The Comprehensive History of the USS Tortuga LSD 26
Compiled by Michael D. Wilson
A group of desert coral islets—60 miles west of Key West, Fla.—which were discovered in 1513 by Spanish explorer Ponce de Leon. In 1861, the United States government completed Fort Jefferson on Garden Key, and this bastion remained in Union hands throughout the Civil War. It later was used as a prison until abandoned in 1874. During the 1880's, the Navy established a base at Tortuga; and it subsequently set up a coaling and a wireless station there as well. During World War I, a seaplane base was established on the islet; but it was abandoned soon thereafter.
What is an LSD? Simply put, LSD stands for Landing Ship, Dock
This is a type of ship that was conceived during World War II as a ship that could sail to the site of an amphibious landing, carry and launch assault boats directly from a well-deck in the rear of the vessel. To do this, the ship floods several tanks in the stern (rear) of the ship and ballasts the ship down, this floods the deck, and allows the boats aboard to come and go.
Originally developed as part of the answer of how to get heavy new armor ashore, the claim to fame for the LSD turned out to be its ability to provide on the spot drydock service for battle damaged small craft of all kinds.
Putting people and weapons ashore on a hostile beach has always been the basic business of amphibious warfare. The essential idea behind an amphibious assault is that of putting a military formation ashore in the face of enemy opposition, in good condition and with the tools it needs to accomplish its mission. In the years before World War II, this was a relatively uncomplicated matter. Landing forces were fairly small. Their task was usually that of raiding or of seizing a small beachhead. Their weapons were usually limited to what they could carry; "heavy weapons" for a landing force meant machine guns, mortars, and "pack" artillery which could be broken down and carried ashore by their crews. Some experiments were conducted in the United States and England between the World Wars with landing craft designed to carry artillery pieces and the small tanks of the period. Actual production of landing craft did not begin until about 1939. These early craft were small, light types, carried on davits and loaded from transports at the landing point.
All this changed by World War II, as the "new" science of amphibious warfare developed at an accelerated pace. Instead of involving the movement of small, lightly-armed raiding parties, it was seen that victory in Europe and the Pacific would require the over water transportation of entire armies, together with the hitherto undreamed-of-weight weaponry and equipment demanded by modern warfare. To put, for instance, even one of the new armored divisions ashore meant moving hundreds of heavy tanks and self-propelled guns, as well as the hundreds of other vehicles needed to keep the division supplied with ammunition, fuel, and food.
By 1940 the British had begun development of tank landing craft, or TLC (later designated LCT). Flat-bottomed, ramped craft capable of carrying several tanks, the TLC proved more seaworthy than expected, but were still slow and incapable of making long ocean passages or of coping with heavy seas. The larger LST was still, at this time, encountering design difficulties and early production was not foreseen.
The LST was an excellent idea - but it did have the disadvantage of having to approach the enemy beach in order to unload its cargo, thus exposing a relatively expensive ship (as opposed to landing craft) to direct enemy fire. Smaller landing craft offered the advantage of being far more expendable and made smaller targets; and, while building them was easy enough, the problem was how to get them within range of the beachhead. The answer as envisioned, was the design of a ship to carry loaded TLC rapidly to distant destinations in any weather. Craft the size of the TLC however, could not be davit-launched as could their small predecessors; the Mark III TLC, for instance was 190 feet long, with a displacement of 300 tons. This problem could be solved by adopting the floating-drydock principle, first used by the French in the early part of the century in the design of the submarine mothership Kangourou. Arrangements were made with the U. S. Navy's Bureau of Ships for design of a dock-type ship capable of carrying three loaded Mark III TLC. The preliminary design, produced in November 1941, emphasized simplicity and ease of construction. In the following month eight of these new ships were authorized for the U.S. Navy; seven more were ordered for the Royal Navy. First classified as Mechanized-Artillery Transports, or APM, on July 1, 1942, the designation Landing Ship Dock, or LSD was adopted.
