, for this electrifying event— putting one o f the first gearless locom otives on L ondon’s tube railways— was the work o f the man w ho spread electric light throughout the w o r ld : C olonel Crompton. The achievements o f this great pioneer ran non-stop from lighting royal palaces and opera houses to supplying safety equipm ent in mines and power installations at such remote spots as Lhasa and Darjeeling. It was C olonel Crompton too, who first introduced house-to-house electric lighting in England. Today his

work is continued in the great Crompton Parkinson organiza­

tion, w hose products include Crompton Lamps and Lighting Equipment and whose lighting engineers are ready always to apply their specialised knowledge to every kind o f lighting problem.

Irom nton

^{l a m p s}

^&

l i g h t i n g

“ ^ E Q U I P M E N T

1687

F O R T H E L A T E S T I N L I G H T I N G

1 2 D ECEM BER 19 4 7 THE E L E C T R IC IA N

THE E L E C T R IC IA N _{1 2} D ECEM BER 19 4 7

DONOVANS IRONCLAD

Announcement of DS Plugs Ltd., Manchester - London - Glasgow. HM47 The rather rummy looking object

ab ove is on e sec tio n of the n ew DS skirt lor surface mounting the DS condu it box type so ck et. The other sectio n is an absolute tw in.

and th ey g e t to­

gether a s show n below .

This e n a b le s the skirt to be fixed after the wiring has b e e n com p leted and m ean s greater e a se for the wirem an.

Just another in g en io u s addition to the DS Fused

Plug and Socket ran ge.

SWITCHBOARDS

FOR CONTROL OF LOW AND MEDIUM PRESSURE POWER A N D LIG H T I NG

CIRCUITS.

All the w ell-kn ow n Donovan feat u res tar g e clearances, careful connections, cool running, easily replaceable fuses (either rew ir- able or H.R.C. ) — are incorporated in every Donovan Switchboard.

DONOVANS

TH E D ON OVAN ELECTRICAL C9 LT? B IR M IN G H A M 9 E L E C T R IC A L E N G IN E E R S A N D S T O C K H O L D E R S

'Pmom- STEchforo 2277 (P. BX) frflAvs-'DONOVAN.^Bir m in g h a m'

1689

out on a London street, The Chloride Ei ec then, the company and twelve years’ experience in battery m nuf ^ ^ ^ ^

British road transport have ^ ^ ^ passeager vehicles, that provide starting, lighting an g ed truck> that manoeuvre that start the big Diesels on bus and m t d ^ ^ ^ ^ ^ clad.

trolley-bus where the cables end, a l ? ^ in Britain rely on Over three out o f five c f t j P £xidc. [ronclad batteries, f l f t y ^ j ^ them In Chloride, Exide_______________________ ^___.— ---

S

^-

acknowledged leadership

the chlori de eLectri cal

storagecompanyli mi ted

E x id e W o r k s , C lifto n lunction near Manchester

P.4.B-B

Switch Trippjng e q u ip m e n t is i n s t a l l e d

1 2 D ECEM BER 19 4 7

TOE

ELECTRICIAN

o

Telephone : A co rn 3 9 0 4 T e le g ro m * ; Isenthol London

Rapid Action

VOLTAGE REGULATOR

0 For A.C. and D.C. Generators, Booster Sets, Steam, Diesel or Hydro - Electric Generating Plant.

0 Constant voltage maintained through wide variations of load, temperature and speed.

0 Extremely rapid and accurate, can be in­

stalled on existing or new generators, are inexpensive in first cost, require little or no maintenance and they are a b so lu te ly reliable.

0 They are easily fitted and we supply full information for installing.

ISilMTHAI<-fÄV0LTAikfES lA,0R

D U C O N W O R K S , V I C T O R I A R O A D , N O R T H A C T O N , L O N D O N , W .3

A Dependable Control Switch A.C.

Slow Make and Break Type. Suitable for Panel Mounting. Rated at 10 Amps.

•250 Volts. Range of Circuit combina­

tions available. Immediate deliveries on most circuits 15/20 amp. A.C. and Universal available shortly.

ÆLJEŒi

AH enquiries to :-

75 H A N WO R T H R OA D

H O U N S L O W • M I D D X Telephone: H OUNSLO W 7 1 1 0

1 2 D ECEM BER 19 4 7

What makes the World go Round ?

R e s e a rc h w o r k e r s a r e liv in g question marks. Their daily bread consists of how, why, where—of

“ifs and ans” . At the BTH Labor­

atories they have a full meal every day.

With so many enquiring minds at work, Nature has a hard job to hide her secrets, and it is scarcely sur­

prising that the BTH team of research workers is always coming forward with new techniques, im­

proved methods and every now and then, a brand new discovery that makes electrical history.

(ife i

^ L A M P S

But although the first stage in all scientific advancement is accom­

plished by “taking thought”, there is a great deal of hard work to follow, with many difficulties and disappointments to overcome before success is finally achieved.

At BTH no effort is spared, no trouble considered too great, in order to carry an idea through to its conclusion. This is undoubtedly one of the reasons why BTH re­

search has accomplished so much in the past, and will accomplish more in the future.

m a s e j a o o t

FITTINGS

The B ritish Thomson-Houston Co. Ltd., Crown House, Aldwych, London, W.C.2.

Lighting Advisory Service, Bridle Path, Watford. Telephone : Watford 7701/8

D ECEM BER 19 4 7 THE E L E C T R IC IA N

N O . I I O F T H E ( Q ^ g ) D I T T I E S

A r c h i m e d e s, y o u m u s t k n o w , W a s a G r e e k o f lo n g a g o : A n d h e d e v is e d a m e th o d n e w O f ra isin g w a t e r (b y a s c r e w )

’T w a s n e w ! ! ’T w a s n e w s ! ! and still its fam e

Is l i nked w ith A r c h im e d e s ’ n am e.

