Seabees in World War II


When World War II broke out the United States Naval Construction Battalions did not exist. The vast oceans between the U.S and the enemy on both sides made the logistics of war a major concern. Rear Admiral Moreell completely understood the issues at hand. What needed to be done was build staging bases and create a military construction force to do build them to take the war to the enemy. The concept of Naval Construction Battalions had been developing at Bureau of Yards and Docks in the 1930s. The onset of war clarified to Radm. Moreell the need to be able to develop advance bases to project American power. The solution was to tap the United States vast pool of skilled labor. Put it in uniform to build anything, anywhere under any conditions and get the Marine Corps to train them. The first volunteers were skilled at enlistment. To obtain these men, military age was modified to take up to 50 years old. It was later found that several past 60 had managed to get in. Men were given advanced rank/pay based upon experience making the Seabees the highest paid group in the U.S. military. The first 60 battalions had an average age of 37.
"In December 1942 voluntary CB enlistments ceased per presidential order. For the next year Seabees were picked by the Selective Service System. Recruits were younger and came with only basic skills." To address this issue the Seabees created training programs in more than 60 trades. They would become renowned for unofficial trades like souvenir making, and the arts of obtaining materials by unofficial and unorthodox means Tools that became synonymous with the Seabees were bulldozers, steel pontoons, steel mat, and corrugated steel, combined with "ingenuity and elbow grease" Nearly 11,400 became officers in the Civil Engineer Corps of which nearly 8,000 served with CBs. The Naval Construction Force worked simultaneously on multiple islands, in multiple theaters supporting U.S forces. On 13 February, 1945 the Chief of Naval Operations, Fleet Admiral Ernest J. King, approved the retention of CBs as a permanent part of the Navy. Before that happened the Seabees would provide the personal for multiple tasks outside the NCF: Naval Combat Demolition Units, UDTs, Marine Corps Engineers/Pioneers and the top secret Chemical Warfare Service Flame tank Group.

Pre-war naval construction development

In the late 1930s the US saw the need to prepare militarily. Congress authorized the expansion of naval Shore Activities in the Caribbean and by 1939 in the Central Pacific. "Following standard peacetime guidelines the Navy awarded contracts to civilian constructions firms. These contractors employed native civilian populations as well as U.S citizens and were answerable to naval officers in charge of construction. By 1941 large bases were being built on Guam, Midway, Wake, Pearl Harbor, Iceland, Newfoundland, Bermuda, and Trinidad to name a few." International law, dictated civilians not to resist enemy military attacks. Resistance meant they could be summarily executed as guerrillas. Wake turned out to be an case in point for Americans.

World War II

The need for a militarized construction force became evident after the Japanese Attack on Pearl Harbor. On December 28 Radm. Moreell requested authority to create Naval Construction Battalions. The Bureau of Navigation gave authorization on 5 January 1942. Three Battalions were officially authorized on 5 March 1942. Enlistment was voluntary until December when the Selective Service System became responsible for recruitment. Seabee Training Centers were named for former heads of the Civil Engineer Corps: Radm. Mordecai T. Endicott, Radm. Harry H. Rousseau, Radm. Richard C. Hollyday, Radm. Charles W. Park. Camp Peary was named for RADM. Robert Peary. The Seabees also named a Center for the first CEC killed in action, Lt. Irwin W. Lee and Lt. George W. Stephenson of the 24th CB.
A pressing issue for the BuDocks was CB command. Navy regulations stated that command of naval personnel was limited to line officers of the fleet. BuDocks deemed it essential that CBs be commanded by CEC officers trained in construction. The Bureau of Naval Personnel strongly objected to this violation of Naval tradition. Radm. Moreell took the issue directly to the Secretary of the Navy. On March 19 the Secretary gave the CEC complete command of all those assigned to naval construction units. With CBs authorized and the command question settled, BuDocks then had to deal with recruitment and training. Following that, was deciding the military organization structure and organizing the logistical support necessary to make everything work. That all happened quickly. Due to the exigencies of war there was a great deal of "improvisation", a quality that became synonymous with Seabees in general.
"At Naval Construction Training Centers and Advanced Base Depots on both coasts, men learned: trade skills, military discipline, and advanced combat training. Although technically designated "support", Seabees frequently found themselves under fire with the Marines. After completing boot training at Camp Allen VA. and later Camp Peary VA, the men were formed into CBs or other smaller CB units. The first five battalions were deployed immediately upon completion of training due to the backlog of projects. Battalions that followed were sent to an ABDs at either Davisville, Rhode Island, or Port Hueneme, California to be staged prior to shipping out. Basic military training was done by the Navy while the Marine Corps provided advanced military training at Camp Peary, Camp Lejeune or Camp Pendelton. About 175,000 Seabees were staged out of Port Hueneme during the war. Units that had seen extended service in the Pacific were returned to the R&R Center at Camp Parks, Shoemaker, CA. There units were reorganized, re-deployed or decommissioned. Men were given 30-day leaves and later, those eligible were discharged. The same was done at the Davisville, Rhode Island, for the east coast."
From California, battalions attached to III Amphibious Corps or V Amphibious Corps, were staged to the Moanalua Ridge Seabee encampment in the Hawaiian Territory. It covered 120 acres and had 20 self-contained areas for CB units. Within each area were 6 two-story barracks served by a 1,200 man galley and messhall plus 8 standard quonsets for offices, dispensary, officers quarters and a single large quonset for the ships store. The entire facility had water, sewer, electricity, pavements, armory and a large outdoor theater. A second CB encampment of 4 additional 1000 man Quonsit areas was built on Iroquois Point. Battalions attached to the 7th Amphibious Fleet were staged at Camp Seabee next to the ABCD in Brisbane Australia.

