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Session VI Buoys Day boards Buoys and Appendages.

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Presentation on theme: "Session VI Buoys Day boards Buoys and Appendages."— Presentation transcript:


2 Session VI Buoys Day boards

3 Buoys and Appendages

4 Lantern Lantern Guard Ring Radar Reflectors Tower Braces Tower Legs Battery Pockets Lifting Padeye Buoy Body Mooring Padeye Gussets Chafe Block Buoy Tube Counterweight Buoy Top Head Bottom Head Counterweight Seat

5 Sound Systems l There are three main types of wave actuated sound signals: Whistle Bell Gong

6 Whistle Whistle is made of cast bronze and is mounted inside the cage. l As air is forced through the whistle it makes the familiar drone sound.

7 Bells l Bells used on lighted and unlighted buoys and are made of a copper-silicon alloy. l External tappers impact the fixed bell when wave motion causes the buoy to roll.

8 Gongs l Gongs are used on lighted and unlighted buoys and are made of a copper-silicon alloy. l External tappers impact the fixed gongs when then buoy rolls. l The gongs emit a different tone when struck thus distinguishing them from a bell.

9 Buoy Moorings l Buoy chain connects the buoy to the sinker. l The bridle distributes the load and minimizes the heel angle caused by the chain.


11 Buoys will move with the current and weather The sinker is really in the actual position Watch Circle Radius

12 Sinkers l Sinkers are used to hold buoys in position. There are two types that we use. –Concrete –Dor-mor

13 Sinkers Concrete - These are cheap, easy to make and easy to retrieve for an inspection. –When made, they must be cast in a single pour. –They range in size from 250 to 20,000 lbs. –If chain or other metal is added, they must be marked with their actual weight.

14 Sinkers DOR MOR Sinker –A cast iron, pyramid shaped sinker intended for use on discrepancy buoys in areas of mud or sandy bottoms.

15 Lighthouse l Enclosed edifice that houses protects, displays, or supports visual, audible, or radio aids to navigation. –Can be manned or unmanned. –Located in an offshore, wave swept, exposed environment. –Or as a landfall object.

16 Single Pile Structure l Used in protected or semi-exposed locations 2

17 Dolphin l Battered pile Three to seven piles driven at an angle with the bottoms spread and the tops secured with wire rope or bolts and shear connectors. 1

18 Dolphin l Cluster pile –Three or more piles driven vertically with their surfaces in contact with each other and wrapped tightly at various heights.

19 Platform Structure l Three or more separate piles driven vertically, connected at the top by a platform that spreads the load over all the piles. Usually is the foundation for skeleton towers.

20 Guyed Skeleton l Commonly called a “TV tower.” l Triangular in shape. l Galvanized 1 1/4” steel pipe and 3/16” guide wires. l Each section is 10 ft. in height. l Usually not built over 30 ft.

21 Free Standing Skeleton Tower l Commonly called “5 ft pipe towers”. l Constructed of galvanized metal. l Can be uniform or tapered. l Usually, not built over 100 ft. in height.

22 Radar Reflector l Installed when the reflectivity of the structure doesn’t meet the operational requirements. l A standard radar set should detect it at 1.5 to 2 NM when mounted 10 ft above the water. l Must be properly oriented to the channel. CHANNEL

23 Dayboards The first letter refers to the shape or purpose of the dayboard. S-Square T-Triangle J-Junction M-Mid-Channel K-Range N-No Lateral Significance

24 Mounting Dayboard may be installed approximately 5 degrees from vertical. 5 o

25 Mounting l Whenever possible, dayboards shall be mounted on an angle to the channel. l The angle will vary to best suit the channel. l For a straight channel about 30 degrees. 3 0 o CHANNEL This makes the number easier to read when abeam.

26 Reflective Material Honeycomb appearance Both materials may be used together on the same aid. Smooth appearance

27 Dayboards l Additional information is shown by letters placed after a dash (-) l I - Intracoastal l SY - yellow square l TY - yellow triangle

28 Nominal Range l As a mariner approaches a dayboard from a distance it is first detected as an object apart from its surroundings. This is the detection range

29 Nominal Range l Upon coming closer to the dayboard it can be recognized as an aid to navigation. This is the recognition range

30 Nominal Range l Finally the aid can be identified when the mariner is close enough to read the numbers and letters. This is the identification range

31 Nominal Range l The nominal range rating is used to classify dayboards 3SG and 4TR –nominal range 1NM 4SG and 6TR –nominal range 2NM 6SG and 8TR –nominal range 3NM

32 Dayboards There is no character for height in the designation. All dayboards including TRs and SGs are as tall as they are wide. 3’ 4’ 3’ 4’

33 Range dayboards Range boards are always twice as tall as they are wide. W 2W

34 Port and Starboard Markers SG TR

35 Junction Markers JGJR

36 Mid - Channel Markers MR


38 No Lateral Significance markers NR NG NB

39 Information and Regulatory Markers Danger Exclusion Area Controlled Area

40 Special Purpose Dayboard NY

41 End of Session VI

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