/A16-3 844 19 JUL 1944 From: Commander Task Force ONE TWO TWO. To : Commander-in-Chief, United States Fleet. Via : Commander, U.S. Naval Forces, Europe. Subject: Naval Combat Demolition Units; report of. Reference: (a) CominCh ltr. FF1/98-2 serial; 001192 of 16 April, 1944. Enclosure: (A) Lt.(Jg) H.L. BLACKWELL, Jr., D-V(G), USNR, ltr. A16-3 of 15 July, 1944 with attached report. 1. Enclosure (A) is forwarded in accordance with reference (a). A.D. STRUBLE, Chief Of Staff.
File No. CTF122 /A16-3 UNITED STATES FLEET TASK FORCE ONE TWO TWO Navy 803 Care Fleet Post Office New York, N. Y. 15 July, 1944. From: Lt. (jg) H.L. BLACKWELL, Jr. D-V(G) USNR. To : Commander Task Force ONE TWO TWO. Subject: Naval Combat Demolition units; report of. Reference: (a) ComNavEu Orders to Lt.(jg) Blackwell P16-3/00 of 3 Tune, 1944 and endorsements thereto. Enclosure: (1) Report on the work of the U.S. Naval Combat Demolition units in operation NEPTUNE. 1. This officer has been on temporary duty with Task Force ONE TWO TWO for the purpose of collecting information on the work of the U.S. Naval Combat Demolition Units in breaching beach obstacles. 2. Some of the material collected has been briefed to make up the report which forms Enclosure (1) of this letter. Respectfully submitted, (signed) H.L. BLACKWELL, JR. Lt. (jg), USNR.
REPORT ON NAVAL COMBAT DEMOLITION UNITS IN OPERATION "NEPTUNE" as part of TASK FORCE 122 Submitted by: Lt.(jg) H. L. Blackwell, Jr. D-V(G) , USNR. Date: 5 July, 1944.
SECTION II THE ACTUAL OPERATION A. Brief Summary of the Section. This section covers the actual assault and post-assault work of breaching the beach obstacles in operation NEPTUNE. It presents information on the Operation Plan, the methods used, the difficulties encountered and the results obtained. It is divided into two sub- sections, one devoted to each Force. B. Force OMAHA 1. The Mission of the NCDUs. (a) The. following is quoted from the Demolition Operation Order, part of Operation order No. 1-44 of Assault Force 'O' of the Western Naval Task Force, dated 31 May, 1944 (Encl. (6) hereof) 1. The Naval Combat Demolition Group is associated and working with an Army Demolition group consisting of two battalions of Combat Engineers attached to the V Corps. One NCDU together with one Army combat demolition unit forms a Gap Assault Team. NCD Sections TWO and ONE will form part Of Assault Group 0-1 and 0-2, respectively, of Force 'O' and will function under the Commanders of those Assault Groups. 2. This (Demolition) Group will: (1) Clear and mark sixteen gaps, fifty yards wide, through the seaward band of obstacles on OMAHA beaches; two on FOX GREEN, six on EASY RED, two on EASY GREEN, two on DOG RED, two on DOG WHITE, and two on DOG GREEN. (2) Widen the gaps in the seaward band of obstacles until the entire band is cleared. (3) Assist the Special Army Engineer Demolition Group in clearing gaps through other bands of obstacles and removing all obstacles from the OMAHA beaches.
SECTION III Recommendations for Future Operations. The recommendations made in this section are based on suggestions made by operational NCDU officers and Army Demolition officers. In other words, they represent the views of some of those who have actually done this type of work, and who will be called on to do it again if there are further operations here. A. General recommendations, for NCDU work under any circumstances. 1. Organization. The lack of a Commanding Officer of some rank meant that much of the valuable early months spent by the first ten units in the U.K. was wasted. This lack had three effects, stated below. (i) it produced a lack of direction within the group itself, where there were ensigns, lieutenants (jg) , and one full lieutenant, none of them officially designated as C.O.; each was officially O-in-C of his own Unit and no more, and therefore none desired to appropriate control of the Group though all were aware of the need for a command. (ii) The group had no representative to look after its interests with the various interested commands. At the same time, this lack was accentuated by the fact that there were several commands having some jurisdiction over the units. (iii) Such a Commanding Officer might well have succeeded in obtaining certain critical items of gear, such as Dunlop U.W. Swim Suits, and Reddy Fox Charges, in time to include their use in the planning of the operation (Swim Suits might enable an Underwater attack, Reddy Fox might obviate hand-placed charges, etc.). It is therefore suggested that NCDUs, when being despatched to a theatre as a group, should be given a formal group organization before leaving the U. S. A. By the time the Units of this Task Force were ready for the operation, they had officers performing all the following functions (whether officially designated as such or not): Commanding Officer, Executive Officer, Supply Officer, Intelligence Officer, and First Lieutenant; and there were men acting as yeomen, storekeepers, mess cooks, etc; all this was either instead of or in addition to regular duties with Naval Combat Demolition Units. By May the group was almost 400 officers and men; and their presence put a heavy demand on facilities of Bases for transportation, feeding, clothing, general and technical supplies, and medical attention. In short, a group or this size should probably become a Commissioned Unit. 2. Army-Navy Cooperation. In all the aspects of Obstacle-clearance work in Neptune with which this observer is familiar, Army-Navy cooperation was virtually perfect. Especially on the beach itself (notably OMAHA) where conditions kept the Army Teams on the beach several days), the two groups of teams and their respective commands operated in complete harmony. The relationship was closest within the Navy units themselves; where five Army men and between five and seven Navy men worked as one team, under a Naval Officer. The recommendation in this instance is not to change but rather to extend such cooperation.
