mailing list
site map

ilp archive : journals

public lighting no. 37 vol. 10
April-June 1945

Editorial p41
"Look To Your Lights" p41
Description of a booklet issued by the British Electrical Development Association. The cover features children looking at a modern stret light - a generation is growing up who have never seen real street lighting.
Lighting: Publications

"Better Lights For Bigger Traffic" p41
With the re-introduction of the basic petrol ration, the question of motor-congested roads will again be a problem. In 1939, there were 70 licensed motor vehicles to every mile of classified road in the country. And the average daily increase in vehicles was nearly 500. To counteract the mounting toll of accidents, street lighting was being installed at the rate of 1000 miles per year. "The night/day ratio risk of accident is over 20/1. No cheaper insurance against cost of lives and money wasted in accidents during dark hours can be found than in adequate street lighting. This can be provided at a cost very much less than the cost of accidents it is calculated to save"
Lighting: Funding, Lighting: Statistics

Spend Public Money On Public Safety p41
Good street lighting will show a return in saving of life and public material and loss of working hours of not less that 5 times the cost of its provision and maintenance.
Lighting: Statistics

July 15th p41
With the conclusion of double-summer time, authority is given for normal street lighting to be re-introduced.
Lighting: ARP

The Glasgow Conference p41
The Conference Of Public Lighting Engineers is to be held in September at Glagow. It will be limited to three days.
APLE: Conference

A Full Programme p41
There will be a full programme of papers, demonstrations of Glasgow's centrally controlled street lighting system, and an exhibition of street lighting equipment by well-known manufacturers.
APLE: Conference

Obituary p42
Obituaries of William Batt, M.Inst.G.E. (Distribution Engineer, Newcastle And Gateshead Gas Co.) and R. M. Harvey (Inspector Of Public Lighting, Greenock).
Lighting: Personnel

Poplar Borough Council p42
Details of new installation
Lighting: Installations

The Brighton Lighting And Electrical Engineering Company: Appointment Of New Director p42
Mr. Ernest Stroud (President of the Illuminating Engineering Society) after 30 years service at Holophane Limited has joined BLEECO as Technical Director.
Lighting: Manufacturers, Lighting: Personnel

Society Of Engineers p42
Mr. Parfett, in his Presidential Address to the Society, suggested that road and street lighting, both main and secondary, should be so illuminated that indvidual lighting on road vehicles would be unnecessary and merely reserved for minor roads.
Lighting: Future, Lighting: Theory

American Highways After The War p42
In a recent issue of The Scientific Amercian, Mr. V. T. Broughton says it is too early to predict what highway lighting developments after the war will be, because of the strides made in Fluorescent Lighting, will make wider use of this type of lighting after the war. Experiments are being conducted by the California Division of Highways that promise to provide a novel method of lighting the sidewalks and roadways of bridges. The plan is the installation of a continuous line of reflectors on the hand rails form which concealed sources of light will emanate their rays. So the lights will not shine into the eyes of motor drivers but will give maximum illumination on teh sidewalks and at the edges of the roadway. It is anticipated that the most economical source of light will be luminous tubes mounted horizontally in a position of maximum security and protection beneath the hand rails.
Lighting: Future, Lighting: Installations, Lighting:Lamps, Lighting: Theory

Street Lantern Designs p43
Showcase of designs from Metro-Vick:
Trafford, Aldwych, Ealing, Gower, Urmston and Poplar.
Lighting: Future, Lighting: Luminaires

The Need For More Uniformity In Street Lighting p47
In the House Of Commons recently, a question was addressed to the Parliamentary Secretary of the Minister of War Transport asking "whether he indended all roads in the post-war years to have standard and uniform lighting, and would he see that a typical specification was issued to ensure this result?" Mr. Noel-Baker, in his reply, stated that the Ministry had no "power to require highways authorities to light main roads." He went on to state "he hoped that the standards proposed in the report of the Departmental Committee on Street Lighting will be generally adopted after the war by competent lighting authorities."
The Member who raised the question was unaware of the limited powers of Parliament over the lighting and maintenance of highways. Public Lighting is, in the main, the prerogative of local authorities.
It is true under the Trunk Roads Act of 1936, no less than 4459 miles of trunk roads were transferred to the Ministry Of Transport and his department became responsible for the maintenance and upkeep of these main highways - but it did not include lighting. There was no call for the lighting of such roadways as they were mostly in open country. Where such highways passed through a built up area, it became the responsibility of the local authority.
However this is a matter that must be dealt with in the post-war period, namely the question of defining and setting up a standard of uniformity for street lighting.
In the last few months some striking examples of a lack of uniformity has been seen in many districts and the Press comment has been very outspoken on the mater. This condition, especially in London, has to be excused, being the direct result of war-time measures. Many complaints have already reached the appropiate authorities, pointing out that as a direct result of roads being lighted in varying degrees of brightness, a number of serious accidents occurred to both pedestrians and drivers of vehicles.

