Nomenclature of lights
Main light. – The major of two or more lights situated on the same support or neighbouring supports.
Auxiliary light. – A light placed on or near the support of a main light and having a special use in navigation.
Sector light. – A light presenting different appearances, either of colour or character, over various parts of the horizon of interest to maritime navigation.
Leading lights. – Two or more lights associated so as to form a leading line to be followed.
Lights, described as “Lts in line” are particular cases, and are intended to mark limits of areas, alignments of cables, alignments for anchoring, etc.; they do not mark a direction to be followed.
Direction light. – A light showing over a very narrow sector, forming a single leading light. This sector may be flanked by sectors of greatly reduced intensity, or by sectors of different colours or character.
Direction lights are also used to mark the limits of areas, etc., in the same way as “Lts in line”.
Vertical lights. – Two or more lights disposed vertically (or horizontally, or in a geometric shape) to give a different character or appearance. If the individual lights serve different purposes, the less important are termed auxiliary lights.
Occasional lights. – Lights exhibited only when specially needed: -
Tidal light, exhibited only when the tide serves.
Fishing light, for the use of fishermen and shown when required by them.
Private light, maintained by a private authority for its own purposes.
A distinction has been made between Reserve lights and Emergency lights. The former normally retain the character of the main light but have a reduced range and their installation is usually restricted to major manned stations.
Description of structures. – Where the colour divisions of a structure, or any part of it, are horizontal, the term “bands” is used; where vertical, “stripes”; and where the marking is in the form of a spiral, “diagonal stripes” is employed. The shape of topmarks and daymarks is often shown diagrammatically.
The height is measured from the top of the structure to the ground.
Fog signals
Fog signals are mainly produced by the following types of emitters:
The Diaphone uses compressed air and generally emits a powerful, low-pitched sound, which often concludes with a brief sound of suddenly lowered pitch termed the “grunt”. Where it is known that the sound does not terminate in a “grunt”, the signal is annotated “No grunt”.
The Horn uses compressed air or electricity to vibrate a diaphragm and exists in a variety of types which differ greatly in their sound and power; some types, particularly those at major fog signal stations, combine emitter units which simultaneously produce sounds of different pitch; these are often very powerful. Other produces a single steady tone, whilst others vary continuously in pitch.
The Siren uses compressed air and exists in a variety of types which differ considerably in their sound and power.
The Reed uses compressed air and emits a weak, high-pitched sound; it is particularly weak when hand-operated.
The Explosive emitter produces short reports by the firing of explosive charges.
The Bell, the Gong and the Whistle may be operated by machinery, sounding a regular character; by hand, sounding a somewhat irregular character; or by wave action, sounding erratically.
Morse code fog signals. – In similar manner to lights, the abbreviation “Mo” is included in the abridged description of fog signals which consist of one or more characters of the Morse code; e.g. Horn Mo (AR), Horn Mo(4), and composite fog signals are described, e.g. Siren (2+3).
Check your comprehension by answering the questions:
Is there any difference between “Leading lights” and “Lts in line”?
What purpose does a Direction light serve?
For what purpose are Occasional lights exhibited?
Is there any difference between Reserve lights and Emergency lights?
Does the term “bands”(“stripes”) mean horizontal or vertical stripes?
In what manner is the height of light structure measured?
What types of emitters are fog signals produced by?
TEXT
Beachy Head Lighthouse (circular grey tower, 14 m in height, disused)
(50º 44′N, 0º 13′ E). The lighthouse stands near the summit of Belle Toute cliff, 1
mile W of Beachy Head. Beachy Head Light (white round tower, red band, 43 m in
height) (50º44′·0N, 0º14′·6E). The lighthouse stands on drying rocks, which extend
from the foot of the cliff below the head. Power cables, marked by red spheres, run
from the lighthouse gallery to the cliff top close N.
