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ilp archive : journals

public lighting no. 41 vol. 11
April-June 1946

Editorial p45
The Danger Lights p45
Reported in the Leading Article of a London evening newspaper. It discussed certain shortcomings in lighting administration which are apparent to the public at large. When the Editor was approached and his attention drawn to these difficulties he commissioned Peter Driffield to ascertain the full facts, and in a later issue of The Evening Standard there appeared Blue Print for Street Safety. Three points were emphasised in his story: (1) Need for uniformity; (2) Wiser co-ordination between local authorities and (3) Improvement in the future siting and planning of lamp columns. The APLE has for many years declared these principles.
Lighting: Authority Organisation, Lighting: Safety

The Public Lighting Engineer's Guide Book p45
Elsewhere in this issue, extracts are given from the M.O.T. Final Report On Street Lighting. A copy should be owned by every Public Lighting Engineer as it's "The Blueprint for Street Lighting." The recommendations of the M.O.T. committee include in the first paragraphs the items in Blue Print for Street Safety. But difficulties still confront the Lighting Engineer. Supplies and equipment are in great demand, and the manufacturers are unable to deal with the flood of orders. Shortage of labour is an all-round cry.
Lighting: Specifications

The Danger Lights p46
Leading article from the "Evening Standard"

During February, 371 people were killed on the road. Many learned bodies have inquired into the cause of accidents. All committees have agreed on one point: that a major cause is bad street lighting. The Royal Commission on Transport in 1928 reported "The present lack of uniformity and the relatively low standard of street lighting in many parts of the country cause danger to pedestrian and motorist." Street lighting is as bad as ever. Worse: the plans for improving it are as unformed and woolly as ever they were before the war. Uniformity is the first requirement. The administrative machinery at present is such that a parish council would have to be consulted and their approval obtained to introduce uniform lighting on trunk roads. Although the Minister of Transport is now the Highway Authority for 8000 miles of trunk roads, he is not the lighting authority. The AA surveyed the Great West Road: in the 16 mile stretch between Hammersmith and Slough they found no fewer than 15 changes of lighting, varying from modern installations to some flickering lamps put up 30 years ago for the use of pedestrians alone. In 1944 the Committee on Road Safety declared that improvement could only be achieved by legislation "making the control of street lighting the responsibility of one central department."
Lighting: Authority Organisation, Lighting: Safety

Blue Print For Street Lighting p46
Repeated from the "Evening Standard"

Britain used to sing "When the Lights Go On Again." They have gone on again - but not as strongly, not as uniformly, not even as cheerfully and certainly not as safely.
(1) The Minister of Transport is the highway authority for 8,150 miles of trunk roads. He is not their lighting authority.
(2) Responsibility for street lighting still rests with local authorities. There are more than 2,500 of these in the country.
(3) The Lighting and Watching Act, 1833, giving permissive but not compulsory powers for lighting, is still in force. A parish, if it wishes, need have no street lights at all.
(4) Reports and recommendations dating from 1928, 9135, 1937, 1939 adn 1944 from responsible invetigating committees have yet to be adopted.
(5) There are 15 changes of street lighting on a 16-mile stretch between Hammersmith and Slough.
The organisations fighting against these anomalies are the A.P.L.E., I.E.S., A.A., R.A.C., R.O.S.P.A., Scotland Yard and progressive borough, urban and rural councils. Their beliefs include:
(1) Street lighting is an important service contributing to the nation's health, prestige, well-being and safety.
(2) Today's sprawling, shambling, uncoordinated authority is a complete anachronism.
(3) That Britain, which once led the world in street lighting, should do so again.
(4) That London should be Britain's brightest city.
(5) That the urban Britain of the future should consist of cities where motor headlights are not only unnecessary, but forbidden.
"We have gone miles since 1937, but in many areas today we're not even back to pre-war standard. The first essential for good visibility is the even distribution of light, the elimination of glare and black pools and unevenness. What is needed is a greater co-operation between lighting authorities. In London, with 28 boroughsm each is a lighting authoritiy on its own. We have urged coordination. We do not stand for nationalisation: we stand for better coordination among existing authorities. One of the difficulties is getting uniform street lighting without dazzle. Low street lights tend to give glare and patchy lighting; high mountngs, in the region of 25 to 30 feet, tend towards scientific distribution of light. Headlights often have the reverse effect to what street lighting is trying to do. Spacing, diffusion, reflection, durability of appartus are all matters which the exprt has investigated. Now a British Standard Specification for street lighting is ready."
London is one of the most variably lit cities in the world. The ideal is that headlights should not be used dates from 1937. "We visualise an era when as you enter a city, you get a direction 'put your lights out' - just as today you get the 30 m.p.h restriction side." Pre-war Purley Way was widely considered a fine example of technique; Glasgow and Sheffield rate high today. Even those lighting experts who oppose nationalisation would prefer some compulsion whereby minimum standards set by a central authority shuold be compiled with. The engineers themselves would like to give their advice in an advisory capacity to the central department.
Lighting: Authority Organisation, Lighting: Safety