The Atlantic theater

"When the war became a two-ocean war, the Panama Canal became geographically strategic. The convergence of shipping lanes necessitated bases to protect its approaches. Agreements in the Caribbean made it possible to obtain the sites needed. The Lend Lease Agreement also made sites available while existing bases were enlarged. Under the Greenslade Program naval bases in Puerto Rico, Cuba, and the Panama Canal Zone were all expanded. The construction program undertaken in Puerto Rico turned Naval Station Roosevelt Roads into the "Pearl Harbor of the Caribbean. Construction on existing bases was done primarily by civilian contractors until late 1943 when CBs took over. In the Atlantic, the bases formed a line from Bermuda to Brazil. On the Pacific side of the Americas the U.S had bases from the Honduras to Ecuador. The 80th CB upgraded Carlson airfield on Trinidad. The 83rd CB cut a highway out of Port of Spain, that required moving a million cubic yards of material." "On the Galapagos Islands, CBD 1012 constructed a seaplane base with tank farm and did the same again at Salinas, Ecuador. Salinas would be the southernmost U.S. base in the Pacific. In general, Seabees in this zone manned bases completed pre-war. While not in combat zones they were necessary to the overall war effort."
"North Africa was the Seabees first combat. Landing with the assault in November 1942, they built facilities at Oran, Casablanca, Sifi and Fedala. Later they would build a string of staging and training areas along the Mediterranean including NAS Port Lyautey, Morocco."
"Once Tunisia was taken the Seabees began a buildup at Bizerte. There they prepped steel pontoon boxes for their first use in combat at Sicily. This Seabee "innovation" was adapted for amphibious warfare. A pontoon box was standardized in size so multiple pontoons could be quickly assembled like to form causeways, piers, or rhinos. As such they could be used to meet the exigencies of amphibious warfare. The beaches of Sicily were considered impossible for an amphibious landing by both the Allies and Axis. The Seabees with their pontoons proved that was not true. The Germans were overwhelmed by the men and material that poured ashore over pontoon causeways.
"Seabee causeways were used again at Salerno and Anzio. The Germans were prepared causing heavy casualties at both. At Anzio Seabees were under continuous fire for an extended period. When Southern Italy finally fell the Seabees had one last task in the Mediterranean, Operation Dragoon."
"Seabee operations in the North Atlantic began early 1942. The first were in Iceland, Newfoundland, and Greenland. These airfields and ports supported Allied convoys in the Northern sealanes. To complete the line of defence theses bases made, Seabees were sent to the UK. Londonderry, Northern Ireland, Lough Erne, Loch Ryan, and Rosneath in Scotland were transformed into depots, fuel farms, and seaplane bases to anchor the line. Once completed the Seabees moved to South for Operation Overlord preparations. They built invasion bases from Milford Haven to Exeter and prepared for their multifaceted role."
D-Day found Seabees amongst the first ashore as Naval Combat Demolition Units. Their task was to remove beach obstacles built to impede amphibious landings. "NCDUs came under very heavy fire and worked until all charges were placed and detonated. The gaps created in the obstacles permitted the assault to hit the beach. With the invasion force waiting, Seabees placed pontoon causeways over which the assault could access the gaps."
"Seabees also brought their Rhinos. Rhino ferries were a motorized or towed variation of the modular pontoon boxes. With them, vast amounts of men and material went ashore. Seabees also assembled offshore piers, and breakwaters into Mulberry A for the American sector. It was a temporary port until French ports could be used. Even after weather disabled the harbor Seabees continued to get thousands of tons supplies and troops ashore daily."
"The liberation of Cherbourg and Le Havre provided CBs major projects. Those harbors were very much needed to replace Mulberry A. Foreseeing the Allieds would want to use those harbors the Germans had left them in ruins. At Cherbourg the first cargo landed within 11 days of the Seabees arrival and within a month the harbor was handling 14 ships simultaneously. They repeated this at Le Havre and again at Brest, Lorient, and St. Nazaire."
"The last Seabee project in Europe was the crossing of the Rhine. The U.S. Army called for Seabees to do the job and General Patton requested they wear U.S.Army uniforms while doing it. The first crossing was at Bad Neuenahr near Remagen. More followed quickly as the Seabees made the operation work as planned. On 22 March 1945, General George S. Patton, put his armor across at Oppenheim. Seabees used pontoon ferries to get the job done. In all, they had more than 300 craft shuttling troops and armor across. One crew even put Prime Minister Churchill across."
"The 69th was the only CB to set foot in Germany. They also were the first CB to deployed by air. They were flown to Bremen in April 1945 setting up camp on the city's outskirts. Their task was to repair damaged buildings and power lines for use by the U.S. Miltary occupation| occupation force as well as the port of Bremerhaven operational. Another detachment was sent to Frankfurt-am-Main to refurbish buildings for the U.S. Navy Hq in Germany. By August 1945 the battalion was back in England concluding Atlantic operations."

