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ilp archive : journals

public lighting no. 2 vol. 1
June 1936

More Light On The Subject p31
Cartoon of Rt. Hon. Leslie Hore-Belisha (Minister Of Transport) and APLE President Maurice Bell, A.M.Inst.G.E
APLE: Organisation

Editorial p32
The new journal and a request for articles and photographs, regististration for the conference at Cheltenham, details of the conference itself in the Town Hall, the exhibition to be held in the Winter Gardens, mention of the debate in the House Of Commons and the importance for every Local Authority to have a qualified Public Lighting Engineer, and a list of new members to the association.
APLE: Journal, APLE:Conference, Lighting: Management, Lighting: Legal, APLE: Organisation

The Annual Conference: Cheltenham, September 4th - 10th p33
Description of Cheltenham ("it reflects the gay atmosphere of the Continental Riviera - without any artificiality"), the Town Hall, the countryside around Cheltenham, the Conference Preliminary Programme, and the Ladies' Programme. (The Conference Preliminary Programme shows some significant differences to the final programme and this is outlined its page).
APLE: Conference

Public Lighting And Road Safety by Maurice Bell, A.M.Inst.G.E p35-p37, p51
(Public Lighting Superintendent, Tottenham And District Gas Company).

This paper has eight parts:
Accident Statistics
During the past decade, one of the dominant factors - which has brought with it other changes profoundly influencing Public Lighting - has been the enormous development in the volume and speed of motor traffic.
The number of accidents has increased almost continuously year by year, with the result that the annual figures (for both fatal and non-fatal) have roughly doubled during the last ten years.
In 1935, 6502 people were killed and 221,726 were injured on the roads in Great Britain.
In a recent report on road accidents prepared by the police for the Ministry Of Transport, (compiled from data collected during the first few months of 1935 where the mean time for the lighting of street lamps was 5.40PM), and which received considerable publicity in the Press, the worst period of the day for accidents is between 5PM and 6PM, and the second worst period is between 6PM and 7PM.
A recent enquiry in the United States has suggested the "the night-hazard is roughly four times the day-hazard" - the need for good road lighting is surely evident.
Much discretion is needed in the interpretation of these statistics e.g. better lighting leads to greater safety, it may enable motorists to proceed at greater speed or lead to an increase in the volume of traffic; or a road may be so badly lighted as to be shunned by traffic, therefore being relatively free from accidents, although of little service to the community.
Illumination Values
In 1922, the home Office Departmental Committeee on Lighting in Factories and Workshops recommended a minium illumination of 5 foot-candles for fine work - a street with a minimum illumination of 0.05 foot candles (Class F) would be considered relatively well lighted. Yet this is only one hundredth of the minimum for industrial lighting, and less than one ten thousandth of the average daylight value. No street carrying substantial traffic should be lighted to less intenstiy than Class F.
In view of the above, it is difficult to understand how any installation of street lighting can be condemned as "extravagant."
However, the provision of a certain minimum illumination isn't all that is necessary to ensure a well-lighted street. New points now better appreciated are: the distracting effect of glare; and the changed view-point in regard to the desirability of extreme uniformity of illumination between post and post - a change occasioned mainly by recognition on the effect of the highly polished road-surfaces of dark texture.
Influence Of Road Surface
There are two schools of thought: those holding to the ideal of general illumination of objects in the same manner as by daylight; and those who want to achieve high and even road brightness so that objects are revealed silhouetted against the brighter background.
One difficulty faced in studying road brightness is the extraordinary difference in appearance of a road in wet conditions as compared with its aspect when dry.
In wet conditions, unexpected regions of "blackness" may be revealed as the point of view of the observer changes. Also the impression caused by the lights themselves at distant bends may easily mislead drivers.
Whilst road surface brightness is a vital factor when considering motor traffic, on other types of roads e.g. shopping centres, residential areas with little traffic, different aspects my prevail.
Greater Uniformity Needed
Uniformity needs to be achieved when passing from one road to another or from one lighting authority to another. These variations undoubtedly constitute a contributory cause of accidents.
The uniformity of lighting could be achieved by the general application of the British Standard Specification (BS 307:1931) and by systematic classification of roads in each area.
Grading of illumination between different classified roads needs care as conflicting opinions have been received.
The Ministry Of Transport Committee
The committee has commenced its task at an opportune moment.
