Edward C. Lennox, M.I.E.E.
(North-Eastern Electric Supply Co., Ltd., Newcastle-Upon-Tyne)

Keywords: APLE: Organisation, Lighting: Specifications, Statistics: Accident Data, Lighting: Authority Organisation, Lighting: Theory

Tuesday, September 8th, 1936

Also published in: Public Lighting, Vol. 1, No. 3. September 1936

Abstract: Lennox splits his address into several main sections, each dealing with one of the varied aspects of the association's work over the previous year.

He describes changes within the organisation and the publication of Public Lighting and the Public Lighting Enginner as well as the forthcoming Education Scheme; the M.O.T. Interim Report is welcomed and it should obviate any delay on the part of Lighting Authorities waiting the Final Report; Lighing Engineers should use current press interest and promote new schemes; Road Accident Data (up to 1935) is analysed and the general conclusion is that if better visibility is provided during dark hours on heavy traffic routes and in built-up areas then the accident rate would decrease materially; the administraiton of lighting authorities, car headlights and the clarification of terms.

Road Accident Data

The greatest number of accidents occur:
(a) In winter months - during the hours of 5PM to 8PM
(b) In summer months - during the hours of 10PM to 11PM

Other figures indicate:
(1) The small amount of night traffic as compared with that during the day. We can assume from the figures quoted that the proportion of night to day traffic throughout the year does not exceed 33%.
(2) A large increase in night traffic during the past seven years of 81%.
Improved lighting lead to a reduction in number and severity of accidents at night despite 81% increase in traffic.

From the Survey Of Accidents 1933 the following conclusions can be drawn:
(1) Over 46% of the total accidents occuring during the winter months - although traffic as expressed in vehicle-miles is probably one half of that of summer. As the radio of accidents winter to summer is approximately 1:1, so the accident rate winter to summer is approximately 2:1 per vehicle mile, this I believe is due mainly to increased dark hours during winter months.
(2) Of the accidents which occur during winter months, 52% occur during dark hours. It is reasonable to suppose that the total vehicles on the roads during dark hours is only one-third of that during daytime, moreover the average miles per vehicle during dark hours is probably half that during daylight, so it is estimated that the figure for vehicle miles during dark hours is at most one-sixth of that during daylight hours. As the proportion of accidents dark hours to daylight hours is greater than 1:1, so the accident risk dark to daylight hours must be said to be greater than 6:1.

In America, more definite accident data is collected. In Cleveland, on a certain highway, despite the fact that traffic density at night is less than half that of day, there were twice as many fatalities by night as by day - ratio of accident risk night to day is therefore 4:1. The cost of lighting these main traffic routes has been estimated to be one-third of the present economic loss from preventable night accidents. In Detroit it was found that the ratio of night to day accidents increased from approximately 1:1 to 2:1 when lighting was curtailed by 35%. "There are approximately 50,000 miles of highway in the United States on which the night accident rate is at least six times that of the day accident rate, and on which corresponding saving can be made by the installation of safety lighting."

"By these and other considerations one is forced to the conclusion that if better visibility were provided during dark hours on heavy traffic routes and in built up areas, the accident rate would decrease materially. One feels justified in believing that the economic gain due to decrease in aciidents would more than meet the extra expenditure necessary to provide adequate public lighting."

Administration

There are too many Lighting Authorities. Parochial areas have increased average wattage by 30% in the past five years yet it is still not enough. The rateable value for street lighting is far too small; and in some cases they are paying to light main traffic routes for the benefits of non-rate payers in that area.

"The benefit [of pooling] is found in an example of a Rural aread which in 1932 adopted Urban powers under Section 161, Public Health Act, 1875, and undertook the responsibility for lighting in the 13 parishes in the area. Actually the "pooling" gave extra bargaining power to the Council, and full benefit of this was passed on to all villages by providing additional lighting points, bigger lamps and increased lighting hours."

"Until legislation is introduced which will make larger authorities the Lighting Authority, lighting in these areas [urban, ruran and parochial] will improve very slowly and certainly not with uniformity."

There are suggestions that the Road Fund should be used to fund lighting.