ENCLOSURE (5) METHODS -- Charges used, placement of charges, results. (a) Explosive Methods. OBSTACLE CHARGE RESULTS Element "C" 18 2-lb Hagensen packs, Obstacle placed to cut face from cleared. rear-frame, & to flatten rear-frame as well. Extra charges used when possible. Ramps one 2-lb Hagensen pack at. Legs cut off base of each leg, unless at bases, blown timbers over 18-20 inches apart at top. diam., or wood very green. Obstacle cleared. If so, 2 packs. Also one 2-lb. pack underside of apex of legs. Piling Single Hagensen pack at Obstacle base, as with ramp timbers; cleared. if extra thick, or green, 2 packs (4 lbs.) Steel hedgehogs 3 Tetrytol blocks; 2 on Obstacle cleared, one side of central gusset but much shrapnel plate, 1 on the other side. projected. (Not necessarily placed for shearing effect.) Steel hedgehogs 2 Hagensen packs; 1 each Obstacle not side of gusset. always cleared. Sometimes members merely bent, leaving hazard to light craft. Concrete tetrahedra 1 Hagensen pack at Obstacle (members wired or apex each triangle. demolished. pinned together at the joints) Concrete posts 2 Hagensen packs at Obstacle (reinforced) base. demolished. Concrete posts 1 Hagensen pack at Concrete cleared (reinforced) base. but reinf. bars left. obstacle could be pushed over by hand afterwards. Tellermines 1 Hagensen pack, or Tellermine 35, 42, 43 1 Tetrytol Block, or countermined. 1 ‡-lb. block TNT Tellermines 1 Number Eight Cap Tellermine 35, 42, 43 placed in detonator detonated. (b) Non-Explosive Methods. All the above obstacles were successfully removed with caterpillars, dozers, tank dozers, or tanks, if the Tellermines had been removed first. Tellermines can be removed by hand after unscrewing detonator, if it is desired to avoid the shrapnel caused by blowing them. Hedgehogs were eliminated by undoing bolts from central gusset plates, allowing obstacle to collapse. (c) Fixed Flamethrowers. From Lt. Smith's description, these were the same as those seen by the writer at Grandcamp, a specimen of which was recovered for forwarding to the U.S.A. These flamethrowers are a simple tank, filled with a petroleum creosote mixture, which is ejected through a goose-neck nozzle by gas pressure from a burning pyrotechnic cartridge. The mixture is ignited by another similar cartridge wired and fired electrically in parallel with the first one. The flame lasts about l‡ minutes and has a range of 50-75 feet depending on the wind. It has a general terror value, and a specific value against vehicles or concentrations of men approaching the seawall within its range.
ENCLOSURE ( 6 ) Operation Order - Force 'O'.
1. Information as in Naval Commander Western Task Force NEPTUNE MONOGRAPH, and Commander Assault Force 'O' Operation Order No. BB-44. The Naval Combat Demolition Group is associated and working with an Army demolition group consisting of two battalions of Combat Engineers attached to the V Corps. One NCDU together with one Army combat demolition unit forms a Gap Assault Team. Tankdozers embarked in LCT(')s will land at H hour and proceed against obstacles as directed by the Army combat demolition unit officers. All paths cleared through minefields will be marked by personnel of the Army demolition units with a standard minefield gap marker, five feet high. Individual mines which have not been removed will be marked by an eighteen inch probing wire with a six inch by six inch piece of rod muslin attached to the top. NCD Sections TWO and ONE will form part of Group O-1 and O-2, respectively, of Force 'O' and will function under the commanders of those assault groups. 2. This Group will: (1) Clear and mark sixteen gaps, fifty yards wide, through the seaward band. of obstacles on the OMAHA Beaches; two on FOX GREEN, six on EASY RED, two on EASY GREEN, two on DOG RED, two on DOG WHITE and two on DOG GREEN. (2) Widen the gaps in the seaward band of obstacles until the entire band is cleared. (3) Assist the special Army Engineer Demolition Group in clearing gaps through other bands of obstacles and removing all obstacles from the OMAHA Beaches. 3. (a) NCD Section No. ONE land as directed by Commander Assault Group O-2, and clear eight gaps through the seaward band of obstacles on Beaches DOG GREEN, DOG WHITE, DOG RED, and EASY GREEN in accordance with the table set forth below.