Essentially a self-propelled seagoing floating drydock, the LSD's unique feature was her central well deck in which landing craft or other small craft were carried. When her well deck was flooded and her stern gate opened, her cargo of small craft could then float in or out under their own power. By the time the LSD began to enter service in 1943 and 1944, the LST was also being commissioned in large numbers and tank transportation was no longer the problem it had been. But the LSD was used to good advantage in the Pacific by the U. S. Navy and in the Atlantic and Mediterranean by the British, transporting landing craft and serving as mobile drydocks for repair of other battle damaged vessels.
The LST certainly achieved a greater degree of notoriety than did the LSD during WWII for who can deny what a spectacular sight these ships were as they rammed the beach, opened their giant doors and disgorged scores of tanks. What is more, LSTs were built in far larger numbers than LSDs. While stateside yards turned out hundreds of LSTs, only 27 LSDs were completed before the end of hostilities, a few being launched too late in the war to join in combat operations. Why such a disparity in numbers? The LSD was a full size ship, the typical WWII version measuring some 457 feet in length with a beam of 72 feet and displacing 4,500 tons. Her slab-sided appearance not-withstanding, the LSD was not a simple ship to build or operate thanks to the complexities of her inner workings and the fact that she was one of the few specifically designed amphibious warfare ships big enough to be powered by steam plant driven turbines. The LST, on the other hand, was a far easier vessel to build with its overall length of 328 feet and 1,625 ton displacement. Their two 1,700 hp diesel engines allowed for even greater engineering simplification.
As it turned out, the first eight LSDs contracted to the Moore Dry Dock
Company of Oakland, California, ended up in the hands of the U. S. Navy.
Additional contracts were led to Newport News Shipbuilding for eleven ships of
the same design, the first seven of which were planned for delivery to the
British. The plan was later changed; however, so that only the first four ships
went to the Royal Navy while the U.S. Navy took the remaining seven. For the
sake of avoiding confusion, it should be noted that names were given to all of
these ships before their launchings and this is why, as it will be noted later,
the first seven ships laid down by Newport News were
given "H.M.S." names, the latter three then undergoing name changes back to American names midway through their construction.
Although approved during December, 1941, the keel for the first LSD was not laid until seven months later on June 22, 1942, this due, no doubt, to production efforts in the first months of the war geared to defense and survival rather than optimistically constructing amphibious warfare ships clearly designed for offensive operations. Six months later the strange looking new ship was ready for launching and on December 21, 1942, to the cheers of enthusiastic yard workers, one Mrs. Jabez Lowell broke the proverbial bottle of champagne against the hull of the USS Ashland (LSD-1). It had earlier been decided to name the first group of LSDs (most smaller amphibious warfare ships such as LSTs receiving only numbers) after the famous homes of famous Americans. Ashland, for instance, for the estate home of the famous statesman Henry Clay at Lexington, Kentucky.
