South Kent Submariners Branch
Did You Know
South Kent Submariners Branch
Did You Know
History was made when, on 16 June 1956, the first television pictures from inside a submarine whilst travelling below the surface were transmitted as part of Saturday Night Out. To enable this programme to be put on, the Royal Navy allowed the BBC to join in an exercide taking place in the English Channel between H.M. Submarine Tapir and the Anti-Submarine Frigate H. M.S. Grenville. Cameras were carried on both ships. Signals from the submarine were relayed by the frigate to a point on shore for onward transmission, and the programme was the climax of many tests carried out earlier in the year by the Royal Navy and all branches of Television Engineering, especially the Outside Broadcasts Experimental Team.
The first submarine was designed in 1578
William Bourne, a British mathematician, drew plans for a submarine in 1578. But it was only in 1620 that Cornelius van Drebbel, a Dutch inventor, managed to build a submarine. He wrapped a wooden rowboat tightly in waterproofed leather and had air tubes with floats to the surface to provide oxygen. Of course, there were no engines yet, so the oars went through the hull at leather gaskets. He took the first trip with 12 oarsmen in the Thames River - staying submerged for 3 hours.
The first submarine used for military purposes was built in 1776 by David Bushnell (1742-1824) of the US. His "Turtle" was a one-man, wooden submarine powered by hand-turned propellers. It was used during the American Revolution against British warships. The Turtle would approach enemy ships partially submerged to attach explosives to the ships's hull. The Turtle worked well but the explosives did not.
Two rival inventors from the US developed the first true submarines in the 1890s. The US Navy purchased submarines built by John P Holland, while Russia and Japan opted for the designs of Simon Lake. Their submarines used petrol or steam engines for surface cruising and electric motors for underwater travel. They also invented torpedoes which were propelled by small electric motors, thereby introducing one of the most dangerous weapons in the world.
The mid 1950s development of the submarine launched Polaris ballistic missile by Lockheed and the US Navy led, eventually, to the signing of the Polaris Sales Agreement between Prime Minister Harold Macmillan and President John F Kennedy.
It was decided that the United Kingdom would have four Polaris submarines to carry the latest A-3 missiles; that the submarines would be British designed and built; that the whole weapon systems and equipment, except warheads, would be purchased from the United States ; and that the warheads would be British. The Government directive was explicit; the four SSBNs (Ship Submersible Ballistic Nuclear) were to be deployed at the earliest possible date and the programme executed within the allotted budget. ‘A challenge had been issued and a challenge was going to be met'.
The programme was authorised in February 1963; the submarines were to be built in pairs, with maximum speed, by Vickers (Lead Yard) and Cammell Laird. The order for a fifth SSBN was announced in 1964, but was cancelled by a new Government the following year. The keel of the first of class, HMS Resolution, was laid down at Barrow on 26th February, 1964, and represented for Vickers the sternest test the yard had had for many a year.
|
POLARIS |
Length overall |
425' |
Beam |
33' |
Displacement |
|
surface |
7500 tons |
submerged |
8400 tons |
|
|
Diving depth |
In excess of 1000' |
Speed |
|
surface |
20 knots |
submerged |
25 knots |
|
|
Armament |
Six 21-inch bow tubes |
|
16 Polaris A-3 tubes |
Complement |
143 (two crews) |
The planning and design effort which went into the Polaris submarine programme was colossal 500 000 man-hours of planning, preparation of more than 10 000 carefully detailed drawings all to be translated into the physical business of construction. Additionally, a full-scale wooden ‘mock-up' was built. Not only did this allow the exact positioning of any piece of equipment to be planned and the routes for cables, pipes and trunking to be decided, but when the crew arrived to stand by their ship, they were able to train on the mock-up and become familiar with their new charge before they even set foot aboard her.
In constructing Resolution, the hull was assembled on the berth from sections prefabricated in the Assembly Shop. The fore and aft parts of the ship were built up simultaneously, and into the space between were placed the prefabricated missile sections, complete with missile tubes. Thirty months was the time occupied from keel laying to launch - which was carried out by Her Majesty Queen Elizabeth The Queen Mother on 15th September 1966 .
The autumn of 1967 was an important one in the history of Vickers. Resolution, having successfully completed her Contractors' Sea Trials, was accepted into the Fleet on 2nd October.
To provide an operational submarine of completely new design, with a complete weapon system from the United States and with adequate support facilities, within 4½ years of ordering the vessel, was a truly remarkable performance. ‘Vickers' workforce had met their challenge!'
Hard on the heels of Resolution's delivery to the Fleet came the launch of Repulse, on 4th November. This launch was not accomplished without one of those heart pounding incidents which sometimes accompany these occasions. Repulse decided to elude the waiting tugs and remain on display in the Walney Channel until the next high tide.
Repulse was fitted-out in Devonshire Dock, and joined the Fleet, ahead of time, on 28th September, 1968 . Her sister ships, Renown and Revenge, built at Cammell Laird, were commissioned in November 1968 and December 1969, respectively.
One of the most important events in the work-up of a Polaris submarine was the Demonstration and Shakedown Operation (DASO), which was conducted off Cape Kennedy in Florida . This operation culminated in the firing of a Polaris missile down the US Air Force Eastern Test Range to a target up to 2500 nautical miles away. The Ministry of Defence planned, in 1963, to fire Britain 's first Polaris missile at 11.15 Eastern Standard Time on 15th February 1968 - HMS Resolution failed to achieve this by 15 milliseconds, but the firing was otherwise fully successful!
