US Navy Auxiliary Ships: Monitor Class (LSV 5-6, 3-4)

USS Saugus (LSV-4) on 5 March 1945
Click on this photograph for links to larger images of this class.

Class:        MONITOR (LSV 5-6, 3-4)
Design:        Navy AN-1
Displacement (tons):        4,626 light, 9,040 lim.
Dimensions (feet):        451.3' oa, 440.0' wl/pp x 60.3' e x 20.0' lim
Original Armament:        4-5"/38 (1x2, 2x1) 4-40mmT 20>8-20mm (LSV-5)
Later armaments:        2-5"/38 4-40mmT 20>18-20mm (LSV 3-4, 6, 1944-45); 2-5"/38 4-40mmT 8-20mT (AKN-6, 1947)
Complement:        374 (1944)
Speed (kts.):        20.3
Propulsion (HP):        11,000
Machinery:        2 G.E. turbines

Construction:

LSV	Name	Ord.	Builder	Keel	Launch	Commiss.
5	MONITOR	16 Dec 40	Ingalls SB, Pascagoula	21 Oct 41	29 Jan 43	14 Jun 44
6	MONTAUK	16 Dec 40	Ingalls SB, Pascagoula	14 Apr 42	14 Apr 43	6 Oct 44
3	OSAGE	16 Dec 40	Ingalls SB, Pascagoula	1 Jun 42	30 Jun 43	30 Dec 44
4	SAUGUS	16 Dec 40	Ingalls SB, Pascagoula	27 Jul 42	4 Sep 43	22 Feb 45

Disposition:

LSV	Name	Decomm.	Strike	Disposal	Fate	MA Sale
5	MONITOR	22 May 47	1 Sep 61	1 Sep 62	MA/T	15 Jul 74
6	MONTAUK	16 Apr 47	1 Sep 61	1 Sep 62	MA/T	26 Jun 73
3	OSAGE	16 May 47	1 Sep 61	1 Sep 62	MA/T	11 Dec 74
4	SAUGUS	24 Mar 47	1 Jul 61	1 Oct 62	MA/T	19 Jul 76

Class Notes:
FY 1941. Included in a large group of auxiliaries whose construction or acquisition was directed on 5 Aug 40 in the 70% Expansion Program (part of the Two Ocean Navy mobilization effort) along with many combatant ships. At the end of 1939 the Navy conceived a requirement for ships to accompany a fleet and lay out and service anti-submarine and other net defenses for harbors and anchorages. The nets to be used were indicator nets, which revealed the presence of intruding submarines by sending up flares. As the ship type was new to the U.S. Navy, careful study was given to two British net layers, HMS GUARDIAN and PROTECTOR, which had the same mission. In September 1940 the Bureau of Construction and Repair presented a design based on PROTECTOR but somewhat larger (3200 tons light against the British 2550 tons). The Bureau also presented an alternative design that was even larger (4570 tons) but had the advantage of using the hull and machinery of the minelayer TERROR (CM-5), the plans for which had already been drawn. The Navy ordered the four ships to the design based on CM-5, which was nearly identical to the minelayer below the second deck and extensively rearranged above it.

In March 1943 the Bureau of Ships proposed the conversion of the four net layers to troop transports (AP) with a vehicle carrying capability. It noted that when it designed the netlayers it had stated that they would be well suited for the transportation of vehicles if that mission became more important than net laying. The Bureau noted that it had no evidence that the British had ever used its two large net layers to lay indicator nets in connection with fleet operations. Its preliminary studies showed that an austere conversion could be done with very little structural alteration, the main change being to remove the net troughs and use the space for carrying motor vehicles. Some 800 troops could also be carried in the former net storage areas. The ships would essentially be convoy-loaded transports, intended to unload at prepared port facilities, but their 14 LCVP landing craft and two pairs of Welin davits would give them a modest amphibious capability. A more complete conversion was soon decided upon, which included building up the stern to the level of the rest of the hull to provide more stowage space. A similar conversion of the two sisters to CM-5 then under construction was also proposed (see the LSV-1 class). OPNAV planners, however, predicted that the Navy would find two net layers useful in operations in the Pacific during the next two years and recommended that the two net layers closest to completion be finished as such. On 3 Apr 43 the conversion of CM 6-7 and AN 3-4 to AP 106-109 was directed.

