Naval Mobile Construction Battalion 133 (NMCB 133) is a United States Navy Construction Battalion, otherwise known as a Seabee battalion, homeported at the Naval Construction Battalion Center (Gulfport, Mississippi). The unit was formed during WWII as the 133rd Naval Construction Battalion. It saw action and was decommissioned shortly after the war ended. The unit was reactivated as Mobile Construction Battalion 133 for the Vietnam War and remains an active unit today.
History WWII – Iwo Jima: 133 Naval Construction Battalion
The unit's history began on 17 September 1943 at Camp Peary, Virginia, where it was commissioned as the 133rd Naval Construction Battalion (NCB). After 7 months of training at Davisville, Gulfport and Port Hueneme the battalion's first overseas assignment was NAS Honolulu, Territory of Hawaii (May–October 1944). While there, the battalion's demolitions men were tasked with scuttling the USS Baltimore (C-3) 15 miles offshore. The battalion created a concrete pre-cast yard that became the sole supplier of pre-cast for all the battalions and was one of the busiest places on the island. In July the battalion sent a small pontoon detachment to take part in the Battle of Peleliu. Some of the men came under heavy mortar fire evacuating U.S. Army troops at one point. On 15 October 1944 word was received that the battalion was going to be attached to the 4th Marine Division.133 NCB File Folder, Seabee Archives, Seabee Museum, Port Hueneme, CA. 93043 On 30 October the assignment came for Operation Detachment at Iwo Jima. D-day was planned for 19 February 1945. When 133 was attached to the 4th it was filling a billet that had been vacated when the 121st CB was released by the Marine Corps. The 121st CB had been transferred to the Marine Corps and re-designated as the 3rd Battalion of the 20th Marine Regiment. After the assault of Tinian the 20th Marines were inactivated. Then both the 1st battalion (4th Engineers) and 2nd battalion (4th Pioneers) were placed under Divisional control. Third battalion 3/20 or the 121st, was returned to the Navy creating the vacancy 133 was posted to. Before joining the 4th at Camp Maui, the 133rd was put through the Army's Pacific Jungle Combat Training Center (CTC) at Punaluu and Kahana Valleys on the North Shore of Oahu, TH.Rainmakers Log, Commander R.P. Murphy, Leo Hart Co. Rochester, N.Y. 1945, p. 96 It was a unit level training center to supplement Army Ranger and Army Combat training Schools.Pacific Jungle Combat Training Center, Army Corps of Engineers, January 2016, Pacific Jungle FUDS Fact Sheet-010616.pdf Camp Maui was located nearby at Haiku-Pauwela. The 133rd was the first unit to complete the course without a casualty, according to their cruise book.
Once assigned to the division the battalion had each company "tasked" to a different element of the 23rd Marines for shore party training. The battalion's (sp) assignment was to provide the beach support required by the forward lines of the 23rd, 24th, and 25th Marines. The division shipped out for Island "X" on 31 December with V Amphibious Corps (VAC) as T.U. 56.2.2 of Baker Landing Group. Baker group was commanded by Major General C.B. Cates(USMC) 4th Marine Division.The Amphibians Came to Conquer, The Story of Admiral Richmond Kelly Turner, Chapter XXIII, Iwo Jima, Death at its Best, by George C. Dryer, Vice Admiral, USN (ret), 1969, U.S. GPO, Washington D.C., Library of Congress Catalog Card No. 71-603853 When they were a few days out the men learned they were heading to a place they had never heard of called Iwo Jima. The assault for Iwo was based upon Tinian where the 2nd and 4th Marine Divisions assault had been "reinforced" by Marine Engineering Regiments with the 18th and 121st CBs as 3rd battalions of the 18th and 20th Marines. On D+3 the Jap airfield was secured and the Seabees had it operational in a few hours.(the Iwo Jima landing map is notated that the Marine Corps planned to have control of Iwo Jima in 3 days also) For Iwo, the 4th and 5th Marine Divisions were "reinforced" by the 133rd and 31st CBs. Marine Corps landing maps indicate that for O-1 (objective Day 1) Motoyama Airfield No. 1 would be secured with the 133rd tasked to get it operational.History of the U.S. Marine Corps in WWII Vol IV- Western Pacific Operations, George W. Garand & Truman R. Strobridge, Historical Branch, G3- Division, Headquarters, U.S. Marine Corps, 1971. pp. 594–595 However, D+5 the assignment was given to the 31st CB due to the losses 133 had suffered. The next day the 62nd CB from V Corps, landed with the 3rd Marine Division and was designated the lead Battalion for Airfield No. 1. The 31st was assigned Airfield No. 2 and the 133rd was given Airfield No. 3. In just seven days the heavy equipment of the 3 combined battalions had Airfield No. 1 operational.