The APLE was invited to give evidence before the committee and was able to present some instructive data illustrating the extraordinary lack of uniformity that prevails in some areas at the present time.
The publication of the Interim Report is a gratifying recognition of the national imporance of public lighting and its direct relation to the safety of the roads.
The advancement in the field of street lighting has not been comparable with that in some other fields of lighting e.g. the lighting of shops and sotres where a direct appeal to business considerations is possible has development immensely.
Bad public lighting is a gamble with fate. Every motorist and pedestrian risks a danger. Good and efficient public lighting can be secured if ratepayers foot the bill.
A Classification Of Roadways
What is required is a systematic study and classifcation of roadways for Public Lighting needs.
Lighting units and installations should be planned to meet, not only present-day requirements, but also future eventualities.
Many routes have changed e.g. merely residential becoming an important channel for outgoing and incoming traffic.
Arterial roads present a particularly difficult problem because they pass through the areas of many local authorities, each acting independently, and not infrequently reluctant to bear the cost of proper lighting; sometimes they are unable to do so.
Cost - A Suggested Solution
Lighting should be paid by a common fund for the purpose, to which local and county authorities should contribute, and which should be aided by a generous contribution from the Road Fund.
The lighting of roadways should be an integral part of their construction and maintenance.
Of a total of 8,760 hours per annum during which roads can be used, the dark hours amount to over 4,000 - approximately 46%. Bearing in mind the heavy cost of construction, it is merely judicious expenditure to equip them with lighting that will enable them to be used with safety by night, thus relieving in part the heavy congestion during the day.
In the interest of satefy, proper lighting should be made compulsory on all roads in and through towns, and on all main arterial roads carrying heavy traffic.
"Patching up" - the maintenance of exisiting installations and their renovation from time to time by the subsitution of more efficient lighting devices - benefits the ratepayers at little, or if any, extra cost.
However, installations that are definitely out of date, not only in equipment but in design, should not be patched up. In such cases, the only real solution is redesign in acccordance with modern methods.
The Public Lighting Engineer
Towns and cities of any size should employ a thoroughly qualified Public Lighting engineer.
Where the expenditure of public money on lighting is considerable, expert supervision is a whole-time job, and it is my conviction that there is quickly approaching a time when the fully trained Public Lighting engineer will be in urgent demand to a continually increasing extent.
The APLE has recently appointed a committee to map out courses of study for those who which to enter the profession.
1. The first object of street lighting is to render motor traffic safe by removing as far as is possible the principle cause of accidents - inability to see clearly at night.
2. The worst period for accidents falls between sunset and darkness (between 5PM and 7PM in the first months of the year.)
3. We are interested chiefly in the part that Public Lighting can play in increasing the utility of roads and enhancing their safety.
4. The inference from the statistics is that good artificial lighting on the roads is even more important than in the past.
5. Illumination values should be increased. A public lighting system of the highest class is hardly extravagant when compared to industrial lighting (which arguably involves similar concentration).
6. A combination of both the direct illumination and road brightness theories (silhouette vision) should be used for different traffic types.
7. Uniformity of lighting could be achieved by the general application of the British Standard Specification (BS 307:1931) and by systematic classification of roads in each area.
8. Grading of illumination still requires research.
9. The publication of the Interim Report is a gratifying recognition of the national imporance of public lighting and its direct relation to the safety of the roads.
10. Poor public lighting could be inherently dangerous. There is no reason why it cannot be improved but ratepayers would have to meet the bill. With no direct tangible results, this is difficult.
11. All roads should be classified for Public Lighting requirements, making sure that future uses of the road are considered.
12. The lighting of arterial roads is especially problematic as the road can pass through many different lighting authorities.
13. Lighting should be paid by a common fund for the purpose, to which local and county authorities should contribute, and which should be aided by a generous contribution from the Road Fund.
14. Existing installations can be improved by "patching up" at little or no cost to the ratepayer.
15. Installations that are definitely out of date, not only in equipment but in design, should not be patched up. In such cases, the only real solution is redesign in acccordance with modern methods.
16. Towns and cities of any size should employ a thoroughly qualified Public Lighting engineer.