Seventeen days short of one year after her keel laying, the new USS Ashland was completed and ready for her commissioning ceremony on June 5, 1943. As the first ship of a new type, to say that her strange lines brought many curious stares would be an understatement. She looked like something that had gotten away from her builders too soon. What made the Ashland so strange in appearance was her huge docking well, a cavernous opening 44 feet wide and 396 feet long which ran from the stern to clear up under the bridge, ending near the bow. Almost one hundred feet longer than a football field, the Ashland's well deck was only 61 feet short of the ship's 457 foot overall length. In it would fit 27 LCVPs, 18 LCMs with one LCVP in each, three LCUs, one LSM-or anything small enough to fit its nose through the stern opening (during the Korean war another LSD would take aboard a destroyer escort for dry dock repairs). The LSD was also designed so that it could be equipped with a removable "superdeck" of steel grating that could span the width and almost the entire open length of the well deck. Made up of six-ton sections, the pieces would typically be lifted off the pier one at a time by one of the ship's two 25-ton swivel cranes and set down amidships. They would then be picked up by a six-ton traveling bridge crane (moving on tracks down either side of the ship) which would haul the piece toward the stern and set it in its appropriate place. On the superdeck could go 350 tons worth of invasion cargo-tanks, cars, trucks, DUWKs, 66 amphibious tanks or any other type of cargo that needed to be moved from point A to B. Tanks and vehicles on the superdeck could simply be lowered by crane into waiting landing craft in the well deck or, in the case of amphibious tractors, could be lowered directly into the partially submerged well deck where they would simply drive off the stern and head for the beach. The possibilities were almost endless and it was realized from the beginning that the new Ashland and her sisters to follow would be very versatile and handy ships to have around-not just during infrequent major amphibious landings but for general transport and day-to-day odd jobs that arise particularly including small craft maintenance. In fact, this is exactly what LSDs became far better know for; their ability to take smaller craft aboard for on the spot dry dock repairs. Each LSD was equipped to change screws, shafts and other parts of smaller craft by virtue of a fully equipped machine shop as well as a complete wood shop for working on the smaller, wooden hulled landing craft and PT-boats.
As mentioned earlier, the LSD was designed for steam power, an engine room being located in the wings amidships on both sides of the docking well. Ashland and her seven sisters built in Oakland were equipped with Skinner eight-cylinder reciprocating uniflow steam engines of 7,000 horsepower each. Later LSDs starting with those launched by Newport News during 1944 would, however, switch to steam turbine power of the high-pressure impulse reaction, single flow Parsons type. LSDs could make 15-16 knots, easily putting them in the "fast transport" category.
The most fascinating aspect of the LSD is, of course, her ability to squat down in the water and flood her well deck up to a depth of about 10 feet. Exactly how is it done? Perhaps the following wartime account by a reporter observing operations aboard the USS Lindenwald (LSD-6) best explains how it is all done:
"It takes 330 men and 18 officers to man this LSD and they're all busy when her snubby bow approaches the embarkation area. Though operations look simple, they are extremely complex. According to the skipper, 'It takes an hour and a half to ballast her down until there's enough water in the docking well to float the small craft. So we start while we're still underway.'
"As the ship plows along, you can see preparations being made. Men with telephone gear stand at six different stations around the ship to report ballasting progress. Each phone connects with the ballast-control center-a tiny shelter on the starboard wing well, lined with huge panels of wavering dial needles reminiscent of the control room in a submarine. The trembling deck underfoot tells you the big pumps are pulling sea water into the ship's 36 tanks, located along the keelson, under the wooden planked floor of the docking well." 'We watch like hawks' explains the skipper, 'to keep from having any half-full tanks with free surface-where water can slosh around. If the ship is rolling in a heavy sea swell, free surface water will slosh steeper than the roll and keep the roll going-an invitation to capsize.' "The engineering officer on the wing wall orders the 45-foot steel stern gate to open a crack, and the first sea spills in around its lower edges as the ship settles in the sea. Slowly, the well fills like a bathtub. Before the destination is reached, 7,000 tons of salt water will flood the docking well. Actually, 3,500 tons are enough to float the 40-foot LCMs sitting snugly side by side, and they soon bob like corks, their steel sides screeching as they rub together in the swell. Gears whirl and down goes the gate, folding neatly in half, the doubling back under the stern. Boat engines roar. A blue, smoky, exhaust haze fills the docking well. Three at a time the boats emerge from the pungent fumes, through the open stern of the mothership."
The exhaust haze to which the wartime report refers was undoubtedly enhanced by the covering superdeck which tended to keep exhaust gases trapped within the well deck. It should be noted, however, that early operations with the first LSDs saw the ships sortie without superdecks in place. The same reporter went on to witness the process of taking the LSD's landing craft back aboard.