The 133rd CB and the 4th Marine Pioneer Battalion were the primary units of the "Assault" shore parties for the 23rd and 25th Regimental Combat Teams (RCT) on the 4th Marine Division's yellow and blue beaches.Appendix 1, Annex DOG 4th Marine Division Operations Report, April 1945, National Archives, College Park, MD 20742, pp. 1–37 open pdf -Part_6 and pdf -Part_7 for Appendix 1 Annex Dog The 4th Marine Division's single Pioneer Battalion was assigned to the 25th RCT. USMC tactical operations required another Pioneer battalion for the 23rd RCT's Assault. The 121st CB had been tasked as such at Roi-Namur, Siapan, and Tinian so giving that task to the 133rd was simply standard 4th Marine Division operations.Iwo Jima Seabees Stay Unsung. Lt. Cdr. Peter S. Marra, U.S. Naval Institute: NAVAL HISTORY, February 1997 pp. 22–25. Tasking Seabees for USMC shore party at Iwo was a fortuitous decision for the Corps. The CBs brought organic elements the Marines did not have, specifically, bulldozers with winches and D8s 132–148 Hp compared to the Marine Corp's TD 18s 72–80 Hp. Afterwards, the after action reports recommended all USMC bulldozers be equipped with winches as they had none. The history is, that "on the beach at Iwo, bulldozers proved to be worth their weights in Gold"Closing In: Marines in the Seizure of Iwo Jima, Col. Joseph H. Alexander, History and Museums Division, Headquarters U.S. Marine Corps, Washington DC, 1994 p. 22 and the CBs had the biggest and the best the Navy could provide.Rainmakers Log, Cdr. R.P. Murphy, Leo Hart Co. Rochester N.Y. 1946, p. 121 The entire 1st Battalion 24th Marines (1/24) replacement draft that was attached to the 133rd.
The Landing Force Shore Party Commander was OIC of the 8th Marine Field Depot.CLOSING IN: Marines in the Seizure of Iwo Jima, Marines in World War II Commemorative Series by Colonel Joseph H. Alexander U.S. Marine Corps (Ret), Diane Publishing Co, June 1994 The 8th Field Depot assigned a squad to liaison with each shore party by beach color. Each shore party had Marine JASCO (Joint Assault Communications Co) men attached as well as personnel from the 442nd U.S. Army Port Company.
Hq Co was posted to the 23rd Marines support group and was the Hq for yellow beaches 1 and 2.Annex FOX 4th Marine Division's Operations Report, April 1945, National Archives, College Park, MD 20742. (Hq Co. Reflects Battalion's correct status for Award Period Protocol-see support group) pp. 3–4 They came ashore at 1445 from the APA 196 – USS Logan. The company had two 30 man infantry security sections plus two 30 cal. machine guns on the beach defense parameter until their ratings were needed. The medics had one Dr. MIA another Dr., the Dentist and six corpsmen were made casualties by a single shell. Even so, 133's corpsman established an evacuation station on blue 1. Also with Hq Co. was a 32-man team from the 8th Marine Depot Company to manage the depots on yellow beaches. On D+2 yellow beach was closed to landing craft due to all the destroyed or inoperable equipment along the water's edge. UDT 14 was assigned to beaches yellow 1 and 2Naked Warriors, Lt. Commander Francis Douglas Fane, USNR, St. Martin's Press, 175 Fifth Ave, NY, NY, 10010, 1996, p. 174 and was ordered back ashore to get the waters edge clear for landing craft to continue the assault.U.S.NSWA Archives, Underwater Demolition Teams Histories, UDT 14 By the afternoon of D+2 half of the 28 CEC on the beach had been killed, wounded or evacuated. On blue 100% of the corpsmen were casualties. On D+4 the 133rd and UDTs were working together to get it done.