Photometry In Relation To Street Lighting by F. M. Hale, B.Sc., A.M.I.E.E. Technical Assistant, Glasgow Corporation Lighing Department p47
It is the yardstick by which the engineer judges the performance of his installations, but the instruments used and the methods involved must be thoroughly understood if reliance is to be placed on the results obtained.

Fitting Characteristics
New installations, and modified old ones, will conform with the recommendations of the M.o.T. Committee, or with a new B.S. Specifciation. Unfortunately the initial cost is usually one of these deciding factors with optical performance and maintenance being subordinated to it. Vert frequently an initially cheaper fitting becomes dearer when the annual maintenance costs are considered.

Optical Properties
In assessing the optical properties of a fitting, the buyer is faced with three alternatives. He can simply accept the manufacturer's specification and trust the fittings may subsequently conform with the claims made. Quoted figures are naturally the best that can be expected whereas in practice such a high standard may be very difficult to obtain or may depend upon the critical adjustment of some part which may not be readily appreciated from a simple visual examination. The manufacturer's specification serves as a basis on which the suitability of a particular type of fitting can be judged. The second alternative is that there may be, in a nearby district, an installation of fittings of the type under consideration which can be viewed - this is where the A.P.L.E. Conferences were so appreciated. The third alternative is to erect a trial installation of about six fittings. This would allow the installation to be observed under service conditions and also illumination measurements to be taken. It is in these circumstances that a well-equipped laboratory or testing section can be of such use.

Testing Equipment
Ranges from a simple photo-electric illumination photometer to apparatus for the measurement of luminous output and of candle-power distribution of large fittings. Only the larger authorities have sufficient resources to equip and maintain such comprehensive testing facilities.

B.S. 307-1931
This classified street lighting according to the average horizontal illumination at the test-point which was usually on the kerb at the mid-span position. Such measurements were easily made and the classifications broad enough to prevent any misclassification. However its requirements were found to be inadequate in serving all the specical functions with which street lighting is concerned. Its shortcomings were particularly accentuated by the special meeds of the increasing number of motorists.

M.O.T. Report
A number of recommendations are made for general adoption on Group A "Traffic Routes" and for general guidance on Group B "Other Roads." Of the seven principle recommendations, three refer to actual lantern charactheristics and involve photometric measurement for their verification. These are for Group A:
(1) Power of sources: Luminous output to be between 3000 and 8000 lumens per 100 ft. linear of road.
(2) Distribution: Two types: (a) Non-cut-off - Peak Intensity near horizontal; (b) Cut-off - Peak Intensity 60°-70° from the downward vertical.
(3) Avoidance of Glare: Ratio of Peak Candle Power to average of values in all directions downward from the source and lying between 30° and 45° from the vertical not to exceed 6, preferably 5.
The Committee also drew attention to the need for a simple type of measurement to ensure the satisfactory maintenance of an installation. Regular measurement of illumination at a number of points in the insallation is suggested, not recommended. It must be remembered that the MOT Report gives recommendations only, it is not a specification.

