Feature Article ARUN KUMAR & N. BABU RAO

The submarine is a deadly danger lurking underwater for enemy ships. But it could be equally lethal for the crew manning it. The Defence Bioengineering & Electromedical Laboratory (DEBEL) based in Bangalore has come up with an indigenous Submarine that has come up to the expectations of the Indian Navy.

is also used for civilian purposes like evident from the crippling damage research, underwater exploration, oil inflicted on British ships by the and gas platform inspection and German U-Boats in the two World pipeline surveys and tourism. Wars. submariner once remarked The concept of submarine Present day submarines are – “What goes up, always development surfaced in the late capable of diving down to a depth of comes down, but what goes nineteenth century and was probably 250 meters or more, stealthily existing down may not always come influenced by the famous science fiction under water for effective military Aup.” Obviously he was referring to the novel 20,000 leagues under the Sea operations. Irrespective of the depth it submarine, which has its operational published by Jules Verne in 1870. The reaches, the submarine is so designed abode under water. His apprehensions novel tells about the adventures of Prof that it always maintains the normal are quite understandable considering Pierre Aronnax and his friends aboard atmospheric of 760 mm of the lethal and hazardous nature of the Nautalis, an electrically powered mercury at sea level inside the . Life submarine built by Captain Nemo. submarine. The total number of crew protection and life support systems Interestingly, some of the author’s inside the submarine generally varies become the primary concerns for safety ideas in the book became a reality with from two or three in a research of personnel engaged in underwater the development of high speed nuclear submarine to several hundreds in a operations. and diesel submarines, which are military attack submarine. The submarine is a hydroplane currently being used for secret In the event of an accident or with tremendous operational underwater operations. The author incapacitation, the submarine crew is capabilities under water and is also seemed to have a faint idea of the forced to abandon the submarine and fundamentally designed to serve the military use of submarines and the reach the surface for safety. Otherwise, needs of defence personnel although it danger they pose to warships, as was they will perish, as it happened some SCIENCE REPORTER, February 2010 45 Feature Article Table-1: Signs and symptoms of sickness (DCS) time back in the case of the Russian submarine, Kursk in August 2000. The crew has to be provided with DCS Type Bubble Location Signs & Symptoms life support systems to guard them (Clinical Manifestations) against environmental such as BENDS Mostly large joints of · Localized deep pain, ranging from cold, reptile attacks, etc as well as from the body (elbows, mild (a “tingle”) to excruciating. Sometimes the crippling effects of high pressure shoulders, hip, wrists, a dull ache, but rarely a sharp pain. on the human body. Besides, they knees, ankles) · Active and passive motion of the joint aggravates should also be provided with the the pain. correct composition of gas mixtures i.e. · The pain may be reduced by bending the joint to Nitrogen, and Helium gases find a more comfortable position at suitable pressure to enable them to · If caused by altitude, pain can occur immediately continue during ascent. or up to many hours later. SKIN BENDS Skin · Itching usually around the ears, face, neck, arms Underwater Physiology and upper torso Any descent into the sea is known to · Sensation of tiny insects crawling over the skin increase the pressure around the (formication) human body alignments significantly. · Mottled or marbled skin usually around the In the case of personnel descending into shoulders, upper chest and abdomen, with itching water, it becomes necessary to supply · Swelling of the skin, accompanied by tiny scar-like air under pressure to prevent the skin depressions (pitting edema) exposure of blood in the lungs to sudden high alveolar gas in NEUROLOGICAL Brain · Confusion or memory loss order to keep the lungs from · Headache collapsing. Normally, nitrogen, · Spots in visual field (scotoma), tunnel vision, oxygen and carbon dioxide are the double vision (diplopia), or blurred vision three gases to which a sea diver is · Unexplained extreme fatigue or behavior exposed, although helium can also be changes used sometimes as a substitute for · Seizures, dizziness, vertigo, nausea, vomiting nitrogen in the breathing mixture. and unconsciousness may occur, mainly due to Nitrogen, which approximately labyrinthitis constitutes four-fifth of the air and Spinal Cord · Abnormal sensations such as burning, stinging, which at sea level pressure is not and tingling around the lower chest and back observed to cause any adverse effect · Symptoms may spread from the feet up and may on the body physiology, can be be accompanied by ascending weakness or expected to produce varying degrees paralysis of narcosis at pressures existing beyond · Girdling abdominal or chest pain 50 meters depth. Sometimes becomes ineffective as a result of Peripheral Nerves · Urinary incontinence and fecal incontinence . To overcome these · Abnormal sensations, such as numbness, environmental hazards, the diving burning, stinging and tingling (paresthesia) underwater personnel need · Muscle weakness or twitching underwater breathing apparatus. CHOKES Lungs · Burning deep chest pain (under the sternum) During ascent, the diver faces yet · Pain is aggravated by breathing another problem in which gases in the · Shortness of breath (dyspnea) breathing bag expand because of · Dry constant cough reduction in surrounding pressure leading to increase in , thereby causing rapid and uncontrolled ascent to The submarine is a the surface. This leads to (DCS). DCS results from gas hydroplane with tremendous coming out of in the body fluids operational capabilities and tissues when a diver ascends too under water serve the needs quickly. DCS is sometimes classified according to symptoms as type I or Type of defence personnel II with the latter characterized by more although it is also used for severe neurological effects. Bubbles can civilian purposes like form anywhere in the body, but symptomatic sensation is most research, underwater frequently observed in the shoulders, exploration, oil etc. elbows, knees, and ankles. 46 SCIENCE REPORTER, February 2010 ReportFeature Article Skin Bends in Submarine Decompression sickness (left) Escape hatch Access hatch

