ww2 Liberty ship Specifications

Liberty ship layout

The SS John W. Brown is a World War II cargo ship built by the U.S. Maritime

Commission. In 1942, she was built in 41 days at the Bethlehem-Fairfield Shipyard in

Baltimore, Maryland. She was launched on Labor Day, September 7, 1942. The ship

was named after an American labor leader who organized workers in shipyards.After

being launched, the ship sailed to New York and departed on its maiden voyage on

September 29, 1942 carrying supplies to the Middle East. In 1943, the ship was

converted to carry troops as well as cargo. Later, the John W. Brown supported combat

operations in the Mediterranean Sea. The ship was involved in the Allied landings at

Sicily and Anzio in Italy, and southern France. After the war ended in Europe, the John

W. Brown carried U.S. military personnel home.About 2,700 Liberty ships were made

during the war, and about 200 were sunk. Where possible, bulky war machines, (like

cargo ships that required much raw material)--were made in the U.S.; allowing

England’s labor force to concentrate more on labor intensive, smaller, technical

machines (like their fine Spitfire fighter planes, and mine detecting and destruction

equipment, and so on).

Liberty ship model

LIBERTY SHIP: It became obvious, after WW2 began, that the Allies’ mounting loss of

ships, to enemy subs (U-boats) was a major obstacle to the Allied effort; and, in fact,

England might starve. And Soviet Russia’s manufacturing capacity and resources were

also soon greatly reduced by initial German territorial gains. And the Soviets lost their

labor force in areas occupied by Germany. So an astute U.S. Administration, with good

advisors and technical experts, drafted plans to manufacture great numbers of

Merchant ships, using cheap, non-scarce materials, and high-efficiency technology. And

the ships were to have great cargo capacity. Welding would replace rivets; large prefab

sectionswould be utilized where possible.

The value of the cargo carried by a Liberty ship often far exceeded the value of the

Liberty ship, itself. If such ship could just make only one successful delivery to the

Allies, it thus “paid for itself”. Suppose, a Liberty ship carried 440 tanks weighing 8000

tons total and worth $18,000,000. That value would obviously dwarf the $1,600,000 cost

of the ship, itself. In fact, that is a strong argument for dispersing especially valuable

cargo among various Liberty ships, so that an Ally receiving it does not find itself totally

lacking in any one class of equipment, indispensable for carrying on the war.

(Occasionally there were “too many of a particular type of ‘eggs put in one basket’, i.e.,

loaded on one Liberty ship”.) Incidentally, a ship’s steam engine is designed to re-

condense, recover, and recycle its de-energized warm steam, after each cycling

sequence. And therefore, it need not make water stops or scoop up cool water for its

engines; which railroad steam locomotives, unfortunately, have to do. (Large WW2

Warships, propelled by steam turbines, produced and utilized high steam pressures of

575 psi., which seems much higher than steamlocomotives of the period, i.e., 250 psi.)

The ships’ shape, propulsion, and general design were based on a cheap, old “tramp”

ship that had been commercially successful.I think it was fortunate, at least, that fuel oil

was chosen, instead of coal to power Liberty ships, because that required much less

crew, who might be killed or injured if the ship was torpedoed. And the U.S. Merchant

Marine Service suffered a higher percent killed than any the large ‘military’ Branch of

the Services; and did not need matters made still worse. (Of course, certain specialty

services within each major Service, such as the U.S. Submariners, suffered even higher

percentage killed.) Oil fuel also increased the Liberty Ship’s efficiency. In 1940, about

40% of the world’s ships still used coal. Coal was much more commonly used in

merchant ships, then; and was generally avoided for military ship propulsion. It was

decided that Liberty ships would used cheap and relatively available engines, ((i.e., the

triple expansion, reciprocating steam engines--even though their relatively low power

output (totaling 2,500 HP) propelled the large ships slowly enough to be followed for a

while, even by submerged U-boats.)

Liberty Ship Technical Specifications

Speed: 10.5 knots (12 mph), presumably even when fully loaded.

Gross weight (i.e., weight of empty ship): 7000 tons

Cargo weight (applicable to ship’s “full load displacement” rating):7000 tons

Full load” Displacement (Gross weight + full-load cargo weight):14,000 tons

The so-called “Deadweight” (i.e., amount of Cargo, and the ship’s own Fuel, etc., which

the ship could carry on emergency missions if seas didn’t become too rough, or in calm

lakes, etc.): …… 10,500 tons

Size:430 feet long; 57 feet beam (max width); 27 feet draft (depth into the water).

Power: total 2,500HP, from reciprocating steam engines.

Fuel: Oil

Crew: about 56 to 80; ((about 12 to 25 of those would likely be Navy personnel (guards)

to man the ship’s several defensive guns. The number of these guns per ship increased

during the war))

Ships

National Archives #80-G-453313

Ships are complex systems, the detailed description of which is beyond the scope of this Encyclopedia. Furthermore, even ships of the same class tended to show small variations, and most ships were extensively modified as the war progressed. In particular, both the Allies and the Japanese tended to add more antiaircraft protection to a ship every time it was refitted. Ship specifications given in this Encyclopedia are therefore nominal values at the time ships of the class were first committed to the Pacific.

