D-Day, the Normandy Invasion: Combat Demolition Units
Related Resources: D-Day, the Normandy Invasion
|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.|
- Enclosure (A) is forwarded in accordance with reference (a).
Chief Of Staff.
UNITED STATES FLEET
TASK FORCE ONE TWO TWO
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 June, 1944 and endorsements thereto.|
|Enclosure:||(1) Report on the work of the U.S. Naval Combat Demolition units in operation NEPTUNE.|
- 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.
- Some of the material collected has been briefed to make up the report which forms Enclosure (1) of this letter.
H.L. BLACKWELL, JR.
Lt. (jg), USNR
Lt.(jg) H. L. Blackwell, Jr. D-V(G) , USNR.
5 July, 1944.
|Section I||Chronological sketch of NCDUs in U.K. November 1943 -- June 6, 1944|
|Section II||The Operation.|
B. Force OMAHA.
C. Force UTAH
|Section III||Recommendations for Future Operations.|
A. General, for NCDU work under
B. Recommendations Specifically for Operations similar to NEPTUNE
|(1)||Tabular summary of Gap Clearance, D-day, Force '0'. [omitted]|
|(2)||OMAHA Beach Map, with trace to show D-day Gap Clearance. [omitted]|
|(3)||Tabular summary of Gap Clearance, D-day, Force 'U'. [omitted]|
|(4)||UTAH Beach Map, with trace to show D-day Gap Clearance. [omitted]|
|(5)||Table of Methods used (Obstacle, Charge employed, Results)|
|(6)||Demolition Operation Order, Force '0'.|
|(7)||Demolition Operation Order, Force 'U'.|
The first U. S. Naval Combat Demolition Unit arrived in England on 31 October, 1943. Between then and 6 June 1944, the number of units rose to 32, training and exercises were conducted, a specialized charge developed, and the clearance of obstacles on NEPTUNE beaches was planned and prepared. A sketch of these events forms the balance of this section.
- Sketch history
31 Oct. 1943 NCDU #11 Arrived in U.K. ordered to Falmouth. 15 Dec. NCDUs 22 through 27 arrived. To Falmouth. 25 Dec. NCDUs 28, 29 and 30 arrived Scotland and after 1 January, 1944, went to Falmouth. All units were then under administration of ComLanCrabEu, acting for Com11thPhib. They were also under the jurisdiction or the C.O. of their base. Within the group itself, there was a Senior Officer (Lt. Robert Smith, CEC, USNR) but no officially designated commanding officer. Units drew up an advanced training program for themselves, but the lack of a Unit Commander caused some difficulty in getting training under way, especially in the matter of getting obstacles constructed for the Units to demolish. Late January Lt.(jg) Heideman ordered to Fort Pierce, Florida, for demonstration there, representing Com11thPhib [Eleventh Amphibious Force]. 14 Feb. 1944
The 10 NCDUs were placed administratively under the Commander, Beach Battalions, ELEVENTH Amphibious Force. They were broken into roughly equal groups numbered I, II, and III, and these assigned to the 7th, 6th and 2nd Beach Battalions. Group Commanders appointed were: Lt.(jg) Heideman, O-V(S), USNR, I, Lt. (jg) Cooper, D-V(G), USNR, II, and Lt. Smith, CEC, USNR, III. The scope of their authority as Group Commanders was never defined, for them; and no one of them was ever officially designated Commanding Officer of the entire group of Units, though Lt. Smith was Senior Officer. By mutual agreement, negotiations with higher commanders were conducted largely through and by Lt. Smith, despite lack of official authority which made his position difficult.
Group I went to Salcombe; Group II, first to Salcombe and thence near Swansea, Wales; and Group III went to Fowey. It was then thought that NCDUs would be operating with troops of the 3rd Army Engineer Special Brigades of First Army. Joint training was undertaken; but this plan was later abandoned.
