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ilp archive : journals

public lighting no. 18 vol. 5
July 1940

Editorial p53
Get On With Street Lighting
In areas where the modifeid form of street lighting has already been installed, the dreaded darkness of the streets at night will be alleviated. In those towns where adequate war-time street lighting has been "put off", the question of low intensity street lighting should be addressed now. A number of towns have already experienced air raid warnings - but the nights were not dark, and so people had no difficulty in finding shelters etc. Consider these same alarms when the night is dark and no lights are provided on the streets. The small amount of illumination officially permitted under BS/ARP 37 gives just that amount of lighting to prevent people groping their way to places of safety. This low intensity lighting does given the public a feeling of reassurance, and enables the ARP officials to get to their duties without difficulty. Again, it is urged "go to it" - order now and be ready for all emergencies during the coming months of autumn and winter.
Lighting: ARP

Lighting Of Street Bollards p53
A decision of the Appeal Court on the 27th June on the subject of lighting street bollards in war-time. A passenger in a taxi recovered damages from the owners which collided with a bollard, the lighting of which had become temporarily extingished. The owners of the taxi clamined a contribution from st. Marylebone Borough Council on the ground that the collision occurred through the refuge, on which the bollard was situated, being temporarily unlit. In dismissing the appeal, the Counrth held that the effect of the Lighting (Restrictions) Order, 1939, No 1098, repealed the obligation imposed by section 130 of the Metropolis Management Act 1855, as to the sufficent lighting of the refuge. As regards the duty of lighting an obstruction, the only obligation was to use reasonable care and there was no absolute duty.
Lighting: ARP, Lighting: Legal

Sheffield Expresses Satisfaction For War-Time Street Lighting p54
The Lighting Engineer of Sheffield, Mr. J. F. Colquhoun, has received letters expressing satisfaction with the new low-intensity lighting.
Lighting: ARP

Bristol Too, Praises War-Time Lighting p54
When the Deputation which visited London to see the test installation came back with their report to the City Council, they recommended that the whole of the City should be converted to this form of lighting. At first, cost was a concern, but the City Council voted for the whole of the City to be converted. The residential areas were converted first, as the heavily trafficked streets had some light from vehicles, street bollards and other directional lighting. The residents looked at the modified street lighting as a boon cmpared with the blackout. It has also been of considerable assistance to the police. It was original intended to switch the lights off during the summer months, buth the Chief Constable, made appeal this should not be done. As a result, the lights are burning 24 hours a day.
Lighting: ARP

Pilot Fittings For War-Time Street Lighting In Germany p54
These two designs consist of a black metal reflector, a diffusing glass bowl and, in the case of the second fitting, a metal cylinder to cover the side walls of the glass body. Designs from different manufacturers differ only slightly. The purpose of these lamps is literally to pilot the vehicles along the road. The fittings shall be visible from a distance of 150 metres and no obstacle like traffic islands etc. should be on the straight path within this distance. In some cases, special poles should be provided. The mounting height is 5-8 metres, with a spacing of 100 metres. The fittings are equipped with 15W-25W GLS lamps. Light is emitted through the bottom of the fitting only (except for specially produced "edges") in a cone of maximum 95 degrees. The maximum illumination should be right beneath the fitting of the order of 0.01 to 0.008 lux. All fittings have to be tested and certified by the ARP Department of the German Air Force. In some cases additional lights are permissible if provisions are made to extingush them at a moment's notice.
Lighting: ARP

Delivery Of Fittings p54
A recent list of 307 lighting authorities showed that 180 had installed or ordered the equipment, and 227 would probably do so or had installed fittings for trial. Manufacturers cannot risk accumulating large stocks and fear that if decisions to order are delayed, deliveries will be very uncertain. Therefore lighting authorities should make their decisions without delay.
Lighting: ARP