References:
[1] Public Lighting: Its Necessity and Administration, E. C. Lennox, A.M.I.E.E., Public Works, Roads and Transport Congress (1935).
[2] MOT Interim Report 1935
[3] Ministry Of Transport, Traffic Census, August 1928
[4] Ministry Of Transport, Traffic Census, August 1930
[5] Ministry Of Transport, Traffic Census, August 1935
[6] Survey Of Accidents, 1933
[7] Ministry Of Transport, Report On Fatal Road Accidents (1935), August 1936

Alderman W. E. Wilford, J.P.
(Chairman, Watch Committee, Leicester)

Keywords: Lighting: Specifications, Lighting: Authority Organisation

Tuesday, September 8th, 1936

Abstract: Wilford agrees with practically the whole of the conclusions recommended in the Interim Report but concentrates almost solely on how continuous, uniform and efficient lighting on main traffic routes can be acheived through a reform of the present methods of administration.

References:
[1] MOT Interim Report 1935

Professor Ir. G. B. v. d. Werfhorst
(University of Utrecht)

Keywords: Lighting: Authority Organisation, Lighting: Distribution, Lighting: Theory, Lighting: Luminaires, Lighting: Glare, Lighting: Levels, Lighting: Lamps, Lighting: Installations

Tuesday, September 8th, 1936

Abstract: Werfhorst describes the organisation of street lighting in Belgium and the rapid changes about to happen due to the new thinking about optical design and the number of new lamp types available.

He notes how "horizontal illumination" or "uniform distribution" theory has been discarded for "good brightness" and "no dazzle." Example luminaries are illustrated – the "globe-band" and "screened concentrating reflector" - and their use in two different scenarios are described.

A major portion of the paper is devoted to analysing the effects of contrast under scotopic and photopic lighting conditions for mercury, sodium and white light. He develops the concept of "apparent brightness" and "richness in contrast" to support the use of sodium for arterial roads under low lighting conditions. The theory rests upon the idea that portions of the field-of-view are viewed photopically and others scotopically at the same time.

The introduction of the new high-pressure mercury lamp is described along with an example installation.

Luminaires: Philips Philulex N.A., Philips Philulex N.D.

References:
[1] Modern Street Lighting, C. C. Paterson, J.I.E. Journal, January 1935.
[2] De Ingenieur, Bouma, BD 290-294, 1934.
[3] Light Und Lampe, Konig, 23, 131, 1934.
[4] Lecture, Dr. Jhr. v. Lennep, Utrecht, February 1936.
[5] The Importance Of Kinematical Factors Of Roadway Illumination, L. J. Davis, M.A., B.Sc.; R. Maxted, B.E. (Elect.), B.E. (Mech.); G. S. Lucas, M.I.E.E., A.P.L.E., 1935

(Note: Originally called Street Lighting Practice In Holland and described as a "short paper." See Public Lighting #2.)

Mr. William J. Gilchrist Davey, B.Sc. (Elm Works Ltd) and A. R. McGibbon, A.M.I.E.E.

Keywords: Lighting: Luminaires, Lighting: Specifications, Lighting: Theory, Lighting: Installations

Wednesday, September 9th, 1936

Also published in: Public Lighting, Vol. 2, No. 5. March 1937

Abstract: "There has been a tendency in past years, especially in papers relating to gas for street lighting, to describe lighting units rather than installations. It is proposed in this paper to give prominence to installations, and to demonstrate by means of street lighting schemes, actually in operation or in course of completion, what can be done in the effective lighting of streets."

"It is hoped to present a plain, unvarnished statement of fact, and to avoid, if possible, any expression of opinion unpon theoretical questions which may give rise to fruitless controversy, but the description of street lighting installations should be prefaced by certain conclusions about the broader field of general street lighting."

The authors discuss their views on the British Standard Specification and the Interim Report by the MOT, the influence of mounting height on illumination and how the move to 25' is not very adventageous, planning the district diversity factor and the use of iso-foot-candle diagrams as the preferred method of presenting and studying installations. They then classifiy various types of gas lantern before presenting 19 modern gas street lighting installations.

Luminaires: Parkinson Warwick Square, Sugg Windsor, Sugg Rochester, Parkinson Stechford, Sugg London B/2, Sugg London C and Parkinson Maxill.

References:
[1] The Planning of Gas Installations to Conform with the British Standard Specification for Street Lighting, F. C. Smith, A.P.L.E., 1932
[2] Retention of Gas for Public Lighting, Davey, Gas Times, 3/9/1935
[3] An Analysis of Modern Views on Street Lighting and their Relation to Visibility, F. C. Smith and K. F. Sawyer, A.P.L.E., 1935
[4] Photographic Representation of Street Lighting Installations, Vol I., No. 2, Trans I.E.S.
[5] MOT Interim Report 1935

(Note: This paper replaced Gas Street Lighting Units which was to be given by Mr. Philip Sugg. See Public Lighting #2.)

