Special Notice No.11: INFORMATION CONCERNING SUBMARINES. Part I - Warning Signals 1. Mariners are warned that considerable hazard to life may result by the disregard of the following warning signals, which denote the presence of submarines: - (a) Visual Signals (i) Indian Vessels fly the International Code Group NE 2 to denote that submarines, which may be submerged, are in the vicinity. Vessels should steer so as to give a wide berth to any vessel flying this signal. If for any reason it is necessary to approach her, vessels should approach at low speed and a good lookout must be kept for submarines whose presence may be indicated only by their periscope or other masts showing above water. (ii) A submarine submerged at a depth too great to show her periscope, may sometimes indicate her position by releasing a "SSE (Submerged Signal Ejector)" or “Smoke candle” which gives off a flare/smoke on first reaching the surface. Her position may sometimes be indicated by red-and-white or red-and-yellow buffs or floats, which are fitted low on the surface, close astern. (iii) Shishumar Class of Submarines - Identification light: In order to enable accompanying vessels to identify the position of a dived Shishumar Class of submarine the identification light is provided in the aft section of the conning tower. This light emits a white light upward through plexi glass and has a luminous range of 7 miles when measured in the air during clear visibility. (iv) All vessels transiting through areas promulgated as Naval Exercise Areas are to bear in mind that submerged/partly submerged submarines are likely to be encountered. As far as possible such vessels are not to switch off navigation lights and stop propulsion whilst within these areas. (v) Movement of oil rigs outside offshore development areas is to be promulgated at least 48 hours prior to their movement for safety of submarine operations. (vi) Promulgation of areas for seismic survey should as far as possible be clear of recommended routes to permit greater flexibility of dived submarine operations. (b) Pyrotechnics and Smoke Candles. A Submerged Submarine in a Submarine Exercise area uses the following signals: - Signal Signification (i) Red grenades/flares fired Keep clear. I am carrying out emergency in quick succession. surfacing procedure. Do not stop propellers. Ships are to clear the area immediately and standby to render assistance. (ii) Two coloured grenades/ Keep clear. My position is as indicated. I flares 3 minutes apart. intend to carryout surfacing procedure. Do The colour of the not stop propellers. Ships are to clear the grenades/flares may be white immediate vicinity. Yellow or Green. 2. It must not be inferred from the above that Submarines exercise only when in company with escorting vessels. 3. The legend "Submarine Exercise Area" shown on certain charts should not be taken to mean that Submarines do not exercise outside such areas. Under certain circumstances a Local Coast Radio Station may broadcast warnings that Submarines are exercising in specified areas. 4. The accompanying diagrams show Sonobuoy DSTV - 2C, Aircraft Float, Smoke and Flame markers. Sonobuoy are dropped from aircraft to detect submarines and may be encountered anywhere at sea. Other countries have similar Sonobuoys but their colour and dimensions are not known. Part II Navigational Lights 5. Submarines are likely to be met on surface by night on approaches to Mumbai, Vishakhapatnam, Kochi, Chennai,Goa, Karwar, Porbandar, Kakinada, Port Blair and Tuticorin. 6. The masthead and sidelights of IN submarines are placed well forward and very low over the water in proportion to the length and tonnage of these vessels. The steaming lights, bow lights and overtaking lights are closely spaced and as a result they give no indication of the submarines length, her course or a change of course. The stern lights are placed very low and may at times be partially obscured by sea spray and wash. The stern lights are invariably lower than the sidelights. 7. In summary the overall arrangement of the submarine navigational lights is unusual and may give the impression of markedly smaller and shorter vessels than they truly represent. Some submarines are fitted with a very quick yellow (amber) anti collision light. These lights flash at between 90 and 105 flashes per minute and are fitted 1 to 2 m above or below the masthead light. They should not be confused with a similar light exhibited by hovercraft with a rate of 120 flashes or more per minute. Part III - Sunken Submarine 8. A bottomed Submarine, which is unable to surface, will try to indicate her position by the following methods: - (a) Releasing an indicator buoy as soon as the accident occurs. (b) Firing of Green/Red/Yellow SSEs(Submerged Signal Ejector). It should be remembered that it might not be possible for the submarine to continuously to fire her SSE. Correspondingly, a partially flooded submarine may only have certain number of SSE and the searching ship should not therefore expect many to appear. (c) Pumping out oil, fuel or lubricating oil. (d) Releasing air bubbles. (e) Blowing of gash/other floats am. (f) Firing of MG 34/SFD (g) Transmitting on UWT, main sonar, and distress sonar/distress after running echo sounder and hull tapping. 