Uniform Street Lighting, a necessity
In the post-war period, the question of uniformity will have to be faced. In London, with its many lighting authorities, each adjoining one another right up to their respective administrative boundaries, there are not only these different systems of street lighting, but there exists a certain amount of rivalry between authorities to go one better than its neighbour, with the obvious result that in some areas the constrast is very marked and pronounced. This should not be so.

The M.O.T. Departmental Report
If the report was followed then it would produce highly satisfactory street lighting for all who use the highway and produce the uniformity which is so desirable, both for the comfort to the driver and the safety of the pedestrian. The report concludes: "The present system of administration is not conductive to the achievement of uniform and effective lighting on traffic routes." If there existed better working arrangement between local authorities, so that before any change of lighting was contemplated, a conference took place between adjoining authorities, it would be a step forward. Also the MOT could give guidance in the matter.
Lighting: Authority Organisation, Lighting: Legal, Lighting: Specifications

A.P.L.E. Conference p48
The first post-war Conference of the Association of Public Lighting Engineerings will be held in Glasgow from Tuesday 11th September to Thursday 13th. Apart from the fact that the conference will celebrate the 21st anniversary of the formation of the Association, it is the first post-war gathering of its kind, and is actually the postponed Conference of 1939.
APLE: Conference

Control Of Street Lighting by A. Stephenson p49
The systems in use are:
Manual Control
Groups of street lights controlled by hand from a local switch pillar or substation. Works for smaller urban and suburban areas. In larger areas becomes uneconomical as the running costs are relatively high when compared with other control schemes.

Time Switches
Used widely. This has allowed authorities to amass considerable economic and operational data which shows that low capital costs tend to be offset by the inherent disadvantages of this type of switch and the high maintenance costs. The standard switch does not allow for the changing hours of darkness and although switches are available with automatic compensation (using "astronomical" or "solar" dials) their cost is higher and they do not operate when unexpected dark periods brought by various causes i.e. fog, occur during the day.

Photo Electric Relays
Operates as a result of changes of light independent of fixed times and in rural and certain suburban areas has proved quite successful. The change in current produced by the photoelectric cell from a change in light value is amplified by valves to operate an auxiliary relay. The deterioration of emission of the thermionic valves and the need for a clean "window" for reliable operation usually results in frequent maintenance. To avoid chattering the simple type has a "spread" between on the ON and OFF periods which results in lamps being switched on or switched off later than is necessary. A typical photoelectric relay has two controls arranged to set the relay to switch on or off at independently adjustable intensities of light; from 0.2 to 10 foot candles. The cell is inclined at 45 per cent. to minimise the collection of dirt, and to obtain a greater exposure to the open sky. Effective operation depends on the cleanliness of the window and on shielding the cell from unwanted light.

Superposed D.C. Systems Using Polarised Relays
A D.C. voltage of given polarity is superposed on the A.C. lamp supply or distribution network, ususally by interposing a battery between the star point and earth or an earthed neutral system; this voltage actuates a polarised motor or telephone type relay arranged to open or close the supply to the lamp; when the polarity is reversed the opposite switching happens. Polarised motors tend to be expensive when compared with the relays used with open of the other superposed audio-frequency systems.

Cascade System For Constant Current and Constant Current Installation
When lamps are connected in series for constant current operation, it's possible to include a small current-operated instantaneous relay, connected in circuit remote from the "feeding" end. When this loop is energised, the relay makes contact to energise the second loop through its associated constant current transformer; further relays are incldued in the cascade of loops in operation. The system has the disadvantage that an open-circuit in any one loop caused succeeding loops to be de-energised until the fault is cleared. Subsidiary loops may be taken from one master loop. System used extensively in the U.S.A. Can also be used for parallel-connected lamps (constant voltage operation).

High Frequency Carrier Systems
High frequency current is injected into the supply network and detected by suitable receivers which directly control the lamps. The frequency is above audible range and of low radiation characteristic. Radiation commences with frequencies of the order of 10,000 to 12,000 cycles per second, but higher frequencies may be used under certain circumstances. The high frequency current is injected in trains of waves, and the receivers are responsive to the injected frequency for a certain duration. Thus to operate the receiver to open and close circuit, two injected trains of waves oo the same frequency but of different durations are necessary. Teh system is flexible, allows for convenient centralised control and is unaffected by surges, lightning or stray currents. Both injection and receiving equipment is costly.

