South African Military History 
Society

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MOWBRAY
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CAPE TOWN BRANCH
NEWSLETTER No 451 - MARCH 2017

Our speaker on 8 February 2017 was fellow-member Captain John Lamont LWM MMM (S.A. Navy Retd), whose topic was 'Operating a Submarine', but not 'Submarine operations' - an entirely different subject. The submarines discussed by our speaker were the Daphne class submarines used by the S.A. Navy, on which Capt Lamont served during his career with the Navy.



The Daphnes were designed and built in France during the years 1964 to 1975 with 25 being built for service with the French, South African, Portuguese, Spanish and Pakistani Navies. Designed for coastal work, they were used as such by the French along their Mediterranean coastline. Two were lost by the French but all the other boats gave good service for their operators.

Of conventional design, they were 58 metres long with a double hull and fuel and ballast tanks outside the pressure hull. They carried 8 torpedo tubes forward and 4 at the stern, with no reloads. The crew was 51 in number, who fitted in somehow with all the machinery, batteries, stores, etc. A cruise in a submarine was no luxury cruise.

A normal surface vessel displaces its own weight and sails on the surface. Submarines operate differently. For a large part of a cruise the submarine operates beneath the surface and uses its snorkel to get fresh air. So the design of a submarine is very different to a surface vessel. A sphere has maximum strength. A cylinder is the next strongest with its cross-sectional shape. The ends of the cylinder are weak but, by placing a hemisphere at each end of a cylinder, its strength is increased. This is the optimum shape for a pressure-resisting hull in a submersible vessel.

The next item to be considered is stability - any vessel travelling underwater needs to be stable. The arrangement of the "contents" of a submarine - operators and their stores, engine/motor and energy in the form of batteries, and especially the latter, need to be in a position below the centre-line which allows the centre of gravity to be below the centre-line, with the vessel remaining upright. The cylinder with domes at both ends is not hydrodynamic so the rear hemisphere is replaced by a cone. Submarines operate under water, water being kept out by a pressure hull. It has energy, motor and operators but it needs to move so a propeller is added at the stern.

The next requirement is buoyancy or the vessel will not float. Buoyancy is an upward force relative to a fluid. The buoyant mass of a vessel is the volume of fluid displaced by the vessel times the density of the fluid it must float in. The specific density of seawater is 1.025 so, for a vessel to float in seawater, the volume of water displaced by the vessel must be less than 1.025 the volume of the vessel. If mass exceeds buoyancy, the vessel will cease to float.

Submarines operate under water. The pressure hull is the critical volume. To submerge, the mass of the pressure hull must be just sufficient to cause the submarine to lose buoyancy. To operate on the surface, the buoyancy of the submarine needs to be adjusted by adding tanks to the outside of the submarine, which can be filled or emptied.

To remain underwater the mass of the submerged submarine must be constantly adjusted to the exact specific density of the surrounding water. This is done using special regulating tanks to add or remove mass from the fixed volume of the pressure hull. For reasons of space either inside or outside the submarine, the volume of these tanks is limited.

When operating on the surface, the buoyancy of the submarine also needs to be adjusted. Sections are added to the outside of the submarine - these are ballast tanks that can be filled or emptied. A surfaced submarine, like a ship, has a mass that is less than its buoyancy. The centre of buoyancy is below the centre of gravity. When it submerges, the submarine's mass remains constant but its buoyancy reduces and enables it to submerge.

If this is not complicated enough, the submarine has a crew who need to live - accommodation (sleeping, relaxing), feeding (cooking, eating) and hygiene (washing, ablutions). But the submarine primarily has a military role to fulfil: the crew are tasked to navigate, gather information on surroundings and contacts, compile this into useful data, control the submarine under water and handle the weapons. It must keep and change course, keep and change depth and alter speed. The crew need to man watches. They must also move around in the submarine. As they move fore and aft, this transfer of mass affects the longitudinal angle of the submarine - the balance of the submarine about its centre of gravity.

This problem is solved by using trim tanks. There are four of these, two each fore and aft. One of each pair contains fresh water. The water volume is a constant and is moved by low pressure air, both fore and aft to compensate for movement of crew, transfer of fresh water from storage tanks, the usage of diesel fuel and other similar daily functions. Trim tanks can be filled with sea water in event of an emergency.

Conventional submarines use diesel to power the generators making electricity to charge the batteries. As diesel is combustible, it is best stored outside the hull as it also takes up a lot of space. To do this ballast tanks are moved and fuel tanks inserted. The specific density of diesel is 0.9. It is positively buoyant, so the more one carries the more buoyant the submarine becomes. Other consumables are loaded such as fresh water, food, lubricants, oxygen generating chemicals, CO2 absorbing chemicals, etc. This all adds mass to the inside the submarine but has the added benefit of compensating for the natural buoyancy of the diesel fuel on board. As the patrol progresses, fuel is consumed, making the submarine less buoyant. The other consumables are also used up making the submarine even lighter, but still partly compensating for the fuel. Any discrepancies and variations in the ballast of the boat are compensated by using the regulating tanks.