Street Lighting In An American City by D. M. Bunn and H. G. Conant p55
The main part of the paper is the description of the "multiple street lighting system" which has been introduced gradually throughout the whole area of Minneapolis since 1922. It refers to the specific layout of the relay-operated control system and supply circuits. Practically the entire installation is overhead wired. Only a few main business streets, bridges and parkways are equipped with underground wired ornamental lamp posts.
In 1922, 5-light ornamental posts existed in the loop district; 5400 6.6A manetite arc lamps wired in series were used for mid-block lighting. There were also 1,100 gas lamps in service. The number of arc lamp circuits amounted to 100 fed from 3 substations.
It was in 1922 that the Town Council decided to substitute all existing gas lamps by arcs of the aforementioned type. As electricity mains were available in all areas, it was expected that such conversion could be effected - but the existing circuits were fully loaded. The Electric Power Company made a counter-proposal: use tungsten lamps instead of arcs, discontinue with wiring in series, and arrange for "circuit units" to supply and control lamps - burning parallel - in groups of 4 to 6.
The works proposal was accepted and a 1,000 c.p. lamp was chosen instead of the 6.6A magnetite arc. This worked will and up to 1930 all arcs and series circuits had been withdrawn. At present the lighting system is: 3,000 500W tungsten lamps; 3,174 300W tungsten lamps; 336 150W tungsten lamps and 3 sodium lamps.
Two types of pilot control systems were considered: a live pilot to close the relay for lighting the lamps or a live pilot in daytime to hold the relay open. The decision was made in favour of the latter: the advantage being that in breakdown or short-circuit during the day would in indicative of the burning of the lamps and during the night no interrruption of service would occur. The pilot and lamp supply circutis depend on a common neutral.
500W is being used at street intersections in densely popualted districts and on traffic arteries; 300W for intersections in residential araes and for mid-block lights. Finally 150W for mid-block lights in less densely populated districts. The 500W and 300W lamps are used in totally enclosed luminaires, pendant units with dome refractor and clear rippled glass globes, the 150W types in open radial wave reflector units. The mounting height of the two former is generally 26' and at street intersections is at 28'. They are fitted to brackets projecting up to 20'. The smaller type is suspended at 20' on brackets projecting up to 12'. The sodium units are installed at particularly dangerous intersections.
The ornamental street lighting portion consistes of 1,600 posts and the Park lighting installation of 422 points. The posts are of the twin light type of 750W each.
Lighting: Control, Lighting: History, Lighting: Installations

The First "Black-Out" Season And Lessons Learned And To Be Learnt p57
1. Some time before the war, the first posters appeared urging the public to provide for "black out conditioning." This drive proved fairly efficient within a short time, but not in the desired direction. Whilst the public took no practical steps, sales in lighting equipment fell to a low level.
2. Some months before the war, results of an investigation were published in Holland, which dealt with the illumination permissable on the ground if observation from air was to be prevented. The values were desperately low.
3. The first large-scale black-out exercises were carried out only a few days before the outbreak of war. Then leakages and deficiences became apparent.
4. War broke out and the British authorities ordered a complete black-out. This was subject to much criticism.
5. The authorities invited the Illuminating Engineering Society and the Association of Public Lighting Engineers to co-operate jointly on the preparation of the necessary emergency measures. The emergency work of the APLE was fully organised in early September and innumerable experiments and investigations were under way.
6. The results of these furnished the basis on which the British Standards Institution drew up their ARP Specifications in quick succession. These dealt with light traps, emergency signs, shop window lighting etc.
7. The last of the 1939 series of these Specifications concerned Public Lighting.
Lighting: ARP, Lighting: History

"Sieray" Fluorescent Tube p58
Siemens Research Department has now produced the Sieray Fluorescent Tube. It is of the electric discharge type, rated at 80W, and designed to operate from standard 200/250V A.C. mains. It consists of a glass tube approximately 5' long, 1½" diameter capped at each end with a bayonet cap of standard dimensions and type. Practically all the light is produced by invisible ultra-violet radiation of fluorescent substances with which the inside of the tube is coated. The surface brightness of the lamp is low and no sensation of glare is experienced even when the light falls directly upon the retina. By virtue of the size of the light source, shadows cast are extremely soft. Its efficiency being three times that of an ordinary gasfilled lamp of comparable wattage. The operating temperature is considerably lower than of a filament lamp. The well diffused light source renders it eminently suitable for the illumination of public buildings, administration offices and interiror lighting generally.
Lighting: Lamps

Annual Report - APLE p58
Many members have been asking for the Annaul Report. It gives a full list of names and addresses of members and associateds and a comprehensive table of details concerning lighting. War conditions have brought many lighting departments to a standstill, so that data would show little or no improvement over the previous year. In other areas, considerable work has been done with wartime street lighting. The Report for 1940 is being compiled.
APLE: Organisation

Overcome "Black-out" Now! p58
If your authoritiy has not installed low intenstity lighting then don't wait longer. The long winter nights will soon be here. Street lightign that can be kept burning during an air raid has already been proved an untold blessing and help to people in a score of towns. The town that is ignoring the question of war-time street lighting is failing in its common duty to the public.
Lighting: ARP

Notes On The Testing of War-Time Street Lighting Fittings And ARP Signs by J. S. Stanley (British Standards Institution) p59
The problem of ARP lighting has been dealt with by the Ministry Of Home Security with the assistance of many experts acting through the Joint Lighting Committee, comprising of the Illuminating Engineering Society and Association Of Public Lighting Engineers. The Committee made a large number of recommendations, some of which were acting on by the Ministry, whilst others were drafted as specifications which were then submitted to the British Standards Institution of issue as British Standards Specifications.
As far as the general public is concerned, the most important specifications are BS/ARP No 32: Illuminated And Non-Illuminated ARP Signs and BS/ARP No 37: Street Lighting.