A Co was the major component of the shore party posted to 1st Battalion 23rd Marines or 1/23 which was the left "Assault" battalion for yellow beach. D-day they landed a 0935 on yellow beach 1 from APA 158 – USS NewberryOur WWII History, chapt.7, Approach and Capture of Iwo-Jima, C Co. 1st Battalion 23rd Marines Official website C Co. 1st Battalion 23rd Marines Official website Amphibious Ships (gators)Fox Annex 4th Marine Div. Op Report, RCT 23 Operation Report, Section V, Comments and Recommendations, p. 67/248 and LSM 206. A Co 4th Pioneers was split in two to share their combat experience/knowledge and was attached to A Co 133.Annex FOX 4th Marine Div. Op Report for the 23rd RCT on Iwo Jima p. 3 One of A Co's security sections (30 men) landed in 4 LCVPs with one 7-man gun crew and 37mm Gun M3 in each craft.From Omaha to Okinawa: The Story of the Seabees, William Bradford Huie, E.P. Dutton, New York 1945 p. 43 One LCVP took a direct hit killing the entire gun crew. 133's gun crews were immediately tasked with supporting the assault. A Co's other security section landed on the heels of the first wave and were the first Seabees to set foot on Iwo Jima. The battalion cruise book states the security section was sent to the front line until their skills were needed on the beach. The USN beach party from the USS Newberry served A Co.Annex FOX 4th Marine Div. Op Report for the 23rd RCT on Iwo Jima p. 11 Also with A Co was a 32-man beach team from the 8th Marine Depot Company as well as A Co. 24th Marines replacement draft (1/24). 1/23 was so decimated that 3/23 relieved them from the line by evening of D-day. D+3 the entire 23rd was in such a bad way that it was placed in Corps Reserve, replaced by the 21st RCT from the 3rd Marines. At that time 133's Shore Parties were consolidated on yellow 1 while the 3rd Pioneers landed on yellow 2 for the 21st until D+6. On D+5 the 133rd was given priority status to unload its equipment on yellow and establish a dump to store it.
B Co was the major component of the shore party posted to 2nd Battalion 23rd Marines or 2/23 which was the right "Assault" battalion for yellow beach. They also landed at 0935, but on blue 2 from the APA 207 – USS Mifflin and LSM-202. That beach had a Homophone "Blew to" Hell beach. Mortar fire was so heavy they could not move to yellow 2, but were ordered to because, the situation became critical for the 4th Pioneers that had made it to y2. A Co. 4th Pioneers was split in two to share their combat experience/knowledge and was attached to B Co 133. On D+1 LSM-202 landed 3 D8s and a crane for B Co. B Co's security sections landed the same as A Co and also went forward until needed. The USN beach party from the USS Mifflin was assigned to serve with B Co.Local veteran remembers, Iwo Jima, KXii News Channel 12, KXii News Channel 12, Iwo Jima Vet Also with B Co was a 32-man beach team from the 8th Marine Depot Company as well as B Co 24th Marines replacement draft. On D+1 the acting Shore Party commander on beach yellow 2 was wounded and command transferred to B Co. Commander 133.
On D-day 133 had demolitions men blasting broached landing craft and the beachmaster put in a request for UDT assistance.Iwo Jima, From Omaha to Okinawa, Blue Jacket Books, William Bradford Huie, Naval Institute Press, Annapolis, Maryland, 1945, p. 38