25 Feb. 1944 First obstacles in NEPTUNE area reported this date. Report based on photo sorties flown on 20 and 21 February. From this date obstacles grew steadily denser till D-day. Late February
Between this time and mid-April, NCDUs at Fowey did considerable experimental work. Tests were run to determine best method of breaching such obstacles as wooden piling, steel wire rope, scaffolding and Element C. However, NCDUs doing this work were not informed what obstacles were being found on intended assault beaches.
The Hagensen Pack charge (2 lbs. of C2 in canvas) was developed by Lt.(jg) C.P. Hagenson CEC-V(S) USNR, primarily for use on steel obstacles (plasticity, small production of shrapnel, ease of attachment, etc.). [This charge commonly referred to as the Hagenson Pack was adopted for use by all NCDUs and the Army Units as well, and was put into production locally.] Obstacles for these experiments were supplied by Engineers of the 1st E.S.B. on Pentwain Beach. Training conducted especially against Element C ("dry runs" in which charges were fitted but not fired.)
Early March Lt.(jg) Heideman returned from USA with understandings that initial quantities of (a) Reddy Fox charges, and (b) Dunlop or substitute Underwater Swim Suits would be delivered for NCDUs in U.K. by April 1. 15 March NCDUs 41 through 46 arrived, and were at once divided among the 3 Beach Battalions. 1 April (about) 50 Swim Suits, substitutes for the Dunlop U.W.S.S. Mk. 1 but not as good, arrived by air. Mid-April Lt. (jg) Padgett and NCDU #127 arrived. Total number of Units now was 17, split almost equally among the three Groups; each unit, 1 officer and five men, usually including a chief or first class. 15 April The Commander, 11th Amphibious Force, in conjunction with V Corps, U. S. Army, called in the Naval Demolition Group Commanders and some other Naval Demolition Officers for advice on obstacle clearance under certain hypothetical conditions. Officers of NCDU guessed, but were never told, that the actual operational plan was being made. The Demolition Operation Orders of the two Forces were not written at till later, but at this time the following basic decisions were made: (a) that obstacles could be expected to continue growing denser until the operation; (b) that the obstacles should be attacked when in three feet of water or less; and (c) that hand placed charges were the most practicable method under the circumstances. Lt.Col. O'Neill, of the 112th Combat Engineer Battalion who had attended the Ft. Pierce Demonstration in February, was called in as an advisor, and later was made Commanding Officer of V Corps' Special Engineer Task Force. (Naval Combat Demolition Units in Force 'O' were nominally a part of this Army Task Force. In actual fact, NCDUs and Army Demolition Units operated in the closest harmony, but under their respective commands.) During all planning, NCDU officers emphasized that men setting hand-placed charges could accomplish their mission only if opposing fire were neutralized. Mid-April
All NCDUs moved to Assault Training Center, Woolacombe, N. Devon, for a special advanced training program based on the intended conditions of actual operation. This training program was arranged largely by the NCDU Group Commanders and officers, with Major Richard Fairbairn, R.E., British Liaison Officer on the Staff of Com11thPhib. (Major Fairbairn had seen the development of U.S.N. Combat Demolition, starting at Fort Pierce, where he went in June 1943, in an advisory capacity when the NCDU training program was first being set up.) At Woolacombe, NCDUs trained with the troops of the 146th, 299th, and 237th Combat Engineer Battalions, with whom they actually worked during the operation. (ComEleventhPhib at this time loaned Lt.(jg) John Martin to the NCDUs.) Lt. Martin's help in procuring, organizing, and loading gear, from this time until the operation, was a major contribution to the success of the Demolition work.)
Naval Scouts joined NCDUs at the A.T.C. for a time, to do gap-marking work. This plan, however, was later abandoned, and gap-marking was made a function of the NCDUs themselves.