Warships of the Second World War benefited from a number of improvements in engineering from the First World War. One was improved metallurgy. High-strength steels gave the same strength as older steels with less weight. Superior alloys for turbine blades made it possible to run ships' machinery at higher temperatures and pressures, yielding more power with greater efficiency. Armor was also superior in quality.

Another area of improvement was in hull forms. All the major naval powers did extensive testing of hulls in model basins. Curiously, American tests demonstrated such advantages to twin-skeg hulls that they were used in almost all major U.S. warships built during the war, including all post-treaty battleships, while British and Japanese model basin tests incorrectly predicted that twin skegs would be counterproductive.

Welding began to replace riveting in ship construction between the wars. Rivets required overlapping plates, and a riveted joint did not have the strength of the solid plate. Welds eliminated the need for

overlapping plates, thereby reducing weight, and a properly welded joint was as strong as the original metal. This was particularly important in underwater protection systems. On the other hand, welding was a relatively new technology and properly welded joints were still difficult to achieve. Riveted joints had the advantage that they tended to halt the propagation of cracks.

Finally, tremendous advances were made in naval electronics, particularly radar, which transformed naval warfare.

Ship SpecificationsDisplacement. The usual measure of the overall size of a warship was its standard displacement, which was the total weight of the ship, measured in long tons (1.016 metric tons), when loaded for combat. For merchant vessels, the usual measure was either the gross register tonnage (G.R.T.) or the deadweight tonnage. G.R.T. was the total volume of the ship in units of 100 cubic feet (2.83 cubic meters). Deadweight tonnage was the maximum weight, in long tons, of crew, passengers, and cargo that the ship could safely carry. In some cases merchant ships are described by light and fully loaded displacement; the deadweight tonnage would be slightly less than the the difference between these two displacements.

Dimensions. These are give as the overall length, beam (width), and draft (maximum depth of the keel). For operational purposes, draft was most important, as it determined how closely a warship could approach shore, and deep-draft vessels could not enter the shallowest harbors. Beam theoretically could have limited passage through the Panama Canal, but for this very reason all U.S. warships launched before and during the war were designed to fit through the Canal. The ratio of length to beam was one of the factors determining maximum speed (the greater the ratio, the faster the ship, up to a value of about 10), but speed is listed separately.

Maximum speed. This is the maximum speed the ship could sustain for any length of time.

Complement. This is the nominal size of the ship's crew. This number tended to go up as the war progressed.

Aircraft. This gives the length of the flight deck, the number of elevators and catapults, and the maximum number of aircraft a carrier could reasonably operate. Most carriers could carry more aircraft, but could not make effective use of them. For other classes of ships, this specification gives the number of seaplanes and seaplane catapults, if any.

Armament. This is the typical armament of the class at the time that members of the class were first committed to combat in the Pacific. Most ships upgraded their antiaircraft armament once or more during the war. Main armament was rarely upgraded without reclassification of the ship.

Protection. Describes the armor protection of the ship. In general, only a portion of an armored warship (called the citadel) was protected. The citadel typically consisted of belts of armor on the sides of the ship, enclosed on top by one or more armored decks, plus armor protection for the main gun turrets and the conning tower. The bulkheads at the ends of the side armor belts were usually also armored.

Not listed is the general toughness of the ship, which is difficult to quantify. American warships often used Special Treatment Steel (STS) for internal structural members and bulkheads, which was resistant to splinters. The British and Japanese likewise used Type D Steel. Other navies probably did something similar. Toughness also depended on sound design, and it was not strongly correlated with the quality of the armor system. Some unarmored destroyers were quite tough for their size, while the heavily armored Yamatos appear to have had significant structural weakness, if the difficulty of satisfactorily repairing torpedo damage is any indication.

Machinery. Gives the number of shafts and boilers and the total shaft horsepower, which have some bearing on the ability of the ship to survive flooding.

Bunkerage. This specifies the amount and type of fuel carried by the ship. It is important in determining refueling requirements. The amount of aviation gasoline carried by aircraft carriers and (when known) seaplane-carrying vessels is also listed.

Range. This is given as the maximum distance that the fully fueled ship could travel at its designed cruising speed before refueling. Some sources quote lesser ranges and higher speeds, indicating that the ship rarely operated at its designed cruising speed. This was particularly the case for lighter escort vessels (cruisers and destroyers.)

Most warships consumed fuel prodigiously at maximum speed. Merchantmen, on the other hand, were designed to cruise at close to their maximum speed, there being no good reason to build excess speed capacity into a commercial vessel. The rule of thumb was that the power required to cruise at a particular speed was proportional to the cube of the speed. Thus, a ship running at 32 knots required ten times the power (and presumably ten times the fuel consumption) of a ship running at 15 knots, reducing its range by a factor of nearly 5.

The actual fuel consumption curve for a particular class departed slightly from the cube law. Wartime figures compiled for the Bagley class showed that these ships burned 1.8 times the fuel at 20 knots as at 15, 3.9 times as much as 25 knots, and 8.4 times as much at 30 knots. Thus the actual performance was slightly steeper than the cube law, with slightly better performance at moderate speeds and slightly worse performance at the highest speeds. Even so, the cube law was a fairly good rule of thumb.