Being the United Kingdom 's contribution to NATOs strategic nuclear deterrent, at least one Polaris submarine is constantly on patrol, sailing submerged ‘one knows not where', but always carrying her deadly ‘cargo' of two-stage ballistic missiles.
‘ Sherwood Forest ' is the nickname given to the compartment housing these 16 missiles, which are 31 feet long, 4½ feet in diameter and weigh 28000 pounds. Fired from the submerged submarine, the multiple nuclear warheads can soar into the stratosphere and devastate a target 2500 nautical miles away. One Polaris submarine carries more destructive potential than the total amount of explosives expended by all sides in the Second World War.
When a Polaris submarine heads out into the open sea, the crew settles down to a life of routine, where days pass relatively quickly, but time seems to stand still. Their main activities are devoted entirely to ensuring that the secrecy of their position is preserved, and that the deadly missiles are always ready to fulfil their ultimate purpose. To make the fullest use of Polaris submarines, each has two crews - known as Port and Starboard - which take turn and turnabout in the two-month patrol cycle.
Food assumes an importance beyond its intrinsic value, and plays a large part in influencing the morale of those onboard. From the small galley of a Polaris submarine, three cooked meals a day are prepared for the 143 officers and men - in an eight-week patrol, the equivalent of feeding a family of four for five years.
The primary source of power for Polaris submarines is a pressurised water nuclear reactor, which provides steam for the propulsion turbines and turbo-generators. Systems for everyday running range from high and low voltage electrical power, steam, hydraulic, pneumatic, lubricating oil and water for essential ship's services, to freshwater, air-conditioning and refrigeration for domestic purposes. A network of communications and control systems is used for the transmission of information, for direction of remote services, and for round-the-clock monitoring of conditions throughout the ship.
Polaris submarines are designed to carry, and maintain in a state of readiness to fire, 16 Type A-3 Polaris missiles in addition to their conventional torpedo armament. The Admiralty believe that if the missiles are ever employed they will have failed in their purpose of preventing war. But to quote Vice-Admiral Sir Hugh Mackenzie (ex Chief Polaris Executive): ‘it is no use pretending to be able to do the job. The stakes are too high to rely on bluff.
Such is the fearsome capability of HMSs Resolution, Renown, Repulse and Revenge that, even in peacetime, the ‘opposition' is extremely unlikely to subscribe to that proverbial saying ‘Out of sight, out of mind'.
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What you think you know about submarine history may not be true.
Almost every book which covers the early history of submarines is riddled with errors. It would appear that the authors, in a hurry to get to the two World Wars and beyond, confined their treatment of the first 300 years of submarine development to a few pages, and their research to a cursory review of other recent books. Let one significant error stand for all: this, from a popular history of the World War I British submarine force:
Almost a hundred years earlier, Pitt had watched Robert Fulton's Nautilus nose her way under the waters of Walmer Roads before attacking and sinking the Danish brig "Dorothea."
There are only two things wrong with this: British Prime Minister Pitt was not present at the demonstration, and Fulton never had his "diving boat" Nautilus in England ; he built only one (many reports to the contrary notwithstanding), which he demonstrated for the French. In France . And which he scrapped in France . There is no evidence that Nautilus was ever used to sink anything, anywhere. Fulton did indeed sink "Dorothea" off the coast of England but he did so with carefully placed explosive charges that he called "torpedoes." To place the charges used boats. Row boats. A short time later, Fulton gave the Earl of St. Vincent (who likewise had not been present at the demonstration) a briefing. The earl's response has ever since been enshrined as the ultimate pithy saying about submarines: "Pitt was the greatest fool who ever lived to encourage a mode of war which they who commanded the seas did not want, and which, if successful, would deprive them of it."
As pithy sayings go, it would be first rate if these were the earl of St. Vincent 's words. However, the statement is Robert Fulton's report of what the earl said. As delivered, the quotation is suspiciously tinged with Fulton 's views of his own transcendent importance.
As pithy sayings go, it would have been even better had the earl been talking about submarine boats. He was not. The conversations centered on Fulton 's schemes for delivering torpedoes by surface boats or rafts, not by submarine.
______________________________________________________________________________
Underwater navigation for submarines
by Robert Derencin
1. Introduction
Navigation is the method of guiding a ship (or a submarine) from one place to another by the most safe and efficient way. The first task of the navigation is to know a ship's (or a submarine's) position at any time. Depending on region of navigation, the navigation is divided into coastal, oceanic (open-sea) and polar navigation. Depending on navigational system, there are terrestrial navigation, astronomical navigation, electronic navigation and dead reckoning navigation. In the case of a submarine navigation there are surface and underwater navigation. In this article will be explained just some navigation systems which can be used when a submarine is submerged (on periscope depth and deeper).
2. A submarine compass and lines of position
2.1. A submarine compass
A ship (a submarine) course is angle between currently direction of navigation and a meridian. The course is controlled by means of compass. From the first days of submarines, there were two kinds of compasses. The very first submarine compasses were magnetic compasses. On the British Royal Navy submarines of Type A (1903) the magnetic compass was located out of the submarine hull, on the submarines' command bridge. The compass was closed inside impermeable stand. Inside the submarine it was possible to keep the submarine's course by means of telescope. The compass and the telescope were improved by the time, but one problem remains. Classic magnetic compasses were not able for navigation on submarines because of the submarines' magnetic shell effect. Because of that, the magnetic compasses' deviations were too big.