War-Time Street Lighting
BS/ARP No 37: Street Lighting is specifically referred to in the Lighting (Restrictions) Order 1940. It represents a system of street ligthing which after extensive test and experiment, was known to meet the technical requirements, and to provide maximum utility from limited amount of light permitted. The fitting was described in terms of its optical characteristics and not by mechanical design. (This was for expediancy - no maker would've started to make the fitting until the design had been worked out in detail, samples made up, tests-made and finally working drawings published.) So all the electrical manufacturers started designing, testing, modifying and re-testing, with the result that there were soon several makers supplying "approved" fittings all with different designs, but having a performance within the limits laid down in the specification. In the gas industry, all the manufacturers agreed to concentrate on one particular design.
If the lighting fittings do not comply with the specification, there is a danger of light being visible from the air, either because direct light rays are emitted in an upward direction or because the intensity of illumination on the ground is too high. It was for this reason that the Lighting (Restrictions) Order, 1940 requires that every street lighting fitting be marked with the certification mark of the British Standards Intitution. This certification mark can only be used by manufacturers who have obtained a licence from the British Standards Institution.
Before a manufacturer can obtain a licence, he must satisfy the Mark Committee of the BSI on two points namely (1) he can produced fittings complying with the specification and (2) In the course of manufacture he exercises such control, by means of inspection and test, as to ensure that all the fittings will conform to the specification. In practice, this means that a sample fitting must be submitted to an approved laboratory for test, and if this sample is found to satisfy the requirements, it becomes an "approved sample" and the polar curve attached to the test report becomes the "approved curve."
The manufacturer then gives an undertaking to conform to a "scheme of testing" which is designed to ensure that all fittings produced are as nearly as possible identical with one of the "approved" samples. This "scheme of testing" is eventually attached to, and forms part of, the licence. The "scheme of testing" is a statement of the steps which the manufacturer considers to be necessary in the way of routine testing and inspection during manufacturer. It is usual practice for the Mark Committee to send an inspection to the manufacturer's works to report on the testing facilities available, and discuss the routine tests and inspection that he proposes to adopt. The routine testing and inspection relates mainly to those parts of the fitting which affect the optical characteristics e.g. every spun component of the optical system should have its significant dimensions by means of "Go" and "No Go" gauges. If the fitting uses an opal glass component, then each batch of glasses must be properly sampled and tested for light transmission. If the light distribution is dependent on spacing bars, such bars must be gauged for length. In addition, every completed fitting must be given a final visual inspection and a photometric test must be made on a certain proportion of the completed fittings.

ARP Signs
In the Lighting (Restrictions) Order 1940, the brightness of the lettering on ARP signs is defined as being such that while the lettering must be clearly legible at a distance of 100', being inconspicuous at a distance of 250'. For the BS/ARP specification, a more precise definition was necessary. The specification lays down that the brightness shall be that the average of all brightness values lies between 0.04 and 0.1 equivalent foot-candle. It was foudn that the legibility of many signs was spoilt by the fact that the brightness varied considerably from one point to another. The specification therefore lays down that the ratio of the maximum to minimum brightness value should not exceed 15 to 1.
It is important that the output of the light source itself shuold be reasonably constant. It is for this reason that, in the case of electric fittings, a 15W lamp complying with BS 161 is recommended. The requisite degree of brightness could be obtained by a "so-called" 5W lamp, but there is no recognised specification for such lamps, and there is no effective control of the tolerances on light output. In the case of signs lit by gas, the use of a Limina or Bijou mantle of normal consumptions of 500 and 875 B.Th.U. is recommended.
Lighting: ARP, Lighting: Distribution, Lighting: Levels, Lighting: Signs, Lighting: Specifications

Personal Note p61
Mr. E. Stroud, for many years Chief Engineering of Holophane Ltd has been appointed General Sales Manager of that company.
Lighting: Personnel