The alignment (356¼º) of the following lights assists fishing vessels beaching: front light (white metal column, 6m in height) (50º 51′·3N, 0º 35′·5 E) standing on the beach. Rear light (white, 5-sided tower, 6 m in height) (357 m from front light), standing on West Hill.
3. The alignments (166ºand 266½º) of two pairs of lights (black shapes, white stripe on white metal framework structure), assist tanker mooring operations in the inner roadstead.
Front Mooring Leading Lights (166°) Rear
4. The lights stand close W of a stone breakwater, which extends 1¾ cable offshore and gives protection to fishing vessels from the S and W winds. The breakwater, which has a light (mast, 4 m in height) at its head, is in poor repair. Two large concrete groynes are 2 and 2¾ cables E of the breakwater. A light is exhibited from the head of the breakwater.
5. Front light (yellow triangle, point down) (51º 04′·6N, 1º 11′·5E) on The Hard. Rear light (yellow triangle, point up) (100 m WNW of front light). The alignment (295º) of these lights, which also assists ferries berthing, leads from seaward to the Ferry Terminal, passing SSW of Copt Rocks.
6. Front directional light (black triangle point up, orange stripe, on white mast)
(51º 19′ ·5N, 1º 25′·0E) on SW corner of marine terminal. Rear light (black triangle point down, orange stripe on white mast) (2½ cables W of front light). The alignment (270º) of these lights leads through the approach channel, which is marked by light-buoys, and harbour entrance, which both lie in the white sector of the directional light.
7. Front light (red and white metal column, 4 m in height) (51º 19′·6N, 1º 25′·5E) standing on the head of East Pier. Rear light (round granite tower, 11 m in height) (91 m WNW of front light) standing on the head of West Pier. The alignment (291½º) of these lights leads through Old Cudd Channel, the original approach to Ramsgate.
8. Front light (white metal mast, green top, 10 m in height) (49º 44′·4N, 0º 18′·6E). A house stands 4 cables E of the front light structure. Rear light (white pylon, green top, on house, 6 m in height) (30 m SSE of front light). The alignment (166º) of these lights leads to the best place on the beach for landing boats.
9. Head of Jetee Sud (grey tower, green top, 10 m in height) (49º 45′·9N, 0º 21′·9 E). Root of Jetee Nord (red circle on white mast, 7 m in height) (230 m E of front light). The alignment of these lights, which may be difficult to distinguish against the town lights at night, leads from the W to a position several hundred metres from Jetee Sud, whence course should be adjusted towards ENE, to pass close N the head of Jetee Sud.
10. Front light (white column, green top, 9 m in height) (51º 01′·7N, 2º 12′·0E). Rear light (white column, green top, 20 m in height) (600 m SW of front light). The alignment (120º) of these high intensity sector lights together with two beacons (radar reflectors), which stand on the leading line, 2 cables and 4 cables NW of the front light, leads through the dredged entrance channel.
11. Front light (X topmark on white metal framework tower, red bands) (51º 14′·2N,
2º 55′·6E). Rear light (X topmark on white metal framework tower, red bands) (180 m SE of front light). The alignment (128º) of these neon strip lights leads through the centerline of the channel between the piers. The pierheads, on which stand lights are 165 m apart, but the piers curve inward and most of the channel is only 120 m wide.
12. From a position SSW of the harbour entrance in Honte the alignment (023º) of front light (green mast, 4 m in height) and rear light (green metal mast, 9 m in height) (100 m NNE of front light) leads through the harbour entrance which lies between two moles, on which stand lights, W molehead (white concrete column, 5 m in height), E molehead (white concrete column, 5 m in height). The navigable channel through the entrance is 200 m wide.
13. A light (3 m in height) is exhibited on North Pier Head. This light is extinguished when vessels cannot enter the harbour. A second light (bracket on building) is exhibited 100 m SE of the harbour entrance.
1
4.The
alignment (171º) of Black Rocks Point Lighthouse with a white house
standing in front of trees (1½ miles S of the lighthouse) leads 5¼
miles through Goldstone Channel.