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 ½-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 creosota 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 l½ 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 conbat 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 attachod 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 obstaclos 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 ll 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 P00LE 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 his 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
OCR and HTML editting by C.Hall 11/2000.