I - Assault Units __________________________________________________________________ Serial No. of Gap & Coordinates Beach Team Craft No. NCDU (Eastings only) No. (LCM) No. __________________________________________________________________ 1. (6522 - 6526) DOG GREEN 1 1 11 2. (6545 - 6549) DOG GREEN 2 2 24 3. (6568 - 6572) DOG WHITE 3 3 27 4. (6588 - 6592) DOG WHITE 4 4 41 5. (6615 - 6619) DOG RED 5 5 42 6. (6635 - 6639) DOG RED 6 6 43 7. (6655 - 6659) EASY GREEN 7 7 140 8. (6675 - 6679) EASY GREEN 8 8 137 II - Support Units DOG GREEN A 17 133 DOG WHITE B 18 130 DOG RED C 19 Army EASY GREEN D 20 128 III - Reserve Craft DOG GREEN 28 DOG WHITE 29 DOG RED 30 EASY GREEN 31 __________________________________________________________________
I - Assault Units __________________________________________________________________ Serial No. of Gap & Coordinates Beach Team Craft No. NCDU (Easting only) No. (LCM) No. __________________________________________________________________ 9. (6740 - 6743) EASY RED 9 9 44 10. (6760 - 6764) EASY RED 10 10 45 11. (6790 - 6794) EASY RED 11 11 46 12. (6811 - 6815) EASY RED 12 12 22 13. (6830 - 6835) EASY RED 13 13 23 14. (6851 - 6856) EASY RED 14 14 141 15. (6872 - 6876) FOX GREEN 15 15 138 16. (6893 - 6898) FOX GREEN 16 16 142 II - Support Units EASY RED E 21 Army EASY RED F 22 131 EASY RED G 23 Army FOX GREEN H 24 129 III - Reserve Craft EASY RED 32 EASY RED 33 EASY RED 34 FOX GREEN 35 FOX GREEN 36 __________________________________________________________________
NCDG/A4-3 WESTERN NAVAL TASK FORCE Serial: 001 ASSAULT FORCE "O" (TASK FORCE ONE TWO FOUR) TOP SECRET -- NEPTUNE NAVAL COMBAT DEMOLITION GROUP PORTLAND DORSET OPERATION ORDER 31 May 1944: 1200 No. 1-44 ANNEX A MOVEMENT, APPROACH, DEPLOYMENT, & LANDING PLAN TASK ORGANIZATION (a) Assault and Command Craft - Lt(jg) Orr, USNR. (LCM 27). LCMs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 19 LCMs 16, 25, 26, 27. (b) Support Craft - Ens. Williams, USNR. (LCM 17). LCMs 17, 18, 19, 20, 21, 22, 23, 24. 8 LCMs (c) Reserve Craft - Ens. Edelfelt, USNR. (LCM 30). LCMs 28, 29, 30, 31, 32, 33, 34, 35, 36. 9 LCMs 1. (a) This plan provides for orderly departure of the LCMs of the Naval Combat Demolition Group from assembly ports, for their movement to the Assault Area; their approach, deployment, and landing, and for replacement of LCMs which become casualties during the movement. (b) Detailed information concerning the convoy in which the LCMs proceed, is to be found in Annex C to Commander Assault Force 'O' Operation Order No. BB-44. (c) Appendix 3 to this Annex shows the location of the Transport Area and the vessels therein relative to the landing beaches and the courses and destinations thereto. 2. LCMs proceed in Convoy Group TWO, arriving off the OMAHA Beaches in time to perform the tasks assigned in the Operation Order and in the Field Order of Army Engineer Demolition Group 3. (a) Assault and Command Craft - LCMs 1 - 16, and 25 - 27 inclusive, proceed from PORTLAND or POOLE as appropriate to the Assault Area in tow of LCT(A)s and LCT(HE)s in Convoy Group TWO as set forth in Appendix 1 to this Annex. When towing craft lie to about 1,000 yards inshore from Point KING LCMs go alongside the LCTs and embark Demolition teams. Then Demolition Teams are loaded, LCM's of each section assemble on the section commander and proceed to line of departure via the route prescribed by the Commanders, Assault Groups O-1 and O-2 respectively. Upon arrival at the line of departure, deploy as indicated in Appendix 2 to this Annex. Leave line of departure when despatched by control vessels, about H - 10 minutes, and land on assigned beaches at H + 3 minutes. After arrival at the line of departure, LCMs 25 and 26 proceed as directed by NCD Section commanders.
ENCLOSURE ( 7 ) Operation Order - Force 'U'.
|Source: Task Force One Two Two Report, Serial 844 of 19 July 1944, US Navy World War II Action Reports, Modern Military Branch, National Archives and Records Administration, College Park, MD 20749-6001|