"Upon the after end of the port wing wall stands the docking officer, holding a power megaphone with which he calls signals. Like the LSO on an aircraft carrier, it is his responsibility to bring each of the boats aboard again safely. Only he "talks" them in like this: 'Number six aboard center; seven and eight follow port and starboard'. In they come, the first LCM roaring right down the center of the mothership right up to her bow. Two others follow, flanking it, until they are wedged in and secured. The loading proceeds, three at a time, until the last of the little craft have disappeared into the dark maw of the big ship. Then the stern gate closes part way, to allow the ocean inside the ship's belly to seep back out where it belongs as the ship deballasts underway.
Reloading landing craft was a pretty smooth operation in a calm sea, but in
a rough sea, the task could become treacherous. Rolling in rough water, it took
skilled crewmen aboard both the ship and the boats to handle and secure the five
ton landing craft. Typically, as they would enter the heaving docking well, they
would whirl and spin, bashing the ship's bulkheads and each other as the action
of the confined sea water tossed them around like corks in a typhoon. To make
matters worse, were such rough water operations being undertaken in an actual
combat area where the ship might be endangered by, say, air attack (indeed, LSDs
accounted for several kamikazes downed during the later stages of the Pacific
war), the skipper often made the decision to order the landing craft to back in.
This would allow them to make a quicker getaway should the need arise. Although
to the untrained eye, the pandemonium of bringing the landing craft back aboard
a rough sea might have seemed like mass confusion - men scrambling along the wing walls, climbing over each other to grab lines and make them fast - the operation was typically well orchestrated. It had been practiced many times. If the captain wanted to get his ship out of the area, everything would be timed to the last second. As the first boats would come aboard, the LSD would begin to deballast at once - forward tanks first. If all went well, the forward end of the docking well would be progressively tipped up and dry, the first boats grounded seconds after being lashed in place thus preventing them from banging about.
The skipper of one LSD once pointed out another minor advantage of this unique ship's abilities. "Plenty of times after deballasting, nice big fresh fish are left flopping around the docking well. We've had lots of fresh sea bass for supper as a result."
After the commissioning of the Ashland in June, 1943, the next Moore-built LSD to enter service was the USS Belle Grove in August followed by Carter Hall, Epping Forrest, Gunston Hall, Lindenwald, Oak Hill and White Marsh in the following months. White Marsh (LSD-8), the last of her type built by Moore, was launched in July, 1943 and commissioned in late January, 1944. About the same time Moore was preparing to launch LSD-5, the USS Gunston Hall, in May, 1943, Newport News Shipbuilding launched the first of their LSDs, the HMS Eastway followed by HMS Highway, HMS Northway and finally the HMS Oceanway which was launched in December 1943 and commissioned in late March 1944. These four ships participated in a number of British operations including the invasions of Normandy and Southern France. After the war, HMS Eastway ended up in the hands of the Greeks who first used her in commercial service as the Hyperion and then later as the HHMS Nafkratoussa, flagship of the Greek Navy's landing forces.
After the first four built-for-Britain ships, Newport News went on to build more LSD's of what would come to be known as the Casa Grande Class. Starting with Casa Grande (LSD-13), the additional ships included, in order of their launching, Rushmore, Shadwell, Cabildo, Catamount, Colonial and Comstock (LSDs 14 through 19). The last two ships were completed too late in the war to see any action, the Colonial being moored at San Francisco and the Comstock on her shakdown when the Japanese surrendered. Cabildo and Catamount were able to see the later stages of action in the Pacific only by virtue of the fact that the ever efficient Newport News Shipbuilding had delivered the two ships some six months ahead of schedule, a rather amazing feat when one considers that the construction of these ships had been tacked on to an already full building schedule.
Eight more LSDs were contracted for during the war years, seven of which were completed and delivered. Donner (LSD-20) and Fort Mandan (LSD-21) were built by the Naval Shipyard at Boston during early 1945 and were both in commission by October of that year. Rather than being assembled and launched in the conventional manner, these two ships were assembled in a drydock and simply floated out upon completion.