Pilot Wire Systems
If pilots are available the system has few drawbacks. Local voltage-operated relays energised by a main control switch are used to switch the lamps; the main control switch can be operated by hand or means of time switch or photo-electric control. Pilot wires are expensive to install and the system is not flexible; capital costs cannot be recovered by using the control system for other services. A fault in the pilot will of course cause relays to be inoperative. The system requires pilot wires and relays to be continuously energised during either the day or the night period, unless a notching device is fitted to each relay.

Audio Frequency Carrier Systems
These are now receiving considerable attention in this country. Audio-frequency oscillations of the order of 300 to 1500 cycles per second are injected into the supply network, and are detected locally by means of a suitable relay. Unlike the relays used in high frequency carrier systems, where detection results from the duration of the signal, the relays in audio-frequency are either: tuned to a selected frequency only; or to a series of pulses of a selected frequency. The relays are relatively cheap, can be used for the control of each lamp, are small enough to be mounted in the base of a lamp standard, and do not require frequency maintenance since there are few moving parts. The capital cost of the injection equipment is offset by the flexibility of the system since it can be used to control off-peak loads: lighting of telephone kiosks, shopping window lights etc. There are two types of relay being the galvanomenter type and the vibrating reed type. The injection equipments are similar for all schemes.
Injection of Ripple Frequency
This presents many problems which are still being solved: loss of signal current, distribution of the signal over wide areas, and limitation of the signal to the required areas. The required current is generated by a variable or fixed frequency generator. On systems where relays are coded by frequency alone, a variable speed ripple current generator is used driven by a DC motor - the motor being driven by a frequency relay. When relays are coded by frequency and time, a single frequency ripple-generator is used driven by an induction motor and contractors inject pulses of the ripple current into the network.

Galvanometer Type Relay
Operates on the product of frequency and tim and consists of a bar magnet fixed to a shaft and allowed to swing in the field of a surrounding coil. This magnet is arranged that it acts as a pendulum. When ripple current is injected, it is selected by a tuned circuit with aperiodic coupling. The ripple current induced in the secondary of the coupling is rectified and applied to the coil surrounding the bar magnet in the form of a series of DC pulses - these cause the magnet to swing with increasing amplitude until the contact on the shaft makes with a fixed contact on the frame (about 7 to 10 pulses are requird). These contacts energise the coil of an auxiliary polarized relay arranged to lock itself in the energised position - contacts on these then complete the external circuit. A similar element but with a magnet assembly having a different time constant is used to reverse the action of the polarized relay.

Reed Type Relay With Differential Cage
Has a reed secured at one end with a pawl fitted to the other. The reed is arranged to lie in the field of a permanent magnet and a coil surrounds the free end of the reed. The coil is tuned by means of a condenser to the required operating ripple frequency. The pawl attached to the free end of the reed is arranged to drive one planet wheel of a differential cage, the other planet reel being driven by a second reed assembly. The satellite or crown reel of the differential cage is fixed to a shaft so that it is driven round in one direction or other by the planet wheels. This movement is translated through gears to a mercury switch which controls the external circuit. When the ripple frequency is injected into the supply network, and the relay is connected in the normal way across the phase and neutral, the resonant circuit consisting of a reed coil and condenser connected in series builds up an alternating magnetic field acround the free end of the redd causing the soft iron reed to vibrate in sympathy. As the reed vibrates it ratchets its associated planet wheel and causes the relay to operate.

Reed Type Relay With Bouncing Circuit
There are no moving ratchets, wheels or swinging magnets. The design is such to give long life and low maintenance. The "Ripplay" Relay consists of a soft iron reed clamped to a heavy base. The reed is polarized by a permanent magnet and the exciting coil surrounds the free end of the reed. Resting on the reed near the root is a bouncing contact which is arranged to short-circuit the heating coil of a thermal relay which is connected across the supply in series with a choke. It is so arranged that a second reed assembly causes the thermal switch to reverse its operation. Once the thermal relay has operated to close contact it is locked in the closed position until the next operation.

Where the Authority concerned has facilities available to control a portion of the total connected load, at the moment that load is about to exceed the maximum demand of the system, it will be apparent that by decreasing the load at that moment by means of a centralised control system, a monetary penalty of possibly considerable magnitude will have been escpaed without interruption to the supply to the more important industrial and domestic demands.

With a suitable tariff amendment, domestic consumers may not be averse to the possible interruption, or reduction to the supply for water-heating during peak load hours, which may only amount to an hour or so during the year. The ability to control such demands may quickly recover the initial cost of the control installation.
Lighting: Control

Developments In The Gas Industry p52
Papers prepared for the Annual General Meeting of The Institution Of Gas Engineers are concerned with various aspects of post-war planning: the provision of staff, the organisation and application of research, and the design and fitting of gas appliances in post-war houses. Greater recognition has been given to the Junior Gas Associations.
The Gas Industry is expecting a great deal from the work of the Gas Research Board. The Director of Research has put together comprehensive ideas how the Board is likely to be organized.
The Institution, at the instance of Lord Reith, convented a Gas Installations Committee to set out the best installation practice.

