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bth full range | lanterns

leeds
This street-lighting lantern consists of a canopy made of copper spinning reinforced with wrought-iron spider, and a globe cage in basket form consisting of wrought-iron strips attached to a cast ring. The globe is of BTH "Nelite" glass. An all-porcelain lampholder and inner reflector in white vitreous enamel are employed.

The BTH "Nelite" glass globe is of the rippled variety with a trace of opal, giving excellent diffusion, but not materially interfering with the directional control. When lighted at night, the rippling gives the effect of innumerable minute crystals which give life and sparkle to the lantern, which is not found with plain opal globes. At the same time there is an absence of glare. The rippling also has the advantage of making the globe practically self-cleaning, since rain falling on it is drained off naturally by the small channels, and carries away a good proportion of any dirt that may have collected.

??? ??? GLS
??? Top Entry No Gear 1928 Journal






mercra "h"
The first lantern to horizontally burn a mercury discharge lamp. Introduced in 1934. A patented magentic deflector is incorporated in the lantern to allow a standard 400W or 250W Mercra lamp to be burned in a horizontal position. The first installation is in Bromford Lane, Birmingham. Suitable for the lighting of wide thoroughfares. In common with all new departures, however, certain manufacturing difficulties were experienced which prevented the lantern from being marketed at a competitive price. General adoption of the lantern was not possible except in those places where a high standard of lighting was more important than the capital cost. This led to a further three years of research work leading to an improved, remodelled version of the lantern.
??? 250-400W MA/H
GES Pole clamp No Gear 1935 Advert
1936 Advert
1936 Advert
1937 Journal



diron
For main road lighting. Uses a series of internal reflectors and refractors and then exterior plate refractors to create its lighting distribution. The top-cap and canopy of the lantern are cast in aluminium alloy - a lightweight material having excellent weather-resisting properties. The remainder of the lantern is of fabricated copper construction. Two phosphor-bronze eyebolts pivoted on phosphor-bronze pins, mounted on the top canopy, hold the top-cap and the main body together. A watershed designed to drain off any condensation is mounted between the top-cap and the canopy. Erection involves mounting the top-cap on the bracket, making connections to the terminals on the watershed, lifting the main lantern body into position and drawing the eyebolts up tight. The top-cap thus forms a connection chamber. The system of reflectors and refractors consists of: (1) A sheet-steel vitreous enambled reflector mounted in the lantern; (2) Two pot opal reflectors mounted on the kerb side of the lantern; these throw the light clear of the buildings and symmetrically in either direction up and down the road. The space between the reflectors and the main lantern body is blanked off to prevent dust accumulating; (3) Two flashed opal reflectors mounted on the road side of the lantern to cut down the light thrown across the road and at the same time to throw the light symmetrically in either direction down the road; (4) Two refractors mounted within the lantern which serve to deflect on to the road a proportion of the light which would normally fall onto the pavement.
Type 304-B3 400W MA/V
GES Side Entry No Gear 1936 Advert
1936 Paper
1936 Advert
1939 Advert
1939 Journal
1944 Journal





dilen
A general purpose lantern of simplified design. Introduced in 1936. Fitted with a prismatic bowl and could be used with either mercury vapour or tungsten filament lamps. Manufactured in two sizes: one could take 250-400W MA/V and a smaller size was used with 150W MA/V. A simplified side entry model was introduced in 1939 after the engineering success of the Sodra "H" lantern. Available with either prismatic bowl or opal bowl. The opal bowl version was designed to meet the demand for a lantern giving symmetrical distribution of light without glare. The top cap is cast-iron and threaded 1¼" B.S.P. to screw directly onto a bracket arm. Three bolts, fitted with locking devices, pass through the top cap to support the main body. The mian body is spun from heavy guage copper, reinforced internally by cadmium plated steel spinning, and carries a watershed fitted with two insulted terminals. Also mentioned as popular in 1945.
Type 100-A7 ???W GLS
150W MA/V
??? ??? No Gear 1936 Journal
1936 Advert
1937 Advert
1937 Advert
1937 Journal
1939 Programme
1944 Journal
1945 Programme
Type 100-A7 ???W GLS
250-400W MA/V
??? ??? No Gear 1936 Journal
1936 Advert
1937 Advert
1937 Advert
1937 Journal
1939 Programme
1944 Journal
1945 Programme