The Pacific theater

"Pacific Seabees were appreciated by those who came behind them. Their deeds were historically unparalleled. With 80 percent of the NCF in the Pacific, CBs literally built the road to V-J-day with all the airfields, piers, ammunition bunkers, supply depots, hospitals, fuel tanks, and barracks required to make it happen. They would serve on over 300 islands."
"From the onset, the entire Pacific, including Alaska and the Aleutians were Japanese targets. Japanese operations of 1942, took the islands of Attu and Kiska. Seabees sent to the North were there to help forestall what appeared at the time to be a major Japanese offensive. By late June 1942 they had begun bases on Adak and Amchitka in the Aleutians. They would serve as a deterrent for the remainder of the war."
"The first CB projects were on Bora Bora where the 1st CB Detachment arrived February 1942. The det took the name "Bobcats" from the Operation's code name BOBCAT. Their task was to construct a fuel depot for ships and planes en route to Australia. The Bobcats learned of many tropical issues: persistent precipitation, 50 types of dysentery, numerous skin diseases, and the dreaded elephantiasis. These all combined to make conditions miserable and were harbingers of what was awaiting Seabees else-wheres. From the start their task was difficult, despite this there was satisfaction when the island's tank farms supported Task Force 44 for the Battle of the Coral Sea."
"While the Bobcats were in transit to Bora Bora the 2nd and 3rd CB Dets were formed. The 2nd CB Det was sent to Tongatapu in the Tonga Islands while the 3rd CB Det went to Efate in the New Hebrides. Both islands were also on routes to Australia..
Bases built on them would support actions in the Coral Sea and the Solomon Islands. Espiritu Santo in the New Hebrides became strategic when the Japanese took Guadalcanal, the southernmost point of their expansion. Destruction of Japanese airfields nearing completion on that island became imperative to stop further expansion. The 3rd CB Det was rushed from Efate to Espiritu Santo to build a countermanding airfield asap. Within 20 days a 6000ft airstrip had been carved from the jungle.
CB 3 sent an A Company detachment to Bora Bora that "merged" with the Bobcats. In the fall of 1943 they had completed their work and had received orders to join CB 3 at Noumea. Enroute there was a change in orders making them 3rd battalion 22nd Marines. At that time the remainder of A Co. was transferred to the 22nd as well. The Bobcats had not received advanced military training before deploying so the 22nd Marines gave all of the Seabees an intense field version. When finished the regiment returned to Hawaii for additional amphibious warfare training. With that completed the men were tasked as shore party, engineers and demolitions men for the landings in the Marshalls. Third battalion would see extensive use at the Battle of Eniwetok. When those operations were over the 22nd Marines were given a Naval Unit Commendation and the Bobcats were released by the Marine Corps.
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On 30 October 1942 the USS Enterprise pulled into Noumea after taking two hits and two near misses in the Battle of Santa Cruz. She was the only air craft carrier remaining in the Pacific west of Pearl Harbor, but had damage to the flight deck at the bow and just aft of the forward elevator. One near miss was midships below the waterline while the other was adjacent the elevator hit. B Co. from CB 3 put a 75-man detail aboard her to assist effect emergency repairs en route to her next engagement in the Solomons. Underway with the ship ordered to engage the enemy, the Seabees focused on effecting repairs even during the battle. They had worked round-the-clock under the Enterprise's damage control officer. He wrote that on 11 November: "She made the open sea with her decks... shaking and echoing to air hammers, with welders' arcs sparking... and with her forward elevator still jammed... since the bomb...broke it in half."
On 13 November the ship's Captain of notified SOPAC in Noumea that "The emergency repairs accomplished by this skillful, well-trained, and enthusiastically energetic force have placed this vessel in condition for further action against the enemy". Those repairs enabled the Enterprise to engage and sink the Japanese battleship Hiei that day. Over the next three days her planes would be involved in the sinking of 16 and damaging another 8. When it was over and Vice Admiral Bull Halsey knew what those Seabee repairs meant to the outcome. He sent a commendatory letter to the Seabee's OIC, Lt. Quayle: "Your commander wishes to express to you and the men of thenstruction Battalion serving under you, his appreciation for the services rendered by you in effecting emergency repairs during action against the enemy. The repairs were completed by these men with speed and efficiency. I hereby commend them for their willingness, zeal, and capability." The Navy learned from this that the fleet could turn to the Seabees for repairs. The 27th CB created a "Ships Repair Shop" as a courtesy to the fleet, with its divers replacing 160 props on all size vessals. The "Shop" logged major repairs on 145 vessels, of 20 different types, including 4 submarines. Even after two large fleet repair ships showed up there was so much work that the 27th did not get relieved to return to its construction.
When Marines made their assault Guadalcanal the 6th CB became the first CB to see combat. Their task was keeping Henderson Field operational. The Japanese made this a never-ending job. As fast as it was repaired they would bomb it again. The first Seabee to be decorated received a Silver Star for actions there." "The Marines made simultaneous landings on Guadalcanal and Tulagi Island with Seabees tasked to both. On Tulagi it was to construct a PT base that would have a role in the famous sea battles in the "slot"" PT Squadron 2 was there and requested Seabee volunteers nightly to fill out its crews. It also would be Hq Motor Torpedo Boat So. Pacific
