CA-134 Des Moines Class
usnc-desmoines01small.jpg
(some parts and underwater details taken from Shipbucket.com)

Ship Characteristics

Dimensions Length 716.5 ft
Beam 76.3 ft
Draft 26 ft
Displacement (Standard) 17,000 tons
Displacement (Full Load) 21,500 tons
Performance Speed (max) 33 knots
Speed (Cruising) 15 knots
Endurance 10,500 nm. at 15 knots
Armament Heavy Guns 9 8 inch L55
Medium Guns 12 5 inch L38
Light guns 24 3 inch L50
Armor Belt 6 inches
Deck 3.5 inches

Background

The Des Moines class heavy cruisers were the last gun cruisers to be built for the U.S. Navy. They were developed as an improved version of the CA-68 Baltimore Class with new machinery, increased internal armor, superior fire control and, most importantly, a new model 8 inch gun that could rival the 6 inch L47 as mounted on contemporary light cruisers for rate of fire. Thus, the Des Moines class offered the volume of fire capability of the 6 inch cruiser with the heavy shells of the 8 inch ships. During the design process, it became apparent that any really satisfactory cruiser would be similar in displacement regardless of whether she was armed with 6 inch or 8 inch guns. The new 8 inch guns meant that the six inch ships had no real advantage over the 8 inch model and plans to build the CL-144 Worcester were cut back from 16 to four ships with the orders being reprogammed as Des Moines class cruisers.

The 1943 cruiser building program was controversial for those reasons. originally, this program had consisted of six CL-106 Fargo class and six Improved Baltimore class cruisers. However, experience gained in the Atlantic. had shown that the smaller and less stable Cleveland class were badly affected by bad weather. Also, experience had shown that the Clevelands were far from ideal in that their gun layouts suffered from mutual interference and they were severely crowded. The even smaller Atlanta class suffered from similar problems. The problems with the Clevelands were not addressed by the Fargo class that was derived from them. This led to the six 1943 program Fargo class cruisers being cancelled and replaced by four of the Worcester class cruiers that represented a near-equivalent in resource terms. Since the Des Moines class was ready for construction and offered multiple advantages over the Baltimore class, six CA-134 Des Moines class cruisers replaced teh Modified Baltimore class. The same arguments resurfaced in the 1944 building program that proposed the construction of a further six Worcester class and six Des Moines class. The Des Moines class was approved but the six Worcesters were dropped in favor of a smaller light cruiser that would have the same general layout but be armed with five inch L54 guns. These also were dropped when the design was considered immature and a further six Des Moines class ships were added to the program. Pressure on shipyards then caused those six ships to be deferred until the 1945 building program.

All of the first batch of six ships were completed as gun cruisers with the first pair reaching the fleet just before The Big One abruptly ended World War Two. None of these ships ever fired their guns in anger. By the end of 1947 they were openly regarded as being battleship-substitutes, offering equivalent command facilities at much lower cost in terms of operating expense and manpower requirements. They served in this role until the late 1960s when they were all broken up for scrap.

The 1944 program ships had still not been launched when the war ended. Two of the ships had already been taken out of the construction program and were being redesigned as command cruisers. The other four were suspended while a decision was taken as to their fate. In 1953 it was decided to complete them as missile cruisers using the same standardized conversion scheme based on prefabricated assemblies that was being applied to the Baltimore and Worcester classes. The larger hull of the Des Moines class meant that these ships could retain a hangar aft that was used for Regulus 1 missiles. The missile conversions remained in service until 1996, having received a mid-life upgrade in the mid-1980s.

The 1945 program ships were theoretically laid down in 1947 although in some cases it appears that only the collection of raw materials took place and no actual construction was started. All six ships were cancelled in June 1947 and any materials on the slips were broken up.

Class Members

Number Name Ordered Laid Down Launched Commissioned Fate
CA-134 Des Moines 1943 1944 1945 1947 Decommissioned and scrapped 1967
CA-139 Salem 1943 1944 1946 1947 Decommissioned and scrapped 1967
CA-140 Dallas 1943 1944 1946 1947 Decommissioned and scrapped 1967
CA-141 Brooklyn 1943 1944 1946 1947 Decommissioned and scrapped 1968
CA-142 Savannah 1943 1944 1946 1947 Decommissioned and scrapped 1968
CA-143 Newport News 1943 1944 1946 1948 Decommissioned and scrapped 1968
CA-148 Honolulu 1944 1945 1950 1954 Reprogrammed as CAC-148 in 1946
CA-149 Omaha 1944 1945 1950 1954 Reprogrammed as CAC-149 in 1946
CA-150 San Diego 1944 1945 1955 1957 Reprogrammed as CG-150 in 1953
CA-151 San Juan 1944 1945 1956 1958 Reprogrammed as CG-151 in 1953
CA-152 Marblehead 1944 1945 1957 1959 Reprogrammed as CG-152 in 1953
CA-153 Niagara Falls 1944 1945 1958 1960 Reprogrammed as CG-153 in 1953
CA-154 Sioux Falls 1945 1947 Cancelled June 1947
CA-155 Dover 1945 1947 Cancelled June 1947
CA-156 Oil City 1945 1947 Cancelled June 1947
CA-156 Abilene 1945 1947 Cancelled June 1947
CA-156 Dodge City 1945 1947 Cancelled June 1947
CA-156 El Paso 1945 1947 Cancelled June 1947

Command Cruiser Conversion

usnc-desmoines03small.jpg
(some parts and underwater details taken from Shipbucket.com)

Ship Characteristics

Dimensions Length 716.5 ft
Beam 76.3 ft
Draft 26 ft
Displacement (Standard) 18,500 tons
Displacement (Full Load) 22,500 tons
Performance Speed (max) 33 knots
Speed (Cruising) 15 knots
Endurance 10,500 nm. at 15 knots
Armament Guns 4 5 inch L54 Mark 42, 8 3 inch L50
Armor Belt 6 inches
Deck 3.5 inches

Background

By mid-1946, it was becoming apparent that the atomic bomb offered the user an unprecedented ability to deliver destruction upon a target while the long-range, ultra-high altitude bomber offered a secure means of delivering these weapons to those targets. In fact, it was obvious at that time no means of defense existed against such an attack and that it would be years before an effective defense became possible. This raised the ugly possibility that the United States could also be a victim of such an attack and attention began to be diverted towards defending against it. The first priority was to ensure that national command and control would be protected. Any land target could be destroyed but a ship afloat would be a much more difficult proposition, especially given the fact that the U.S. navy dominated the world's oceans. Thus, the concept of a National Emergency Command Post Afloat (NECPA, colloquially known as Neckpain) was raised. Two Des Moines class cruiser hulls were selected for conversion to this role. For security reasons, they were referred to as amphibious warfare command ships with the cover story that they were the command ships for the invasion of Europe.

The conversion was massive. All the armament was stripped out and an extra deck built into the hull to provide command space. The ship layout was determined by the demands of those command spaces and the communications antennas required to fulfil the ship's functions. The new armament, originally intended to be four twin 5 inch L38, these being replaced by four single 5 inch L54 Mark 19s and finally by four single 5 inch L54 Mark 42s, was placed so that not one of the mounts was actually on the ship's centerline, all being offset due to the office space requirements in their vicinity. A combination of the extent of the redesign and the post-war work slow-down meant that they were not launched until 1950 and did not enter service until 1954.

Their life in the NECPA role was short. By 1960, the growth of NORAD and ARADCOM defenses meant that the territory of the United States was more or less secure and the NECPA role was stood down. The Honolulu and Omaha were therefore retasked as fleet flagships for the Pacific Fleet in anticipation of a war against Chipan. They remained in this assignment until 1975 when a new generation of larger and more capable command ships was built to replace them.

Class Members

Number Name Ordered Laid Down Launched Commissioned Fate
CAC-148 Honolulu 1944 1945 1950 1954 Decommissioned and scrapped 1975
CAC-149 Omaha 1944 1945 1950 1954 Decommissioned and scrapped 1976

Missile Conversion.

usnc-desmoines02small.jpg
(some parts and underwater details taken from Shipbucket.com)

Ship Characteristics

Dimensions Length 716.5 ft
Beam 76.3 ft
Draft 26 ft
Displacement (Standard) 17,000 tons
Displacement (Full Load) 21,500 tons
Performance Speed (max) 33 knots
Speed (Cruising) 15 knots
Endurance 10,500 nm. at 15 knots
Armament Long range SAM 92 Talos
Short range SAM 80 Tartar
Anti-Surface Missiless 4 Regulus 1
Armor Belt 6 inches
Deck 3.5 inches

Background

With 12 active task forces, there was a requirement for 24 large missile cruisers and 24 small missile cruisers to screen them. The planned CG-123 Albany and Worcester class conversions provided 16 large missile cruisers, leaving the fleet eight short. The four remaining incomplete Des Moines class ships offered to fill half this requirement and it is possible to guess that the 1947 decision to scrap the third group of six was deeply regretted. However, work on the four hulls was started and these ships were the last of the Tall Lady conversions to be implemented. They received the New Threat Upgrade in 1984 - 86 that gave them Regulus III missiles, Sea Falcon CIWS, Standard AAW missiles and new radars. They were finally decommissioned in 1996 with the last of the class, CG-153 Niagara Falls being preserved as a museum, the only U.S. cruiser to survive.

Class Members

Number Name Ordered Laid Down Launched Commissioned Fate
CG-150 San Diego 1944 1945 1955 1957 Decommissioned and scrapped 1996
CG-151 San Juan 1944 1945 1956 1958 Decommissioned and scrapped 1996
CG-152 Marblehead 1944 1945 1957 1959 Decommissioned and scrapped 1996
CG-153 Niagara Falls 1944 1945 1958 1960 Decommissioned and presereved as museum 1996
Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License