While the submarine is operating, the crew are moving about and the surrounding sea is changing, there needs to be an immediate means of controlling the vessel. Diving planes, which are in effect horizontal rudders, are used for this purpose. A set is placed forward and another pair aft. The optimum effect is gained by using the aft diving plane which has the best water-flow from the propellers. The diving plane is put in the positive position (pointing up), this pulls the stern down and the propeller pushes the submarine up. Conversely, to go down put the aft diving plane in the negative position, pointing downwards. This lifts the stern and the propellers push the submarine down. The forward diving plane has its best effect at slow speed when it nudges the bow up using a positive angle or down using a negative angle. At higher speed, this does not add to the control of the submarine but causes noise, the enemy of a submarine, and is not used.

From all the above, it must be obvious that submarine crews need to be very highly trained and intelligent people. In the SAN they are all volunteers and specially selected to ensure that they can live in harmony with a large number of others in a very confined space for an extended period. All of them need to be multi-skilled. Capt Lamont rather modestly said that our submariners are really very normal people. Very normal maybe but very skilled at their job. Unlike the S.A. Navy, in other navies with large numbers of submarines the crews are not all volunteers - sailors are conscripted to the submarine service when needed to make up the numbers.

Capt Lamont then discussed the waters round the South African coast which are ideally suited for submarine operations. The different thermal layers caused by contact between warm surface waters and cold subsurface water propelled by currents of varying power and depths, help submarines escape detection by the sonar systems of anti-submarine warfare vessels. Our submariners have a good knowledge of these thermal layers.

Captain Lamont then described the tactical exercise Casex D6 held in local waters on 9 July 1973. The participating ships were a Royal Navy force consisting of the cruiser Tiger (which carried Sea King anti-submarine (A/S) helicopters), the frigates Hermione, Dido and Mohawk, along with the nuclear submarine Dreadnought. These were escorting three Royal Fleet Auxiliaries (RFAs) Stromness, Tidereach and Regent. Supporting these were the South African frigates President Kruger and President Steyn, the destroyer Jan van Riebeeck and the tanker Tafelberg. Aircraft were supplied by 35 Squadron S.A.A.F. and 826 Squadron F.A.A.

Opposing this array was the "enemy submarine" SAS Emily Hobhouse commanded by Lt Cdr (later Vice Admiral) L.J. Woodburne, whose mission was to penetrate the screen and "sink" the Fleet Auxiliaries. The RN believed that an old-fashioned diesel submarine would find it almost impossible to penetrate such a large screen. But Senior Officer S.A. Submarines Capt E. M. Kramer (later Rear Admiral) made the following signal to Emily Hobhouse "Remember David and Goliath. I am confident that you can also do it".

Emily Hobhouse did penetrate the screen and was judged to have "sunk" all three RFAs and the nuclear submarine Dreadnought. This achievement was all the more remarkable because safety requirements had necessitated the South African submarine remaining above 280 feet (91 metres), which was to her disadvantage. However Cdr Woodburne and his crew had a good knowledge of the thermal layers off our coast and used it to good effect.

The Royal Navy were shocked by the result of the exercise and were very keen to know what modifications had been made to our submarines. The answer to that there was "none", but local knowledge and well-trained crews made the difference.

Capt Lamont spoke of the freak waves that occur along our coastline between Cape Town and Durban. The effect of these could be felt even at the depths our submarines operated and the effect on other ships caught on the surface could be catastrophic.

Our speaker noted that the submarine service can be a very dangerous one and mentioned some of the disasters that have occurred in the past, including the loss of the Russian submarine Kursk. She was lost in the Arctic Ocean during a Russian Navy exercise. The full details are not readily available but it is thought that an experimental torpedo using an unstable propellant exploded, setting off the entire set of torpedoes carried. This propellant had been rejected by most navies at that time.

Cdr Bisset thanked Capt Lamont for a very interesting lecture and presented him with the customary gift. Tea followed with an extended further discussion.

MEMBERS
We welcome Mr A C Thorndike and Mr D Swanepoel who joined us at the last meeting and hope to see them at our future meetings.

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FORTHCOMING MEETINGS

09 MARCH 2017: COLONEL R J GORDON AND HIS ROLL IN THE COLLAPSE OF THE VOC GOVERNMENT AT THE CAPE IN 1795 by Dr. Dan Sleigh.

Our speaker for this coming meeting (next week), certainly needs no introduction. Dr Dan Sleigh, as historian, writer and novelist has been the recipient of numerous literary and also cultural awards for his in-depth and diligent recording of the history and the role of the Vereenigde Oostindische Compagnie (VOC) in the establishment of a European settlement at the Cape during the mid-17th century.

The history of the VOC is a topic with which our speaker is well acquainted. The demise of the VOC at the Cape in September 1795 is known to most, but few know the intricate details and the skullduggery behind the actions of some leading military figures during this period. The illustrated talk will highlight various aspects of human relationships during the three-month campaign leading up to the first British occupation of the Cape, and in particular, the role played by Colonel Robert J. Gordon, who was in charge of the Dutch troops during the campaign. His controversial surrender of the defending troops and the defences of the Cape to the British invaders had resulted in many acrimonious reproaches and accusations and the fierce slandering of his actions and character, eventually forcing him to commit suicide.