Command MTBSoPac.
News worthy to the troops at the time, off Tassafaronga Point on Guadalcanal, Seabees in a Higgins boat ran into the periscope of a sunk Japanese two-man sub offshore. It was in of water and with improvised diving gear they hooked cables for bulldozers to pull it ashore. With bulldozers straining, eight sticks of dynamite blast it free of the mud suction force and it was beached. It became a "must see" for U.S troops on Guadalcanal.
Like CBs, PTs were new in WWII. The Seabees would build PT Squadrons 119 bases not identified as Cubs. The largest would be on Mios Woendi. Many battalions were involved, however, the 113th and 116th Construction Battalions had PT Advance Base construction detachments. The 113th's det was attached to Task Group 70.1 through the end of the war. It was a precursor to today's Seabee teams. Each man was cross-trained in at least three trades with some qualified as corpsmen and divers.
"As the Allies island-hopped the Solomons, the Russells, Rendova, New Georgia, and Bougainville CBs turned all into some kind of advanced base.
"By mid-1943 at Merauke, New Guinea Seabees built an air strip and comm station at Port Moresby. In December Seabees transferred to the 1st Marine Division landed at Cape Gloucester. During the battle, Seabees of the 3rd Battalion 19th Marines bulldozed paths to the Japanese lines so Marine tanks could attack. They had to be told to hold up because they were so far beyond the lines. By New Year's, the Marines had taken the enemy airfields on the Cape."
"Taking the Admiralities became key to isolating Rabaul and the neutralizing of New Britain. Seizure of Manus Island and Los Negros Island cut supplies from all points north and east. By 1944 Seabees had transformed those islands into the largest Lion and Oak in the Southwest Pacific. It became the main supply and repair depot of the Seventh Fleet. The capture of Emirau completed the encirclement of Rabaul. A strategic two-field Oak, with depots, dry dock, and PT base was constructed there."
"In the Central Pacific CBs we're both directly and indirectly involved in the fighting. After landing in all the Marine assaults, CBs built the bases from which the U.S. moved relentlessly toward the Japanese homeland. Tarawa in the Gilberts was bad, but in fifteen hours Seabees had the airfield operational. They turned Majuro Atoll into one of the fleet's Lions and similarly transformed Kwajalein Atoll into a Oak."
"Seizure of the Marianas marked the beginning of the end. Their loss cut a Japanese line of defense. More important, they placed Japan within range of U.S. bombers. During Operation "Forager," Seabees made some of their most significant contributions in the Pacific landing with the Marines at Kwajalein, Saipan, Guam, and Tinian. The day the Marines captured Aslito on Saipan, the Seabees went to work to get it operational in four days. During the battle for Guam, CB Specials did stevedoring while others were combat engineers for the Marines. When they were done CBs turned Guam into a Lion HQ for the fleet and an Oak for B-29s. The invasion of Tinian was a showcase of Seabee ingenuity and engineering. The CEC engineered detachable ramps mounted on LVT-2s making landings possible where the Japanese thought it was impossible. Before the island was even secure, Seabees were completing an unfinished Japanese airfield."
"After the Marianas B-29s were in need of an emergency landing field and a forward base for fighter escorts. The island chosen was Iwo Jima which V Amphibious Corps assaulted on 19 February 1945. For the assault the 133rd CB and the 31st CB were attached to the 4th and 5th Marine Divisions as shore party. The 133rd suffered the most casualties in Seabee History tasked to the 23rd Marines. Only basic road construction was accomplished during the first days. Work on the first airfield began until D+5
"Island hopping with Gen. MacArthur CBs reached Hollandia making it instrumental in the liberation of the Philippines. The 3rd Naval Construction Brigade was with MacArthur for return to Leyte. Seabee pontoon barges and causeways brought MacArthur's Forces ashore. Those Seabees were joined by the 2nd and 7th Naval Construction Brigades. This NCF totaled 37,000 and would turn the Philippines into a forward base for the assault on Japan. The 7th Fleet Hq was moved to the there with Seabees building everything required: fleet anchorages, sub bases, fleet repair facilities, fuel and supply depots, Pt bases and air stations. At Dulag, Leyte Seabee activity finally became a priority to the Japanese. There the 61st CB had a detachment building a fighter strip come under aerial assault by Japanese paratroopers. The battle lasted 72 hours with the Japanese losing over 350 men. As in the South Pacific PT boats picked up Seabees for their nightly runs near Halmahera along the Lembeh Strait.
"At Okinawa the 24th Army Corps and Third Marine Amphibious Corps landed off Rhinos and causeways of the 130th CB. The 58th, 71st, and 145th CBs were all attached the 1st, 2nd and 6th Marine Divisions for the assault. Numerous CBs followed as Okinawa became the anticipated jumping-off point for invasion of Japan. Nearly 55,000 Seabees in four brigades would work there. By August 1945 everything was prepped for the invasion."
When the arrived at Tinian 6th Brigade Seabees unloaded the Atomic bomb components. Everything was stored in a shed they had constructed and supplied the guard for. Scientists assembled the weapon utilizing Seabee assistance when needed. On 6 August it was loaded into the Enola Gay on an North Field for the bombing of Hiroshima. When the war ended 258,872 officers and enlisted had served in the Seabees. Their authorized allotment of 321,056 was never reached. The war saw over 300 Seabees killed in action while over 500 died on the job site. U.S. Fleet Admiral Halsey: "The Seabees helped crush the Japs in every South Pacific campaign".

