USS Ashland (LSD 1) on 10 April 1957 experimenting with a P5M-2 seaplane in her well dock.
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Class: ASHLAND (AV 21, ex LSD)
Design: Conversion of Navy LSD to AV, SCB 186, no approved characteristics
Displacement (tons): 4,960 light, 8,700 full
Dimensions (feet): 458' oa, 454' wl x 72' e/wl x 18' max nav/full load
Armament: 2-3"/50T
Accommodations: 50 officers and warrants (including 20 VP squadron), 497 enlisted (including 36 VP squadron)
Speed (kts.): 15
Propulsion (HP): 7,400
Machinery: Skinner Unaflow steam reciprocating, 2 boilers (250psi/saturated), 2 screws
Construction:
| AV | Name | Reclas | Builder | Keel | Launch | Recomm |
| 21 | ASHLAND | (1 Oct 1959) | Moore DD | 22 Jun 1942 | 21 Dec 1942 | -- |
Disposition:
| AV | Name | T | Decomm | Strike | Disposal | Fate | MA Sale/Depart |
| 21 | ASHLAND | 22 Nov 1969 | 25 Nov 1969 | 15 May 1970 | Navy sale | -- |
Class Notes:
On 28 December 1954 CNO Carney wrote that, inspired by his experience as DCNO (Logistics) in 1946-50 with the military potential of seaplanes, he planned to establish a seaplane program committee within his office (OPNAV) to prosecute studies and projects on an energetic basis. On 5 January 1955 SECNAV Thomas responded with his hearty approval, agreeing that "the imaginative possibilities of jet seaplanes, both as to surprise and mobility, appear to be unlimited" and stating that it was his opinion "that the seaplane, as a future offensive weapon, offers to the Navy the opportunity to lead in the delivery of atomic weapons." On 14 July 1955 the Martin P6M Seamaster, a swept-wing seaplane powered with four J-71 jet engines and incorporating a new hull design, made its first flight. Designed for minelaying and reconnaissance tasks but adaptable to other missions, this plane seemed to offer great promise for the offensive potential of naval operating forces. The efforts of the seaplane program during 1955 included an ambitious effort to develop support ships for the P6M. These included a new design AV (approved characteristics for a Seaplane Tender (AV), SCB Project No. 201, were promulgated on 6 June 1958 without later changes), and conversions of ALBEMARLE (AV 5), CURRITUCK (AV 7), LSDs, CVEs, LSTs, and new nuclear submarines. The projects that got the farthest were the AV 5, AV 7, and LSD conversions. In August 1956 the proposed FY 1958 program was changed to delete one new construction AV in favor of conversions of three CVE 105 class escort carriers (SCB Project 176), which could be converted for about the same cost and would confer a great support capability to the P6M program. This was reduced to two in September 1956, one in December, and none by March 1957.
Preliminary design work for the LSD conversion was in progress by October 1955. On 8 September 1956 CNO cancelled the inactivation of ASHLAND (LSD 1), LINDENWALD (LSD 6) and WHITEMARSH (LSD 8). LSD 6 and LSD 8 were to be transferred to MSTS (LSD 6 in December 1956, LSD 8 placed in service 8 November 1956) and it was proposed to assign LSD 1 to AIRLANT in November 1956 and to transfer her to MSTS prior 15 May 1957 to enable MSTS to complete her conversion prior to planned Arctic resupply operations. On 1 November 1956 Ashland was transferred to the control of Commander, Naval Air Forces, Atlantic, for alterations enabling the ship to tend aircraft, and by July 1957 she was configured to handle six P5M-2 aircraft. The FY 1959 program as drafted included the conversion of three LSDs to AV. A memo of 13 July 1957 stated that one factor was that the cost of a CVE conversion to AV had risen from $18 to $29 million. Another was that it was now felt that in view of doubt on the effectiveness of the lifting device in the AV 5 conversion, the fact that docking type (LSD) tenders appeared preferable, and the limited funds available in FY 1959, no additional AV should be included in the 1959 program to replace the one deleted in 1958. LSD 1 became a candidate in July 1957 for initial conversion to tend seaplanes and was placed out of commission on 14 Sep 1957. Approved characteristics for the conversion of an LSD to an Aviation Seaplane Support Ship (AVD), SCB Project No. 186, were promulgated by CNO on 13 August 1957 with a single change on 22 May 1959. (The "D" probably stood for "Dock" instead of "Destroyer" as for the World War II four-piper destroyers AVD 1-14.) The characteristics stated that the P6M aircraft would normally be operated with a Task Group of ships whose size would be dependent upon the number of aircraft to be supported, The LSD would usually function as one of the ships in the Task Group and would be expected to be capable of supporting a detachment of three or four P6M aircraft. Inasmuch as the LSD was a suitable ship for docking a seaplane, the maintenance function would be emphasized in its design and employment, but facilities would also be provided for refueling and rearming. The LSD would also provide accommodations for squadron personnel as space utilization permitted. A memo of 21 October 1957 contained design criteria for "AVD, conversion of LSD, Project No. 186." The document stated "Continuing the program of providing improved facilities for servicing seaplanes, it is tentatively planned that the FY 1959 Program will include the conversion of three ships of the LSD 1 class to AVD. This is designated as SCB Project No. 186 for which characteristics have been received (on 13 August 1957). An AVD, one of three satellite ships, will operate in company with an AV to support a squadron of 12 P6M jet seaplanes. The facilities of an AVD should be sufficient to control and support at least three of these planes and to dock this type seaplane for repairs." The "AVD 15 LSD 1 conversion" was an active project between October 1957 and March 1958 that reached preparation of contract plans and specifications. The ship was still being referred to within BUSHIPS in March 1958 as AVD 15.