11 APRIL 2017*: A HANDFUL OF HARD MEN - THE SAS AND THE BATTLE FOR RHODESIA, by Hannes Wessels.

Our speaker will be Hannes Wessels, journalist and author of books on the then Rhodesia, of which the title of the evening's lecture is also the title of his most recent book, A Handful of Hard Men; The SAS and the Battle for Rhodesia. During the West's great transition into the post-Colonial age, Rhodesia refused to succumb quietly, and throughout the 1970s resisted the determined and internationally-supported onslaught of so-called "popular liberation" movements. During this long war, many heroes emerged, but none more skilful and courageous than Captain Darrell Watt of the Rhodesian Special Air Service (SAS), who himself was at the vanguard in the ferocious battle to resist the insurgent forces of Robert Mugabe and Joshua Nkomo.

Intertwined with the story of Capt Watt, our speaker will also recount the engaging history of an elite force of fighting men waging war on behalf of a seemingly-doomed cause and to provide a human face to what many Americans and Europeans ignored at the time as a struggle for just another piece of real estate of this conflict-ridden globe we call "home".

The battle for Rhodesia and for South Africa was just one localised segment of the struggle between the Soviet bloc and the West then underway on a global scale. While the Marxists never forgot the greater context for each regional conflict, the United States and its European allies made a regular practice of abandoning their friends and betraying their allies in Asia, Africa and elsewhere for economic gain. As our speaker will explain, the battle for Southern Africa was a crucial aspect of the overall conflict.

The proxy war for the world was on and with Southern Africa, particularly South Africa, possessing enormous mineral and strategic value, the Sino-Soviet sights were firmly on the region. But a primary obstacle was Rhodesia, so it should come as no surprise that Moscow and Beijing supported the 'liberation' movements energetically and generously. It was into this vortex that the Rhodesian soldier was thrown and so it begs the question: what if they had chosen not to fight and capitulated in the mid-1960s as the world demanded they do? Stalinist-type rule would almost certainly have followed and powerful direct economic, political and military pressure would have immediately been applied to South Africa. Just how this would have affected world history is impossible to deduce but the ramifications would have been enormous. Simply put, this did not happen because the Rhodesians chose to fight and this is the story of some of the stalwarts of that struggle.

While the globalist political "elite" in Western Europe and the United States regularly assented to, and often supported, "wars for liberation" throughout the Third World (especially if the rebels were "agrarian reformers", albeit with a strong socialist leaning), from the moment Rhodesia declared independence in November 1965, the fury of the United Kingdom and the United States was unleashed.

As Mr. Wessels has succinctly described it in his above-mentioned book:
To the best of my knowledge, history offers no record of a nation more isolated, ostracised and bereft of allies and no soldiers who fought against greater odds with fewer men or resources as paltry, than those of what was known as Rhodesia. Nor does history tell us of any polity that developed as fast: from tribal primitivism to First World civility and sophistication in sixty years, only to be destroyed with even greater rapidity in little more than two decades.

The Rhodesian SAS often penetrated deep into so-called "liberated areas" inside Rhodesia and safe havens inside neighbouring countries to strike at the training and base camps harbouring the ZANU / ZANLA leadership and cadres. The Rhodesian Security Forces developed counter-insurgency (COIN) tactics and operations into a fine art and the SAS was, along with a few other Rhodesian elite units, without a doubt at the very top of the list of COIN operators internationally who specialised in small unit operations executed with surgical precision:

The sum of it all was that a handful of hard, dedicated soldiers were making life miserable for ZANLA and their Frelimo allies in their very heartland, and at the same time severely curtailing their ability to cross into Rhodesia. A land mass the size of England had been infiltrated by no more than sixty SAS operators at any given time and they had gunned, mined and ambushed it into a state of confused disorder. Their aggression created a situation where the enemy had to be ever vigilant and defensive in territory it would have liked to call home.

Our speaker will endeavour to paint the broad canvas of events in the limited time at his disposal and through his account connect the events in southern Africa to the larger scope of international power games and intrigue. The war was not lost on the battlefield - its end was the result of treachery in Washington D.C. and London, as well as in New York at the United Nations and even within the halls of government in Salisbury, Rhodesia, where (it is alleged) agents of influence played a role in undermining the young nation. The account of the SAS ends with the dawning of the new nation called Zimbabwe as the brave men of the SAS stood down. They were an embarrassment to the new dispensation, if not an existential threat to them. They did their duty; the loss of Rhodesia was a tragedy willed by forces beyond their control.

* PLEASE NOTE: As the 2nd Thursday of April falls on the 13th, the day before Good Friday and the Easter weekend, the committee thought it prudent to move the meeting forward to Tuesday, the 11th of April. The proposal was put to the vote at the February meeting and was supported by the vast majority of the members present.

BOB BUSER: Treasurer/Asst. Scribe
Phone: 021-689-1639 (Home)
Email: bobbuser@webafrica.org.za

RAY HATTINGH: Secretary
Phone: 021-592-1279 (Office)
Email: ray@saarp.net


South African Military History Society / scribe@samilitaryhistory.org