B u t w e r e o ld A rc h , aliv e to d a y W e h o p e fu lly b e lie v e h e ’d say :

“ H a r k u n t o m e, all ye w h o use P re s s -w o rk , t u r n e d p a r ts , in s e r ts o r

s c r e w s —

If y e s e e k u n if o rm ity

In smal l s c r e w e d p a r ts — t r y D & T ! ”

High efficiency light dispersal without glare and with mini­

mum shadows.

R e a s o n a b l y good delivery offered.

TIMMINS I?

H e a d O ffic e : B IL L E T R D ., W A L T H A M S T O W L O N D O N , E . I7

P h o n e : L a r k s w o o d 2 3 1 3 (6 lin es)

A b rid ged ca talogue J L/L.33 rev. c v o il c t k

D I F F U S E R

u n i t s b y

T H E W A R D L E E N G I N E E R I N G C O . L T D .

O L D T R A F F O R D M A N C H E S T E R 1 6

TeL : TRAfford P a rk 1801 (3 lines)

L O N D O N O F F I C E 3 4 V I C T O R I A S T R E E T • L O N D O N S W I

THE E L E C T R IC IA N

dm W A I

1693

RATCHET S C R E W D R I V E R

E a s i e r a n d f a s t e r w o r k w i t h o u t d i s e n g a g i n g .

A d j u s t a b l e f o r f o r w a r d a n d r e v e r s e a c t i o n .

S e l e c t e d h a r d e n e d s t e e l c h u c k p a r t s a n d c a r b o n

s t e e l s p i n d l e .

S u p p l i e d w i t h t h r e e b i t s .

A p p r o x i m a t e W e i g h t \ \ lb s .

H. & D. C HURCHI LL LTD.

Wholesale and Export Distributors

WALNUT TREE WALK, KENNINGTON, LONDON, S.E.II

A l s o a t B I R M I N G H A M , M A N C H E S T E R , G L A S G O W and N E W C A S T L E

1 2 D ECEM BER 19 4 7 T H E E L E C T R IC IA N

D

H O P K I N S O M

E l e c t r i c C o m p a n y L t d

RANGE INCLUDES:

Three-phase Induction Motors from J-100 BHP S in g le -p h a s e M otors:

Split-phase, C apacitor R e p u ls io n - I n d u c t ion

an d Slip Ring

H ead O ffice a n d W orks:

B irchgrove C A R D I F F T elep h on e :

W H I T C H U R C H 1 6 9 1 - 5 C a b les :

ORIGIMOTOR CARDIFF

scenes

W h e t h e r a cathode ray tube is used for television, radar o r electronic in­

struments, it must always be protected from magnetic interference, and this is achieved by means of a nickel-iron alloy shield.

It is the high magnetic permeability possessed by the nickel-iron alloys which has led to their use for this end many other purposes.

W e shall be pleased to give advice on materials for the electrical industry.

T h e M o r i d N i c k e l G o . L t d

GROSVENCR HOUSE. PARK LANE, LONDON. W 1

< a/m/3

THE E L E C T R IC IA N 1 2 D ECEM BER 19 4 7

1695

S A N D E R S

W E D N E S B U R Y

i d A c c e s s o r i e s f o r d D o m e s t i c n e e d s

¡ 0. ( W E D N E S B U R Y ) L T D

Sanders products are distributed through accredited electrical wholesalers. In the interests of good service, the trade is earnestly requested to follow its normal practice of obtaining supplies from such sources.

1 2 D ECEM BER 19 47 THE E L E C T R IC IA N

lechnical leaders since 1821, Riley of Rochdale are able to supply springs both commonplace and Intricate for all electrical needs. Quality, precision and dependability are, as always, the outstanding features.

BT RILEY LTD

MILKSTONE SPRING WORKS, ROCHDALE

hone: Rochdale 2 2 8 7 -8 . G ra m s ' ,eRilost>rins ’ Rochdale

T he insulating value o f used transform er and switch oils by one passage through the M eta­

filter is raised to a higher breakdown voltage than the new oil.

T h e plant is purely mechanical and extremely

simple in operation. C a p a c it ie s p ro m 2 0 g a llo n s to 1 ,0 0 0 g a llo n s p e r hour.

M t T A F U IR A n O N * " » » " - s ' - - -

T H E M E T A F I L T R A T I O N C O . L IM I T E D , B E L G R A V E R O A D , H O U N S L O W , M I D D L E S E X

D ECEM BER

1697

s m a ll d ia m e t e r s p in d le s

E n g i n e e r s w h o h a v e fe lt th e need f o r a r e a lly sm all eirc lip will w elc o m e the T w ic k lip w h ich fits in a g r o o v e just lik e a S e e g e r ; (.arelip and w hich is m a d e in sizes fro m '/« to , ⁵ / ³² .

fo r (it.script h r lite ra tu re |

Manufactured by

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T h e o n ly circlip w h ich alw ays re m a in s tru ly c irc u la r on th e c o n ta c t p e rip h e ry . I t e x e rts g re a t a n d u n ifo rm p ressu re on th e groove in w hich it is fitte d a n d c a n b e relied o n as a com ­ p le te ly safe fixture«

1 5 , 0 0 0 N I F E BATTERIES

on duty 10 years

f o r r e p a i r s !