[1] National Safety First Association, Survey, 1935
[2] MOT's Report Of Road Accidents, 1935
[3] National Safety First Association, 1933
[4] MOT's Report Of Road Accidents, 1934

Statistics: Accident Data, Lighting: Levels, Lighting: Theory, Lighting: Specifications, Lighting: Authority Organisation, Lighting: Funding and APLE: Organisation.

The Maxill Gas Lamp p38
Description of the Maxill gas lamp by Parkinson.
Lighting: Luminaires

The Universal Horizontal Illumination Chart p38
Description of the horizontal illumination chart designed by William J. G. Davey, B.Sc., Research Illuminating Engineer to Parkinson. The chart incorporates nine separate logarithmic scales and enables horizontal illumation to be rapidly calculated from the perpendicular distance to the lamps, the radial distance to the lamp, the mounting height of the lamp and the intensity.
Lighting: Theory

The 150 Watt OSIRA Electric Discharge Lamp p38
Announcement of the introduction fo the new 150W GEC OSIRA lamp.
Lighting: Lamps

The Public Lighting Engineer At Work p39-40,p45,p51
Lengthy interview with Thomas Wilkie, the Public Lighting Engineer of Leicester. The article, which is written as a question and answer interview, includes such topics as: the use of gas or electricity, number of gas and electric lamps to service, a brief history of the expansion and improvement of the lighting department since Wilkie's appointment in 1923, various statistics concerning the current installation, description of the equipment in the test laboratory, the remote control of lamps via a switch board and a description of the workshop and stores. Small pictures of some of the installations are included. The use of an old fire escape ladder mounted on the back of a Bedford Truck for street lighting work is also noted - it was rescued from the Fire Department.
Lighting: Installations, Lighting: Management and Lighting: Theory

Glare In Street Lighting by D. G. Sandeman, B.Sc., A.M.I.E.E. p46-47
(Assistant Inspector of Lighting, Edinburgh)

Sandeman makes the argument that it is necessary to expose street lighting light souces with consequent glare. As glare is governed by three factors (brightness of lamps, their position relative to the observer, the relative movement of observer with lamp), Sandeman suggests the solution (especially due to the last factor) is a type of lighting which will produce a constant amount of glare.

Some practical experience in Street Lighting shows that an installation can be improved by:
(1) Increasing the number of lamps.
(2) Raising the level of illumination.
(3) Changing the position of the lamps.
(4) Altering the light distribution by means of enamelled reflectors, opal glass, mirrors or glass prisms.
(5) Departing from the principle of directing a beam of light towards the B.E.S.A. Test Point.
An equation for glare is derived from the general illumination equation (without cosine adjustment for horizontal illumination) and divided by θ3/2. [I am unable to find the source of this formula.] The expression can be used to produce of Polar Curve for a fitting which will give the same degree of glare no matter where the observer is situated, and is applicable to both fixed and moving lights. Having the square of the height in the denominator means that glare is reduced twofold by every increase in height. This could form the basis of a new specification where the total lumens and mounting height could be the two factors expressed. In the case of the car driver, the sudden loss of the near lamps as he passed under them can be smoothed by the employment of a grduated filter along the top of the windscreen.