Lions, Cubs, Oaks, Acorns advance base units

Advance base construction operations were given a code name as a numbered metaphor for the size/type of base the Seabees were to construct and assigned to it the "unit" charged with development and administration of that base. These were Lion, Cub, Oak and Acorn with a Lion being a large Fleet Base numbered 1–6. Cubs were Secondary Fleet Bases 1/4 the size of a Lion Oak and Acorn were the names given airfields, new or captured enemy fields. Cubs were quickly adopted as the primary type airfield with few Oaks. Of the three base types Lions, Cubs and Acorns, Acorns received priority due to their tactical importance and the speed at which the Seabees could make one operational. The Navy believed the Seabees could produce an operational runway overnight. In the Office of Naval Operations manual for Logistics of Advance Bases it reads " Highly mobile Acorns...can be established by surprise tactics between sunset and sunrise on enemy territory... strategically important... offensive instruments possessing tactical surprise to a highly portentous degree."
Camp Bedilion was home to the Acorn Assembly and Training Detachment responsible for training and organizing Acorn units. It shared a common fenceline with Camp Rousseau at Port Hueneme. A Lion, Cub, or Acorn was composed of three components: Base Operation units, Fleet/Aviation repair-maintenance units and Construction Battalion personnel. CBs constructed, repaired or upgraded 111 major airfields with the number of acorn fields not published. When the code was first created the Navy thought it would require two CBs to construct a Lion. By 1944 entire Construction Regiments were being used to build Lions.
Lions, Cubs, Oaks, Acorns USN Administration in WWII: ACORN: acronym for Aviation, Construction, Ordnance, Repair. A CBMU was attached to every ACORN. A single island could have multiple Acorns on it. It was common practice to separate airfields for bombers and fighters. In December 1944 the Navy took over an unused Army Air Corps base at Thermal, CA. making it Naval Air Field Thermal. The Navy made it the pre-embarkation and training center for Acorns, CASUs, and CBMUs.
  • Lion 1 Espirtu Santo
  • Lion 4 Manus
  • Lion 6 Guam
  • Cub 1 Guadalcanal
  • Cub 2 Tulagi
  • Cub 9 Guadalcanal
  • Cub 12 Emirau
  • Acorn 1 Guadalcanal
  • Acorn Red 1 Guadalcanal
  • Acorn 2 Espirto Santo
  • Acorn 3 Banika/south
  • Acorn Red 3 Green Island
  • Acorn 4 Tulagi
  • Acorn 5 Woodlark
  • Acorn 7 Emirau
  • Acorn 8 Noumea
  • *Munda Point
  • * Biak
  • Acorn 10 Green Island
  • Acorn 11 Nouméa
  • Acorn 12 Banika/Sterling Island
  • Acorn 13 Espirtu Santo
  • Acorn 14 Tarawa
  • Acorn 15 Green Island
  • Acorn 16 Apamama
  • Acorn 17 South Tarawa
  • Acorn 18 Espirto Santo
  • Acorn 19 Mindoro
  • Acorn 22 Eniwetok
  • Acorn 21 Roi-Namur
  • Acorn 23 Kwajalein
  • Acorn 24 Los Negros
  • Acorn 29 Yonabara
  • Acorn 30 Jinamoc Tacloban, Leyte
  • Acorn 33 Samar
  • Acorn 38 Saipan
  • Acorn 41 Marpi point, Saipan
  • Acorn 44 Okinawa
  • Acorn 45 Sangley Point, Cavite
  • Acorn 46 Marpi, Saipan
  • Acorn 47 Puerto Princesa
  • Acorn 50 Kobler, Saipan
  • Acorn 51 Cebu/Mactan Island
  • Acorn 55 commissioned at the Argus Assembly and Training Unit, Port Hueneme

    Espirto Santo war's end

At the end of WWII Espiritu Santo had become the second largest base the U.S. had in the Pacific. To deal with the vast quantities of supplies and equipment staged there the military had to find a solution.
It cost too much to send back to the states and would hurt industry by flooding the market with cheap military surplus. Additionally, the Navy was more concerned about discharging men and mothballing ships. The answer was to offer to sell it to the French for 6 cents on the dollar. The French thought they wouldn't offer anything and the U.S would abandon it all. Instead the U.S ordered the Seabees to build a ramp into the sea by Luganville Airfield. There, day after day the surplus went into the water. Seabees wept at what they had to do. Today the site is a tourist attraction called Million Dollar Point. Individual CBs were ordered to do the same across the Pacific with Guam another example.

CB rates

These indicate the construction trade in which a Seabee is skilled. During WWII, the Seabees were the highest-paid group in the U.S. military, due to all the skilled journeymen in their ranks.
Camp Endicott had roughly 45 vocational schools plus additional specialized classes. These included Air compressors, Arc welding, BAR, Bridge building, Bulldozer, Camouflage, Carpentry, Concrete, Cranes, Dams, Diving, Diesel engines, Distillation and water purification, Dock building, Drafting, Drilling, Dry docks, Dynamite and demolition, Electricity, Electric motors, First aid, Fire fighting, Gasoline Engines, Generators, Grading roads and airfields, Ice makers, Ignition systems, Judo, Huts and tents, Lubrication, Machine gun, Marine engines, Marston Matting, Mosquito control, Photography, Pile driving, Pipe-fitting/plumbing, Pontoons, Power-shovel operation, Pumps, Radio, Refrigeration, Rifle, Riveting, Road building, Road Scrapers, Sheet metal, Soil testing, Steelworking, Storage tanks wood or steel, Tire repair, Tractor operation, Transformers, Vulcanizing, Water front, and Well-drilling.
  • BMB : Boatswains Mate Seabee
  • CB : Construction Battalion
  • CMCBB : Carpenters Mate CB Builder
  • CMCBD : Carpenters Mate CB Draftsman
  • CMCBE : Carpenters Mate CB Excavation foreman
  • CMCBS : Carpenters Mate CB Surveyor
  • EMCBC : Electricians Mate CB Communications
  • EMCBD : Electricians Mate CB Draftsman
  • EMCBG : Electricians Mate CB General
  • EMCBL : Electricians Mate CB Line and Station
  • GMCB : Gunners Mate CB
  • GMCBG : Gunners Mate CB Armorer
  • GMCBP : Gunners Mate CB Powder-man
  • MMCBE : Machinists Mate CB Equipment Operator
  • SFCBB : Ship Fitter CB Blacksmith
  • SFCBM : Ship Fitter CB Draftsman
  • SFCBP : Ship Fitter CB Pipe-fitter and Plumber
  • SFCBR : Ship Fitter CB Rigger
  • SFCBS : Ship Fitter CB Steelworker
  • SFCBW : Ship Fitter CB Welder
  • Diver
, Solomon Islands, Nov. 8, 1943 installing a
marine railway.
The Seabees had a divers school of their own to qualify 2nd class divers. During WWII being a diver was not a "rate", it was a "qualification" that had four grades: Master, 1st Class, Salvage, and 2nd Class. CBs would put men in the water from the tropics to the Arctic circle. In the Aleutians CB 4 had divers doing salvage on the Russian freighter SS Turksib in 42°F water.. In the tropics Seabee divers would be sent close to an enemy airfield to retrieve a Japanese aircraft. At Halavo on Florida Island divers from the 27th CB would recover a Disburser's safe full of money plus change 160 props on vessels of all sizes. The Seabees of the 27th CB alone, logged 2.550 diving hours with 1,345 classified as "extra hazardous". Seabees would also blur the definition of diver with the development of the Underwater Demolition Teams. Another historic note to the Seabees is that they had African American divers in the 34th CB. Those men fabricated their diving gear in the field using Navy Mk-III gas masks as taught at diving school. Twice, while at Milne Bay, the 105th CB sent special diving details on undisclosed missions. At Pearl Harbor Seabee Divers were involved in the salvage of many of the ships hit on 7 December as well as the recovery of bodies for a long time after the attack.