Gulf Shipbuilding of Chickasaw, Alabama received contracts for LSDs 22, 23 and 24, but the war was drawing to a close. LSD-22, the USS Fort Marion, was launched in May, 1945 but was not completed until January, 1946, six months after Japan's surrender. She was nevertheless commissioned and went on to enjoy a long and distinguished career serving into the 1970s. LSD-23 was originally given the name Fort Snelling but was completed as a merchant ship and christened TMT Carib Queen in 1956 after sitting derelict for 10 years. Two years later the ship was repossessed by the Government and acquired by the Navy. She was renamed the USNS Tarus and became part of the MSTS civil service manned fleet. LSD-24, given the name Point Defiance was also cancelled during August 1945 and what little had been laid of her keel was simply scrapped. The USS San Marcos (LSD-25), the single example of that type was built by the Philadelphia Naval Shipyard. Laid down in September 1941 and commissioned in mid April 1945, she had just arrived off Okinawa with her first war cargo when the Japanese surrendered in August. This ship, too, went on to enjoy a lengthy career with the U. S. Navy and then was finally transferred to the Spanish Navy in mid 1971 where she currently serves as the Galicia.
The last two war-built LSDs, numbers 26 and 27, were also built by the Boston Naval Shipyard, but were launched too late in the war to participate in combat operations. Both of these ships, the USS Tortuga (LSD-26) and the USS Whetstone (LSD-27), went on, however, to enjoy long service lives with the Navy.
For administrative purposes, those LSDs constructed during WWII were classed as follows: LSDs 1 through 8 were called the Ashland Class, 13 through 15 were called the Casa Grande Class and 16 through 27 were the Cabildo Class. It should be pointed out; however, that differences between the WWII ships were minor although post war modifications which continued up until the early 1970s eventually produced a group of ships where no two were configured exactly alike.
The Navy thought so much of the capabilities of the LSD that in the early 1950s it was decided to build a new class of eight ships. Along with the lead ship of the Thomaston class, the USS Thomaston (LSD-28) which was launched in September 1954, the seven additional ships included Plymouth Rock (LSD-29), Fort Snelling (LSD-30), picking up the name from the WWII LSD-23 which had been cancelled, Point Definace (LSD-31), also picking up the name of the cancelled LSD-24, Spiegel Grove (LSD-32), Alamo (LSD-33), Hermitage (LSD-34) and Monticello (LSD-35). Monticello, as the first ship in the new class, was launched in March 1957. The principle of operation for these ships was exactly the same as with those ships constructed in WWII. They did, however, sport redesigned, superstructures as well as sleeker and more eye pleasing hull lines. Clearly, it was not hard to improve the looks of those ships built during the war. The well deck on these new ships was five feet shorter in length than the WWII ships (391' versus 396') but was four feet wider (48' versus 44'). The class could be identified from the earlier ships in their main lifting cranes and smoke stacks being offset from one side to the other. The lifting capacity of the two big cranes carried aboard each ship was also increased from 35 tons to 50 tons. All eight of the ships were built by Ingalls Shipbuilding, Pascagoula, Mississippi, and all are still in active service with the Navy. With an overall length of 510 feet and displacing 6,880 tons, the new ships could make a top speed of 23 knots, a considerable improvement over their predecessors.
A decade later, the Navy once again decided to build new LSDs. Authorized in 1965-66, this would be the five ship class named after the lead ship, the USS Anchorage which was launched in 1965 by Ingalls but not commissioned until March 1969. The remaining four ships of the class were built by General Dynamics at their Quincy, Massachusetts facility, all being launched during 1966-67 and commissioned between 1970-72. Differing somewhat in superstructure and side view appearance from the Thomaston Class, the five Anchorage Class ships (Portland, Pensacola, Mount Vernon and Fort Fisher) were, at 553 feet in length, 43 feet longer than the earlier ships and could carry a slightly heavier load with a well deck measuring 430' x 50'. The ships are easily distinguished from earlier LSDs by their enclosed twin 3-inch gun mounts on either side just ahead of the bridge.