W. J. Jones, M.Sc., M.I.E.E.
(Manager, E.L.M.A. Lighting Service Bureau)

Keywords: Lighting: Installations, Lighting: Lamps, Lighting: Levels, Statistics: Road Data

Wednesday, September 9th, 1936

Abstract: "With the greater availability of electricity supply and the vast improvements in the efficiency of electric light sources, it is evident that phenomenal extensions in electric street lighting have been made during recent years. The public gain by obtaining an improved standard of street lighting, with due regard to the economies affecting public expenditure."

Jones sums up the progress of electric street lighting by summarising the events of the last 25 years. He singles out increased mounting heights, the increase of road traffic and electric lighting costs, improvements in electric lamps (from carbon through to electric discharge), the group replacement of lamps, improvements in electric discharge lighting, the classification of road types, examples of modern installations and finally the situation in Europe.

References:
[1] The High-Pressure Mercury Vapour Lamp in Public Lighting, G. H. Wilson, B.Sc. (Eng), E. L. Damant, Lieut.-Commander R.N. (Retd), Associate Member, J. M. Waldram, B.Sc. (Eng), I.E.E., 4th February 1936
[2] The Physical Characteristics of Electric Discharge Lamps, L. J. Davies, M.A., B.Sc., ???, ???
[3] Some further Aspects in Gases and Vapours of Electric Discharge, J. N. Aldington, Engineering Supplement to the Siemens Magazine, No. 131, April 1936.
[4] Electric Discharge Lamps, William Rule, M.Sc., F.Inst.P, ???, December 1935.

(Note: Originally called Progress In Electric Street Lighting. See Public Lighting #2.)

H. W. Gregory, M.I.E.E continued the discussion in Public Lighting #3.

F. C. Smith, F.C.S., Assoc. M.Inst.G.E., K. F. Sawyer, B.Sc. and D. G. Winslow

Keywords: Lighting: Distribution, Lighting: Installations, Lighting: Theory

Wednesday, September 9th, 1936

Abstract: "Much has been said and written from time to time about the lighting requirements of the rodaway and how these may be met in practice; but little attention, so far as the authors are aware, has been given to ensuring that the margins of the roadway are suitably and clearly defined. In this paper an account is given of some preliminary work on the investigation of this problem both from the theoretical and practical aspects."

(Note: This paper replaced a short paper called Some Further Aspects Of The Street Lighting Problem which was to be given by Mr. C. A. Masterman. See Public Lighting #2.)

J. N. Aldington, B.Sc., A.I.C.
(Of the Laboratories of Siemens Electric Lamps and Supplies, Limited, Preston, Lancs.)

Keywords: Lighting: Lamps

Thursday, September 10th, 1936

Also published in: Public Lighting, Vol. 1, No. 4. December 1936

Abstract: Aldington summarises the current research into the mercury discharge lamp. He firstly discusses the current range of lamps (150W, 250W and 400W) before describing current research: colour modulated high pressure discharge lamps (by additives to the mercury), the development of the Dual Lamp, the improvement of the mercury discharge by using quartz discharge tubes, air cooled quartz discharge tubes (including a 100W experimental lamp), the effect of pressure on the mercury discharge lamp, colour modulation by means of fluorescent substances, combinations of quartz lamps and incandescent lamps, and super high pressure mercury lamps. This paper provides the groundwork for many of the commerical lamps which would appear the following year.

References:
[1] Electric Discharge Lamps and their Application to Public Lighting, G. H. Wilson, B.Sc. (Eng), A.P.L.E., September 1933
[2] Electric Discharge Lamps. J. W. Ryde Journal of the Royal Society of Arts. Vol. 82.
[3] Electric Discharge Lamps and their Application to Road Lighting, L. J. Davis and H. Warren, Institution of Automobile Engineers, February 1936
[4] The High-Pressure Mercury Vapour Lamp in Public Lighting, G. H. Wilson, B.Sc. (Eng), E. L. Damant, Lieut.-Commander R.N. (Retd), Associate Member, J. M. Waldram, B.Sc. (Eng), I.E.E., 4th February 1936
[5] Some Recent Developments in the Electric Lamp, J. N. Aldington, Association of Engineers, Belfast, 5th February 1936.
[6] Some Further Aspects of the Electrical Discharge in Gases and Vapours, J. N. Aldington, Engineering Supplement to the Siemens Magazine, No. 131, April 1936.

(Note: This paper replaced Recent Developments Of The Electric Discharge Lamps which was to be given by Mr. C. Hughes. See Public Lighting #2.)