9. Since oil streaks or debris may be the only indication of the presence or whereabouts of the Sunken Submarine, it is vitally important that surface ships refrain from discharging anything which might appear to have come from a submarine while they are in the submarine probability area. Searching ships and aircraft can waste many valuable hours investigating these false contacts. 10. In any submarine accident, time is the most vital factor affecting the chances of rescue of survivors and as the sighting of an indicator buoy may be the first indication that an accident has in fact occurred, it is vital that no time should be lost in taking action. 11. At any time after a submarine accident, survivors may start attempting to escape. Conditions inside are likely to deteriorate rapidly and postponement of escape will only be made in order to allow the rescue ships to reach the scene. Any ship finding a moored Submarine Indicator Buoy should not therefore leave the position but should standby well clear ready to pick up survivors. The latter will ascend nearly vertically, and it is important that plenty of sea room is given to enable them to do so safely. On arrival on the surface, men may be exhausted or ill, and if circumstances are favourable, the presence of a boat already lowered is very desirable. Some men may require a recompression chamber and it will therefore, be the aim of the Naval authorities to get such a chamber to the scene as soon as possible. To sum up, the aims of a Submarine Rescue Operation are:- (a) To fix the exact position of the Submarine. (b) To get a ship standing by to pick up survivors, if practicable with boats already lowered. (c) To get medical assistance to survivors picked up. (d) To get a diver's re-compression chamber to the scene in case this is required by those seriously ill after being exposed to great pressure. (e) To inform the trapped men that help is at hand. Submarine Indicator Buoy 12. I.N. Submarines are fitted with 3 different types of emergency indication buoys. While the Vela class carry two indicator buoys, the Shishumar and Shindhughosh class carry only one indicator buoy each. The physical dimensions, identifying marks and distress facilities of these buoys are described briefly in the succeeding paragraphs. Emergency Indicator Buoy - Vela Class of Submarines 13. The diameter of the Submarine Indicator Buoy is 132 cms. When in water, the buoy floats 15 to 23 cms, above the water level. The buoy is painted in 4 quadrants. Diagonally opposite quadrants are painted yellow and orange. The identification number of the Submarine is painted on the buoy. Each buoy has a light, which can either burn steadily or flash at the rate of 120 flashes per minute. A sound-powered telephone is fitted in each buoy under the base of the light for communication with the submarine. No radio beacon or wireless transmitter is fitted to the buoy. Emergency Indicator Buoy - Sindhughosh Class of Submarines 14. The diameter of the buoy is 115 cms. The buoy is painted in 4 quadrants. Alternate quadrants are painted yellow and orange. The identification number of the Submarine is painted on the buoy. The buoy has a white flashing light flashing every 3 seconds. A powered telephone (from the batteries of the submarine) is fitted on top for two-way communication with the submarines. Two-way radiotelephony communication can be established with the submarine on 121.5 MHz when the buoy is recovered. A radio beacon transmitting at 51.2 MHz (continuous or transmitting for 20 seconds with a pause of 60 seconds) is fitted on the buoy. Emergency Indictor Buoy - Shishumar Class of Submarines 15. The buoy is made of expanded plastic foam covered with GRP skin for physical protection. The buoy is semi spherical in shape, 76 cms in diameter and 90 cms high. The buoy floats end up with a freeboard of about 15 cms. It is covered with longitudinal strips of reflective tape alternative red and white. A 3-digit identification number is displayed on each side of ultra violet light flashing centre of the top surface. In darkness and good weather the unassisted visibility of the light is 5 miles. The buoy carries HF and UHF whip aerial (168 cms and 100 cms long respectively). The transmitters are automatically activated when the indicator buoy is released. The HF Transmission frequency of 8364Khz contains the international distress call, SOS together with the submarine identification number. The UHF Sarbe tone is transmitted at a frequency of 243 MHZ. No two-way telephone communication with the submarine is possible. The indicator buoy is also equipped with an emergency ‘Xenon’ light flashing at 32 flashes per minute with a range of approx 5 nm in good visibility conditions. 16. The finder of any of these buoys should inform the nearest Naval/ Coastguard// Port/Police authorities and should not attempt to secure to or lift the buoy. The accompanying diagram shows the Submarine Indicator Buoy.