Star I & II Lantern for Group 'B' Roads
Single piece dome refractor lantern
Crompton Lamps :-
| 100/200W. | Tungsten filament | (GLS) |
| 80/125W. | Mercury Electric Discharge | (MB/U) |
| 80/125W | Mercury Fluorescent Discharge | (MBF/U) |
These simple but robust lanterns, available with two sizes of reflector, embody the following features:-
- Automatic focusing of lamp and registration of refractor.
- Totally enclosed quick release clips for removal of refractor.
- Single piece prismatic refractor in three distributions.
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STAR I
10" dia. | 60/200W GLS | B.C. | S101AS | S101AN | S101AX |
STAR I
10" dia. | 60/200W GLS | E.S. | S101BS | S101BN | S101BX |
STAR I
10" dia. | 80/125W MB/U
80/125W MBF/U | 3-pin B.C. | S101CS | S101CN | S101CX |
STAR II
12" dia. | 60/200W GLS | B.C. | S111AS | S111AN | S111AX |
STAR II
12" dia. | 60/200W GLS | E.S. | S111BS | S111BN | S111BX |
STAR II
12" dia. | 80/125W MB/U
80/125W MBF/U | 3-pin B.C. | S111CS | S111CN | S111CX |
Unless otherwise specified lanterns will be supplied with standrad ¾ B.S.P. tapping.
Photograph and Drawing show 10" Star I |
| Dimensions, Tapping & Height |
| Type S101 | Type S111 |
| Height | 9" | 9 3/8" |
| Diameter | 10" | 12" |
| Tapping B.S.P. | ¾" | ¾" |
| Minimum length of thread required | 7/8" | 7/8" |
| Weight | 4¾lbs. | 6½lbs. |
| Refractor Catalogue Numbers |
| Symmetrical | 4116 |
| Non-Axial | 2/4116 |
| Axial | 22/4116 |
1. Construction
Both sizes of lantern are similarly constructed. There are only three main parts, viz. body casting, lampholder bridge assembly
and refractor. The reflector is cast with the body which is arranged for top entry and provided internally with three sets
of tapped bosses for the fixing of the lampholder bridge assembly. This consists of a simple bridge pice, carrying the
lampholder, with bayonet slots to engage fixing screws in the bosses. The bayonet slots allow the bridge to be changed from
one set of bosses to another or to be removed for wiring without the complete removal of fixing screws.
The body has two totally enclosed spring loaded clips for the retention of the refractor glassware. This is of the
single piece dome type with prisms moulded on both its internal and external surfaces. A projection on the neck of the
refractor engages with a recess in the body casting and ensures correct angular location.
2. Material And Finish
| Body | Silicon aluminium alloy LM6M, exterior finish aluminium, interior finish white and
underside of reflector white |
| Bridge piece | Mild steel cadmium plated |
| Refractor clips | Mild steel cadmium plated |
| Refractor | Crystal glass |
3. Distribution
Typical Polar Curves and an Iso-Candle diagram for the most popular 2/4116 non-axial refractor are given in Figs. 1 and 2.
FIG. 1
Polar distribution for 2/4116 refractor with 200W 2725-lumen lamp
A: In vertical plane through the centre of the main beam
B: Plan distribution of 80° cone
FIG. 2
Iso-candle diagram for 2/4116 refractor with 200W. 2725-lumen lamp.
4. Focusing
The bosses to which the lampholder bridge should be fixed for each lamp size are clearly marked within the lantern.
5. Maintenance
The aluminium alloy from which this lantern is cast is highly resistant to corrosion in both industrial and marine atmospheres.
Additional protection can be provided by occasional painting in service.
6. Optical Data For 2/4116 Refractor
| GLS | MB/V |
| Beam Angle Horizontal | 170° | 170° |
| Beam Angle Vertical | 80° | 80° |
| Light output ratio | 81% | 80% |
| Light flux in lower hemisphere | 90% | 86% |
| Directional Intensity Ratio | 3.9 | 2.9 |
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