T h is w as th e actual exp erien ce o f a R ailw ay C om p an y operating N I F E B atteries u n d er very severe co n d itio n s. O b v io u sly N I F E is n o ordinary b attery. It is an A lk a lin e c e ll o f a l l - s t e e l c o n ­ stru ction , practically in d estru ctib le, en tirely free from corrosive fum es an d im m u n e from d am age ev en by d ead " s h o r tin g .”

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more life ... N I F E

N ife Batteries are not y e t available fo r private cars or domestic wireless.

N IF E B A T T E R IE S R e d d itch - W o rc e ste rsh ire .

12 D E C E M B E R 1947

Bouverie House - 154 Fleet Street - London E C 4 Telegrams: “b e n b ro tric f l e e t London” Telephone: c e n tr a l 3212 (16 lines)

Editor : S ta n le y G. R a tte e , A .M .I.E.E. Publisher and Manager: Jo h n V estey

Number 3626 12 D E C E M B E R 1947 Vol. C X X X IX No. 24

C O N T E N T S

Views on Current Affairs ... 1699 Portrait—Mr. J . G. Craven ... 1700 About Transformers ... 1703 Contrants Open ... 1706 Speech Communication ... 1707 Councils and Electricity Problems ... 1709 What Manufacturers Are Doing ... 1710 Electrical Personalities ... 1711 Anglo-Dutch Submarine Cable ... 1713 The Capital Cuts ... 1714 Electricity Supply ... 1715 London Transport Nationalisation ... 1716 Book Reviews ... 1717 In Parliament ... 1718 Industrial Information ... 1719 B .E .A . Areas of Supply ... 1721 Area Board Appointments ... 1722 Company News ... 1723 Commercial Information ... 1724

MIDLANDS OFFICE:

Daimler House, Paradise Street, Birmingham Telephone : Midlands 0 7 8 4 - 5

SCOTTISH OFFICE:

116, Hope Street, Glasgow, C.2. Telephone • Central 3 9 7 0

The offices o f Th e E l e c t r i c i a n are closed on S a tu rd a ys in accordance zvith the "F ive-day W eek” pla n adopted by B en n Brothers, L td .

SINGLE COPY ( F r i d a y ) - - 6d .

(BY PO ST ) - - - 8d .

ANNUAL SUBSCRIPTION

HOME AND OVERSEAS 3 0s.

N e w S t e e l C u r r e n c y

I

" 'H E re v is e d p la n s fo r d is trib u tin g s te e l to in d u s tr y w h ich M r. H . A.

M a r q tja n d , th e P a y m a s te r-G e n e ra l, a n n o u n c e d to th e N a tio n a l P ro d u c tio n A d v iso ry C ouncil la s t F r id a y a fte rn o o n , a r e th e p r o d u c t o f a jo in t co m m ittee, c o n sistin g o f re p r e s e n ta tiv e s o f th e I r o n a n d S teel F e d e ra tio n , th e F .B .I., th e T.U .C . a n d officials of th e in te re s te d G o v e rn m e n t d e p a rtm e n ts , s e t u p in S e p te m b e r u n d e r M r. M a r q u a n d ’s c h a ir­

m a n s h ip to s tu d y th e w o rk in g o f th e e x is tin g m a c h in e ry . T h e f irs t a n d m a in o b je c t o f th e n ew sch em e is to rem o v e th e a c c u m u la tio n o f o u t-o f-d a te o rd e rs fo r tw o m illio n to n s of steel, w h ic h a re a t p r e s e n t m a k in g n o n se n se o f th e w o rd

“ a llo c a tio n .” A seco n d a im is to e x te n d f u r th e r th e s y s te m of d ir e c t b u lk a u th o r is a tio n s t o m a k e r s o f c o m p o n e n ts a n d com m o n se rv ic e p ro d u c ts , su c h a s sm all e le c tric m o to rs, in a ll b u t a few sp e c ia l cases, th u s reliev in g th e m o f th e p re s e n t c o m p lic a tio n s o f c o llectin g sub- a u th o r is a tio n s fro m e a c h o f th e ir c u sto m e rs.

W h ile th is l a t t e r d ecision w ill b e g e n e r­

a lly w elcom e, i t m u s t n o t b e o v erlo o k ed t h a t m u c h of its success w ill d e p e n d o n th e s ta f f s of th e v a rio u s M in istrie s co n ­ c e rn e d in i t s o p e ra tio n , w ho now ta k e o n a d d e d re sp o n sib ilitie s fo r a u th o r is in g t h e c o r r e c t a m o u n ts o f ste e l d ir e c t to a la rg e n u m b e r of m a n u f a c tu r e rs . T h e t a s k w ill d e m a n d im a g in a tio n a n d th e a b ilitv to m a k e r a p i d decisions, a n d it is to be h o p e d t h a t fo r o n ce th e s e q u a li­

tie s w ill b e fo rth c o m in g . A t h i r d p a r t o f th e new p la n is th e a p p o in tm e n t of tr a v e llin g officials, w hose d u ty i t w ill b e to w a tc h o v e r a n d a s s is t in d u s tr y in

o p e ra tin g t h e sch em e, in th e v a r io u s reg io n s. T o ju d g e fro m th e d e ta ils so f a r a n n o u n c e d , th e y w ill fin d th e m se lv e s g r e a tly in d e m a n d .