Fundamental Ideas
The power of sources can be measured using an integrating sphere and photometer.
Candle power distribution cab be measured using a polar distribution apparatus.

Laboratories vs. Street Tests
Street measurements are normally confined to simple illumination or road brightness measurements. An iso-candle diagram may give the theoretical horizontal or vertical illumination, practice shows that the actual measured illumination frquently differs from the calculated value. This is not surprising, for there are a number of factors influencing street tets which do not arise in the laboratory. Chief amongst these is the supply voltage, incorrect alignment of asymmetric fittings relative to the road axis, so fitting which is not plumb, or the presence of reflecting surfaces near the surface. Other influences also arise: the fitting of a new lamp may increase candle-power by 10%; where prismatic glassware is fitted and adjustment of lamp position may result in a considerable change in light distribution, and the effect of dirt.

Typical Street Tests
The most common is horizontal illumination taken on the street surface or at pre-arranged test-points. In recent years, some preference has been expressed for vertical, instead of horizontal, illumination (because of greater accuracy of readings with incident light being nearer the normal, and any light reflected from the street surface is included). In practice, surface brightness, particularly of the road, is more important than mere illumination, due to the silhouette theory.

Brightness Measurements
Road brightness measurements are not ordinarily undertaken by the avertage user, who usually just takes illumination readings. Whilst readings are easy to take, difficulties arise in their representation, as apparent road brightness varies according to the position of the observer on the road. A common method is by iso-equivalent foot-candle contours drawn on an actual photograph of the street. Appraisement of street lighting isntallations according to road brightness has not been given any official backing; but it is an aspect which might be given consideration by the B.S.I. Street Lighting Committee. one of the chief difficulties is the fact that the road surface is under control of the municipal or county engineer: cost, durability and considerations of traffic safety are their deciding factors.

Testing Facilities
Only the larger authorities could be expected to provide all the equipment necessary. Most of the larger manufacturers possess such facilities as part of their design and research organisation. There does appear a need for independent testing facilities to be made available at nominal costs.

Training of Lighting Engineers
Theoretical training can be reached by those preparing for the City and Guilds Examinations in Illuminating Engineering (which were originally sponsored by the IES and APLE). The exams are without value unless it can be supplemented by practical experience in photometry.
Lighting: Distribution, Lighting: Education, Lighting: Maintenance, Lighting: Specifications, Lighting: Theory

Keith Blackman, Ltd., at War! p56
Details of "The K.B. War Effort" brochure issued by Keith Blackman Ltd. This included the manufacture of specialities such as fans, blowers, compressors, heaters etc.
Lighting: ARP

Newton "Sieray" Minor Lantern p56
This street lighting lantern is designed for Group B roads and is of the single piece dome refractor type. It is made with a one-piece cast canopy and relfecd is tapped ¾-in. gas thread as standard (with provision for 1-in. if required). In the top of the lantern are three pairs of cast lugs, to one of which a strap is fixed which carried the appropiate lampholder. These are arranged that any lamp for which the fitting is designed will take up its correct focal position. The strap carries a porcelain skirted pattern and is of the B.C., E.S., or 3-pin B.C. type. The reflector is stove enamelled white on the reflecting surface. The glassware is available with two types of distribution: symmetric and 2-way non-axial with 170° between the main beams. The maximum candle power is at 78° to the downward vertical. The glassware is held in position by two phosphor bronze rods which are secured to the main casting, the necessary locking being obtained by two phosphor bronze springs. Provision is made for locating the glassware correctly in respect to the body of the lamp.
Lighting: Luminaires

Royal Visit to G.E.C. Research Laboratories p56
Details of a royal visit, by Queen Mary and Princess Elizabeth, to the GEC Research Laboratories at Wembley.
Lighting: Events, Lighting: Manufacturers