Organization

The primary Seabee unit was the battalion, composed of a headquarters company and four construction companies. Each company could do smaller jobs independently as they each had all the basic ratings for doing any job. Hq. Co. was made up primarily of fleet rates plus surveyors and draftsman. A CB's complement was 32 officers and 1,073 enlisted.
"By 1944 construction projects grew in scope and scale. Often more than one CB was assigned to a job. To promote efficient administrative control 3-4 battalions would be organized into a regiment, if necessary, two or more regiments were organized into a brigade. This happened on Okinawa where 55,000 Seabees deployed. All were under the Commander, Construction Troops, Commodore Andrew G. Bisset. He also had 45,000 U.S. Army engineers under his command making it the largest concentration of construction troops ever."
The overall cost of all Seabee projects was $11 billion. At wars end they would number over 258,000. The NCF grew into 12 Naval Construction Brigades of: 54 Construction Regiments, 151 CBs, 39 Special CBs, 136 CB Maintaince Units, 118 CB Detachments, and 5 Pontoon Assembly Detachments. In addition, many Seabees served in the NCDUs, UDTs, Cubs, Lions, Acorns and Marine Corps.
While the CB itself was versatile it was apparent that some units could be smaller and/or specialized for task specific units. "The first departure from the standard CB was the "Special" Construction Battalion, or the "CB Special". "Special" CBs were composed of stevedores and longshoremen who were badly needed for the unloading of cargo in combat zones. Many officers for "Specials" were recruited from the Merchant Marine while stevedoring companies were the source of many of the enlisted. Soon, the efficiency of cargo handling in combat zones was on a par to that found in the most efficient ports in the U.S." There were five battalions specialized in pontoons, barges, and causeways: 70th, 81st, 111th, 128th, 302nd. The 134th & 139th CBs were made trucking units due to the transportation and logistic needs on Guam and Okinawa.
"Several types of smaller, specialized units were created. Construction Battalion Maintenance Units/CBMUs, a quarter the size of a CB were one. They were Public Works units intended to assume base maintenance of newly constructed bases. Another unit type was the Construction Battalion Detachment/CBD, of 6 to 600 men. CBDs did everything from running tire-repair shops to operating dredges. Many were tasked with the handling, launching, assembly, installation of pontoon causeways. Others were petroleum dets specializing in pipelines or petroleum facilities)."

The Seabee

The Seabee's machinegun totten bumblebee insignia was created by Frank J. Iafrate, a file clerk employed at the Camp Endicott, Quonset Point, Rhode Island. Iafrate was known for his drawings. A lieutenant asked if he could do a "Disney style" insignia of a Sea Bee design that had been created for CB equipment. After a bit of thought, he settled on the bumblebee for his model. Image-wise they have more "heft" than the honeybee and "heft" suited the whole idea. He spent three hours of an afternoon sketching a sailor's cap, with petty officer ranks on each arm plus the tools and rates of the gunner's mate, machinist mate, and carpenter's mate. On each wrist he placed the CEC insignia. For a border he set the Bee inside a letter Q for Quonset Point. He gave the design to the lieutenant. The lieutenant showed it to his captain, who sent it off to Radm. Moreell. All the Admiral requested was that the border be changed from a Q to a hawser "rope" in keeping with Naval tradition for Naval insignia.