E nding th e Inflation

T H E d r a s tic e x p e d ie n t o f c a llin g in a n d re p la c in g a n e x is tin g c u rr e n c y w h en , in th e c o u rs e o f a ru n a w a y in fla tio n , th e n o rm a l re la tio n s h ip b e tw e e n m o n e y a n d re a l v a lu e d is a p p e a rs , is n o t n ew in th e field o f fin a n c ia l policy. T h is, in fa c t, is th e re m e d y p ro p o s e d fo r th e p re s e n t in fla tio n a ry s itu a tio n of to o m a n y a u th o r is a tio n s — t h e e q u iv a le n t o f on e q u a r t e r ’s p ro d u c tio n , to b e p recise—

c h a s in g to o little steel, w ith t h e “ M ” fo rm s r e p r e s e n tin g t h e c u rr e n c y a b o u t to b e ^ c ra p p e d . E x p la in in g t h e new m a c h in e ry , Mr. M a rq u a n d to ld th e N .P .A .C . t h a t , a lth o u g h i n d u s tr y in th e m a in h a d a lr e a d y b e e n g iv e n its steel a u th o r is a tio n s o n “ M ” fo r m s fo r th e se c o n d q u a r t e r o f 1948, n e w fo rm s a r e to b e is s u e d to a ll c o n su m e rs a t th e b e g in ­ n in g o f J a n u a r y , g iv in g fre s h a u th o r is a ­ tio n s fo r th e ir w h o le a llo c a tio n s fo r t h a t q u a r t e r a n d , w h e re n e c e ss a ry , fo r w a rd a u th o r is a tio n s fo r la t e r p e rio d s. T h ese n e w “ I r o n a n d S te e l ” fo rm s, a s th e y a re to b e k n o w n , w ill re p la c e t h e o v e r­

c o m p lic a te d a n d g e n e ra lly u n s a tis f a c to r y

“ M ” fo rm s fro m M a r c h 31, a t w h ic h d a te a ll o u ts ta n d in g o rd e r s p la c e d on t h e a u t h o r i t y o f “ M ” fo rm s w ill be c a n c e lle d u n le s s “ re - v a lid a te d ” b y th e c o n s u m e r u n d e r h is n e w a u th o r is a tio n . R e-ord erin g N ecessary

M A N U F A C T U R E R S a r e th u s fa c e d w ith th e t a s k o f u n d o in g m u c h o f th e w o rk th e y h a v e a lr e a d y done. A s so o n a s th e a p p r o x im a te a llo c a tio n fo r t h e s e c o n d q u a r t e r of 1948 is k n o w n b y a firm , i t m u s t re v ie w i t s o rd e r b o o k s to d e te r m in e w h a t o rd e r s fo r s te e l w ill p r o b a b ly b e u n d e liv e re d a t M a rc h 31 a n d t h e n fra m e a p ro g ra m m e o f d e liv e rie s d e sire d , -both fo r th e p u rp o s e of th e se c o n d q u a r t e r a n d fo r a n y fo r­

w a r d a u th o r is a tio n s . E a c h p ro g ra m m e , w h ich w ill th u s c o n s is t o f a p r o p o r tio n of p a s t u n d e liv e re d o rd e r s , o r d e r s a lr e a d y p la c e d a n d e n tir e ly n ew o rd e rs, m u s t th e n b e v a li d a te d u n d e r t h e firm ’s new a u th o r is a t io n in o rd e r t h a t th e s te e l­

m a k e r m a y fra m e h is o w n p ro d u c tio n p ro g r a m m e a c c o rd in g ly . A d e ta ile d a n d , i t is to b e h o p e d , lu c id — a lth o u g h p a s t p ro n o u n c e m e n ts o n s te e l fro m -this q u a r t e r o f th e G o v e rn m e n t in v ite m is ­

g iv in g s o n th e p o in t— e x p o sitio n of th e s e c o m p lex r e a r r a n g e m e n ts is s h o r tly to b e is s u e d to in d u s try . M eanw hile, th e jo in t c o m m itte e , w h ich is to re m a in in b ein g u n d e r th e P a y m a s te r- G e n e r a l to s u p e r ­ v ise th e p u tt in g in to o p e ra tio n of th e n e w sy s te m , will, th r o u g h its in d u s tr ia l re p r e s e n ta tiv e s , b e a b le to p a s s o n th e re a c tio n s of in d iv id u a l m a n u f a c tu r e r s to th e n ew p ro p o s a ls. T h e ir im m e d ia te effect w ill b e to th r o w o n to in d u s tr y a n e x t r a b u r d e n o f a p p re c ia b le w eight.

S in ce th e e n d o f th e w a r, h o w ev er, th e s te e l a u th o r is a tio n sy s te m h a s b e e n allo w ed to d r if t in to a s itu a tio n w h ich is no w little less t h a n c h a o tic a n d if, a s M r. M a r q u a n d h o p es, th e p ro p o s a ls o u t­

lin e d a b o v e p ro v id e a fr a m e w o rk w ith in w h ic h th e o rd e r s o n s te e lm a k e rs ’ b o o k s w ill e v e n tu a lly c o rr e s p o n d closely to th e q u a n t i t y o f s te e l a v a ila b le , o n e a t le a s t of th e p r e s e n t c a u se s o f f r u s tr a tio n , c o n ­ cealed u n e m p lo y m e n t a n d lo s s of p r o ­ d u c tio n m a y b e re m o v e d .