For a type that has served so well for so long, it now seems likely that the LSD building program has reached the end of the line. If, in fact, large amphibious operations remain a viable concept, by the time the newest of the LSDs are ready for retirement, ships along the lines of the Tarawa Class of General Purpose Amphibious Assault Ships will probably have stepped in to fill the gap. But for the next two decades, anyway, the LSD should remain a viable part of the nation's offensive strike capability.
USS Tortuga (LSD-26) ballasted down. A good example of the use of the LSD to embark and debark landing craft and other vessels. Ballast tanks located on each side of the ship are filled with water. The stern gate is opened and as the LSD settles down into the water, the water enters the well deck. Ballasting down stops when sufficient water is in the well deck to launch or receive vessels. When the water is pumped from the tank, the ship rises and the water in the well deck drains back into the sea. The stern gate is then closed.
Casa Grande Class Dock Landing Ship:
Laid down, 16 October 1944, at Boston Navy Yard, Boston, MA. – largest type of ship being built by the yard
(as reported by Office of Naval Intelligence, 7 April 1944)
Displacement 4,032 (light draft), 7,930 (seagoing - loaded)
Length 457' 9" o.a.
Draft 8' 2 ½" fwd, 10' ½" aft (light draft); 15' 5 ½" fwd, 16' 2" aft (seagoing loaded)
Speed 17 knots maximum (design speed)
Endurance 8,000 miles @ 15 knots
Crew Complement 17 officers, 237 men; Landing Craft: 6 officers, 30 men
Troop Complement 22 officers, 218 men
Well Deck Capacity (varies with mission)
· 3 LCT (Mk V or VI) each w/ 5 medium tanks or
· 2 LCT (Mk III or IV) each w/ 12 medium tanks or
· 14 LCM (Mk III) each w/ 1 medium tank or 1, 500 long tons cargo or
· 47 DUKW or
· 41 LVT or
Any combination of landing vehicles and landing craft up to capacity
Well Deck Capacity (with prefabricated "Super-Decks" installed)
· 108 DUKWs or
· 92 LVTs or
Any combination of tracked/wheeled vehicles up to capacity.
(Note: Incapable of repairing larger landing craft and ships in this configuration)
Aircraft LSDs 1 - 27 (still in commission in late 40's or early 50's) were fitted/retro-fitted with a prefabricated steel grated "Portable Deck" suspended between the wing walls and supported by removable I-beam girders. The aft end of the portable deck contained a wooden helicopter platform, enabling the ship to land and launch 1 helicopter at a time. Stowage of helicopters was limited to capacity of the portable deck installed for the mission. Aircraft servicing was limited to re-fueling. With portable deck and aircraft platform installed, the Landing ship, dock was still capable of transporting, launching and repairing smaller amphibious craft and vehicles up to the size of a Landing craft, utility (LCU) in their well decks.
· 1 - 5"/.38 caliber Dual Purpose single barrel mount in open tub (w/director)
· 2 - 40MM quad barrel Anti-Aircraft mounts (w/directors)
· 2 - 40MM twin barrel Anti-Aircraft mounts (w/directors)
16- 20MM single barrel Anti-Aircraft mounts (local control)
2 - Babcock and Wilcox Boilers, D Type, 2 Drum, Single Furnace, Single Uptake,
· 2 - Skinner Engines - steam geared turbine (geared)
2 - Twin screws
· Launched, 21 January 1945 ; sponsored by Mrs. George D. Payne
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Bow View, Boston Harbor 1945.
Stern View, Boston Harbor 1945.
Port Bow View, Boston Harbor 1945. Port Side View, Boston Harbor 1945.
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