The figures given are nominal. There was a marked tendency for ships to consume fuel more quickly under wartime operating conditions than experience in peacetime exercises suggested. This may have been due to reduced opportunities for maintenance of engines and for scraping the hull.

Sensors. This specifies the radars and sonars typically available to units of the class when committed to the Pacific. Like antiaircraft armament, these were upgraded frequently during the war.

Modifications. Most ships were modified during the war, typically to increase their light antiaircraft armament and to add or upgrade radar. This sometimes varied greatly from ship to ship within a class, so modifications may be described only in general terms.

Units in the Pacific. This table gives the names and fates of ships that saw service in the Pacific War. Starting locations are given for those ships already in the Pacific when war broke out. Ships completed at shipyards within the Pacific Theater are so indicated along with the yard.

For ships arriving from outside the Pacific Theater, arrival dates are given. Unless otherwise specified, the arrival date is the approximate date the ship transited the Panama Canal if it was an American ship or the approximate date the ship reached Durban if it was a British ship.

Production Schedule. For certain kinds of mass-produced ships, particularly Japanese standard vessels and escorts, individual completion dates are not available, but production rates are known or can be estimated.

CGN 36 California Class

OverviewThe mission of CALIFORNIA-class nuclear-powered guided missile cruisers is to operate offensively in the presence of air, surface, and subsurface threats. These actions may be performed independently or in support of sealift convoys, high-speed aircraft carrier task forces, or amphibious task forces. The nuclear-powered engineering plant allows the cruiser to conduct operations over extended periods of time anywhere in the world. To accomplish its mission, these ships are equipped with the latest technology and equipment including the New Threat Upgrade modernization. With a fully integrated combat system, it has the capabilities to quickly detect modern threat platforms, perform high-speed data processing and employ powerful weaponry.

This was the first class of nuclear-propelled surface warships intended for series production. These ships essentially are nuclear-propelled version of guided missile designs proposed in the early 1960s. To aid in accomplishing their assigned tasks, these ships are equiped with an extensive array of weapons and sensors. They have the older SM-1 series SAM on single arm, Mk13 Mod 3 launchers (fore and aft), two 5 inch guns (fore and aft), anti-ship capability with Harpoon SSMs, the 20mm Close In Weapon System (CIWS) and USW capability with ASROCs, These do not carry TLAMs. Sensors include a 3D air search radar, 2D air search radar, an array of surface search radars and fire control radar systems. They are also equiped with passive electronic surveillance and jamming systems unequaled by any other cruiser in the Navy. These weapons and sensors give them the ability to attack and defend against targets that are over 70 nautical miles away while being able to protect themselfs from close range attacks. Two nuclear reactors provide all the energy required for the propulsion plant and electric generators. The two propulsion plants deliver 70,000 shaft horsepower, allowing sustained speeds in excess of 30 knots (nautical miles per hour) all over the world.

Specifications

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On the 04 September 1998 USS South Carolina completed her service to the active fleet of The United States Navy. Beginning the final Deactivation process, on 04 November 1998, the ship entered Drydock 4 at Norfolk Naval Shipyard. As of 01 October 1998 CGN-36 California was in commission in Reserve (Stand Down) at Bremerton WA at the start of the inactivation cycle.

Specifications Return to Top

Power Plant Two D2G General Electric nuclear reactors,two shafts, 60,000 shp

Length Overall Length: 596 ftWaterline Length: 570 ft

Beam Extreme Beam: 61 ftWaterline Beam: 60 ft

Draft Maximum Navigational Draft: 32 ftDraft Limit: 23 ft

Displacement Light Displacement: 10373 tonsFull Displacement: 11320 tons

Speed 30 plus knots

Aircraft None

Helicopter Landing Capability

Landing area only, no support facilities

Armament Standard Missiles (MR)ASROC8 - Harpoon (from two Mk141 quad launchers)4 - MK 46 torpedoes (from fixed single tubes)2 - Mk45 5-inch/54 caliber lightweight gun2 - 20mm Phalanx CIWS

Combat Systems SPS-40 Air Search RadarSPS-48 3D Air Search RadarSPS-67 Surface Search Radar SQQ-26 Sonar [bow mounted] 1 Mk14 Weapon Direction System

2 Mk74 Missile Fire Control System1 Mk86 Gun Fire Control System1 Mk114 ASW Fire Control System4 SPG-51 Radars SLQ-25 NIXIESLQ-32 EW system

Crew 40 Officers, 544 Enlisted

Unit Operating CostAnnual Average

~$40,000,000 [source: [FY1996 VAMOSC]

Ships Return to Top

NameNumber

Builder Homeport OrderedCommissioned

Decommissioned

California CGN 36Newport News

Bremerton

13 Jun 1968

16 Feb 1974 01 Oct 1998

South Carolina

CGN 37Newport News

Norfolk13 Jun 1968

25 Jan 1975 04 Sep 1998