N ew G reater London B ody

I N view o f t h e f a c t t h a t u n d e r th e E le c ­ tr ic ity A c t of 1947 m u n ic ip a l a u th o r is e d e le c tric ity u n d e r ta k e r s w ill cease to e x is t a f t e r th e v e s tin g d a te , t h e v o lu n ta r y w in d in g -u p a n d re c o n s titu tio n on a w id er b a sis o f t h e C onference of L o c a l A u th o ri­

tie s O w n in g E le c tr ic ity U n d e rta k in g s in G r e a te r L o n d o n h a s b e e n re so lv e d b y t h a t b o d y . A n e w a sso c ia tio n r e p r e ­ s e n ta tiv e o f all lo c a l a u th o r itie s in t h e a r e a o f th e L o n d o n E le c tric ity B o a rd to d e a l specifically w ith e le c tric ity p r o b ­ le m s is p ro p o sed . T h e p r im a r y re a s o n s w h ic h h a v e in flu en ced th e C onference in it s d ecisio n t o ta k e s te p s to fo rm a n ew a n d e n la rg e d b o d y a r e e n u m e r a te d in a m e m o ra n d u m a c c o m p a n y in g a c irc u la r le tte r in v itin g th e lo cal a u th o r itie s to b e c o m e c o n s titu e n t m e m b e rs, a n d a re g iv en fu lly o n a n o th e r page. T h e y p r o ­ v id e co n v in c in g a rg u m e n t in fa v o u r of th e f o r m a tio n o f su c h a n a ss o c ia tio n a n d th e p ro p o s a l is e x p e c te d to re c e iv e th e s u p p o r t of th e co u n cils in th e a re a . I t is p o in te d o u t th a t , a p a r t fro m th e ir in te r e s t o n b e h a lf of t h e ra te p a y e r s in th e p ro v isio n o f a ch e a p a n d a b u n d a n t su p p ly o f e le c tric ity , m o s t local a u th o r i­

tie s a re s u b s ta n tia l u se rs of e le c tric ity fo r s tr e e t lig h tin g , fo r p u b lic b u ild in g s a n d so on, a n d a r e p r e s e n ta tiv e a sso cia­

tio n c o u ld c o n v e n ie n tly d eal w ith q u e s ­ tio n s a risin g fro m O rd e rs a n d R e g u la ­ tio n s m a d e u n d e r th e A ct, w h ic h w ould

TH E E L E C T R IC IA N 1 2 D E C E M B E R 1947

1701 a ffe c t local a u th o r itie s a n d th e ir r a t e ­

p a y e rs . Also, i t is u rg e d , i t w o u ld b e d e sira b le a n d c o n v e n ie n t to th e M inister of F u e l a n d P o w e r if h e c o u ld be in a p o sitio n to a p p ly t o o n e a sso c ia tio n or b o d y re p re s e n tin g a ll lo cal a u th o ritie s in th e a re a fo r n o m in ees t o th e p an el fro m w h ich to a p p o in t m e m b e rs of th e L o n d o n a r e a C o n s u lta tiv e C ouncil.

S upply P erson n el

P E R S O N N E L in th e g e n e ra tio n a n d tra n sm issio n sid e of th e su p p ly in d u s ­ tr y h a v e fo r so m e tim e b e e n a n x io u s for in f o rm a tio n a s to h o w th e y will fit in to th e n a tio n a lis a tio n p ic tu re , a n d th e a n ­ n o u n c e m e n t b y th e B .E .A . w ith re s p e c t to a p p o in tm e n ts to b e m a d e in th e g e n e ­ r a tio n divisions, p u b lis h e d o n p. 1611 in o u r la s t issue, will, th e re fo re , b e w el­

com ed. T h e a n n o u n c e m e n t c o n cern s th e C e n tra l A u th o r ity o n ly , a n d a rr a n g e ­ m e n ts fo r a p p o in tm e n ts w ith d is tr ib u ­ tio n a s th e m a in in te r e s t will, i t is u n d e r ­ sto o d , be m a d e b y th e A re a B o a rd s when t h e la t t e r h a v e b e e n fo rm ed . T he im m e d ia te n e e d is t o m a k e t h e h ig h er a p p o in tm e n ts in th e fo u r te e n divisions w h ich w ill fo rm t h e o rg a n isa tio n for g e n e ra tio n a n d tra n s m is s io n u n d e r the C e n tra l A u th o rity , a n d1 u n d e rta k in g s will, if th e y h a v e n o t a lr e a d y b e e n a p p ro a c h e d , s h o r tly b e a s k e d to d ra w t h e a tte n tio n of th e ir sta ffs to th is a n d o th e r details.

A p p o in tm e n ts below t h e level of D iv isio n al C o n tro lle r w ill b e a p p ro p r i­

a te ly g ra d e d a n d w h e re d u tie s a n d r e ­ sp o n sib ilitie s a re an alo g o u s w ith e x istin g g ra d e s a n d scales, th e s e l a t t e r w ill b e o bserved. I n o th e r cases sa la rie s will b e re g a rd e d a s p ro v isio n a l u n til final scales h a v e b e e n n e g o tia te d w ith th e a p p r o p r ia te o rg an isatio n s.

E xp lain in g A tom ic Ph ysics

T H E n ew d o c u m e n ta ry film “ A tom ic P h y s ic s ,” rev iew ed o n a la t e r page, can go fa r to m e e t th e n e e d re c e n tly vo iced b y Mr. D a v i d L i l i e n t h a l , c h a irm a n of th e U .S. A to m ic E n e rg y C om m ission, for t h e w id e st p ro p a g a tio n of in fo rm a tio n o n th is v ita l s u b je c t. A to m ic e n erg y h a s r e ta in e d its new s v a lu e fo r tw o y e a rs in m o s t c o u n trie s of th e w orld, y e t ev en to -d a y , a m o n g th e o th e rw ise w ell-in­

fo rm ed , o n e e n c o u n te rs d is tu rb in g m is­

co n cep tio n s. ra n g in g fro m o v e r-o p tim istic e s tim a te s o f th e c o n tr ib u tio n w h ic h it is lik ely to m a k e to in d u s try , to a m o re d a n g e ro u s d elu sio n t h a t t h e p o w e rs of