The German Hermann Anschutz-Kaempfe designed a gyro-compass equipped with one spinning top (gyroscope) in 1907 (1908). In 1912 he designed gyro-compass equipped with three spinning tops. The new gyro-compass was better for use on rough sea. In 1925 started production of improved gyro-compass (equipped with two spinning tops). Elmer Sperry (USA) patented his type of gyro compass (with one spinning top) in 1911. Also, Sidney Brown (UK) patented his type of gyro-compass in 1916.
A gyro-compass' gyroscope, under influence of the Earth's revolution and gravitation, try to keep its axis parallel with the Earth's axis. On this way, the gyro-compass shows direction of true meridian (i.e. true North). The gyro-compass is insensible from magnetic effects of a submarine or from the Earth's magnetism.
The biggest influence on a gyro-compass is change of geographical latitude. With the increasing of the latitude angle between the gyroscope axis and the Earth axis is bigger and the compass' direction force is weaker. The gyro-compass is useful up to latitude of 70 degrees North and South. Between 70 to 85 degrees North and South the compass is useful with correction of "latitude error" by means of special tables. Above latitude of 85 degrees North and South normally constructed gyro-compass is not useful.
The gyro-compass errors are geographical latitude error, sailing (navigation) error, a submarine acceleration error, a submarine rolling and vibrating error and the compass installation error.
AC (Alternating Current) electric current powers a gyro compass. The current frequency is (for example) 210 Hz, 333 Hz or (these days) 400 Hz. The current can be produced by motor-generator, but these days a semiconductor-converter is used. Because of safety, there must be reserve power-supply.
After starting of a gyro-compass, a gyroscope must to get required speed of its rotation. After the gyroscope gets the required speed it is stabilised in direction of true meridian. Because of that, a gyro-compass must be started from 1 to 4 hours before navigation.
2.2. Lines of position
A submarine position is determined by crossing of (at least) two lines of position. The line of position can be:
3. Terrestrial navigation
In terrestrial navigation a submarine position is fixed by direct visual observing of characteristic natural or artificial coastal objects and/or by measuring of sea depths. Position determined on that way is called "fix" or "observed fix". The characteristic objects are lighthouses, trigonometric points, church-towers, towers, chimneys, buildings, mountain peaks etc.
The observing can be done simultaneously or in time intervals. Position determined by simultaneously observing is more correct. If a submarine speed is up to 10 knots, the simultaneously observing must be done within time period of 1 minute. If a submarine speed is from 10 to 20 knots, the time period is within half of minute, etc.
The terrestrial navigation is used when a submarine navigates in coastal waters. Primarily, the terrestrial navigation is intended for surface navigation. But, when a submarine dives to periscope depth, the submarine is able to fix her position by means of the terrestrial navigation, too. It is more difficult, especially during rough sea, rain and overcast. Observing range is limited because of low altitude of the periscope. But, it is possible to fix the submarine position.
Picture 1 shows situation in which a submarine fixes her position by means of observing of two coastal objects. Azimuth of the first object is 0 (zero) degrees and azimuth of the second object is 90 degrees (from the submarine). Because positions of the objects are known (the object are drawn in navigational chart) and the submarine position is not known, both azimuths must be summed-up with 180 degrees.
1st azimuth: 0 degrees + 180 degrees = 180 degrees
2nd azimuth: 90 degrees + 180 degrees = 270 degrees
Then, two lines of position must be drawn on the navigational chart. The first line of position azimuth is 180 degrees from the first object. Second line of position azimuth is 270 degrees from the second object. Intersection of the two lines of position is the submarine position. In this case, both lines of position are straight lines. Beside the position must be registered time of the last observing. For example, if the second object was observed lately than the first object, time of the second object observing must be written (in this example- 1930 Z).
Picture 2 shows situation when a submarine navigates towards a coast and on the coast is just one object (drawn on navigational chart). But, on the chart are also drawn sea depths (i.e. isobar). The submarine observed the object. Azimuth (from the submarine) is 0 (zero) degrees. As in example mentioned above, the azimuth must be summed-up with 180 degrees, because position of the object is known, position of the submarine is unknown and line of position must be drawn from the object.
0 degrees + 180 degrees = 180 degrees.
The line of position is drawn 180 degrees from the observed coastal object. In meantime, sea depth is continuously measuring. When the depth of 140 metres is measured, the submarine position is fixed. In this case, the position is intersection of two lines of position- the azimuth (a straight line) and the isobaric (a curve). As mentioned in the first example, beside the position must be registered time of fixed position (in this example, 0645 Z).
In the two examples mentioned above the positions are fixed by intersections of two lines of positions. Because of safety, in practice a navigator must try to fix a position by three or more lines of positions. If that is not possible, and there are just two coastal objects and position is fixed by intersection of two azimuths, it is good to check the position by sea depth measurement, for example.
4. Dead reckoning navigation
Submarines used dead reckoning navigation for their underwater navigation from the first days. In this chapter will be described the simplest way of the dead reckoning navigation, used in WW1 and WW2. Even today, if there are not any another navigational system, this way is usable for a submarine underwater navigation.
