Shifting Colors

When a ship is anchored or moored between the hours of 8:00 a.m. and sunset, it flies its ensign at the flagstaff and the union jack at the jackstaff. When it is under way, the ensign is flown at the gaff (the diagonal spar projecting aft from the mast) and the jack is not flown at all. The process of changing from one display to the other is known as shifting colors. 

As the ship prepares to get under way, sailors are positioned at the bow, fantail, and bottom of the halyards running to the gaff and the signal yards. The "steaming" ensign is attached--or "bent on"--to its halyard in preparation for hoisting. The ship's call sign and any other prescribed signal flags are run up, packed to be "broken" at the right moment. At the instant that the last mooring line leaves the pier or buoy, or the moment that the anchor is aweigh, the boatswain's mate of the watch blows a long blast on his whistle and passes the word, "Underway--shift colors." Immediately and simultaneously: 

• the ensign at the flagstaff and the jack at the jackstaff are hauled down smartly (rapidly).
• the steaming ensign is run up smartly to the gaff.
• any flags or pennants that are displayed only when not under way, such as award pennants or  the personal flag or pennant of an officer who is not aboard, are hauled down smartly.
• the call sign is broken at the signal yard. 

A ship mooring or coming to anchor goes through the same process in reverse, with the boatswain's mate giving the word "Moored--shift colors" when the first mooring line is made fast or the anchor is let go. In either case, the desired effect is one set of flags vanishing and another flashing out at precisely the same time. 

Calculating Breaking Strength, Safe Work Load and Weight of Hawserlaid Ropes

CALCULATION OF APPROXIMATE BREAKING STRENGTH (B.S) AND SAFE WORKING LOAD (S.W.L) FOR MANILA ROPE

Method of finding the Breaking Strength (B.S) is to divide the square of the diameter of the rope in millimetres by 200.

Example of a diameter 24mm Manila Rope:

Breaking strength        =          diameter² / 200

                                    =          24² / 200

                                    =          576 / 200

                                    =          2.88 tonnes (approx. 3 tonnes) 

Safe Working Load (S.W.L)

Method of finding the Safe Working Load (S.W.L) is to divide the Breaking Strength by factor of safety.

 The following factors of safety for ropes are used generally:

Lifts and hoist                           -           12

Running rigging and slings       -             8

Other purposes                         -             6  

Safe Working Load     =          Breaking Strength / Safety Factor

                                    =          3 tonnes / 6

                                    =          0.5 tonnes

CALCULATION OF APPROXIMATE BREAKING STRENGTH (B.S) AND SAFE WORKING LOAD (S.W.L) FOR POLYPROPYLENE ROPE

Method of finding the Breaking Strength (B.S) is to divide the square of the diameter of the rope in millimetres by 77 tonnes.

Example of a diameter 24mm Polypropylene Rope:

Breaking strength        =          diameter² / 77

                                    =          24² / 77

                                    =          576 / 77

                                    =          7.48 tonnes (approx. 7 tonnes) 

Method of finding the Safe Working Load (S.W.L) is to divide the Breaking Strength by a safety factor of 6.

Safe Working Load     =          Breaking Strength / Safety Factor

                                    =          7 tonnes / 6

                                    =          1.18 tonnes( approx. 1 ton) 

CALCULATION OF APPROXIMATE BREAKING STRENGTH (B.S) AND SAFE WORKING LOAD (S.W.L) FOR POLYETHYLENE ROPE

Method of finding the Breaking Strength (B.S) is to divide the square of the diameter of the rope in millimetres by 106 tonnes.

Example of a diameter 24mm Polyethylene Rope: 

Breaking strength        =          diameter² / 106

                                    =          24² / 106

                                    =          576 / 106

                                    =          5.43 tonnes (approx. 5 tonnes) 

Method of finding the Safe Working Load (S.W.L) is to divide the Breaking Strength by a safety factor of 6.

Safe Working Load     =          Breaking Strength / Safety Factor

                                    =          5 tonnes / 6

                                    =          .83  tonnes

FORMULA TO CALCULATE WEIGHT OF DIFFERENT 3 STRAND ROPES.

220 meter coil of Manila/Sisal - d² /6.6 kilograms
220 meter coil of Polyamide(Nylon) - d² /7 kilograms
220 meter coil of Polyester - d² /5.6 kilograms
220 meter coil of Polyethylene - d² /9 kilograms
220 meter coil of Polypropylene - d² /10 kilograms

(Reference: Admiralty Seamanship Vol 2, Page 684)

Hand Salute

The hand salute in the Navy came by way of the British Navy.  It is generally agreed that the salute is the first part of the movements of uncovering.  That there was nothing in the hand is a possible explanation of the British salute with the palm turned out.  From the earliest days of organized military units, the junior has uncovered in addressing or meeting the senior.  Lord St. Vincent, in 1796, promulgated an order to the effect that all officers were to take off their hats when receiving orders from superiors.

 In 1890, the hand salute only was decreed by Queen Victoria because of her displeasure at seeing officers and men stand uncovered when they appeared for royal commendation.
   

In the United States Navy, officers in the open uncover only for divine services.  Men uncover when at "mast" for reports and requests, and in officers' country unless under arms or wearing a watch belt.