a to m ic w eap o n s h a v e b e e n ex ag g erated . B o th th e s e fallacies th is a d m ira b ly w r itte n film w ill d o m u c h to cu re, a n d o n th o s e g ro u n d s alo n e i t d eserv es a w ide show ing. W e g a th e r t h a t th e p ro d u c e rs h a v e in m in d a u d ie n c e s p re s e n te d b y v a rio u s e d u c a tio n a l e s ta b lis h m e n ts ; th is is a p ity . “ A to m ic P h y sic s,” a lth o u g h d e m a n d in g fa irly close a tte n tio n , e x ­ p la in s th e m a in s te p s le a d in g to th e r e ­ lease of a to m ic e n e rg y w ith a c la r ity a n d a b se n c e of o v e r-e m p h a sis w h ich will e n su re its w elcom e b y m a n y m e m b e rs of t h e n o n -scien tific p u b lic. Y e t a n o th e r a r g u m e n t fo r a b ro a d d is trib u tio n is t h a t th e film w ill m a k e clear, to th o s e w ho te n d to fo rg e t th e fa c t, t h a t o n alm o st e v e ry m ile s to n e of a to m ic p h y sic s is w r itte n t h e n a m e o f a B r itis h p h y s ic is t o r a B r itis h scientific in s titu tio n . The

1 951

E xhib ition

L A S T w eek ’s a n n o u n c e m e n t t h a t th e G o v e rn m e n t in te n d s to m a r k th e c e n ­ te n a r y of th e G re a t E x h ib itio n of 1851 b y a n a tio n a l d is p la y illu s tr a tin g th e B r it is h c o n tr ib u tio n to c iv ilisa tio n in th e a r ts , science a n d te ch n o lo g y a n d in d u s ­ tr y , is a w elcom e a s s u ra n c e t h a t , d e sp ite t h e official d ecision l a s t M a rc h n o t to p ro c e e d w ith th e a m b itio u s p la n s p u t fo r w a rd b y th e R a m s d e n C o m m ittee, th e o ccasio n is n o t to p a s s u n re c o rd e d . T h e B o a r d o f T ra d e is to in v ite th e C ouncil of I n d u s tr i a l D esign to sp o n s o r a design d isp la y , w h ic h w ill in c lu d e co n su m er goods, c e rta in classes o f c a p ita l goods a n d d is p la y s sh o w in g th e h is to ric a l d e v e lo p m e n t of som e in d u s tr ie s ; a n d a n e x h ib itio n of B r itis h a c h ie v e m e n ts in science a n d te c h n o lo g y w ill b e o rg a n ise d b y th e C e n tra l Office of In f o rm a tio n on b e h a lf of th e re s e a rc h co u n cils a n d o th e r scientific bodies. P ro d u c tio n a n d e n g i­

n e e rin g w ill b e le f t to th e B .I.F ., w h ich w ill b e h e ld e a rly in th e sa m e y e a r. T h e G o v e rn m e n t, i t is s ta te d , is a n x io u s to re c e iv e su g g estio n s fro m o u ts id e bodies.

A t th i s sta g e , a n y fo r e c a s t o f c o n d itio n s in 1951 w o u ld b e d a n g e ro u s, b u t i t is sa fe to co n clu d e t h a t b y th e n th e se lje rs’

m a r k e t fo r m a n y classes of g o ods will h a v e com e to a n en d . T h e fo rth c o m in g e x h ib itio n , th e re fo re , a lth o u g h i t w ill be s ta g e d a g a in s t a b a c k g ro u n d v e ry d iffer­

e n t fro m t h a t o f i t s p red ecesso r, 1 0 0

y e a r s ago, w ill p ro v id e to t h e w o rld v a lu a b le ev id e n c e o f th e te c h n ic a l a n d scientific em in en ce to w h ich we, in th e se isla n d s, c a n still ju s tly la y claim .

r 2 D E C E M B E R 1947 TH E E L E C T R IC IA N

J. G. Craven Portrait—Mr.

1

(7 E L L -w alking is one of th e recreations enjoyed b y Mr. J . G. C raven, M .I.E .E ., jo in t m anaging d irecto r of G reen a n d S m ith, L td ., electrical engineers an d con­

tra c to rs, of Leeds, a n d a m em ber of th e I .E .E . Council. H e has clim bed m ost p eak s over 1 000 ft., chiefly in th e L ake D istric t, durin g th e la st 35 years. M otor­

ing h a s claim ed his adherence since 1009 w hen he learned to driv e a 4 J n .p . single- cylinder, tw o-seater R o v er to u rin g car.

H e p la y s golf, a fte r giving u p hockey, an d is th is y e a r’s c a p ta in of H eadingley Golf Club, Leeds, is keen ly in terested in p h o to ­ g rap h y , m akes gardening a n d vegetable grow ing a n o th e r h o bby.

M r. C raven received h is technical ed u ca­

tion a t evening classes a t th e Leeds College of Technology, th e U n iv ersity of Leeds, w here h e h eld a n electrical technological scholarship ex ten d ed over th re e y e a r s ; a n d a t A rm strong College (now K in g ’s College), N ew castle-on-Tyne. H av in g served an ap p ren ticesh ip in th e electrical d e p a rtm e n t of Greenwood an d B atley , L td ., Leeds, he becam e a ju n io r a ss ista n t engineer w ith th e N ew castle E lectric S upply Co., L td . (now th e N o rth E a ste rn E lectric S upply Co., L td .), a n d for th e n e x t tw o years w as m ain ly concerned w ith su b -statio n operation. H e th e n held, successively, th e positions of a ss ista n t engineer in th e relay a n d p ro tectiv e g ear d e p a rtm e n ts, an d ass ista n t d istric t su p e rin te n d e n t in th e Cullercoats d istrict.