Picture 3 shows an example of the dead reckoning navigation. Position P1 is starting or any another precisely fixed submarine position. From the position P1 is drawn the submarine course, in this example the course is 75 degrees. The submarine speed is 10 knots (by the submarine log). It means that in one hour the submarine passed distance of 10 nautical miles. In one and half-hours the submarine passed 15 nautical miles. In this example the first position is fixed at 1900 Z. At 2030 Z the submarine position is 15 nautical miles from the first position. Distance of 15 nautical miles is plotted on the submarine course; intersection of the course and little tiny line is the submarine dead reckoning position at 2030 Z (P2).
The dead reckoning navigation is based on the first precisely fixed position; a submarine's course (drawn on nautical chart), a submarine speed and passed time. The dead reckoning navigation is important for a submarine underwater navigation and for the polar navigation.
The dead reckoning position is fixed by means of compass and log. Externals (negative) factors are sea currents. The sea currents are streams (because of tides, mainly in coastal waters) and permanent (ocean) currents. Currents and streams together make flows. Their direction and rate (speed) define the sea currents.
In some channels and coastal waters the streams rate is from 4 to 5 knots, somewhere up to 10 knots and more. If the sea current direction is exactly opposite to a submarine course, the submarine speed will be lower. If the sea current direction is same as a submarine course, the submarine speed will be higher. All other current directions get a submarine away from her course. Graphically solution of underwater navigation in the area of permanent current is based on adding of vectors.
Picture 4 shows situation when a submarine navigates underwater in area of permanent current. Position P1 is precisely fixed the submarine position. The submarine course (75 degrees) is drawn from the position P1. Firstly, dead reckoning position (P2) must be fixed, without influence of the sea current. Position P2 is fixed by means of the submarine speed and passed time. Line between P1 and P2 is the first vector. The sea current direction (SE) and the current rate define second vector. Position P2 is moved in direction of the second vector (sea current). At the end of the second vector is position P3. Position P3 is dead reckoning position, given by influence of the submarine course and speed, passed time and the sea current. Vector P1-P3 is result of adding of vector P1-P2 and vector P2-P3.
If a sea current change its direction and rate, it is necessary to fix a submarine (dead reckoning) position at any change of the current direction and rate. Fixing of dead reckoning position is delicate work, which requires a lot of practice in navigation. Even then, the dead reckoning position can be incorrect. The dead reckoning position is just approximate. Reliability of dead reckoning navigation depends on determining of (as precisely as possible):
Sources of errors in dead reckoning navigation are incorrectly steering, imperfection of navigational instruments (compass, log...) and external influence (sea currents). During the underwater navigation it is necessary to keep ordered course and speed as correct as possible.
5. Omega navigation system
Omega navigation system is phased hyperbolic radio navigation system of the biggest range. The Omega system covers the whole Earth. The system uses Very Low Frequencies (VLF), from 10 kHz to 14 kHz. The system is in experimental work from 1960. From 1972 to 1975 a network of transmitters is built (8 transmitters positioned all around the Word). The Omega system consisted of land transmitters and Omega receivers on ships and submarines.
Because of used frequencies (10 kHz to 14 kHz) submarines are able to use the system even when they are submerged, up to depth of 10 to 30 metres.
Working principles of the Omega system:
The land transmitters transmit signal on three frequencies, 10.2 kHz, 13.6 kHz and 11.33 kHz. Frequency 10.2 kHz is main frequency. A submarine Omega receiver measures phase difference of signals (frequency 10.2 kHz) which are transmitted by two Omegas transmitters. If the submarine position is already known within limits of plus/minus 4 nautical miles, it is enough to fix the submarine position. If the position is not already known within limits of plus/minus 4 nautical miles, it is necessary that the Omega receiver receive signals of 13.6 kHz and 11.33 kHz. Those signals are intended for identification of lane. The first Omega receivers display marks of the hyperbolas. There is also Omega plotting charts, with drawn hyperbolas. The Omega plotting charts are intended just for fixing of a ship (a submarine) position by means of the Omega system. The position is determined by intersection of two hyperbolas, which marks are displayed by the Omega receiver. It means that in the Omega system lines of position are hyperbolas. On the Omega plotting charts theoretical spreading of electromagnetic waves draws the hyperbolas. Because of that there are also Omega propagation correction tables for 10.2 kHz, which partly solve problem of hyperbolas deformation. The modern Omega receivers the phase difference of signals transmitted by two or more pairs of the Omega transmitters transform directly in geographical coordinates.
Accuracy of the Omega navigation system decreases by distance between the Omega transmitter(s) and a submarine. At the Omega system signal final range errors are 1.5 to 2 nautical miles during the day, 2 to 3 nautical miles during the night and more than 3 nautical miles during the sunrise and the sundown.
6. Hydro-acoustical navigation system
Hydro-acoustical devices help a submarine to "see" environment around itself. The hydro-acoustical devices are sonar (active and passive), echo sounder, ultrasonic log (Doppler Sonar Navigator) etc. There are ultrasonic transmitters positioned on the ocean floor. Positions of the transmitters are drawn on special (naval) charts. Each transmitter has its own signal characteristic.
A submarine fixes azimuth and distance of particular transmitters by means of its sonar. That way the submarine fixes its position. Of course, one particular navy has the underwater transmitters just for its submarines and just submarines of that particular navy know positions and types of the transmitters. A submarine also uses the hydro-acoustical navigation during navigation in polar area, under ice cover.