Lighting Of Street Refuges - No Absolute Duty Reprinted from The Times (27/06/1940) p61
The plaintiff, Miss Edna Greenwood, was injured at 8PM on October 7th 1939, in a taxi owned by Central Service Company Limited, along Goodge Street, as a result of the taxi colliding with a temporarily unlighted bollard of a refuge. She was awarded 80 damages and costs against Central Services Company Limited on the grounds that the taxi was being driven too fast. Central Service Company Limited claimed contribution from St. Marylebone Borough Council on the ground that the collision was caused by the unlighted bollard.
It appeared that Goodge Street was normally lit in compliance with Section 130 of the Metropolis Management Act, 1855, but that lighting was forbidden under the Lighting (Restrictions) Order, 1939, paragraph 1. However, paragraph 4 allowed lamps to be used on obstructions provided the lights were of one candle-power and threw no light upwards. St. Marylebone Borough Council accordingly hung one candle-power hurricane lamps on the bollards of each refuge in their distrcit and employed men to go around the district in a lorry to see that the lights remained lighted. The lights in question had gone out at the time of the accident.
The Deputy County Court Judge held that St. Marylebone Borough Council had not been guilty in negligence and there was no liability on them, and dismissed the claim.
The defendents, Central Service Company Limited, appealed but the appeal only raised the questions (1) Whether the council had committed a breach of an absolute statutory duty in not keeping the refuge lighted, and no question of negligence arose; (2) Had created a nuisance by having an unlighted obstruction.
Had the accident occurred in time of peace no doubt the obligation would have been imposed on the borough council, but it was under Lighting (Restrictions) Order 1939, No 1098. The effect of the order was to repeal the obligation imposed by Section 130 of the 1855 act. But there remained the common law obligation, after having erected an obstruction in the carriageway, to use reasonable care to prevent it being a danger. However, there was a lamp on the bollard, and it had been lit but had gone out, but the council had taken steps to guard against this by having men going out.
It depended on whether there was an absolute obligation on the council to light the obstruction, or only an obligation to use reasonable diligence and care. The county court Judge had held that the only obligation was to use reasonable diligence and care, and found no neligence. The appeal failed and was dismissed.
Lighting: ARP, Lighting: Legal

A New Double-Sided Illuminated ARP Sign p62
A new doubled-sided gas-illuminated ARP Location or Direction signs has recently been put on the market by Sugg. The construction of the sign represents a notable advance in rigidity and freedom from distortion, and at the same time a simple means of fixing by clips is applicable for either central or off-set mounting. By the use of two plane mirrors inside the hood, doubled sided illumination is obtained from one centrally disposed light source, with resultant economy in operation and maintenance. The source of the light is a standard limina mantle and burner consuming one cubic foot of gas per hour mounted centrally above the sign panel. The burner is of the "lift off" type and may be removed for re-mantling etc. The mantle is surrounded by a silica cylinder of the type used on the war-time street lighting fittings - this cylinder is tested for light transmission in exactly the same way as it is tested to comply with BS/ARP 37. The use of the silica reduces the brightness of the source, and by obscuring all but the portion adjacent ot the mantle with metal cylinders and by using a suitable baffle, a form of light distribution is obtained which, in conjunction with the mirrors, illuminate the sign panel with unusal uniformity.
Lighting: ARP

A Throught For Lighting Engineers p62
A verse from a Tennyson poem.
Lighting: Social Comment

Reasons For Maintaining Public Lighting Installations In War Time p63
The best service the public lighting community can do is to maintain its apparatus in such a condition that it can be brought into full use after the war is over. Therefore it is necessary for lamps and glassware to be kept in a reasonable state of cleanliness - which can be obtained by cleaning at about three times the peace-time interval - and for the rest of the apparatus to be kept in repair and in good working order. Stocks of lamps, mantles and glassware should be kept in hand. Painting may be postponed for cast iron columns and copper lanterns, but steel columns and other corrodible parts should be painted as often as is necessary for preservation.
Glassware should be replaced as quickly as possible to preserve the fittings inside the lanterns, and prevent difficulty due to a shortage of glass if extensive bombing occurs. The question of removing lanterns entirely cannot be considered seriously on either economic or practical grounds, where there are large numbers to contend with. The cost of removal, storage under cover, and refixing, will exceed the cost of maintenance in the street. Further, the amount of damage resulting from a bomb striking the store would be incomparably greater than that possible if the lanterns remained scattered over a wide area. Lanterns could also be damaged during removal, transport, storage and refixing.

Clock Controller
The maintenance of control apparatus is also of primary importance. Time switches, chokes, transformers, gas controllers, governors, igniters and other auxiliary fittings must be kept clean and dry. If these items are neglected, not only will it be impossible for lighting to be resumed promptly, but the cost of repairs and replacements, would be enormous. In the case of clock-work apparatus, it is suggested that this should be kept in a going condition by winding at regular intervals, not necessarily so frequently as to keep the movements going continually. All fittings should be repaired or replaced as soon as a defect is noticed, to prevent a flood of work when lighting is required.