On Septem ber 9, 1912, Mr. C raven re­

tu rn e d to G reenwood an d B atley, L td ., in th e capacity of chief electrical testin g engineer, a n d a y ear la te r w as a p p o in ted ass ista n t m anager of th e electrical d e p a rt­

m e n t of th e com pany. I n Ju ly , 1919, he left t h a t p o st to ta k e u p th e position of technical director for G reen an d Sm ith, L td .

A dm itted to th e I.E .E . as a g rad u ate in 1912, Mr. C raven w as a founder m em ­ b e r of th e N o rth -E a s t Coast Centre S tu d e n ts’ Section. H e w as m ad e a n asso­

ciate m em ber in 1913, a m em ber of th e in stitu tio n in 1937, a n d w as elected to th e Council in 1946. F o r th e y ear 1937-38 he held th e office of chairm an of th e I .E .E . N o rth M idland C entre, an d in 1946 w as elected chairm an of th e N .M . C entre In sta lla tio n s G roup. H e h a s served on th e Com m ittee of t h a t centre since 1933, as well as on th e W iring R egulations Com­

m itte e an d th e W iring R egulations I n te r­

p re ta tio n A dvisory Sub-C om m ittee from 1945, th e E d u catio n a n d E xam inations C om m ittee for 1946-47, th e Local C entre C om m ittee from 1945, a n d on th e N o rth M idland C entre B enevolent F u n d Golf C om petition C om m ittee.

T h e E lectrical C ontractors’ A ssociation also claims m u ch of his tim e a n d th e benefit of his experience a n d technical know ledge. H e w as ch airm an of th e W est Y orkshire b ra n c h for th e y ear 1931-32, a n d is now a m em ber of th e L ondon T ech­

nical C om m ittee a n d h as served on th e N o rth ern Counties Sectional B oard. His o th e r activities em brace m em bership of th e I.E .S . Leeds C entre C om m ittee since 1941, h e h av in g becom e a n associate m em ­ b e r of th e society in 1940; th e E .I.B .A . W est Y orkshire A rea C om m ittee, a n d h o n o ra ry m em bership of th e Leeds Asso­

ciation of E ngineers. H is in te re st in tech ­ nical education an d tra in in g found a n o u t­

let in th e w ork of th e E lectrical E ngineer­

ing T ra d e s’ A dvisory Sub-C om m ittee con­

n ecte d w ith th e Leeds E d u catio n D e p a rt­

m en t, a n d h e w as chairm an of t h a t body from 1941 to 1947.

P u b lish ed articles b y Mr. C raven in ­ clude “ T he C ontractors’ Sphere of A ctivi­

ties in th e E lectrical In d u s trv ” (N.M.

Centre, I .E .E ., C hairm an’s A ddress, 1937),

“ In d u s tria l Pow er In sta lla tio n in New F acto ries ” (1939). “ F lexibility in F a c ­ to ry Pow er D istrib u tio n ” (joint a u th o r w ith J . Collins— 1934), an d “ Some I n te r ­ m itte n t Im pressions of 45 Y ears in th e Electrical In d u s try ” (N.M. C entre, L .E .E ., In sta lla tio n G roup. C hairm an’s A ddress— 1946).

12 D E C E M B E R 1947

About Transformers*

1703

by G . O . C A S T E L L , M .I.E .E .

I

F a tran sfo rm er is well designed and soundly constructed, th e m aintenance of th e oil in good condition is th e m ajo r factor in avoiding outages due to transform er breakdow n, a n d several of th e stan d ard ta n k fittings are designed to th is end. The m ost im p o rta n t of th e fittings w hich fall

Breathing Vent Conservator Vessel Trapped Moisture Buchho/z Relay

Dehydrating Breather

Fig. I.—Sketch showing arrangement generally adopted for conservator vessel, dehydrating

breather and Buchholz relay in to this category is th e oil conservator.

T his device consists of a n auxiliary ta n k w ith a capacity of a b o u t 1 0 p er cent, of th e m ain ta n k , m ou n ted above th e la tte r a n d connected to it b y a sm all pipe, Fig. 1.

T his arran g em en t m ain tain s a sm all head over th e m ain ta n k , all th e joints of which m u s t be oil-tight in order to ensure th a t it shall alw ays be full of oil, subject to a periodical ex am in atio n of th e oil gauge, w hich in th is case is m o u n ted on th e con­

serv ato r vessel itself. T he connecting pipe m u st be of sm all inside d iam eter so th a t no circulation of th e oil shall ta k e place betw een th e tw o ta n k s, b u t only a small rise a n d fall o f th e oil level in th e con­

serv ato r as th e oil expands an d contracts w ith changing tem p eratu re. T he conserva­

to r vessel is open to th e atm osphere, b u t as th e oil in it should never reach a te m p e ra tu re approaching t h a t of th e m ain ta n k , a n d as th e area of oil in co n tact w ith air is relatively small, oxidation is m inim ised. T he connecting pipe is m ade to p ro ject several inches above th e bottom of th e conservator vessel, th u s providing

* P a rts I , I I , m , IV , V , a n d V I, o f th is series w ere p u b lish e d in Th e El e c t r i c i a no f A u g u st 15, 22, O c to b e r 3, 17, 31, a n d N o v e m b e r 21, resp ectiv ely .

a sum p to tr a p an y w ater w hich m ay find in g ress; a d rain cock is usually provided so t h a t i t m ay be em ptied periodically. So, b y reducing oxidation an d preventing m o istu re o r atm ospheric con tam in an ts from finding th e ir 'way into th e m ain body of th e oil, th e conservator plays its p a rt in p ro tectin g th e transform er. I n th e past, th e fittin g of conservator vessels has been generally restricted to high voltage tra n s ­ form ers o r o utdoor u n its of large capacity, b u t th e m anifest ad v an ta g es to be gained in increased reliability a n d th e saving in oil m aintenance is leading to a m u ch w ider ad o p tio n of th is feature. I t is undoubtedly tr u e t h a t th e sm all additional first cost a n d th e slight tro u b le necessary to m ake a n d m ain tain oil tig h t jo in ts w ould b e more th a n rep aid if every tran sfo rm er installed w as specified to include a conservator, or to be of th e sealed type.