Picture 5 shows example of polar navigation. By means of special echo sounder a submarine simultaneously measures sea depth under its keel (signal 2) and distance between the submarine and ice cover (signal 1). By means of its sonar (in active mode) the submarine measure azimuth and distance of barrier (signal 3) which stay on the submarine course.
7. Inertial navigation system
Inertial Navigation System (INS) is passive and autonomously navigational system, which is based on inertial and gyroscope principles. The INS determines dead reckoning position by double integration of measured accelerations (of a submarine).
The INS was used for the first time in the German rockets V2 in 1944. For the underwater navigation (for the first time), the INS was used on the American nuclear submarine USS Nautilus when the submarine navigated over the North Pole, under ice cover, in 1958. The INS consists of stabilized platform, accelerometers, integrators and computer. There is also a unit for elimination of accelerations registered by accelerometers, which are not included in real movements of a submarine. Stabilized platform insures precisely horizontal position and correct orientation of accelerometers, by means of gyroscopes.
Accelerometer is an instrument for measuring acceleration. The acceleration is a change of velocity. The two accelerometers are enough for a surface ship, i.e. an object that is moving in two dimensions. A submarine is moving in all three dimensions and because of that for the underwater navigation the three accelerometers are needed, two accelerometers are directed towards axis North-South and axis East-West and one is directed towards the Earth midpoint. Accelerometers determine acceleration of an object in particular direction, which is named measuring axis of accelerometer. Inside of an accelerometer is positioned a sensor mass (i.e. measuring sensor). Mainly, the sensor mass is plunged into a liquid, all together are inside of an accelerometer's cylinder.
Any change of velocity (acceleration) of a submarine makes change of position of the measuring sensor inside of accelerometer. The change of the measuring sensor position is transformed into electrical voltage and sent to the integrators.
Integrator is an instrument for performing numerical integration. In the INS integrators integrated a submarine acceleration (measured by the accelerometers) and get the submarine true velocity. By integration of the velocity the integrators get the submarine travelled distance. All data (information) are entered into computer: starting or the last precisely fixed position, correction of gyroscope axis deviation and (after the second integration) travelled distances in axis North-South, axis East-West and axis which is directed in direction of the Earth midpoint. The travelled distances are differences of geographical coordinates (latitude and longitude).
By means of the all data the computer get geographical position. Errors in the INS increase by time and not by travelled distance. Because of that, the INS is not fully autonomous during longer period of time. The INS requires control and correction by some other navigational system, as hyperbolic navigational system, satellite navigational system etc.
Good point of the INS is that the INS not required any external information. Because the INS not transmits any energy and not receives any external signals, the system keeps its presence in secret. The INS not requires any other navigational unit, as gyrocompass, log etc. The INS independently gets current velocity, a ship (a submarine) true course and travelled distance.
Once again, a submarine need the INS equipped with three accelerometers. One accelerometer is directed in direction of axis North-South, one accelerometer is directed in direction of axis East-West and one accelerometer is directed in direction of the Earth midpoint. The reason why a submarine needs three accelerometers is because the submarine navigates in all three dimensions, unlike a surface ship, which navigate in just two dimensions. And because of that a surface ship need the INS equipped with two accelerometers.
Picture 6 shows example of part of an INS equipped with just two accelerometers because of more easily understanding. The accelerometers are positioned on stabilized platform, which is always in horizontal position. The first accelerometer (A1) is directed in direction of axis North-South and measure acceleration in this axis. The measured accelerations (a1) get to the first integrator (INT). Result of the first integration is true velocity (v1) in direction of axis North-South. The true velocity (v1) goes to the second integrator. Result of the second integration is travelled distance (s1) in direction of axis North-South, i.e. difference of geographical latitude.
The second accelerometer (A2) is directed in direction of axis East-West and measure acceleration in this axis. Measured acceleration (a2) gets to the first integrator. Result of the first integration is true velocity (v2) in direction of axis East-West.
The true velocity (v2) goes to the second integrator. Result of the second integration is travelled distance (s2) in direction of axis East-West, i.e. difference of geographical longitude. The travelled distances (i.e. differences of geographical latitude and longitude) get to the computer (not shown on picture 6). After the computer add the travelled distances (s1 and s2) and starting (precisely fixed) position, the computer gets current position.
In this chapter the INS is explained in a simplified manner. In reality the INS is very sophisticated. As a matter of fact, nothing is simple on a submarine.
8. Conclusion
There are many preparations for efficacious navigation. In this chapter will be explained the few ones. After a submarine get out of a shipyard the submarine first goes to test-voyage. Any submarine has its own manoeuvring elements as velocity, maximum range of navigation, inertia, diameter and period of a submarine turning, angle-velocity of a course change, decreasing of velocity when a submarine change its course etc.
There are specially equipped submarine testing sites for measuring velocity of a submarine, particularly during the submarine surface navigation, navigation on periscope depth and finally full underwater navigation. Underwater cables (at the bottom of the sea) are placed vertical to direction of a submarine motion. The cables are parallel one to another and positioned on the precisely fixed distances. Special indicators, positioned on land, show maximum induction of electromagnetic energy in a particular cable, when a submarine passes over it. This way it is known how much time the submarine needs to travel from one cable to another, i.e. the submarine velocity.
