tailieunhanh - Seamanship Techniques 2 Episode 9

Tham khảo tài liệu 'seamanship techniques 2 episode 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Speed and Depth 23 Frog Sennet laid line Shaped fin on Rotator stray length rotator Figure Frog and rotator. bronze to resist the corrosive action of salt water. The rotator is a hollow tube having curved vanes attached to the sides and seized to a hollow frog often referred to as a bottle by a short length of sennet laid line stray length . The opposite end of the frog receives the log line and is secured in the manner shown in Figure . To Hand the Log heaving the log back aboard 1. Disconnect the bridge connection to the bridge repeater. 2. Stop the governor from rotating and bring in a little of the log line by hand. 3. Unclip the Englefield clip from the governor. 4. Continue to heave the log line inboard taking the bare end to the opposite quarter of the vessel. Pay out the bare Englefield clip end as the rotator is heaved in. 5. Allow time for any kinks in the rope caused by the rotator to be turned out . Heave in the line coiling down left-handed. 6. A light grease should be applied to the log clock after removal of any salt crust on the casing. All equipment should then be returned to a safe stowage place except for the line which should be left to dry naturally. When heaving the log back aboard mariners should be aware that the rotator when breaking the surface has the tendency to fall back into and under the stern. This could cause damage to the vanes of the rotator and render it useless for future operation. Length of Log Line The length required for reasonable accuracy will vary it is found by experience when comparing logged distance against observed distance. However as an approximate guide for vessels with the following speeds the recommended length is approximately a 75 m to 95 m for speeds of about 12 knots. b 100 m to 125 m for speeds of about 15 knots. c 130 m to 160 m for speeds of about 20 knots. The length of the log line will effectively change as a vessel changes her draught especially in high freeboard vessels when in ballast. To .