T he sealing of a tran sfo rm er is a more m odern, an d , in som e respects, a b e tte r w ay of achieving th e sam e resu lts as those ob tain ed b y fitting a conservator. There are tw o m ethods of solving th is problem . T he first is to fill th e transform er full of oil, allowing no air space w hatever, to provide oil-tight joints a t all points, and accom m odate th e norm al expansion of th e oil b y m eans of a m echanical device. The only a p p a ra tu s of th is ty p e which, in th e a u th o r’s know ledge, has proved successful, is th a t developed b y th e Lindley Thom pson T ransform er Co. T his consists of an

Inspection Window

Oil Level.

Indicator

Inner Container ''o f'"

Silica Gel

r r

Oil-sealed

¿opening to Breather Fig. 2 .—Arrangement of silica gel breather auxiliary vessel m ounted above th e m ain tan k , som ew hat ak in to th e sta n d a rd con­

serv ato r b u t constructed of corrugated copper an d sealed to th e a tm o sp h e re ; th is vessel allows th e oil to ex p an d b y a con­

certina-like action.

T he second m eth o d is to include an air space above th e oil w hich will provide a buffer an d ta k e u p th e norm al expansion.

12 D E C E M B E R 1947 TH E E L E C T R IC IA N

Some- pressure m u s t be developed, b u t if i t is designed so t h a t th e re shall be none a t norm al w orking te m p e ra tu re , say 55°

C., th e n th e pressures w hich will develop, positive a t m axim um te m p e ra tu re a n d n ega­

tiv e a t red u ced te m ­ p e ra tu re s, can be k ep t dow n to sm all values.

T he filling m edium for t h e buffer space should be carefully dried before it is a d ­ m itte d a n d th e ta n k

sealed. I f i t consists of a n in e rt gas, such as nitrogen, no oxida­

tio n of th e oil is possible; if of air, th e q u a n tity of oxygen av ailab le is strictly lim ited an d should be insufficient to cause appreciable d eterio ra­

tion.

I n A m erica, sealed tran sfo rm ers of th e Fig. 2 a. — Actual la tte r ty p e w ith th e silica gel breather buffer space filled w ith n itro g e n . h a v e been m ade a n d p u t into service w ith all joints w elded; in fa c t, herm etically sealed tr a n s ­ form ers. M any of th e u su al fittin g s, such a s d ra in valves a n d oil gauges, are o m itted a n d no servicing of th e oil is a tte m p te d . T he a u th o r h a s n o d etailed know ledge of th e service experience o b tain ed w ith these u n its, b u t general re p o rts speak of them as being satisfactory.

I n th e early d ays, no p a rtic u la r a tte n ­ tio n was given to th e q uestion of providing a n y facilities for a tran sfo rm er to b reath e.

I t w as realised t h a t w ith changing tem p era­

tu r e th e volum e of a ir above th e oil w ould change also, b u t cover jo in ts w ere n o t p a r­

tic u la rly w ell-m ade an d m an y of th e term in al arran g em en ts consisted of slotted w ooden cleats w ith n o t v ery w ell fittin g c o n d u c to rs; all -these tran sfo rm ers were, of course, for in d o o r service. As jointing im proved a n d tran sfo rm ers w ere designed

for in stallatio n o u t of doors, it becam e necessary to provide a definite b reath in g v e n t, an d from th is it w as a s h o rt step to fittin g a n a tta c h m e n t to th e v e n t designed to ensure t h a t th e air a d m itte d to th e tran sfo rm er w as d ry , a n d to a certain e x te n t cleaned. A pipe extension to th e

HINGE TOALARM

CIRCUIT To ATMOSPHc.

POT COCK TOR GAS COLLECTION

FLOAT CO.) MERCURY SWITCH

^ALARM CLOSED

TO HIGHEST POINT IN TRANSFORMER TANK

\FLOAT (b)

\MERCURY SWITCH HINGE

Fig. ?.—Diagrammatic representation of the Buchholz relay

Fig. 4.—Conservator vessel, mounted direct on tank lid, as used for small transformers v e n t ends w ith a container filled w ith a desiccating m aterial th ro u g h w hich th e a ir is draw n. V arious m aterials h a v e been u sed, b u t calcium chloride an d silica gel h a v e p roved m o st successful. T he la tte r h a s o u tsta n d in g a d v a n ta g e s ; i t is cleaner, does n o t corrode or cake, can b e easily re a c tiv a te d b y b a k in g a n d b y changing in colour gives a n indication w hen its desic­

cating q u ality is giving o u t. A ty p ical de­

h y d ra tin g b re a th e r a tta c h m e n t is show n in Fig. 2. T he gel is contained in an in n er vessel w hich e t a be rem oved w hen e x h au sted , i t being usual to keep a spare d ry charge so th a t th e tran sfo rm er shall n o t be left u n p ro te c te d during th e (period in w hich th e w et charge is being re a c ti­

v a te d . An inspection w indow allows th e gel to be s e e n ; it will change in colour from a deep blue w hen com pletely d ry to a pale pin k w hen in need of tre a tm e n t. I t