DID YOU KNOW? SEABEE unit designations and rating title changes since 1942?

By Bill Hildebrand, President, CEC/Seabee Historical Foundation

On the NCBs vs NMCBs:

During WWII, the term NCB was used - the 10th Naval Construction Battalion. There were 150 in all with the first commissioned in March 1942. There was an earlier group, which became known as the Bobcats because they were sent to Borabora, code name "Bobcat". They were put together in Jan 1942 and shipped out. They never became a numbered battalion, probably because they were well below a battalion in size. A typical NCB was 1000-1200 men. There were also Special NCBs which were basically stevedoring units - today they are the Cargo Handling Battalions. They had enough construction capability to build their own camps, run their own equipment, maintenance operations, etc, but their mission was loading/unloading ships. There were 39 in all with the first commissioned in Dec 1942.

There were also Construction Battalion Maintenance Units (CBMUs) that would go in and operate a base the NCBs built when the NCBs moved on. There were 136 CBMUs in all with the first commissioned in March 1943. There were also Construction Battalion Detachments. They were stand-alone units, ranging in size from as few as 15-20 men up to several hundred, put together to do a specific task. Some existed only months, others, the entire war. There were a little under 100 of them, with the first commissioned in Nov 1942.

The last group was the Pontoon Assembly Detachments. The PADs actually were manufacturing shops set up in remote areas to turn plate steel into thousands of pontoons. The five PADs worked generally two twelve-hour shifts each day to keep the production moving. The first was commissioned in Dec 1942. Add in a dozen Brigades and 54 Regiments (not all in existence at the same time) and there were over 450 Seabee units in WWII. At the end of the war, all of the units except two of the NCBs (the 103rd and 124th) were decommissioned, and Davisville and Gulfport mothballed. However, even though the number of Seabees had dropped to less than 4000, there were too many for two battalions, so the 104th and 105th were reestablished.

In 1947 after a study by the Navy about whether to keep the Seabees (during WWII they were a temporary organization put together to solve a temporary problem - the need for bases in a war zone), the decision was made to keep the Seabees. The mission of the Special NCBs was transferred to the Bureau of Supplies and Accounts and the Cargo Handling Battalions were established. The word "Mobile" was added to the NCBs and the number put last - NMCB1 as opposed to 1st NCB. (The Bees dragged their heels for years on acknowledging that the "N" was there, but it was.) Beginning in 1949 and continuing through 1953, eleven NMCBs were commissioned, and Davisville was reopened to house some of the units.

During WWII, a few of the NCBs had become known as "pontoon battalions" because their specific mission had become the assembly and launching of the pontoon causeways. In the same directive in 1947 that created the NMCBs, the Navy also authorized the ACBs - one in Norfolk, the other in San Diego. The 104th NCB which had been reestablished in 1947 at Coronado was renamed ACB1, and the 105th NCB which had been reestablished in 1947 at Little Creek was renamed ACB2.

The 103rd became NMCB10 and the 124th, which was at Adak, was disestablished in 1953.

For some of the smaller missions, the Navy revived the use of the CBDs, establishing CBDs in the 1500 series with the first being CBD1501 on Johnston Island sometime in 1946-47. (The WWII CBDs were in the 1000-1100 series.) Later there was an 1800 series. I have not run across the reasoning behind the two different series.

That same 1947 decision by the Navy also created the rating structure used today, although today's EO's started out as CDs (Construction Drivers) and the EAs were originally SVs (Surveyor). Both were changed to their present designations sometime in the late 50s, early 60s.

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