Torpedo room Table 1 gives symptoms for different types of DCS. The “bends” (joint pain) account for about 60 to 70% of all altitude DCS cases, with the Torpedo shoulder being the most common site. These types are classified medically as DCS I. Neurological symptoms are Schematic Diagram A present in 10 to 15% of all DCS cases of a Submarine with headache and visual disturbances Escape Hatch (inset) being the most common. DCS cases with Neurological symptoms are complicated generally classified as DCS II. The operation for “chokes” are rare and occur in less than which rigorous 2% of all DCS cases. Skin indoctrination manifestations are present in about 10 is required for to 15% of all DCS cases. the sailor. All F The large difference between the the escape drills and that of the have to be D human body’s air containing cavities followed may cause injury by damaging the meticulously. tissues involved. This injury is called G Various . The different types of countries all barotraumas that commonly occur are: over the world C Aural barotraumas (damage to the have attempted E eardrum), Pulmonary Barotramuma and perfected (pressure damage to the lungs), Sinus systems to meet Barotrauma (painful inflammation of this goal. the membrane of paranasal sinus Different cavities), and Pneumothorax (lung over B countries use expansion injury causing lung different collapse). A: Rescue Ship; B: Sunken Submarine; C: deep Submeragence Rescue Vehicle (DSRV); D: McCann methods of Bell; E: Remote Operated Vehicle (ROV); F: REMORA; G: Free ascent escape by submarine escape set. rescue such as: Escape Mechanisms With the advent of underwater Submarine Rescue Chamber As these devices are critical to save the lives technologies underwater operations (McCann Bell) (Turkey, USA, Italy); of users, a lot of prudence has to be exercised DSRV (Deep Submergence Rescue are becoming increasingly pertinent. in designing the equipment. A lot of underwater strategic missions Vehicle) (USA, Russia); are conducted by various Naval LR5 (UK), few countries have perfected. services across the globe. So, in case of ASRV (Australian Submergence Depending upon the situation in the any accident, rescue and life support of Rescue Vehicle) (USA, Russia); sunken submarine, individuals can don personnel involved in underwater REMORA (Australia); the SES and escape through either the operations assumes great significance. URF (Sweden); escape hatch or conning tower or As these devices are critical to save the SRV 300 (Submergence Rescue torpedo tubes of the submarine. lives of users, a lot of prudence has to Vehicle) (Italy). be exercised in designing the equipment. These rescue vehicles get attached Indigenous Submarine Escape Rescue from sunken/abandoned to the escape hatch of the submarine Set submarines is a very difficult and during rescue operations. However, Presently, a fleet of 16 submarines is complicated process. The mortality the Submarine Escape Set (SES) is for under operation with the Indian Navy rate depends on the nature of individual escape. This is the only set and the crew is entirely dependent on wreckage and availability of facilities that allows unaided safe escape. Escape Sets (ISP-6)) imported from and the time lapsed. Globally, Submarine escape systems are a Russia. With 20 more submarines submarine escape is a highly technology by themselves, which very likely to be inducted in the near future SCIENCE REPORTER, February 2010 47 Feature Article