The submarine testing sites could be equipped with hydro-acoustical devices (active and/or passive). The hydro-acoustical devices are positioned underwater, anchored on some depth. By means of a submarine's sonar (in active and/or passive mode) and the anchored hydro-acoustical devices it is easy to fix the submarine current positions and finally to fix the submarine underwater velocity.
By the manners mentioned above, a submarine velocity is determined with specific number of the submarine's propeller revolution. The velocity is determined for 1/4, 1/2, 3/4 power of the submarine's engine and for maximum permanent velocity of the submarine.
Before any navigation a navigator must research navigational charts and navigational manuals which are concerned for the navigational area. In the manuals there are information about sea currents, sea tides etc. Depths of the sea (marked with isobaths) are especially important.
Finally, during the navigation, any new information about sea conditions in the navigational area (especially about sea currents) and about the submarine navigational characteristics under the influence of the sea conditions must be recorded because of further researching.
A submarine's position must be known at all times during the navigation of the submarine. The first reason is safety of the submarine. Also, just the submarine's precisely fixed position ensures that the submarine is ready for combat at any time. There is currently no perfect and absolutely accurately navigational system. Accuracy of the any navigational system must be checked by another navigational system(s).
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UB
(former HMS Seal)
Type: Porpoise (British mine laying submarine; 6 built)
Builder: Admiralty Dockyard, Chatham
Ordered:
Laid down:
Launched: Sep 27, 1938
Commissioned: Jan 28, 1939 under Lieutenant Commander Rupert Philip Lonsdale
The officers:
Commander: Ltd. Cdr. Rupert Philip Lonsdale
Number One: Lieut. Terence Butler
Navigation Off.: Lieut. Trevor Beet
Sub-Lieut L. Henderson
Sub-Lieut Philip Boulnois
Engineer: Lieut. (E) R. H. S. Clark
The career
HMS Seal reached the message about the beginning of the war in Aden. So they absolved the first patrol in the Gulf of Aden . After return to England there were some patrols in the North Sea and one convoy-protecting patrol in the Atlantic .
Then HMS Seal was transferred to the 6st Submarine-Flotilla under the command of Commander S. J. S. Bethell .
The last patrol of HMS Seal
April 29, 1940 . HMS Seal started its journey for the operation "DF 7" with 50 Mines from Immingham. The operational aim was to lay a mine barrier near by the Swedish island Vinga. That location was in the German transport route to Norway .
May 04, 1940 02.30 a. m. HMS Seal was attacked by a German "He 115" aircraft from the "Küstenfliegergruppe 76" in Aalborg . The boat was slightly damaged.
May 04, 1940 09.00 a. m. They started to lay the mine barrier. After 45 minutes all 50 mines have been correctly laid.
May 04, 1940 06.30 p. m. HMS Seal was badly damaged by a mine hit and laid on ground at 30 meter depth.
May 05, 1940 01.30 a. m. The crew managed to surface the boat and attempted to reach Swedish waters, but one hour later a German Ar 196 seaplane discovered the submarine. The "Arado" under Oblt. Mehrens attacked HMS Seal with 2 bombs and machine-gun fire. A few minutes later a second "Arado" under Oblt. Schmidt also attacked the boat. On board the HMS Seal some of the crew were wounded. Then the boat was captured by the German seaplanes.
May 05, 1940 06.30 a. m. German "UJ 128" (Unterseebootsjäger 128; the pre-war trawler Franken ) commanded by Kptlt. Otto Lang arrived the place and towed the submarine to the now German naval base Frederikshavn (where the German 12th UJ-flotilla. was located)
May 11, 1940 02.30 p. m. HMS Seal was towed by the German tug "Seeteufel" (Sea Devil) and reached Kiel and was brought in to the Germaniawerft <../technical/shipyards/germania.htm> yard in Kiel , where the submarine was repaired.
UB
On Nov 30, 1940 the former HMS Seal was commissioned as UB commanded by Fregkpt. Bruno Mahn . He was an U-Boat veteran from the World War I (Commander of SM UB-21 ) and at this time 52 years old. The UB had limited value for the Kriegsmarine except for training and propaganda uses. One benefit for the Germans was that through analysis on the British torpedoes they were influenced to make a better torpedo-detonation device for the German weapons which were at that time highly unreliable.
On July 31, 1941 UB was decommissioned from the Kriegsmarine and on May 3, 1945 she was scuttled <../fates/scuttled.htm> in Heikendorf Bay (in position 54.22N, 10.11E). Her wreck was later raised and broken up.
Technical information
Displacement (tons) 1770 sf 2113 sm Length (m) 89.30 oa Breath (m) 7.74 oa 5.79ph Draught/ Height (m) 5.18
Power (hp) 3300 ehp sf 1630 ehp sm Speed (kts) 14.75-16.00 sf 8.7 sm Oil Supply (tons) 138t max Torpedoes/ Mines 12 120 Mines
HMS/m Seal
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Four hundred feet below the gale-lashed surface of the North Atlantic, Chef Stuart Young and Leading Chef "Shiner" Wright of Her Majesty's submarine service are baking bread. It's nearly midnight, and in a galley measuring eight feet by ten, the two men are kneading the dough that, six hours later, will be fresh rolls on the breakfast menu for the 120-strong crew of HMS Sceptre.
"If it wasn't for the food, you'd forget what day of the week it was," says Young. "Your day on a submarine is split up between eating, working and sleeping, so food's vital."