The original P6M Seamaster program consisted of two XP6M aircraft, to be followed by six YP6M-1 and 24 P6M-2 aircraft. On 24 Jun 1957 the quantity of aircraft was reduced to six YP6M-1 and 18 P6M-2 aircraft. Another revision of the P6M program on 24 November 1958 provided for six YP6M-1 already accepted by the Navy and eight P6M-2 aircraft then in production and to be accepted between January and November 1959. As a result of these curtailments in the P6M program, the number of LSD conversions to AV was reduced to two during 1957-58, and on 23 December 1958 the President rescinded authority for the conversion of one of the two seaplane tender (AV) conversions in the FY 1959 conversion because of the curtailment in the P6M program. The Seamaster program as of 20 January 1959 called for the first group of four P6M-2 aircraft to be delivered to its operating squadron at NAS Harvey Point beginning in September 1960 and the second group of four to follow in May 1961. Ultimately six P6M-2 aircraft with two P6M-2 logistic support or pipeline aircraft were to be operated as one squadron with NAS Harvey Point as home port. Afloat support was to be provided by AV 5 (6 aircraft), "AVD 1" (3 aircraft), and AOSS 362.
The full conversion of an LSD to an AV for the Seamaster program was ordered on 11 February 1959 at NSY Philadelphia. Project 186 was probably used. LSD 1 was scheduled to be reclassified AV 21 (not AVD 1) upon arrival at the yard (to be 1 Oct 1959) but the P6M program was cancelled on 21 August 1959 and the Navy decided that the requirement no longer existed for the one remaining AV conversion in its FY 1959 program and cancelled the conversion. LSD 1 was back in commission as an LSD from 29 November 1961 to 22 November 1969.
LSD 1-8 were unusual in having Skinner Unaflow engines, as did the CASABLANCA (CVE 55) class escort carriers, the Army mine planters that became the ACM 1 and ACM 11 classes, and the Maritime Commission's S3 cable ships that became ARC 2 and 6. The AK 261 class had uniflow engines not made by Skinner, "uniflow" being the generic term for this type of engine while "Unaflow" was Skinner's trademark for their product. In a Unaflow or uniflow engine steam entered alternatively at the ends of the cylinder, which were always hot, and exhausted at the center, which was cooler, reducing the energy spent in a conventional reciprocating steam engine in alternatively heating and cooling the cylinder walls.
Ship Notes:
| AV | Name | MA | Notes |
| 21 | ASHLAND | (ex-LSD 1, ex-APM 1). Completed as LSD 5 Jun 1943. Decomm. 14 Sep 1957 for possible conversion to AV. Conversion cancelled ca. Aug 1959, recomm. as LSD 29 November 1961. Sold by Navy 15 May 1970. |
Page Notes:
Compiled: 31 Jul 2021
© Stephen S. Roberts, 2021
Special sources: NARA: RG 19 Item S-13 Entry P 61 Box 37 (Landing Ship Dock Conversion), RG 19 Item S-13 Entry P 62 Box 10 (Ship Hull Design/Job Order 47-55), RG 19 Item S-15 Entry UD 1024-S (Ship Machinery), RG 19 BUSHIPS General Corresp 1953-57 File 1956 SBG PGM (Shipbuilding Program).