In June 1943 the Director of the Base Maintenance Division of OPNAV noted that the weight and bulk of submarine indicator nets had been dramatically reduced, obviating the need for large net layers of the AN-1 type. The AN-1 had been designed for nets weighing 180 tons per mile, but in 1941 a net weighing 37 tons per mile had been developed and in March 1943 a net weighing only four tons per mile had been successfully tested. The conversion of AN 1-2 to AP 160-161 was directed in July. The Bureau of Ships noted that the conversion of AN 1-2 to transports like AN 3-4 would be easy technically but would disrupt work at Ingalls, where the ships were being built. It proposed that the two ships be completed to their original design to the point where they could be ferried to another shipyard for conversion. Due to unsatisfactory rates of construction at Ingalls (which was also building merchant ships), all four ships were ultimately moved to other yards for conversion, the more advanced pair under their own power to New York and the less advanced pair under tow to Tampa, Florida. The New York pair (AP 160-161) differed slightly from the Tampa pair (AP 108-109) because they were further advanced when conversion began. The main visible difference in MONITOR as completed was that she could accommodate only 10 LCVPs and a single pair of Welin davits instead of the 14 and two pairs of davits in the Tampa pair.

When the conversion of AN 1-2 was directed, the Bureau of Ships was also directed to investigate the possibility of modifying its plans for all four AN conversions to permit the stern launching of amphibious vehicles, notably DUKW and LVT types. The Bureau changed the design to include a gate and ramp in the stern. It did not similarly modify the two former minelayers, which could carry DUKWs but not LVTs, until directed to do so in January 1944. On 21 Apr 44 the six ships were redesignated Vehicle Landing Ships (LSV) to reflect their increased amphibious capability. The first of the former net layers, MONITOR (now with a hull number buried in the middle of the class because of the order in which the ships had been reclassified) was inclined upon completion in June 1944 and her righting arm (GZ) was found to be very poor. To compensate, the Bureau of Ships recommended a reduction and rearrangement of the armament, the twin 5"/38 mount aft being deleted and one of the forward 5"/38 mounts being moved aft. This change was approved by CNO for the two New York ships (LSV 5-6) on 22 Jul 44 and for the Tampa pair (LSV 3-4) on 10 Aug 44, but LSV-5 had already entered the operating force and was never modified. LSV-6 was completed to the same configuration (more boats and reduced armament) as the Tampa ships.

After the end of the war the Navy decided that the postwar fleet needed a net cargo ship (AKN) to transport and lay light torpedo nets (type LT1). On 7 Jan 46 CNO directed the conversion of LSV-3 for this purpose, but on 25 Feb 46 he substituted LSV-6 to keep the cost of the conversion at a minimum. The hinged ramp and ramp portion of the main deck aft were to be removed and the structure and arrangement of the stern were to be modified, with additional winches being fitted to handle the nets and their anchors. The decks and bulkheads were to be flush (free of projections) in the areas where nets were to be stored and handled. The conversion was also to include flag quarters for COMINLANT and tender repair facilities for minesweepers (YMS and AM). The conversion was delayed until after the beginning of Fiscal Year 1947 and LSV-6 was used in the meantime to dump at sea ammunition from the depots at Earle, N.J. and Yorktown, Va. Conversion began at the Charleston (S.C.) Naval Shipyard on 1 Sep 46, and work was about 86 percent complete, with an expected completion date of 17 Jan 47, when on 27 Dec 46 CNO ordered the conversion cancelled. He reaffirmed the cancellation three days later, explaining that in order to effect maximum savings of funds he did not desire to complete the conversion. The amount saved was estimated by the shipyard at about $30,000 out of a total conversion cost of about $350,000. Items not completed included just over half of the net stowage and handling arrangements on the main deck and the three roller curtain doors that were to close off the after end of this deck just forward of the transom.

Ship Notes:

LSV	Name	Notes
5	MONITOR	Launched as AN-1, to AP-160 2 Aug 43 and to LSV-5 21 Apr 44. To Todd, Brooklyn for completion (contract 28 Mar 44, ferry commission 18-30 Mar 44). In USN reserve 1946-60 (in service in reserve at Orange, Texas, 1951-56). To MCS-5 18 Oct 56. To NDRF 3 Oct 60. To buyer 24 Jul 74.
6	MONTAUK	Launched as AN-2, to AP-161 2 Aug 43 and to LSV-6 21 Apr 44. To Todd, Brooklyn for completion (contract 28 Mar 44, ferry commission 25 May-6 Jun 44). To AKN-6 and renamed GALILEA effective 1 Oct 46 but conversion cancelled when 86% complete. In USN reserve 1946-60 (in service in reserve at Charleston from 1951). To NDRF 5 Aug 60. To buyer 27 Jul 73.
3	OSAGE	Laid down as AN-3, to-AP-108 1 May 43 and to LSV-3 21 Apr 44. To Tampa SB for completion (contract 9 Mar 44, towed 23-25 Mar 44). In USN reserve 1946-60. To MCS-3 18 Oct 56. To NDRF 19 Sep 60. To buyer 6 Jan 75.
4	SAUGUS	Laid down as AN-4, to-AP-109 1 May 43 and to LSV-4 21 Apr 44. To Tampa SB for completion (contract 9 Mar 44, towed 4-6 Apr 44). In USN reserve 1946-60. To MCS-4 18 Oct 56. To NDRF 28 Oct 60. To buyer 9 Aug 76.