The paper concludes with photographs and polar diagrams of a 500W bare lamp, refractor fitting and mirror fitting showing the important of throwing light at angles near the horizontal.

Lighting: Theory and Lighting: Distribution

Light-Actuated Control For Street Lighting p48
For many years, lights have been controlled where dusk to dawn illumination is required by selenium cells with a single valve amplifier circuit. But new circuits requiring the use of a valve have been superseded by those using a bridge. These new Radiovisor Bridge units have been installed in traffic islands on all new by-pass roads in Surrey and has since spread to all parts of the country. (For a description of the circuit, see Radiovisor.) Position of the bridge in its weatherproof housing is essential so that light from the lamps controlled do not affect it. A separate unit box (with the relay circuit) can be fixed in the base of the poles or bollards. As the control unit now includes no expendable part, a very long life can be anticipated.
Lighting: Control

Public Lighting Discussed In The House Of Commons p49
(Report of an Informative Debate from "The Times," 30th April, 1936)
Report of a debate which took place on the 29th April.
Mr Salt (Birmingham, Yardley, U.) moved the following amendment: "That, having regard to the number of road accidents that occur after dark and to the desirability of affording adequate illumination for the convenience and safety of the public and for the prevention of crime, it is expedient that the lighting of highways should be dealt with on a national basis." He said that the reason why the lighting of the roads of this country was bad was that it was controlled by 1,400 different local authorities. A tremendous number of the accidents which took place today could be avoided if better lighting were introduced. Seconded by Mr. Lyons (Leicester, E., U.) who called for the Minister Of Transport to establish some kind of central authority in the form of a centralised Highways Board to tackle the question.

Mr. Denman (Leeds, Central, Nat. Lab.) disagreed: "[I] wish to make a strong protest against spending 3,500,000 on an object which he put extremely low in the scale of national expenditure. There might be those who did not know the pleasure of walking about in the night and finding their way in the dark. Those who remembered what London was like in the air riads would know that one could then at lesat see the shape of buildings against the sky and once more realise that the God Who made day and night knew what He was doing... Anybody who drove a motor-car knew that in the present artificial lighting he wsa far less safe than in the dark. If we had this elaborate system of lighting it would simply mean that people would drive rather faster and would go up to the limit of speed. The we should have increased accidents."

Liuet.-Col J. Sandeman Allen (Birkenhead, W., U.) also mentioned how advertisement lights and signs were often mistaken for street lighting.

Captain A. Hudson, Parliamentary Secretary, Ministry of Transport (Hackney, N., U.), said that before the Government could bring before the House a scheme for the lighting of the Class 1 roads they would want to be certain that it had almost universal approval in the House. It was understood that the Final Report of The Departmental Committee on Street Lighting would be in the main an amplification of the technical recommendations made in its interim report. They hoped to have the final report next year. It had been necessary to give time for a number of experiments to take place; so that they might know the exact type of light which was suitable. The ideal which they required in the lighting of the roads was to achieve a standard which would be adequate for police purposes and allow motor vehicles to proceed at a reasonable speed without headlights, that was at a speed of 30 miles an hour. An interesting point in the report was that the committee were unable to point to any large number of accidents being caused by bad lighting, a view which had been confirmed by the Commissioner of Metropolitan Police. The committee added that lighting which was patchy was worse than no lighting at all.

The committee estimated that the cost of a system of the high standard they suggested would be between 300 and 400 a mile, and that if that standard was applied to all classified roads in county boroughs and to 20 per cent of the classified roads in counties the cost would be 3,500,000 a year.

A national standard of lighting over the whole country for the most important roads was the goal to be attained. The Government were doing their best to get towards that goal, but in view of their already genuous grants towards the maintenance of roads they did not feel at the present moment, and in present circumstances, that they could contemplate the necessary legislation to that end. He did not wish the House to think that what he had just said meant that having a national standard of lighting was being indefinitely shelved. It did not rule out the possibility of future action. In the meanwhile they must await the final report of the Departmental Committee and the results of the experiments which were being made.