British Firm Establishes New Laboratories p56
Standard Telephones and Cables announce a new central laboratory organisation to undertake long-term research and development in the telecommunication, electrons and allied fields. Standard Telecommunication Laboratories Limited will be housed at Progress Way, Great Cambridge Road, Enfield.
Lighting: Manufacturers

Application of the Principles of Penumbra to Street Lighting p57
Penumbra effect of a solar eclipse is well known, the principle has not been used in illuminating engineering until the recent "dim-out" when a device working on the idea was used fairly extensively. It is particularly applicable to public lighting and consists of placing a screen under and so close to the source of light that the light is gradually cut off. The screen is adjusted that a bright pool of light, that is normally found underneath lamps, giving the very undesirable well-known "spotty" effect, is eliminated and the illumination evened out, giving better visibility.

The Penumbra Metal Reflector
The metal sheild shows the principles of Penumbra, Reflection and Regeneration. It is a very efficient device where, and in proportion to, its excess under the lamp and re-directing it farther from the lamp where it is more useful.

The Penumbra Internal Reflecting Prism
The second device is made of glass in the form of a triangular prism and is fitted immediately under a source of light so that the upper face is horizontal, the two inclined faces meeting underneath so as to point downwards. The prism shows the principles of Penumbra, Totla Internal Reflection, Refraction and Rengeration.

Advantages of Prism
The prism has many advantages: once fitted it is permanently correct and does not have to be refocused or adjusted. It is so simple that it does not depend on the intelligence of the attendant for adjustment. It is easy to remove and replace and, being made of solid glass, it will not corrode or tarnish. Owing to its high reflecting factor it is more efficient than a metal reflector. By its 2-way cross-over action, it operates both up and down the street and can be made with a slight taper to give any desired bias to direct the beam slightly. It complies with the requirements of the Street Lighting Committee's Final Report in that it is well within the Glare Factor for both A and B class roads, the figure being in the neighbourhood of three. Further it complies with the Police requirements in that it cuts off no light from the fronts of houses.
Lighting: Distribution, Lighting: Maintenance, Lighting: Specifications, Lighting: Theory

The Street Lighting of Paris by Mons. A. Herzog p59
Brings up-to-date a similar article by J. W. Partridge delivered to the Margate Conference in 1933.
Lighting: Control, Lighting: Energy, Lighting: Installations, Lighting: Lamps

Ministry of Transport Final Report on Street Lighting p62
Reproduction of the conclusions and recommendations of the Departmental Committee.
Lighting: Specifications

The A.P.L.E. Conference p63
In this year of Victory it is appropriate that the Conference should be again staged in the Capital. The meeting will be opened by Minister of Transport, The Rt. Hon. Alfred Barnes, M.P.
APLE: Conference

Enemy-owned British Patents p64
The number of British Patent Applications of Germany origin stood at 5449 in 1938. Therefore the Council of the Chartered Institute of Patent Agents appointed a Committee to consider the position of enemy-owned pantents and applications for patents made by enemy nationals. They concluded: The United Kingdon should take no separate action to deny to enemy nationals after the war, convention rights which arise out of basic applications filed after the end of hostilities; the International Convention is a reciprocal affair, to the spirit of which any unilateral arrangement forced on enemies would be contrary; this does not extent to patent applications by enemeis which werepending in this country at the beginning of the war which should be considered void;
Lighting: ARP, Lighting: Legal

