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The BI-MULTI SYSTEM
of
STREET LIGHTING

GROUP "AL/2VS" & "AL/1HS"
for
50 Watt
Sodium Discharge Lamps

Group "AL/2 VS"
Two Way 165^o

Group "AL/1 HS"
Two Way 165^o

GROUP "AL/2 VS" & "AL/1 HS"

BI-MULTI REFLECTORS

For use with 50-watt Sodium Electric
Discharge Lamps in vertical and horizontal
positions

(Patent Nos. 228294 & 426069)

THE FOUNDRY
CANTERBURY, KENT

Telegrams:
ESLA, 17 Canterbury
Telphone:
Canterbury 17

general construction

The reflectors consist of one piece castings glazed with silvered glass facets, cut from flat sheet, embedded in a special atmospheric resisting cement. Each facet is set at the exact angle and is of a calculated size to produce the desired light distribution.

Material: Cast iron or Aluminium non-corrosive alloy.
Finish: Green or Aluminium. Other colours to order.
Tapping: ¾" gas thread as standard. Tappings to 1¼" to order.
Lamp Holders: Bayonet Cap.

approximate dimensions and weights

Type	Approx Dimensions						Approx Weight
	"AL/2 VS"			"AL/1 HS"			"AL/2 VS"		"AL/1 HS"
	Length	Width	Height	Length	Width	Height	Cast Iron	Aluminium	Cast Iron	Aluminium
Two Way	12¼"	11¼"	14½"	12¼"	13"	7"	22 lbs	10 lbs	14 lbs	6 lbs
Three Way	11¼"	11¼"	14½"	-	-	-	20 lbs	9 lbs	-	-
Four Way	11¼"	11¼"	14½"	-	-	-	20 lbs	9 lbs	-	-

technical description

The reflectors are designed to produce a light distribution of the required characteristics to ensure good uniformity of illumination and road brightness. The peak candle power is projected at an angle of 10^o below the horizontal.

Group "AL/2 VS" employs a special patented method of light control by which the elongated light source is split into two imaginary sections, each reflector redirecting the light flux from the respective sections.

This optical design is such that the light from the discharge lamp is applied to the road with the maximum of utility, latitude, and precision. This reflector can be applied to all unusual road conditions (bends, intersections, etc.) with the same ease and efficiency as for a straight normal road.

Group "AL1/ HS" produces a light distribution suitable for normal and close spacings and wide roads. The maximum candle power intensity is not so high as with the double reflector but the width of the light spread is more adaptable to the conditions mentioned.

Both these reflectors greatly enhance the advantages of these new light sources in a very practical and economical matter.

mounting height

When considering the question of the height at which these lighting units may be erected, it must be remembered that although the rated wattage is only 50, the light output is approximately equivalent to that of a 200-watt filament lamp. We do not therefore consider it advisable to erect these units at a height of less than 17', although the Group "AL/1 HS" reflector might, with great care, be applied to a mounting height less than this figure.

angular settings

Group "AL2/ VS": THis reflector is available in all the various angles as scheduled on the Catalogue section dealing with the Group "AL" filament lamp reflector.

In addition, a very interesting modification may be adpoted in the case of three way and four way road intersections by which the light flux may be directed on to the various roads in approximate proportion to their traffic denisty and importance. This fexibility is effected by combining a three way upper reflector with a two way lower, or a four way upper with a three or two way lower.

For example, taking a simple case of a central suspension unit at a "T" intersection of exactly right angles; the branch road being of less importance than the straight through road; a 180^o/90^o/90^o three way upper reflector might be combined with a 180^o two way lower reflector. Thus there would be two pairs of reflector wings operating up and down the main road, but only one reflector wing projecting down the branch road. This is a very useful procedure where it is not desired to sacrifice the light on the main road too much for the sake of the side road.

Group "AL1/ HS": This reflector is mainly for the economical application of sodium lamps to the usual two way lighting, the vertical fitting being employed if desired for junctions.

technical service

The personal services of our technical staff at the works are at our clients' disposal at all times. They are prepared to visit a district in order to advise on all street lighting problems, also to inspect every individual lighting position to ascertain the correct reflector, or this latter work can be done reasonably well from plans.