At this time, in order to provide the Navy with additional trained demolition personnel considered necessary, the Combat Engineer Battalions turned over five soldiers to the NCDUs. (And it is worth note that though it is often the practice, when lending men, to get rid of dead-wood, these men were generally capable, intelligent, and well-trained.) These five men remained an integral part of each NCD Unit till after the assault when they were gradually returned to their companies. While NCDUs were at Assault Training Center, Col. Reinhardt, C.O. of the 1278th Engineers, U.S. Army, took an active part in obstacle work, and became especially closely associate during D-day with demolition units of Force 'U'.
Air photos this date showed the sympathetic detonation of regularly-placed small charges, caused by bomb explosion below water line. Investigation (confirmed by reconnaissance parties sent to the beaches) showed these small charges to be Tellermines, used on top of obstacles against craft.
Capt. T. F. Wellings, Force Gunnery Officer of CTF 122, took charge of NCDUs; as previously pointed out, they had suffered since their arrival for lack of, a single, high-ranking Commanding Officer.
3 May 1944 Lt.Cdr. Joseph H. Gibbons, USN, and Lt.Cdr. Herbert A. Peterson USN, arrived by air in response to despatches sent by Com11thPhib and CTF 122, which requested Commanding Officers for Demolition Units of the two forces. They took charge of the NCDUs, under general supervision of Capt. Wellings. 5 May 1944 Approximately 100 Seamen 2c arrived from Rosneath to augment NCDUs. These men had volunteered, with very vague ideas of what they were volunteering for. They were inexperienced in demolition work end therefore were apportioned evenly among the Units for training. Just before the operation, those unsuited for demolition work were turned over to Salcombe Base while two (or sometimes three) of the others were retained with each unit. Those retained, however, were given non-technical work such as tending rubber boats etc. 6 May 1944 Units 128 and 130 through 142 arrived by air, and went direct to Assault Training Center. 15 May 1944 All NCDUs moved into Salcombe. The time here was spent in obtaining final items of gear, and in preparing Hagensen and other charges, detonator assemblies, and and personal equipment. Mid-May Several freighters arrived in scattered U. K. ports, carrying Reddy Foxes, Apex boat components, etc. These were stored "for future reference." 27 May NCDUs of Force 'U' went to marshalling area near Dartmouth. Officers received partial briefing. 31 May 1 NCDUs of Force '0' went to Portland for embarkation. Support Units were put aboard the LSI Princess Maud. Assault Units went aboard LCTs. 2 June NCDUs of Force 'U' were loaded aboard LSTs, with their LCVPs which would carry them to the beach. 2 June All officers of NCDUs of Force 'O' were briefed aboard the USS Ancon. 3 June Force 'U' officers further briefed. Crews briefed aboard their craft. Craft got under way, but bad weather forced postponement of the Operation. 4 June Craft again got under way. 6 June
From about 0200 on, craft arrived off coast of France. NCDUs and Army Demolition Units embarked in their smaller craft. Boat Team #6 had made almost entire crossing in their LCM when LCT (HE) 2075 foundered; Boat Team #2 had embarked in LCM at 2300 and cast loose at 0330, when LCT(A) 2227 was crippled by flooded engine room; and Boat Team #11 had to abandon their LCT at 0200, in sinking condition. Foundering of 2075 was result of water coming in where starboard rail had been out away and replaced; replaced section swung one way only, like a valve, admitting water and then impounding it. The Assault Units of Force '0' went ashore to fulfill their mission after almost a week aboard LCTs (whose decks were often awash), having had no hot food or exercise. Support NCDUs of Force '0' were fairly fresh after crossing on LSI; and NCDUs of Force 'U' had been on LSTs. It is felt that use of LSTs, if available, is preferable.
The story of the actual operation is told in Section II.
THE ACTUAL OPERATION
- 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.
- Force OMAHA
- The Mission of the NCDUs.
- 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)
- The Naval Combat Demolition Groupis 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.
- 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.
- The Naval Combat Demolition Groupis 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.