Lighting Innovation at Victoria Station p65
The introduction of high tension, cold cathode fluorescent tube lighting virtually came to a standstill during the war period. it was fast replacing tungsten filament in stores, hotels, cinema and theatre foyers. In 1937 Osram fluorescent tubes were installed at several railway stations serving the Southern Electric line in Surrey. One new installation of particular interest is the "Golden Arrow" Continental platform at Victoria Station. 96 Osram fluorescent tubes, giving an intermediate white light (between "daylight" and "warmlight") are arranged in two lines, each covering 250 of platform. They are placed 8 feet apart and mounted under a canopy 14 feet high. Each line comprised 24 units butted together to form a continuous run. Tow standard 8'6" tubes are used in each unit. The new lighting gives four times the illumination of the original and is loaded at 4½kW. The scheme was prepared by the Illuminating Engineering Department of the General Electric Co. Ltd to the requirements of the Southern Railway Lighting Eningeer. The installation of tubes, transformers and high tension wiring was carried out by Claude-General Neon Lights, Ltd. and the low tension wiring was undertaken by Southern Railway engineers.
Lighting: Lamps, Lighting: Installations

Knighthood For Dr. C. C. Paterson p66
Sir Clifford Paterson has contributed a great deal in the science of illumination. He joined the GEC in 1919 to establish and direct the Research Laboratories at Wembley. It started with a staff of 29 and by the outbreak of war, it had a staff of 550. During the war, the Establishment was most concerned with Radar research and the staff swelled to 1750.
Lighting: Personnel

I.M.E.A. p66
At the I.M.E.A. Convention, Siemens Electric Lamps and Supplies Ltd displayed some lanterns for Group A and Group B roads. For Group A lighting, the two lanterns were the: (1) The "Barnet-Sieray" lantern for use with 300-500W Sieray-Dual lamps MAT/V or 250-400W Sieray lamps type MA/V. It is fitted with prismatic glass panels giving an asymmetric light distribution with an angle of 160° or 180° between the main beams; (2) The "Bi-Way" designed for use with 250-400W Sieray lamps MA/V uses a Holophane one piece bowl refractor which can be supplied to give two-way axial, two-way non-axial or symmetrical light distribution. For Group "B" roads the "Newton-Sieray Minor" lantern was shown with and without a clear glass outer globe. It is designed for 100-200 GLS or 80-125 Sieray lamps type MB/V. Various fluorescent fittings for both 40-watt and 80-watt "Sieray" Fluorescent Tubular lamps MCF/U were exhibited.
Lighting: Luminaires

Mr. Louis Agius, M.B.E. p66
Louis Agius, street lighting engineer in Valetta, Malta, marches in the Victory Parade.
Lighting: Personnel

Correcting A Mis-statement p67
Letter from Mr. W. J. Jones, director of E.L.M.A., correcting a statement published in a Sunday newspaper, on the marketing of multi-filament lamps.
Lighting: Lamps

Obtaining Public Opinion p67
Details of an experiment in Wandsworth, where the people of the borough can react to different forms of lighting. Included in the types are Fluorescent, Sodium, Mercury-Vapour, Sieray-Dual and metal filament lamps. The roads chosen include Wandsworth High Street, Putney High Street and Trinity Road.
Lighting: Lamps

Adverts: Poles Ltd The Association Of Metal Sprayers, Stanton Ironworks Co., Ltd, Siemens Electric Lamps And Supplies Ltd., Metropolitan Vickers Electrical Co. Ltd, Engineering And Lighting Equipment Co. Ltd., Holophane Ltd., British Gas Council, British Electrical Development Association, Inc, Stewarts And Lloyds Co., Ltd., The British Thomson-Houston Co. Ltd., APLE Conference, The Horstmann Gear Co., Ltd., William Sugg And Co., Ltd., Automatic Telephone And Electrical Co., Ltd., British, Foreign And Colonial Automatic Light Controlling Co., Ltd., Gowshall Ltd., Broad And Co. Ltd., Willey And Co. Ltd., Falk, Stadelmann Co., Ltd., E. K. Cole Ltd, The Clockwork Engineers (J. W. and R. E. Hughes), Peebles Co., Ltd., James Keith And Blackman Co., Ltd. Brighton Lighting and Electrical Engineering Co. Ltd, Sangamo Weston Ltd. and The General Electric Co., Ltd.