diref
Introduced in 1936. An open reflector type of lantern with well-glass for side street lighting. Suitable for the lighting of narrow thoroughfares.
??? 150W MA/V
250W MA/V
GES Top Entry No Gear 1936 Journal
1936 Advert



ranger
Introduced in 1936. Intended for side mounting and is particularly applicable where there are tram or trolleybus standards spaced at 120'. Its water trap prevents damage to the lamp due to water entering through faulty joints or condensation in the bracket. It uses a simple refractor and reflector for light control. The cap and body of the lantern are constructed from high-grade cast-iron. All screws and nuts are brass. The glazing frame and canopy are one-piece sheet copper. The canopy is fixed to the body by means of screws. The cap issecured to the body by two long studs of which only two short lengths are threaded. With the lantern in the operating position the upper thread is engaged in the body, but with the lantern in wiring or suspended position, the lower thread is engaged. The watershed carries the porcelain lampholder and two insulated terminals marked LINE and NEUTRAL, permanent connection being made between the lampholder and terminals by asbestos insulted flexible leads. The watershed prevents any moisture due to condensation or joint leaks from reaching the lampholder and lamp. And earthing terminal is also provided on the watershed. The hinged bottom panel is stiffened by an added frame and is secured by a simple sliding catch.
Type 301-A3 250W MA/V
GES Side Entry No Gear 1936 Advert
1939 Journal
1944 Journal





crown
A general purpose lantern. Strongly constructed and embodies certain unique features which reduces maintenance to a minimum. Lamp adjustment and focussing are obtained by the two knurled knobs on the cap, one for height and the other for the horizontal plane. The height adjustment knob is attached to a screwed spindle passing through two bushed clamping plates. Between the clamping plates is fitted a ball member which carries the lamp holder. This ball is released for horizontal adjustment by means of a spindle which rotates a screwed bush in the clamping plates so releasing, or clamping, as desired. The reflector sits on four phosphor-bronze springs and held firmly in position by a spring mounted baffle, which fits the top of the reflector. This baffle prevents accidental contact with the live parts of the lampholder.
300 300-500W GLS
GES Top Entry No Gear 1936 Advert
1939 Journal
1944 Journal





county
??? 500W GLS GES
Top entry No Gear 1939 Journal



county junior
Especially designed for the new 80W and 125W MB lamps and introduced in early 1937 at around the same time as the lamps. For Group B roads. It was stressed that the lantern could also acccomodate 60-200W GLS and was fitted with a focusing device (unlike most lanterns of its type and price). Weighs 7½lbs. There are three main parts of the lantern body: the top cap (cast iron), main spinning (heavy gauge copper) and reflector (sheet steel vitreous enamel). The lampholder is fixed on a focussing carriage actuated by one knurled knob. The glassware and reflector can be removed from the lantern by removing one screw for cleaning. Light redirection achieved by means of a special one-piece refractor band which is arranged to give a singly axially asymmetrical form of light distribution. Vertical prisms are formed on the inside to produce the required brightness distribution on thr road surface.
??? 60-200W GLS
80-125W MB/V
BC
3BC
Top entry No Gear 1937 Advert
1937 Advert
1937 Journal
1937 Advert
1937 Journal
1937 Programme
1939 Journal
1939 Journal
1944 Journal
1945 Programme



county cadet
Designed as a general purpose lantern for side street lighting with a low wattage lamp.
Type 300 60-200W GLS
80-125W MB/V
BC
3BC
Top entry No Gear 1944 Journal
1945 Programme



