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ilp archive : journals

public lighting no. 29 vol. 8
April-June 1943

Editorial p21
Lamp Columns Again p21
Too much emphasis cannot be placed upon the need to keep all street lighting equipment in first-clas order and condition. This is the policy of the Journal and the A.P.L.E. Public Lighting is definitely a service of outstanding importance. From the lack of it, the public have been made aware of its usefulness.
Lighting: ARP

High Mountings In Texas p21
A young pilot officer, who attended the last A.P.L.E. Conference, and now serving as an instructor with the U.S. Air Corps, flew recently over Austin, the capital of Texas. He was very struck with the lighting of the City and few to Austin Airfield to meet with the Lighting Engineer Of The City. He was interested in the series of tall lamp standards that are "dotted" around the city area from which the main street lighting is obtained. Mr. Walter E. Seaholm, of the city of Austin, has given a brief description of these "lighting towers". Now fresh arguments for high mountings are being made, some useful data should be available from Austin.
Lighting: Installations

Tower Wagon - A Court Finding p21
Summary of a claim by two linesmen against the Manchester Corporation for injuries following an electric shock whilst working on a tower wagon which, the plaintiffs maintained, was imperfectly insulated. It was proved that the Corporation was not at fault and the tower wagon, whilst not being modern, complied with safety requirements.
Lighting: Legal

New Members To The A.P.L.E. p21
Membership of the Association of Public Lighting Engineers has increased very considerably in recent months. The Association is now embracing in its membership most of the principle towns and lighting authorities in the country.
APLE: Organisation

"Starlight" Street Lighting p21
The Ministry of Home Security, after consultation with the Ministries of War Transport and Fuel and Power, has stated that "starlight" street lighting should be extinguished during daytime whereever possible to save fuel. Some "starlight" lighting cannot be switched on and off day by day. In view of its low fuel consumption and its great contribution to road safety, the authorities have decided that such lighting should be retained during most of the year; but they consider that it should be turned out altogether from May 1st to August 14th. It is estimated that this would mean a saving of nearly 40,000 tons of coal.
Lighting: ARP

Linesman's Claim Fails p22
In an unsuccessful action at Manchester Assizes, William Norman Winterbottom, overhead linesman, claimed damages from the Manchester Corporation for injuries following an electric shock. In May 1942, Winterbottom and another linesman called Sutton, were adjusting an electric wire. Sutton was on the platform of a tower-wagon which was wet due to the weather. He was handling a live wire and Winterbottom recevied a shock while climbing the tower. He fell and substained a fracture of the left elbow and other injuries. It was alleged that the wagon was an old one which had been much repaired with iron and that it provided imperfect insultation when wet. Winterbottom was wearing rubber roots but not gloves. Sutton stated he was relying on the platform to provide insulation.
Mr. Justice Stable said although the tower-wagon was not a modern one it complied with safety standards. The men were provided with rubber gloves and boots. Due to the weather, the men were working inside the depot, after a morning outside in the pouring rain. No specific fault was attributed by the plaintiff against Manchester Corporation: he simply asserted that the tower-wagon was "not made safe".
Lighting: Legal