Chemical Warfare Service and Flame Tank Group

During WWII Seabees modified/created all of the main armament flame throwing tanks that the USMC put in the field on Saipan, Tinian, Iwo Jima, and the U.S. Army on Okinawa. They were a weapon Japanese troops feared and the Marine Corps said was the best weapon they had in the taking of Iwo Jima. After Okinawa the Army stated that the tanks had a psychological presence on the battlefield. U.S. troops preferred to follow them over standard armor for the fear they put in the enemy.
Pacific field commanders had tried field modified mechanized flame throwers early on, with the Marine Corps deciding to leave further development to the Army. A top secret composite unit was assembled at Schofield Barracks Hawaii. Headed by Colonel Unmacht of the US Army Chemical Warfare Service, Central Pacific Area Col. Unmacht began the project with only the 43rd Chemical Laboratory Company. They modified the first light tank designating it a "Satan". The flame tank group was expanded with men from the 5th Marine tank battalion and 25 from the 117th CB.
V Amphibious Corps wanted mechanized flamethrowing capabilities for the Marianas operations. VAC had ordered and received two shipments of Canadian Ronson F.U.L. Mk IV flamethrowers to field modify tanks. With a war to wage field modification was much quicker than going through official military procurement channels. The 117th CB was assigned to the upcoming Saipan operation. Col Unmacht worked out an arrangement to not only keep the 117th Seabees he had, but get more. Augmented by the additional Seabees, the group worked sun up to sundown and, with Seabee Can-do twenty-four M3s were modified to start the campaign. The very first, made by the 43rd Co, was christened "Hells Afire". The installation configuration of the flamethrower components limited the turret's traverse to 180°. As Satans were produced Colonel Unmacht had the Seabees conduct a comprehensive series of 40-hour classes on flame tank operation with first and second eschelon maintenance. First for officers and enlisted of the Marine Corps and then later for the Army. The Satans had a range of and were the first tanks to have the main armament swapped for flame throwers. They were divided between the 2nd and 4th Marine Divisions for Siapan and Tinian with Tinian being more favorable to their use.
  • Four Seabees received commendations for their work from Lt. Gen. Holland M. Smith Commanding General FMF Pacific.
  • At least 7 were awarded the Bronze Star.
Mid-September the Army decided to form a "Flame Thrower Group" and Col Unmacht requested 56 additional Seabees. The group included more CWS and ordnance personnel as well. It was apparent that a larger flamethrower on a bigger tank would be more desirable, but very few tanks were available for conversion. Operation Detachment was next and Col Unmacht's group located eight M4A3 Sherman medium tanks for it. The Seabees worked to combine the best elements from three different flame units: the Ronson and the Navy model I and the Navy Mk-1. MMS1c A.A. Reiche and EM2c Joseph Kissel are credited with designing the CB-H1. Installation required 150 lbs of welding rod, 1100 electrical connections, and cost between $20,000-25,000 per tank. The CB-H1 flamethrower had a range of and could transverse 270°. This model was quickly superseded by the CB-H2 that was far better. EM2c Kissel and another Bee accompanied the tanks to oversee maintenance during the battle of Iwo Jima. Kissel filled in as an assistant driver/gunner with tank crews on 20 days of the operation.
In November 1944, prior to the rave USMC reviews of Iwo Jima, the Fleet Marine Force had requested 54 mechanized flame throwers, nine for each of the Marine Corps Divisions On Iwo the tanks all landed D-day and went into action on D+2, sparingly at first. As the battle progressed, portable flame units sustained casualty rates up to 92%, leaving few troops trained to use the weapon. More and more calls came for the Mark-1s to the point that the Marines became dependent upon the tanks and would hold up their assault until a flame tank was available. Since each tank battalion had only four they were not assigned. Rather, they were "pooled" and would dispatch from their respective refueling locations as the battle progressed. One the 4th Division tanks had a 50 cal. machine gun coaxial to the flamethrower as well as concrete armor to counter placement of magnetic charges. Towards the end of the battle, 5th Marine tanks used between gallons per day.
For Okinawa the 10th Army decided that the entire 713th Tank Battalion would provisionally convert to flame. The Battalion was tasked to support both the Army and the Marine Corps assault. It was ordered to Schofield Barracks on Nov 10. There the Seabees supervised three officers and 60 enlisted of the 713th convert all 54 of their tanks to Ronsons. The Ronsons did not have the range of either the CB-H1 or CB-H2.
In June 1945, the 43rd Chemical Lab. Co. had developed a stabilized flamethrower fuel. They oversaw CB construction of an Activating Plant that produced over 250,000 gallons. The 713th went through 200,000 gallons on Okinawa. Also in June, the Army cancelled all further production orders for any more M4 Sherman's. This caused Under Secretary of War Robert Patterson to place an expedite on Col. Unmacht's production of flame tanks. They were given a "Triple A" procurement priority, the same given to the B-29 and the Atomic bomb projects.
Another 72 tanks were ordered by the Marine Corps for the planned invasion of Japan of which Col. Unmacht's crews had 70 ready by Victory over Japan Day. In total Unmacht's Flame Tank Group produced 354 tanks.
The military did not have uniform terminology for referencing mechanized flamethrowers so there is some wording variation in documents.
The Seabees produced 11 different models of flamethrowing tanks off three basic variations identified with a POA-CWS-H number
"Primary" where the main armament was removed and replaced.
  • The first eight had Navy CB-H1 or CB-H2 flamethrowers. US Army Chemical Corps variously identified these tanks as POA-CWS-H1, CWS-POA-H2, CWS-POA-H1 H2, OR CWS-"75"-H1 H2 mechanized flamethrowers. US Marine and US Army observer documents from Iwo Jima refer to them as the CB-Mk-1 or CB-H1. Marines on the lines simply called them the Mark I. The official USMC designation was "M4 A3R5". The Japanese referred to them as M1 tanks and it is speculated that they did so due to a poor translation of "MH-1".
  • The next 54 tanks had Ronson flamethrowers. That made them the third tank variant produced. Army records identify them as POA-CWS-H1s.
  • Some of these tanks were configured with an external long hose supplying a M2-2 portable flamethrower that ground troops could use. This variation could throw some. A drawback to this attachment was all the fuel it took to charge the hose line so it could fire diminished the tank's overall effectiveness. Army documents post-war refer to this variation as being a CWS-POA-H1.
"Auxiliary" where the flame thrower was mounted coaxial to the main armament. Eighteen of the first generation model were on the way to the 10th Army on Okinawa, but the island was taken before they arrived, so they were given to the 3rd Marine Division tank battalion on Guam.
  • 75mm main armament with Ronson
  • 75mm main armament H1a-H5a
  • 105mm main armament with Ronson
  • 105mm main armament with H1a-H5a USMC designation M4-A3E8. These would be at Inchon in 1950.
In mid-1945 the Seabees started producing the second generation of these tanks. These H1a-H5a Shermans, with either 75mm or 105mm main armaments, wewre jointly referred to as CWS-POA-5s.
"Periscope Mount" This model was based upon work done by the U.S. Army at Fort Knox. The flame thrower was mounted through the assistant driver's hatch alongside their tank periscope which meant that the bow machine gun could be retained. 176 were produced. Word spread that one of these tanks lost a crew when the flamethrower nozzle took a hit. The Marine Corps did not want this design.
  • H1 periscope
  • H1A periscope
  • H1B periscope
  • Examples labeled POA-CWS-H1 and POA-CWS-H5 are on display at the Mahaffey Museum at Fort Leonard Wood Missouri.
  • 5th Marine CB-H1 in action on D+22,
  • Example M42 B1E9
The Marines preferred the CB tanks to any produced in the U.S. at that time. The Marine Corps and Army both felt that the flamethrowing tanks saved U.S. troops lives and kept the causality numbers lower than they would have been had the tanks not been used. They also agreed that they would need many for the invasion of the Japanese homeland.
Postwar the Army stood down the provisional 713th keeping no flame tanks. The Marine Corps came close to doing the same. When Korea broke out they were able to put together nine CWS-POA-H5s from Pendelton and Hawaii. Together they formed a platoon, named the "Flame Dragons", in the 1st tank battalion. They landed at Inchon in 1950 and were the only U.S. mechanized flame unit to be in Korea.
  • Col Unmacht 1946 Military Review flame tank article.