mercra "h"
The newly designed Mercra "H" lantern is introduced in 1937. First exhibited at the APLE's Folkestone Conference with an trial installation along Sandgate Road. Improved and less expensive version of the original model. Highly efficient unit for the lighting of main and arterial roads as it incorporates the BTH Controller Cut-Off Principle. Designed for side mounting. The rectangular light distribution curve makes the lantern particularly suitable for the lighting of wide thoroughfares. Weighs 28lb and the finish is Battleship Grey. A horizontally disposed line source of light lends itself to simple optical control with higher efficiency of utilisation. The horizontal light source, gives greater accuracy of light control, in both vertical and horizontal planes, than in possible with vertically burning lamps. A sharp cut-off is provided below the horizontal, obviating glare and increasing the amount of light available for the illumination of the road surface. This modified lantern is designed for side mounting and incorporates a patented magnetic deflector which makes it possible to burn horizontally standard 250 watt or 400 watt Mercra Lamp. (This also simplifies lamp stocks.) It is constructed mainly of non-corrosive aluminium alloy and weighs 28 lbs. The reflectors are made of a special quality anodised-aluminium which is durable and easily cleaned, and is highly efficient optically. Two years later the latern is still extremely popular despite A.R.P. expenditure. The optical system is now described as a "controlled cut-off" (which is a semi-cut-off). The patented method of mounting the top reflectors ensures the preservation of correct contour, while the simplicity of wiring and connecting, accessibility of the whole unit for cleaning, make for economical and trouble-free operation. The light output is redirected to give a wide beam along the road, maintained to a high value of 25° on the road side and 10° on the kerb side. Full advantage is thereby taken of the reflecting properties of the road surface and surrounds. The beam is maintained at a high intensity in the vertical plane to an angle of 86° At a mounting height of 25', this represents a distance of 350' so that with normal staggered formation and a spacing of 150', the road brightness is maintained completely from one unit to the next in the same line. Above 86° in the vertical plane, the candle power is graded to a low value at the horizontal, this controlled cut-off thus almost eliminating glare. The light source is still left visible, to maintain uniform accommodation of vision of the eye.
Type 320 250-400W MA/H
GES Top Entry No Gear 1937 Advert
1937 Journal
1938 Advert
1938 Journal
1938 Advert
1938 Journal
1938 Advert
1938 Journal
1939 Advert
1939 Advert
1939 Programme
1939 Paper
1944 Journal
1945 Programme 1945 Paper



sodra "h"
After the success of the Mercra "H" lantern with its controlled cut-off optics (semi-cut-off), the firm introduce this sodium version of the lantern in 1939 for all sodium lamp types. The lantern is side-entry but an adaptor is available for a top-entry option. (Provision for side entry allows the design to be simplified and for less metal to be used in the body of the lantern.) Aluminium alloy is used throughout the lantern with the exception of the reflectors which are of anodised aluminium of high purity. It is designed to give, at an angle of 84° representing a distance of 240' at the customary 25' mounting height an intensity of over 75% of the main beam thus ensuring a continious surface brightness as far as the road surface will permit. The two refractor panels diffuse the light and tend to eliminate glare, as well as redirecting downward a large amount of light which would otherwise be wasted. Suitable for lighting wide roads.
??? 45 SO/H
BC Side Entry No Gear 1939 Programme
??? 60 SO/H
BC Side Entry No Gear 1939 Programme
??? 85 SO/H
BC Side Entry No Gear 1939 Programme
??? 140 SO/H
BC Side Entry No Gear 1939 Programme
1940 Journal



circra
Designed to give a circular dispersive light distribution so well suited for the lighting of open spaces, car parks, or central suspension street lighting systems. Top cap is cast iron and tapped to 1" B.S.P. Side entrance for cables is also provided in the cap and screwed ¾" B.S. conduit - this opening is normally sealed with a removable plug. The cap carries a copper canopy to which the lantern body is attached, the porcelean lampholder being independently fixed to the underside of the cap. This construction has been chosen to facilitate the initial installation of the lantern and periodical cleaning. The main and inner steel reflectors are of high quality white vitreous enamel. The cylinder enclosing the lamp is of electric opal glass. For lamp replacement and normal cleaning a hinged door, fitted with a wire gauze panel, is provided at the bottom of the cylinder. Adequate ventilation is provided by a cooling air stream which enters through the gauze in the door, flows over the lamp, and is deflected by a cast-iron baffle in the canopy through the air space provided between the canopy and the reflector. This airduct is protected by an internal copper gauze, the ingress of rain being thus rendered practically impossible. The baffle tends to prevent undue heating at the lamp cap and lampholder.
Type 102 250-400W MA/V
GES Top Entry No Gear 1944 Journal



arp lantern
Lantern for war-time use. Designed to produce "comfort" lighting as specified by BS/ARP 37. The upper and lower limits of lantern light distribution imposed by the specification require a precision design of lantern. B.T.H. have designed and produced a lantern, bearing the hallmark of the the B.S.I., depending on its precision and permanence of performance on the use of die-cast parts, which are accurate to a thousandth of an inch, and cannot be deranged or distorted. The slaient features of these lanterns are: Easy Erection - It can be supplied completely assembled and wired to its own adaptor for screwing into existing lamp sockets. or alternatively threaded 1½ B.S.P. for screwing direct on to the bracket arm; Simple Cleaning - Access can readily be obtained to every optical component; Minimum Of Servicing - No adjustments are necessary at any time to allow for normal tolerances in light centre lengths of lamps; Freedom From Glare - The distribution is produced from secondary sources of low brightness. The bare lamp is not visible from any point of view.

Three methods of support have been designed: (1) Top caps tapped to ¾" and 1¼" BSP for screwing directly onto bracket arms; (2) Mechanical suspension devices for holding the lantern rigidly into existing lanterns together with flexible electrical connectors to plug into the existing lamp sockets. (3) Rigid electrical connectors to support the lantern from lamp sockets.

25W GLS is used for mounting heights with normal spacing. 15W GLS is used for 10' mounting height with spacing of less than 100'

??? 15W GLS
25W GLS
BC Top Entry No Gear 1940 Journal
1940 Advert
1940 Journal



600 series (clear bowl and refractor dome)
A new series of Mazdalux Side-Entry lanterns been designed to meet the demand for a complete range of lanterns accommodating every type and size of vertically operated Mazda and Mercra street-lighting lamp. Introduced in 1946-7. This new "Stylized" range consists of sixteen lanterns and, for the first time, lanterns with a uniform appearance can be installed throughout an entire city and on all the roads leading to it. The varied requirements of such locations as shopping centres, side streets and car parks are all catered for in difference of size, glassware and types of lamp. The shape and apperance of the lantern have been carefully designed to blend well with all types of surroundings and to match both steel and concrete standards.
SL600 1500W GLS
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL601 750/1000W GLS
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL602 125W MAF/V
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL603 60-150W GLS
BC Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL604 150-200W GLS ES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL605 80-125W MA/V
80W MAF/V
3BC Side Entry No Gear 1947 Book
1951 Book
1950s Book



600 series (refractor bowl)
A new series of Mazdalux Side-Entry lanterns been designed to meet the demand for a complete range of lanterns accommodating every type and size of vertically operated Mazda and Mercra street-lighting lamp. Introduced in 1946-7. This new "Stylized" range consists of sixteen lanterns and, for the first time, lanterns with a uniform appearance can be installed throughout an entire city and on all the roads leading to it. The varied requirements of such locations as shopping centres, side streets and car parks are all catered for in difference of size, glassware and types of lamp. The shape and apperance of the lantern have been carefully designed to blend well with all types of surroundings and to match both steel and concrete standards.
SL612 250-400W MA/V
125W MAF/V
400W MAF/V
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL615 80-125W MA/V
80W MAF/V
3BC Side Entry No Gear 1947 Book
1951 Book
1950s Book



600 series (refractor bowl and refractor band)
A new series of Mazdalux Side-Entry lanterns been designed to meet the demand for a complete range of lanterns accommodating every type and size of vertically operated Mazda and Mercra street-lighting lamp. Introduced in 1946-7. This new "Stylized" range consists of sixteen lanterns and, for the first time, lanterns with a uniform appearance can be installed throughout an entire city and on all the roads leading to it. The varied requirements of such locations as shopping centres, side streets and car parks are all catered for in difference of size, glassware and types of lamp. The shape and apperance of the lantern have been carefully designed to blend well with all types of surroundings and to match both steel and concrete standards.
SL622 300-500W GLS
125W MAF/V
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL623 60-150W GLS
BC Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL624 150-200W GLS
ES Side Entry No Gear 1947 Book
1951 Book
1950s Book