So it is that when the weekly menus of HMS Sceptre are pinned up outside the galley in the submarine's cramped catering corridor, the same items appear on the same days of week. Fish on Friday, surf 'n' turf - steak or scampi - on Saturday, pizza on Sunday, and so on.
Some of the names on the menu are submarine jargon, that mixture of English and the traditional language of the Royal Navy, known as "Jackspeak". For instance, "yellow peril" is kippers, "seggies" are tinned grapefruit segments, and a dish that Chef Young won't make, deep-fried Spam, is known as "Elly's wellies".
With 120 men on board what is essentially a heavily armed, 85-metre-long tube of nuclear-powered steel weighing in at nearly 5,000 tons, there's a lot of cooking to be done. The galley staff produce hundreds of meals per day for the ship's crew who work a constant round of shifts of six hours on, six hours off. After 12 hours on board a submarine, it becomes impossible to remember if it's day or night.
One deck up from the galley, the operations, or "ops", room is busy. In the raised swivel seat at the centre of the room is the Officer of the Watch, at this late hour, 32-year-old Lieutenant James Stilwell from Hampshire. He's wearing the new submariner's uniform, which consists of dark navy trousers and shirt, with a small Union Jack flag stitched on to the left arm. The two thick gold rings of his lieutenant's badge of rank are in the centre of his chest.
"This job is horrible for your body," he smiles, "but what makes the whole thing so enjoyable is the exclusivity of it, and the exclusivity of those you're working with. The whole thing's unusual, different, and something that other people don't get to do."
As the father-of-two explains how he celebrated his birthday the day before, and how he misses his wife and two children, he breaks off to issue a quiet command, repeat a correction of course to the helmsman, or to acknowledge any one of a number of pieces of information coming from the sonar room, the engine room aft, the periscope operator or the helmsman in front of him. He is surrounded by a mass of dials, pipes, screens, control panels and lights. With space at an absolute premium, every square inch is put to good use.
HMS Sceptre is a 30-year-old nuclear-powered submarine, or "SSN", which stands for "Ship Submersible Nuclear". Four hundred feet above her are the stormy waters of the Sound of Rona, a stretch of open water that lies between the barren mainland of north-west Scotland and the island of Skye. Sceptre is running sea-trials, two days into the beginning of a five-month patrol that will see her visit Gibraltar, the Gulf and the Middle East.
Here in the Sound of Rona, she's carrying out a series of exercises in order to find out her "noise signature" - in other words how easy it is for her presence to be picked up by the sonar equipment of surface ships or other submarines.
"The great thing about submarines is that there's no room for passengers or bullshitters."
The "exclusivity" that Stilwell talks of is manifested in the ops room by a sense of quiet, confident professionalism, from people who know that they are good at what they do and are in an environment where excellence is crucial. Every man's life is in the hands of those around him. As one sailor says: "There's no question of cocking up when you're driving a 5,000 ton nuclear reactor 400 feet underwater, loaded with high explosives."
"The great thing about submarines," says another lieutenant on board, "is that there's no room for passengers or bullshitters."
This would not be to say that the five cramped, crowded decks of HMS Sceptre are devoid of humour. Far from it. When the simple constituent parts of life - eating, sleeping, moving, exercising - have to be carried out in an environment that is completely removed from most people's everyday existence, keeping a balanced perspective helps. The men's gripes are those of serviceman everywhere: pay, the deleterious effect of the job on relationships and marriages, poor accommodation. But most admit to liking the life. Many seem to love it.
"Things these days on a submarine are done at a slower pace. We're not having to dive in a hurry to escape attack by aircraft."
A deck below the ops room, the Junior Rates Mess is bustling. In the outside world it may be one o'clock in the morning, but on board HMS Sceptre men are just about to get up and work, go to bed, have a shower, exercise or, in the case of four able seamen in the mess, play a game of Trivial Pursuit.
Next to the board game, the mess is crowded. Lightly obscene, personalised teasing hangs in the air. Everybody seems to have a nickname.
On the padded cushions of the mess Able Seamen "Dusty" Miller and "Whisky" Walker are watching the game of Trivial Pursuit. Operator Mechanic "Sandra" Bulloch is reading a book by Michael Moore. Above their heads on the walls are wooden-framed posters of the tennis player Anna Kournikova, and a busty nurse. Copies of Loaded and Zoo are in evidence, while in the DVD cupboard films such as Gladiator and Heat are stacked. What seem absent are the totemic films of submarine iconography, Das Boot, Above Us the Waves and Grey Lady Down.
Because most people will never see the inside of a modern nuclear submarine, perceptions of submarine life are based on movies like 1990's Hunt for Red October starring Sir Sean Connery or, more recently, U-571 which was in cinemas in 2000.
The enormous ballistic nuclear submarines of the Vanguard Class might be slightly more spacious than the subs you see on film, especially the diesel-powered Second World War ships, but the principles remain.
"Things these days on a submarine are done at a slower pace," explains Lieutenant Stilwell. "We're not having to dive in a hurry to escape attack by aircraft."
Three decks below, the torpedoes are stacked high in the torpedo room, or "bomb room". The Spearfish torpedoes are massive black missiles, 20 feet long, and the width, say, of a firmly girthed submariner who's been living on the high-carbohydrate dishes pushed out by the galley. There are five torpedo tubes, including one that points downwards.