Patents In America And Canada by S. T. Madeley p53
Details on how the British, American and Canadian patent systems are operating during the war years.

Street Lighting Records At The Liverpool Gas Company by T. A. Crabtree A.C.I.S. p54
Records kepted for recording and charging for the gas consumed by public lamps. The company supplies gas for 25,000 lamps. Variable factors involved in the charge had to be considered. Also gas was supplied to seven local Authorities who each had a normal standard schedule of hours, which varied from week to week, and there was also the variable range of consumption per lamp.
A record of the total number of lamps lighted in each street was kept, primarily to settle any queries involved in our charge, and secondly to have a schedule of the whole of the lamps in street order so that the Company's Inspectors may take a visible spot check and prove the correctness of the charge.
There was also the date on which any lamp was lighted or discontinued.
The general method of charging for the gas supplied is: Number of days, number of hours lit per day, consumption of lamp per hour in cubic feet, and total number of lamps in the category. This is then converted to therms and evaluated.
All the data is stored on punched cards.
Lighting: Equipment, Lighting: Maintenance, Lighting: Management, Lighting: Statistics

Bradford's VE Illuminations p55
Last Autumn, the Bradford Electricity Department made a start on the design of simple, but topical, illuminations, for VE day. Fuel, labour and materials had to be conserved so it was only possible to cover features of special interest: The Town Hall, the Department's Power Station and Head Office. It created a great deal of local enthusiasm. The Town Hall was decorated with the head of Mr. Churchill with his big cigar - it took 900 lamps and the two wings measured approximately 60 ft. by 30 ft. The Cathedral, Royal Infirmary and Cenotaph were also floodlit - using multiple 1000W units. It is hoped to celebrate VJ day in a similar manner.
Lighting: Events, Lighting: Floodlighting

Personalia p55
Nottingham - Mr. E. Howard appointed as Lighting Engineer of the City from Lighting Superintendent.
Uxbridge - Mr. Howard E. G. Stripp, Borough Engineer and Surveyor of Beddington and Wallington has been appointed deputy to the Uxbridge U.D.C.
Bolton - Mr Morrison, Public Lighting Superintendent, states that since lamps were relighted three months ago, the works of the Department have been handicapped by 365 panes of glass hving been broken.
Southampton - Mr. F. L. Wooldridge has been appointed Borough Engineer and Surveyor of Southampton.
Lighting: Personnel

Street Lighting Notes p55
The Metropolitan Boroughs Standing Joint Committee, after negotiations with the London County Council and the Ministry of Town and County Planning, have reached agreement safeguarding the interests of the borough councils, which were not covered in the Town Planning Act, among such, the control of new roads constructed by the County Council to devolve upon the Borough Council: for the maintenace of uniform type of surface; the maintenance of uniform type of surface; and the lighting of roads traversing more than one borough.
Lighting: Authority Organisation

The Electrical Engineer of Bedford, Mr. P. G. Campling, in a report to The Highways Committee of the Bedford Corporation, suggests that all future Group B lamp standards should be concrete: the existing cast iron columns are shattered during collisions constituting a grave risk to pedestrians; steel cannot be purchased at the current time; but concrete posts are obtainable. The capital cost is higher than cast iron, but they do not require painting, thus reducing maintenance costs. The Committee recommended the use of concrete posts in the future.
Lighting: Materials

Letter to The Daily Telegraph suggesting that lamp posts should have a light at the foot to be switched on to guide drivers in foggy weather. It would be good if all street lighting was near the ground. We do not need light at chimney-pot level.
Lighting: Weather

Street Lighting Fuse Box p56
Details of Siemens Electric Lamps & Supplies Ltd fuse box 1860.
Lighting: Lamp Auxiliaries

Annual Conference p56
Preliminary Programme for the forthcoming APLE 1945 Conference.
APLE: Conference

Daylight And Its Penetration Into The Sea by Dr. W. R. G. Atkins, O.B.E., F.R.C p57
Summary of photometers, measuring sunlight illumination and measuring submarine illumination and plant/life activity.

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, Brighton Lighting and Electrical Engineering Co. Ltd, The British Thomson-Houston Co. Ltd., The Horstmann Gear Co., Ltd., Falk, Stadelmann Co., Ltd., Automatic Telephone And Electrical Co., Ltd., William Sugg And Co., Ltd., Foster And Pullen Ltd., Hobbs, Offen and Co., Ltd., Sordoviso Switchgear Ltd., British, Foreign And Colonial Automatic Light Controlling Co., Ltd., Girlings Ferro-Concrete Co. Ltd, Sangamo Weston Ltd. and The General Electric Co., Ltd.