Lateral Street Lighting After The War by Francis F. Middleton, F.I.E.S. p21
In the last issue, Mr. Sandeman pleaded for the production of specially designed or adapted lanterns with a candlepower emission at various angles varied so that equal eye disturbance is caused for different points of view. There are many arguments for and against each of the main systems of lighting prevalent before the war, and it is a very bold claim that this is the best distribution to aim at.
It is usual for objects which have to be seen and negotiated in street lighting to be in dark contrast against a lighter background. It is the lighting engineer's task to produce this background.
The motorist is the fastest moving unit in traffic and at 30 miles per hour requries upwards of two seconds to bring his vehicle to a standstill. To ensure the safe performance of this duty, the driver should have a perfectly clear view of an pedestrian, as well as other objects, from at least 200 feet distance.
On a straight, level road, 30 feet wide, the kerb lines appear to the motorist to converge to a point in the distance. The pedestrian, as seen by night buy the motorist, is not in complete silhouette against this view of the road until he has moved in line with the converging point.
The apparent area of this pedestrian will comprise only about 2000th part of the motorist's feild of view at 200 feet distance, while the road beyond him will comprise a 140th part of the same view, and the pedestrian's silhouette would obscure a fourteenth part of the road converging to the point at infinity.
For this reason the apparent area of the road should be supplememnted by an illuminated area of pavement or verge on each side of the roadway, so that the pedestrian is in silhouette against the lighter background thus formed, for such distance from the kerb that the motorist can clearly see and anticipate the pedestrian's intentions with ample time to take avoiding action.
The bright streaks produced by the type of distribution favoured by Mr. Sandeman would fail entirely to produce this essential background to the pedestrian situated on the pavement. Neglect to provide the same type of backgrounds on the pavements will tend to induce that sense of false security and the frequent expression that a pedestrian appeared from nowhere.
It is from this reasoning preferable that streaks of brightness should extend well across the road and pavement and not along the road only in streaks, for pedestrians are of sufficient height to cross several lateral streaks and be clearly seen, whereas with longitudinal streaks he frequently annot be seen when passing between them.
Lighting: Distribution, Lighting: Theory

Centralized Lighting Control p23
The Ripplay system of centralised control, developed by Metropolitan Vickers, affords a means of switching, from one point, large numbers of individual pieces of apparatus connected to all parts of a distribution system. It appeals to those electricity supply authorities who wish to exercise, for the purpose of load-levelling, control of certain classes of load, such as water-heaters and space-heaters.
This system is suitable also for controlling street lighting units, air-raid warnings and so on. All apparatus of one or several kinds can be switched on by one signal or can be divided into groups each responsibe to a different signal.
For street lighting, this system comprises a cental ripple injecting plant, which takes the form of a motor-driven high frequency generator, the output injected into the power system through static condensers connected to the H.V. busbars, either directly or through a coupling transformer. At each of the street lights, or a section of street lights, a Ripplay switch is required. This switch is suitable for making and breaking up to 5A (inductive) and 15A (non-inductive) at 400V D.C.
In the Ripplay system, a tuned relay on each controlled device is actuated by means of a high-frequency ripple superimposed simultaneously on the three phases of the 50-cycle H.V. supply to the network. The ripple passes through all stepdown transformers to the low-voltage circuits.
THe ripple-injecting equipment is connected to the distributing system at one point only, and its application calls for no alteration to an existing network.
The ripple is generated in a motor-driven high frequency generator which is connected directly in parallel with the 50-cycle high voltage busbars through a suitable three-phase coupling circuit. The frequency of the ripple is variable in steps over a range of 400 to 1000 cycles per second. This waveband has been carefully chosen to avoid interference.
The Ripplay Switch, which constitutes the receiving device, enables it to be operated at an extremely small voltage - about 1/4 volt at thre relay terminals. As a result, the ripple generator required is of very modest output i.e. 15 to 20 kW. Each switch is designed to respond to two separate high frequencies, which respectively open and close the circuit through the controlled device. A large number of different signals can be accommodated within the limits of the standard wave-band. It contains no clockwork or wheels - it has two carefully tuned reeds, one for the opening signal and one for the closing signal.
Had such a system been universal among all lighting authoritiess at the present time, it is quite possible that a more generous degree of war-time street lighting would have been made possible.
Lighting: ARP, Lighting: Control

Before And After p24
Pictures of a factory, lit by pre-war tungsten lighting, and war-time fluorescent lighting. It was installed by Siemens Electric Lamps and Supplies using Sieray fluorescent tubes.
Lighting: Lamps, Lighting: Installations