    Seabee Awards in the NCF

During WWII Seabees would be awarded 5 Navy Crosses, 33 Silver Stars, and over 2000 Purple Hearts. Many would receive citations and commendations from the Marine Corps. The most decorated officer was Lt. Jerry Steward : Navy Cross, Purple
Heart with 3 Gold Stars, Army Distinguished Unit Badge with Oak leaf and the Philippine Distinguished Service Star. Another CEC with an unusual set of awards was Capt. Wilfred L. Painter: Legion of Merit with Combat "V" and 4 Gold Stars.
Presidential Unit Citation USN/USMC :
  • 75 men 3rd CB, Guadalcanal, USS Enterprise
  • 6th CB, Guadalcanal, 1st Marine Division
  • 202 men 33rd CB, Peleliu, 1st Marine Pioneers
  • 241 men, 73rd CB, Peleliu, 1st Marine Pioneers
U.S. Army Distinguished Unit Citation :
  • 40th CB Los Negros, 1st Cavalry Division
  • 12 men 78th CB Los Negros, 1st Cavalry Division
Navy Unit Commendation
  • 3rd Naval Construction Detachment- Espirto Santo
  • 11th Special CB, Okinawa
  • 31st CB, Iwo Jima, 5th Marine Shore party Regiment
  • 33rd CB, Peleliu 1st Marine Pioneers
  • 58th CB, Vella Lavella
  • 62nd CB, Iwo Jima, V Amphibious Corps
  • 71st CB, Okinawa
  • 53 men 113th CB, PT boat Advance Base Construction Detachment, Balikpapan Borneo/Philippines
  • 133rd CB, Iwo Jima, 23rd Marine Regiment
  • 301st CB, Siapan, Tinian, Guam, Peleliu, Iwo Jima, Okinawa
  • CBMU 515, Guam, 22nd Marine Regiment
  • CBMU 617, Okinawa
  • CBMU 624, Okinawa
  • CBD 1006, Sicily
U.S.ARMY Meritorious Unit Commendation
  • 60th CB, Los Negros, 1st Cavalry Division

    Seabee Awards outside the NCF

Seabees serving outside the NCF received numerous awards as well. The Navy does not make a distinction for awards given inside or outside the NCF nor does it identify
Seabees in the NCDUs or UDTs awards. Admiral Turner recommended over 60 Silver Stars and over 300 Bronze Stars with Combat "Vs" for the Seabees and other service members of UDTs 1-7 That was unpresendented in USN/USMC history. For UDTs 3 and 4 at Guam and UDTs 5 and 7 at Tinian and all officers received silver stars and all enlisted received bronze stars with Combat "Vs".
Presidential Unit Citation USN/USMC
  • 3rd Battalion 18th Marines Tarawa, 2nd Marine Division
  • 12 men of 3rd Battalion 20th Marines Saipan and Tinian 4th Marine Division
  • Naval Combat Demolition Units assault force O Normandy
  • *NCDU 11, NCDU 22, NCDU 23, NCDU 27
  • *NCDU 41, NCDU 42, NCDU 43, NCDU 44
  • *NCDU 45, NCDU 46, NCDU 128, NCDU 129
  • *NCDU 130, NCDU 131, NCDU 133, NCDU 137
  • UDT 11 Bruni Bay, Borneo
  • UDT 11 Balikpapan, Borneo
Navy Unit Commendation
  • 3rd Battalion 22nd Marines Eniwetok
  • ACORN 14, Tarawa, 2nd Marine Division
  • Naval Combat Demolition Units force U Normandy
  • *NCDU 25, NCDU 26, NCDU 28, NCDU 29
  • *NCDU 30, NCDU 127, NCDU 132, NCDU 134
  • *NCDU 135, NCDU 136, NCDU 139
  • UDT 4, Guam
  • UDT 4, Leyte
  • UDT 4, Okinawa
  • UDT 7, Marianas
  • UDT 7, Western Carolina's
The Seabee Record

Post-war legacy

During the war many of the bases the Seabees built were disassembled for the materials to be reused in new bases closer to the front. However, the airfields could not be moved and remained post war. The Seabees built or repaired dozens across the Pacific. Today, after upgrades and modernization, many are still in use or remain usable.
Pacific:
;Atlantic:
;Military installations WWII:
;Military installations built post-war: