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SISTER SHIPS The Thetis Class Coast Guard Patrol Boats Prepared for the Potomac Association By Les Dropkin, January 2002 CONTENTS PAGE The Thetis Class Coast Guard Patrol Boats 2 Background to the building of the new patrol boats The Thetis Class Design 5 The forward areas The wheel house The deck house The engine room The aftermost areas – below The aftermost areas - topside The Thetis Class Patrol Boats in World War II 16 Prologue The transition year – 1941 The start of the war First blood for the Coast Guard – the Icarus The second kill – the Thetis The rescue missions Epilogue The Later Years 22 The story of the Cyane The story of the Calypso and that of the Argo, the Perseus, the Nike and the Triton 1 Sister Ships The Thetis Class Coast Guard Patrol Boats When the Electra was launched on 30 June 1934 at the Manitowac Shipbuilding Corp. yard in Manitowac, Wisconsin, she became one of eighteen new cutters that made up the Thetis class patrol boats built for the Coast Guard between 1931 and 1934. The Electra, of course, would go on to become the presidential yacht Potomac and have an almost unbelievable future history. As a class, all the ships were built to the same basic design and it is of some interest to discuss, compare and contrast that design with that of the Potomac. Moreover, her sister ships also have a remarkable history and their stories deserve to be told. Background to the building of the new patrol boats One consequence of prohibition in the United States was that enormous profit could be made by those involved in successfully smuggling liquor into the country. Using ships – “rumrunners” – to get the contraband in became a growth industry and it fell to the Coast Guard to interdict such traffic. Unfortunately the vessels available for the task were often obsolete, uneconomical and inefficient. (See Figure 1) Figure 1 An Old, Pre-prohibition Coast Guard Cutter (1909 Photo – Ship Name Unknown) What was needed was a seaworthy ship that would combine speed with economical operation. By 1930 a design that would provide vessels that were as 2 light as possible and yet develop maximum speed had been agreed upon after model tests at the United States Experimental Model Basin at the Washington Navy Yard. After competitive bidding in January 1931, a contract to build seven of these newly designed cutters was awarded to the Bath Iron Works Inc. in Bath, Maine. The first ship built was the Thetis, launched 9 November 1931. The next five months saw the launching of the next six. They too took their names from Greek mythology, as would be so for all the ships in this class: the Aurora, the Calypso, the Daphne, the Hermes, the Icarus and the Perseus. The class was expanded in 1932 with the construction of the Argo and the Galatea by the John H. Mathis Co. in Camden, New Jersey. With the launching of these two in November and December 1932 the building program came to a halt – temporarily, as it turned out. Repeal of the 18th (Prohibition) Amendment would presumably remove the need for more of the Thetis class ships and, indeed, by the early thirties momentum was building for repeal. Ratification of the 21st (Repeal) Amendment finally was secured in December 1933. Although the sale of liquor was now legal, in fact repeal of prohibition did not diminish the need for patrol boats to chase down rumrunners because the avoidance of liquor taxes had taken over as a reason for smuggling. There was another reason, however, behind the resumption of the building of additional Thetis class vessels – one not always stated. After the first World War, the great naval powers had signed agreements limiting the size and composition of their navies. The London Conference of 1930 saw the last of these treaties. As the decade of the 30’s progressed the naval powers sought ways of getting around the treaties. One way, for example, was to build a ship that was a heavy cruiser in all respects but have it carry 6” rather than 8” guns so, technically, it could still be called a light cruiser. Another way was to look to ships built for the Coast Guard as potential naval craft, since the Coast Guard was part of the Treasury Department and not the Navy Department. New contracts were let to three yards for the construction of three ships each: the Lake Union and Dry Dock Machine Co. in Seattle, Washington which built the Atalanta, the Ariadne and the Cyane; the Marietta Manufacturing Co. in Point Pleasant, West Virginia which built the Nemesis, the Nike and the Triton; and the Manitowac Shipbuilding Corp. in Manitowac, Wisconsin which built the Dione, the Electra and the Pandora. These nine ships were launched in 1934. Table 1 lists the dates when each ship was launched, commissioned and decommisioned, together with the shipyard. For the Electra and for those ships built by Bath Iron Works – that is, for the first seven built – the date of delivery is also shown. For the Electra, the dates of commisioning and decommissioning are with respect to the Coast Guard, not the U. S. Navy. 3 TABLE 1 SHIPYARDS and DATES LAUNCHED, DELIVERED, COMMISIONED & DECOMMISIONED SHIP SHIPYARD LAUNCHED DELIVERED Thetis Bath Iron Works Inc., Bath, Maine 9 November 1931 27 November 1931 Aurora Bath Iron Works Inc., Bath, Maine 28 November 1931 18 December 1931 Calypso Bath Iron Works Inc., Bath, Maine 1 January 1932 16 January 1932 Daphne Bath Iron Works Inc., Bath, Maine 27 January 1932 20 February 1932 Hermes Bath Iron Works Inc., Bath, Maine 23 February 1932 4 March 1932 Icarus Bath Iron Works Inc., Bath, Maine 19 March 1932 29 March 1932 Perseus Bath Iron Works Inc., Bath, Maine 11 april 1932 23 April 1932 Argo John H. Mathis Co., Camden New Jersey 6 January 1933 Galatea John H. Mathis Co.,Camden New Jersey 3 February 1933 Atalanta Lake Union and Dry Dock Co., Seattle, Washington 16 June 1934 Dione Manitowac Manufacturing Co., Manitowac, Wisconsin 30 June 1934 Ariadne Lake Union and Dry Dock Co.,Seattle, Washington 26 March 1934 Nemesis Marietta Manufacturing Co., Point Pleasant, West Virginia 7 July 1934 Nike Marietta Manufacturing Co., Point Pleasant, West Virginia 7 July 1934 Cyane Lake Union and Dry Dock Co.; Seattle, Washington 30 August 1934 Electra Manitowac Manufacturing Co., Manitowac, Wisconsin 30 June 1934 26 October 1934 Pandora Manitowac Manufacturing Co., Manitowac, Wisconsin 30 June 1934 Triton Marietta Manufacturing Co., Point Pleasant, West Virginia 7 July 1934 SHIP COMMISIONED DECOMMISIONED Thetis 1 December 1931 1 July 1947 Aurora 21 December 1931 17 January 1968 Calypso 16 January 1932 18 July 1947 Daphne 21 February 1932 1 August 1950 Hermes 7 March 1932 2 November 1948 Icarus 1 April 1932 21 October 1946 Perseus 27 april 1932 26 June 1959 Argo 6 January 1933 30 October 1948 Galatea 3 February 1933 15 March 1948 Atalanta 20 september 1934 1 August 1950 Dione 5 October 1934 8 February 1963 Ariadne 9 October 1934 23 December 1968 Nemesis 10 October 1934 20 November 1964 Nike 24 October 1934 5 November 1964 Cyane 25 October 1934 1 August 1950 Electra 26 October 1934 23 May 1946 Pandora 1 November 1934 1May 1959 Triton 20 November 1934 12 June 1967 4 The Thetis Class Design Figu re 2 The Perseus - A Typical Thetis Class Patrol Boat If you look at the overall lines of a Thetis class ship (See Figure 2), a basic design characteristic is immediately apparent – it is high forward, with the midship section dropping off rapidly to afford only the necessary freeboard (the vertical distance between the waterline and the top of the hull). The height forward helps assure dryness – an evident need when the ship is going ahead at a good speed, as may be seen from Figure 3. Figure 3 The Thetis (Photo Taken Shortly After Commissioning) 5 Before getting into a more detailed consideration of various ship features, it might be well to note the principle ship measurements. (See Table 2) TABLE 2 PRINCIPLE MEASUREMENTS Length Overall 165’ Length at Waterline 160’ Molded Beam at Waterline 24’ 1” Molded Beam at Main Deck 25’ 3 ¾ “ Molded Depth, Amidships 13’ 2 ½” Mean Draft at Full Load 7’ 6” Displacement at Full Load 332 tons Cruising Radius 4000 miles Bunker Fuel Capacity 7687 gallons 25 tons Main Engines (2) 670 horsepower at 450 revolutions Maximum Sustained Speed 13 knots for 1600 miles Economic Speed 10 knots for 3100 miles The most obvious differences in overall profile between the Electra (as converted to be the Potomac) and that of a typical Thetis class ship are those resulting from creation of the presidential areas and the addition of the boat deck. On the other hand, and speaking broadly, the respective profiles from the wheelhouse forward are quite similar. (See Figures 4a and 4b) In reality, of course, there are differences and we will turn to these next. Figure 4a Figure 4b POTOMAC CYANE 6 A convenient way of making comparisions is to imagine that we are taking a “tour”. We will start on the main deck at the bow and work our way aft, commenting on the several features as we come to them; and, as appropriate, comparing and contrasting a Thetis class patrol boat with the Potomac. By and large the Electra can be taken as a “typical” Thetis class boat; where it differs in some important respect, that will be noted. Also, it must be remembered that during the ten years she was the presidential yacht some changes to the Potomac occurred.

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