MacCann Rescue Tower in Submarine Chamber Hydro suit

Breathing Apparatus

Test Facility It is very essential that the Hydro suit Submergance and the Breathing apparatus, which are Rescue Vehicle critical life saving equipment are tested Submarine before each use. The Hydro suit parts Escape Set like front and spinal buoyancy compartments and the main body have along with the indigenously developed to be tested for water and airtight Advanced Technology Vessel (ATV) integrity. Similarly the breathing and the Akula class Russian nuclear apparatus components such as oxygen attack submarine the demand for SES reducer flow, mixture gases flow is bound to increase. through automatic demand valve, The development of Submarine The breathing apparatus caters to pressure release valve, valve chest and Escape Set involves technologies from the breathing needs of the wearer until regenerative canister are also required several areas like Mechanical the wearer comes to the surface. This to be tested for their functional Engineering, Chemical Engineering, is a self-contained close-circuit parameters. Textile Engineering (Coated and Heavy breathing apparatus that allows the Test facilities are not available textiles), Polymer Science and submariners to pass through various commercially and hence need to be underwater Physiology. depths from 100 m to surface with stops developed in-house. For this purpose Since DEBEL belongs to the Life at intervals of 10 meters during buoy Sciences Cluster of DRDO and is a rope ascent. This is a vital life saving multi-disciplinary Laboratory equipment that provides breathing having considerable knowledge and gases of varying compositions from expertise in all the above areas and oxygen and mixture cylinders fitted since it also has the capability for with reducers that work as per depth development of Life Support Systems requirements. A canister is provided it has undertaken the task of in the breathing circuit for removing indigenously developing suitable the carbon dioxide thus enhances the SES for use in Indian Navy. set’s endurance. The total of the SES does The SES consists of a hydro suit Testing Facilities and a breathing apparatus. The hydro not exceed 25 kg with the weight of the suit is a full coverage rubberized suit hydro suit being 11 kg and that of DEBEL has indigenously developed a to protect the wearer from the breathing apparatus being 14 kg. suitable test facility for functional parasitical effects of and The hydro suit as well as the evaluation of their components. This reptile bites. It is made up of air and breathing apparatus were subjected to Test Facility, which is not only complex watertight costume of neoprene coated trials at the laboratory and field level. but also unique, is the only test facility nylon fabric. The hydro suit has been The functional evaluation of the available for carrying out all the critical designed in two sizes: medium (upto a breathing apparatus components and tests of the indigenous SES developed height of 198 cm) and large (in the hydro suit were done under simulated by DEBEL. The Indian Navy has height range of 199-216 cm). The boots conditions at DEBEL. After this, the SES procured this also. are of size 43. The hydro suit maintains was tested by sailors and officers at its air/watertight integrity when the Vishakhapatnam and Mumbai. After Mr Arun Kumar and Mr N. Babu Rao are with the pressure in the main body is 350 + 10 successful completion of all the stages of Defence Bioengineering & Electromedical Laboratory mm wc. The buoyancy compartments the tests, the equipment has been accepted (DEBEL), Defence Research & Development maintain their airtight integrity when by the Navy. The item is expected to go Organisation (DRDO), P.B. 9326, C.V. Raman inflated to 450 + mm wc. into production in the near future. Nagar P.O., Bangalore-560093 48 SCIENCE REPORTER, February 2010