600 series (opal bowl)
A new series of Mazdalux Side-Entry lanterns been designed to meet the demand for a complete range of lanterns accommodating every type and size of vertically operated Mazda and Mercra street-lighting lamp. Introduced in 1946-7. This new "Stylized" range consists of sixteen lanterns and, for the first time, lanterns with a uniform appearance can be installed throughout an entire city and on all the roads leading to it. The varied requirements of such locations as shopping centres, side streets and car parks are all catered for in difference of size, glassware and types of lamp. The shape and apperance of the lantern have been carefully designed to blend well with all types of surroundings and to match both steel and concrete standards.
SL630 1500 GLS GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL631 750-1000W GLS
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL632 250W-400W MA/V
125W MAF/V
400W MAF/V
GES Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL633 60-150W GLS
BC Side Entry No Gear 1947 Book
1951 Book
1950s Book
SL634 150-200W GLS
ES Side Entry No Gear 1947 Book
1951 Book
1950s Book



horizontal enclosed lantern/ horizontal enclosed series 700 / mazdalux horizontal
For Group A lighting. A street lighting lantern which was the product of past-experience and recent post-war research. Introduced in 1947. The main feature of the lantern are a first class optical performance and fine appearance combined with very simple erection and maintenance. Magnetic arc control enables the standard type of vertical-burning Mercra lamp to be used in a horizontal position. The well-known BTH< principle of controlled cut-off is employed to give constant visual accommodation and a minimum of glare. This allied to the horizontal light source, gives the maximum continuity of road brightness and optimum seeing conditions. Built almost entirely from silicon-aluminium alloy. It consists of a main casting and a refractor bowl-retraining frame which is attached to the main casting by an adjustable hinge and is locked by a quick action spring catch. Includes a magnetic arc control to allow the standard mercury discharge lamp to be used in a horizontal position. Has a controlled-cut-off (semi-cut-off) distribution. Closely graded control of the light output in the vertical plane near the horizontal ensures that glare is kept to a minimum. At the same time sufficient light is emitted up to the horizontal to maintain continuity of visual accommodation.
SL700 250W/400W MA/H
BC Side Entry No Gear 1947 Book
1950s Book
1951 Book



fluorescent lantern
Introduced in 1948. This lantern has now been operating for more than three years in many of the world's most famous highways so was introduced in 1948. It houses three 5 ft. 80-watt fluorescent lamps. It can be mounted directly on street standards, or over thecentre of the roadway on catenary wires. The complete absence of glare creates safer road conditions for both driver and pedestrian. Constructed from light silicon-aluminium castings with a sheet metal roof and a clear plastic cover held in position by four toggle catches. All necessary gear assembled within the lantern. Various options allow for different mounting options. Lamps and gear can be changed by removing one of the ends.
SLB750 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book
SLB751 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book
SLB752 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book
SLB753 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book
SLB754 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book
SLB755 3x80W MCF
BC Side Entry Gear 1950s Book
1951 Book



parish
The firm's Open Type Conical lantern. For Group B roads.
ST275 60-100W GLS
BC Top Entry No Gear 1950s Book
ST276 60-100W GLS
BC Side Entry No Gear 1950s Book



rural open (dome refractor)
For Group B lighting.
ST286 60-150W GLS
BC Side Entry No Gear 1950s Book
ST287 150-200W GLS
BC Side Entry No Gear 1950s Book
SM288 80-125W MA/V
3BC Side Entry No Gear 1950s Book
ST289 60-150W GLS
BC Top Entry No Gear 1950s Book
ST290 150-200W GLS
BC Top Entry No Gear 1950s Book
SM291 80-125W MA/V
3BC Top Entry No Gear 1950s Book