He could assure the House that the Minister of Transport was fully alive to the problem of street lighting and was at present studying the whole subject with great care. The return which was now being made of all accidents involving personal injury would give a good indication as to the exact effect of bad lighting. While the Government could not promise immediate national action to set up a national lighting system for the whole country, they were endeavouring to enlarge the area as suggested by the committee and thus ensure greater uniformity. They were at prescent experimenting, but they were not prepared at the moment to bring any scheme before the House.

The amendment was, by leave, withdrawn.
Lighting: Legal, Lighting: Authority Organisation

"Supervia" Lighting In The Borough Of WandsWorth p50-p51
Detailed description of the new installation to be installed in the Borough Of Wandsworth. Supervia gas lamps (both high and low pressure) to be used throughout, and lighting levels to be between Classes "E" and "G" of the British Standard (although recommendations of the Interim Report were also followed).
Lighting: Lamps and Lighting: Installations

Sodium Lamps For Oldham p51
Description of a new sodium installation.
Lighting: Installations

Public Works, Roads And Transport Congress 1937 p51
Details of the papers competition and prizes for the congress next year.

"Rochester" Lamps On The Great West Road p51
Brief description and picture of Suggs' new installation.
Lighting: Installations

News Items p52
Brief comments on two headlines appearing in a weekly journal: Good Lighting Reduces Accidents where the Victoria Embankment accident rates from 1928 and 1930 are reported; and in Bad Lighting Increases Accidents the correspondence between the Harwich Vigilance Committee and the Electrical Engineer of the local council is quoted.
Statistics: Accident Data and Lighting: Installations

Richmond's New Public Lighting System p52
The new GEC installation in Richmond is briefly described. It includes GEC Tunbridge Wells lanterns on 25' steel columns.
Lighting: Installations

Mercury Vapour Street Lighting p52
General description of the increasing number of mercury vapour street lighting installations with details of more units being installed in Croydon. Most have been installed in shopping areas.
Lighting: Installations

Purley Way Lighting p52
Brief description of the new Purley Way sodium lighting which will replace the 1932 installation. A fuller report is promised for the next issue.
Lighting: Installations

Conference Badges p52
Special conference badges bearing the wearer's name and local authority can be purchased for the conference.
APLE: Conference

Removing Old Paint From Lamp Pillars And Metal Surfaces p53
Details of Oldham Corportation Lighting Committee patented portable sectional furnace which can be used to remove paint from old columns. It has been found to be much cheaper than blow-lamps, chemical paint removers, pneumatic chisels, scrapers, oxy-acetylene burners etc. It burns liquid fuel such as paraffin, crude oil or spent oil etc. Absorbent burner pads are fixed inside the furnace. It four to five minutes it will reduce paint up to ¼" thick to a condition where it can be easily scraped and brushed off by scrapers and wire brushes. A suitably shaped sheet metal guard is fixed to the frog to protect the lantern from the heat; this enables the work to be done without removing any fittings from the lamp pillar. The whole process can be operated by two men in 45 minutes per pillar; this includes a priming coat of paint.
APLE: Equipment

Adverts: British Commercial Gas Association, REVO Electric Co., Ltd., Foster And Pullen Ltd., William Sugg And Co., Ltd., British Foreign and Colonial Automatic Light Controlling Co., Ltd., The British Thomson-Houston Co. Ltd., Gowshall Ltd., The Horstmann Gear Co., Ltd., Simplex Electric Co., Ltd., Siemens Electric Lamps And Supplies Ltd., W. Parkinson and Co., Radiovisor Parent Ltd., South Metropolitan Gas Co., James Keith And Blackman Co., Ltd., Bromford Tube Co., Ltd., Alder And Mackay Ltd., Walter Slingsby and Co., Ltd. and The General Electric Co., Ltd.