Austin - Texas - USA by Walter E. Seaholm, Supt. of Utilities, City Of Austin p25
The city has converted its historic lighting towers to modern mercury vapour lighting. The towers are 165 feet tall steel skeletons and dot the entire city.
It is hard to understand what these towers contribute to the street lighting which is modern and complete. In a cyclone some years ago, one tower was blown down. The city replaced the tower with 30 street lights but the residents signed a petition to replace the tower - it was signed by persons residing four miles away who claimed they could read a newspaper by the light of the tower. The original manufacturer's guarantee was :"We guarantee that with an ordinary pocket watch you will be able to read the time on the darkest night within a circle of 3,000 feet, using the base of the tower as the centre of the circle."
The towers have been in use since 1895, first lit by six carbon arcs, to give general street illumination. They initially cost $50,000 and 31 towers were erected. All but two are still in service. With the introduction of modern type street lighting, that has been constantly installed, these towers continue today.
Incandescent lamps replaced the carbon arcs. Then, as part of the Texas Centennial, the towers were converted to mercury vapour. The demonstration tower was lit on 6th May, 1936, exactly 41 years to the day when the first tower was lit with carbon arcs.
Westinghouse reactor-capacitor units and minor parts were all that was required to convert the towers to mercury vapour. This gives twice the amount of light for the same electrical energy. All 29 towers now have six 400W mercury lamps. The general effect is of a very bright moonlit street.
Police records show that the percentage of burglarised homes in the vicinity of the towers is negligible. The safety factor, both to homes and pedestrians, has been greatly increased with the new mercury vapour lamps.
Lighting: Installations

Should Lamp-Columns Be Scrapped? by "A. Maple" p26
"They stand gaunt, bare and useless." So, spoke a Councillor recently, but his words didn't carry sufficient argument, and so the resolution was turned down. To call the columns "useless" is foolishness indeed. To maintain these columns, and all the fitments belonging to them, in good and first-class condition, and made ready for service, is the first and chief duty of every street lighting engineer. Did the councillor consider: the small amount of metal obtained from a street lighting columm?; the amount of capital expenditure locked up in those columns and compare with the scrap value of 25s per ton?; did he give any through to labour charges for up-rooting, carting and making good?; the increased costs for purchasing new equipment and reinstalling at a later date?
The officials at Whitehall have intimated that there is no call for the destruction of street light columns.
There is an urgent need for conserving and preserving our apparatus and equipment. Money should be voted and spent in preparing now for post-war days.
Lighting: ARP

The N.I.C. - Report Of Annual Meeting p26
The Annual Meeting of the National Illumination Committee was held on March 9th, 1943. Summary of meeting including financial report and British Standard Specifications issued.

Fifty Candles On The Working Plane p27
By British Standards, this class of illumination may be classed as unusually high. This is achieved in a new building of 35,000 square feet which will be devoted to the manufacture of small and very intricate mechanisms, lit by Osram fluorescent tubes. It used the Osram T.T. (Twin Tube) circuit with pairs of tubes in continuous troughing and mounted 10ft. above the flour. (The T.T. circuit is not more complicated, and the cost is not increased, it gives unity power and it almost eliminates stroboscopic effects). It has twenty continuous rows of twenty-two units, each using two 80W Osram tubes. No diversity factor is present, there is no glare, there is perfect diffusion and no shadows.
Lighting: Lamps, Lighting: Installations

New Members Elected To The A.P.L.E. p27
List of new members elected.
Lighting: Personnel

Lamp Columns For Sale p28
Details of a number of 9' cast-iron columns for sale by the Bedwellty Urban District Council.

The I.E.S. In Lighter Vein p28
Details of the music events by the Illuminating Engineering Society at their meeting on the 11th May 1943.

Adverts: Poles Ltd, The Association Of Metal Sprayers, British, Foreign And Colonial Automatic Light Controlling Co., Ltd., Siemens Electric Lamps And Supplies Ltd., Metropolitan Vickers Electrical Co. Ltd, Engineering And Lighting Equipment Co. Ltd., Philips Lamps Ltd., British Commercial Gas Association, The British Thomson-Houston Co. Ltd., William Sugg And Co., Ltd. abd The General Electric Co., Ltd.