"The best way to get a submarine is from another sub," explains Chief Petty Officer Dave Diffey, pointing at this tube. Then, looking around him at the cramped conditions, he adds: "The only things that could stop us from staying at sea forever are food and the sanity of the crew."
With 22 years of service, he is effectively the vessel's sergeant-major, responsible for discipline and the smooth running of HMS Sceptre. Around him the "bomb room" is cramped. On bunks set in, around, above and below the torpedoes, are sleeping men. A foot protrudes from under a blue quilt; an occasional snore erupts. The smell is of a mixture of electronically scrubbed air, oil, blankets and other people's lives. Hundreds of cartons of UHT milk are lashed to a platform between bunks. Holdalls containing the men's possessions are stacked everywhere. The only sound, 400 feet underwater, is a slick, gliding purr.
Curiously, there is also a place for the men to smoke.
On the deck above, behind drawn curtains, are the rows and rows of bunks where the men sleep. The "racks" are stacked three high, each about two feet high by six long. Privacy is almost non-existent. Nowadays most of the submarine's crew have their own designated sleeping accommodation, but "hot-bunking", sharing of bunks, continues for some, mainly the recent additions to the crew.
Those who are off duty but not sleeping are elsewhere in the submarine. In a crowded room filled with protruding metallic edges and equipment, one man is training on an exercise bike. There's a rowing machine crammed into the torpedo room, enabling men who hardly have space to walk from one day to another to take exercise.
Curiously, there is also a place for the men to smoke. Like smoking rooms everywhere, this cramped cupboard smells of old nicotine; a stub-filled, catering-size jam tin is the ashtray. A nuclear submarine produces its own air, water and power, and extractor fans suck the cigarette smoke out, but the smell lingers.
Talk in the smoking room is of the tattoos that one man intends to get done when HMS Sceptre reaches Singapore.
"Bloody great pink dragon, this long," he explains. Then there's a lengthy anecdote, or "dit", about the unfortunate sailor from the sonar room who went to get "Bernadette" tattooed onto his chest while drunk.
"He woke up and all there was written was ‘Bernard'," laughs the submariner, pinching a cigarette between thumb and forefinger. "So he got a socking great black panther done over it."
By six o'clock in the morning, it's nearly time for the watch to hand over and breakfast to be served. In the officers' wardroom, or mess, a steward has laid out places and is serving food. Bacon, sausages, baked beans, tinned tomatoes, fish cakes and eggs, fried or poached, are on offer. A cereal selection sits on the tiny sideboard, underneath the small glass-fronted cupboard where HMS Sceptre's wardroom silver is stacked.
The officers eat in two shifts. At the head of the table, just under the photograph of the Queen and the Duke of Edinburgh attached to the curving bulkhead, sits the ship's executive officer, or second-in-command. This is the calm and laconic Lieutenant-Commander "Stu" Capes. In conjunction with the captain, he oversees the smooth running of the submarine. A small tray in the corner with a silver-plated napkin ring is being made up for the captain who'll be eating in his cabin.
The bread rolls cooked six hours earlier are served. The galley are clearly dab hands, for the rolls wouldn't taste out of place in a Viennese café. They are known in submarine-speak as "fat pills", and the process of trying to fill your bread roll with each item on your breakfast plate is known as "wedging up a fat pill". Talk is of a fellow submarine officer who once managed to get everything into a roll. "Christ, could that man wedge," sighs one officer in admiration.
No work is discussed at the table; all attention is fixed on the new electric pepper-grinder, which has a light on the bottom enabling it to be used in the dark. The atmosphere is calmly assured and humorous.
"Submarines are just as relevant as they have ever been"
The captain's tray is walked through to his tiny cabin behind the ops room. Neat and with that air of authority that senior command seems to produce, Commander Mark Titcomb is the captain of HMS Sceptre. He doesn't have a nickname, but is referred to as "the old man", even though he is only around 40.
Titcomb has been in the Navy for 16 years, mostly in submarines, serving in the Adriatic during the Bosnian campaign, as well as tours in the Pacific with the US Navy, and in the Atlantic and the Caribbean. He also served as the captain of a minesweeper working in a search capacity off Northern Ireland.
The crew of HMS Sceptre are keen to avoid discussion of anything tactical or operational, but one question begs an answer. What is the role of submarines with the Cold War now over?
"Submarines are just as relevant as they have ever been," says Titcomb. "They can be used for operating with Special Forces, intelligence gathering, operating covertly or overtly and in the delivery of Land Attack Missiles as in Kosovo or Afghanistan."
Shortly after breakfast, HMS Sceptre surfaces. It's eight o'clock in the morning, but this far north no dawn has yet broken. The Sound of Rona is storm-tossed, with sleet and rain driving in horizontally from the darkness. Getting to the top of the "fin", or conning tower, requires a slippery climb up a 25 foot oil-coated ladder in pitch darkness.
At the top the wind hits like a frozen mallet. An officer and a lookout, well wrapped up in hooded waterproofs, are standing in a cramped space under the base of the periscope, scanning the horizon. The Union Jack insignia of the Royal Navy's White Ensign flaps bravely, taut in the freezing wind of the Western Isles.
But it's not for long. In a few days the helmsman will alter his course, taking the black form of HMS Sceptre southwards to the Bay of Biscay, and first landfall in Gibraltar. The previous night, quiet talk among the men at scattered points throughout the submarine had been of the sun, and what the first beer will taste like on the southernmost tip of Europe.
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