The Question Of Expense
It might be imagined that all this work will prove unduly expensive. It will cost no more than one-third of the normal cost of maintenance, excluding energy. It will be found - in many areas - that the cost of maintenance is largely compensated for by the reduced amount of damage caused maliciously. A dirty lamp, that beings to have a derelict appearance, exerts a strange fascination in the average small boy.

An Uplift To Public Morale
Derelict and sordid surroundings are the first steps towards a careless mind and a weakening of public morale. This then is a small contribution that the Public Lighting Engineer can make towards uplifting the public spirit.
Lighting: ARP, Lighting: Maintenance

Public Lighting Engineer p63
Lighting Engineer looking for new position after closure of his lighting department due to the war.
Lighting: Personnel

Road Obstruction Lanterns p64
The use of electric obstruction lanterns for fixing to street bollards has many advantages. It means a saving of 2d. to 6d. per lamp per day but saves oil and man power. The GEC have developed a road obstruction lantern which complies strictly with Lighting (Restrictions) Order 1940. The lantern is constructed of lead-coated sheet steel and has three sides stencilled with the approved St. Andrew's Cross sign and backed with white opal glass. Inside is a detachable baffle and B.C. lampholder for use with 15W Osram lamp, which provides the correct amount of light (0.5 candle per square foot) on the crosses. The lantern can be supplied finished either black or white. A two-lamp unit is preferred by some authorities because of the advantages of ensuring there is light on the island even if one lamp fails.
Lighting: ARP

To The Editor: War-Time Street lighting p64
Letter urging the installation of war-time street lighting as midsummer will soon be over, and darker evenings will return.
Lighting: ARP

A Simple Portable ARP Lighting Unit p64
Ediswan have introduced an accumulator hand lamp which will give 50 to 60 hours light for one charge. The Ensur-a-lite Junior consists only of the small 2V Ediswan Extra-Life accumulator with bulb attachment and switch. The lamp attachment and switch knob are of bakelite; the container is moulded glass and the electrolyte is unspillable. The bulb is hooded to ensure concentration of light in the downward direction. It will be found particularly useful in private air raid shelters, first aid stations, wardens posts and other ARP purposes where controlled light is an absolute necessity.
Lighting: ARP

Street Lighting Notes p45
Brief description of the installations at: Belfast, Barking, Bedwelty, Birkenhead, Blackpool, Brierfield U.D.C., Bristol, Chislehurst and Sidcup U.D.C., Derby, Egham, Fulham, Fraserburgh, Gellygaer, Glasgow, Grantham, Hoston And Isleworth, Hornby, Houghton-Le-Spring U.D.C., City Of London, Mansfield, Paisley, Peterborough, Reigate, sheffield, Sutton, Torquay and Wombwell.
Lighting: Installations

Progress In South Wales p46
Brief description of the installations at: Cardiff, Llandrindod Wells, Milford Haven, Neath, Penybont and Pontypridd.
Lighting: Installations

Further Progress p46
Very brief descriptions of the installations at: Hamilton, Johnston, Stalybridge, Urmston, Wallasey, Oldham, Worksop, Blantyre, Bellshill, Busby, East Kilbridge, Cambuslang, Pudsey, Chesterfield, Leeds, Burnley, Ashton-Under-Lyne, Darwen, Hyde, Morecambe, Heysham, Darlington, Mexborough, Preston, Manchester, St. Marylebone and St. Pancras.
Lighting: Installations

Interior Lighting p46
Description of interior lighting scheme installed in the new dress factory of Selincourt & Sons Ltd, in Shropshire House, London, W.C.2.

War-time Lighting Equipment p46
The Wardle Restricted Street Lighting Fittings have been improved. The upper and lower steel spinnings are vitreous enamelled inside and outside. The Adaptor Type Fitting is suitable for direct connection to the lampholder in existing Street Lighting Fittings. The Bracket Type Fitting is provided with a cast iron dome for bracket mounting and is fitted with B.C. lampholder. Maximum tapping is 1" gas.
Lighting: ARP, Lighting: Luminaries

Adverts: The General Electric Co., Ltd, APLE, Public Lighting, William Sugg And Co., Ltd., Siemens Electric Lamps And Supplies Ltd., Metropolitan Vickers Electrical Co. Ltd, Standard Telephones And Cables Ltd., The British Thomson-Houston Co. Ltd., Crompton Parkinson Ltd., British, Foreign And Colonial Automatic Light Controlling Co., Ltd., British Electrical Development Association, Inc, Automatic Telephone And Electrical Co., Ltd. and British Commercial Gas Association