rural enclosed (clear bowl)
For Group B lighting.
ST293 60-150W GLS
BC Side Entry No Gear 1950s Book
SM296 80-125W MA/V
3xBC Side Entry No Gear 1950s Book
ST299 60-150W GLS
BC Top Entry No Gear 1950s Book
ST294 150-200W GLS
ES Side Entry No Gear 1950s Book
ST300 150-200W GLS
ES Top Entry No Gear 1950s Book
SM302 80-125W MA/V
3xBC Top Entry No Gear 1950s Book



urban enclosed (clear bowl)
For Group A lighting.
ST277 300-500W GLS
GES Top Entry No Gear 1950s Book
SM278 250-400W MA/V GES Top Entry No Gear 1950s Book
ST305 300-500W GLS
GES Side Entry No Gear 1950s Book
SM307 250-400W MA/V GES Side Entry No Gear 1950s Book



urban enclosed (refractor bowl)
For Group A lighting.
ST907 300-500W GLS
GES Top Entry No Gear 1950s Book
ST908 300-500W GLS
GES Side Entry No Gear 1950s Book



urban enclosed (opal bowl)
For Group A lighting.
STM279 300-500W GLS
250-400W MA/V
GES Top Entry No Gear 1950s Book
STM309 300-500W GLS
250-400W MA/V
GES Side Entry No Gear 1950s Book



urban open (dome refractor)
For Group A lighting.
ST284 300-500W GLS
GES Top Entry No Gear 1950s Book
ST311 300-500W GLS
GES Side Entry No Gear 1950s Book



sodium enclosed lantern
For Group A lighting. Described as an "improved design" in 1953. Constructed from high grade corrosion-resistant alloy. Lamp support, side panels and an anodised aluminium reflector are mounted to form a single optical unit. Includes a clear Perspex cover.
SL.721 140W SO
BC Top Entry No Gear 1950s Book
1953 Advert
SL.722 85W SO
BC Top Entry No Gear 1950s Book
1953 Advert
SL.730 140W SO
BC Side Entry No Gear 1950s Book
1953 Advert
SL.731 85W SO
BC Side Entry No Gear 1950s Book
1953 Advert



sodium open lantern
For Group A lighting.
SL.715 140W SO
BC Top Entry No Gear 1950s Book
SL.716 85W SO
BC Top Entry No Gear 1950s Book
SL.735 140W SO
BC Side Entry No Gear 1950s Book
SL.736 85W SO
BC Side Entry No Gear 1950s Book



fluorescent lantern
Described as the "latest model" in 1953.
SLX3535 3x80W MCF
BC Side Entry Gear 1953 Advert
1953 Journal



fluorescent lantern
For Group B lighting. Ideally suited for the lighting of residential and shopping areas. All the auxiliary gear is included in the lantern. Can either be mounted on a concrete bracket or a steel bracket arm. Used for the side-street lighting in Stevenage New Town.
SL.3500 2x40W MCF
BC Top Entry Gear 1950s Book
1953 Advert



horizontal sodium open lantern
For Group A lighting.
?? 85W SO
BC Side/Top Entry No Gear 1953 Journal
?? 140W SO
BC Side/Top Entry No Gear 1953 Journal



sapphire
Introduced in 1953. Can be fitted with a magnetic deflector if required. Light distribution is of the "non-cut-off medium angle beam" type as defined in BSCP1004:1952. Also complies with Street Lighting Lanterns BS 1788:1951.The glass bowl has diffusing ripples which are self-cleaning in the rain. Made from corrosion-resistant casting LM6M alloy.
SL??? 250-400W MA/H
ES Side Entry No Gear 1953 Advert
1953 Journal
1955 Advert



amber
For Group A lighting. Gives a non-cut-off medium-angle beam. Gear optional.
?? 85W-140W SO
BC Side Entry No Gear 1955 Advert
?? 85W-140W SO
BC Side Entry Gear 1955 Advert



diadem lantern
For Group A lighting. With built-in gear for either Switch-Start or Instant-Start lamps.
??? ??? MCF
BC Side Entry Gear 1955 Advert