They are also ready to carry out photometric tests on site, for which purpose they are equipped with the latest portable photometers available.

schedule of angles

Group "AL/2 VS"
Two Way	Three Way	Four Way
180^o 175^o 170^o 165^o 160^o 155^o 150^o 140^o 135^o 130^o 120^o 110^o 100^o 90^o 80^o 40^o	120^o 120^o 120^o 130^o 130^o 100^o 130^o 110^o 120^o 135^o 135^o 90^o 135^o 112½^o 112½^o 140^o 140^o 80^o 140^o 130^o 90^o 140^o 120^o 100^o 140^o 100^o 120^o 150^o 140^o 70^o 150^o 130^o 80^o 150^o 120^o 90^o 150^o 95^o 115^o 150^o 80^o 130^o 150^o 70^o 140^o 155^o 150^o 55^o 155^o 135^o 70^o 155^o 115^o 90^o 155^o 102½^o 102½^o 155^o 90^o 115^o 155^o 80^o 125^o 155^o 55^o 150^o 160^o 155^o 45^o 160^o 120^o 80^o 160^o 105^o 95^o 160^o 90^o 110^o 160^o 80^o 120^o 160^o 70^o 130^o 160^o 60^o 140^o 165^o 165^o 30^o 165^o 145^o 50^o 165^o 140^o 55^o 165^o 125^o 70^o 165^o 115^o 80^o 165^o 112½^o 82½^o 165^o 105^o 90^o 165^o 97½^o 97½^o 165^o 95^o 100^o 165^o 90^o 105^o 165^o 82½^o 112½^o 165^o 77½^o 117½^o 165^o 60^o 135^o 165^o 45^o 150^o 165^o 35^o 160^o 170^o 145^o 45^o 170^o 100^o 90^o 170^o 95^o 95^o 170^o 75^o 115^o 175^o 115^o 70^o 175^o 45^o 140^o 180^o 125^o 55^o 180^o 120^o 60^o 180^o 110^o 70^o 180^o 100^o 80^o 180^o 95^o 85^o 180^o 90^o 90^o 180^o 80^o 100^o 180^o 70^o 110^o 180^o 65^o 115^o 180^o 55^o 125^o 180^o 30^o 150^o 185^o 145^o 30^o 185^o 80^o 95^o 190^o 95^o 75^o 190^o 90^o 80^o 190^o 85^o 85^o 190^o 75^o 95^o 190^o 70^o 100^o 190^o 55^o 115^o 190^o 40^o 130^o 195^o 130^o 35^o 195^o 115^o 50^o 195^o 100^o 65^o 195^o 82½^o 82½^o 195^o 75^o 90^o 195^o 55^o 110^o 195^o 40^o 125^o 200^o 135^o 25^o 200^o 100^o 60^o 200^o 80^o 80^o 200^o 70^o 90^o 200^o 60^o 100^o 205^o 90^o 65^o 205^o 77½^o 77½^o 210^o 50^o 100^o 215^o 90^o 55^o 220^o 65^o 75^o 225^o 45^o 90^o 230^o 75^o 55^o	90^o 90^o 90^o 90^o 100^o 80^o 100^o 80^o 100^o 100^o 80^o 80^o 105^o 50^o 102½^o 102½^o 105^o 80^o 85^o 90^o 105^o 90^o 65^o 100^o 105^o 90^o 75^o 90^o 110^o 70^o 90^o 90^o 110^o 80^o 80^o 90^o 110^o 90^o 70^o 90^o 120^o 40^o 105^o 95^o 120^o 80^o 70^o 90^o 120^o 100^o 90^o 50^o 120^o 105^o 40^o 95^o 121^o 73^o 100^o 66^o 125^o 50^o 105^o 80^o 125^o 70^o 90^o 75^o 125^o 90^o 80^o 65^o 130^o 35^o 125^o 70^o 135^o 65^o 95^o 65^o 140^o 70^o 55^o 95^o 145^o 40^o 120^o 55^o 145^o 55^o 75^o 85^o 145^o 65^o 70^o 80^o 145^o 75^o 85^o 55^o 165^o 15^o 155^o 25^o
Group "AL/1 HS"
Two Way
165^o

GROUP "AL/2 VS" & "AL/1 HS"

BI-MULTI REFLECTORS

For use with 50-watt Sodium Electric Discharge Lamps in vertical and horizontal positions

(Patent Nos. 228294 & 426069)

For use with 50-watt Sodium Electric
Discharge Lamps in vertical and horizontal
positions