- In detail, this mission involved clearance of obstacles in
roughly the following order from seaward to landward:
- Scattered Element C, either interspersed with ramps (ii. below) or placed in continuous linear groups; most of it the newer, smaller type, about 8' high;
- wooden ramps, having one sloped log running from the beach level to the apex of a triangular frame or to the top of a single vertical log; logs 10-18" diameter (some larger on UTAH); height 10-12 feet; sloping member 15-18 feet long; sloping log supported by 1, 2, or 3 legs; these ramps were 20-30 feet apart, in rough bands, either with pilings or Element C;
- single log pilings, 10-18 inches diameter (UTAH reports some almost 24"), set at 15-25 foot intervals, either in a single row or in staggered bands;
- steel hedgehogs, each leg about 4 feet, made of channel irons (about 4"x 4") welded to central gusset plates, which were in turn bolted together; ends of channels closed with a welded triangular plate to prevent sinking into sand-clay;
- Tellermines 35, 42, and 43, on seaward face of high (usually
inshore) end of ramps, or on tops of pilings (bevelled, sloping
seaward so as to expose mine to horizontal pressure as well as
vertical), or at top-center of Element C; the average was about
1 Tellermine to every seventh obstacle, but they were denser
or less dense at many places (UTAH NCDUs encountered NO Tellermines
in Assault area, but on originally-planned beaches they were
present); mines had normal T. Mi. Z. igniters, were not booby-trapped;
they were waterproofed with black, tarry compound very like DuPont
product, and it is assumed this must have been effective as mines
were still active (mining having been first noticed 23 April).
Individual Tellermines were buried in the sand at many scattered points, and damaged vehicles as late as D Plus 4; but beach was swept by engineers with SCR 625 detector, and no minefield was found within the tidal range; it is therefor believed that mines within tidal range had fallen or been blown from obstacles, for they were neither dense nor regular enough to have been a deliberate field.
- 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)
- Gap Clearance.
A tabular summary, and a map, showing gaps cleared in obstacles on OMAHA beaches are attached as Enclosures (1) and (2) respectively [omitted]. The same material, generalized, is presented herewith in narrative form.
The Assault NCDUs and Army Demolition Units (collectively called Gap Assault Teams) touched down on OMAHA beaches at 0633 - 0635, with a single exception. All were to the left of their assigned beaches, starting with Team No. 1 on DOG WHITE, 700 yards east of their intended landing on DOG GREEN. Others were as much as 1500 yards east of their assigned landings, though still within the OMAHA beaches. The error is variously attributed to haze over the shoreline, absence or failure of guiding craft, and shore currents.
The type and intensity of the fire that met them is by now well known.
Many Boat Teams arrived ahead of the Assault infantry, others simultaneously with them, and a few after them as planned. Two tanks and a tank dozer were assigned with each Army Demolition unit. Some of these arrived successfully and did yeoman service in drawing fire away from the Demolition personnel, and returning fire, and later (especially D-day afternoon low tide) in dozing out the obstacles. (Of the rest, some were lost with their LCTs, some were landed late in the day, and some, landed successfully, were knocked out traversing the beach from their landing-point to their assigned Gap Area).
Almost all units proceeded at once to lay charges; and they were ready to fire in a maximum of 20 minutes. [Enclosure (5) presents details of charges used, their placement, etc.]
Six complete gaps, through all bands of obstacles, were blown during the assault low-tide, most of them by H plus 30 minutes. Three partial gaps, through either the seaward or the landward bands, were also blown at this time.
Four additional clear gaps were made as the tide receded that afternoon, and the three partial gaps were completed; meanwhile some of the morning gaps were being widened leftwards, as planned, so that there were at least 13 gaps averaging about 70 yards each that afternoon.
Of the Teams who failed to fire, at least five Army or Navy units were prevented from setting off charges which they had fitted by the presence among the obstacles of either assault or later waves of infantry, and even vehicles. (At least two units report misfires caused by the fact that the primacord linking their various charged obstacles was cut by troops and vehicles, passing through the gaps despite efforts to signal them away.) Death prevented three other Navy units from firing. (Of these, one was caught aboard the LCM by machine gun fire, while they strove to off-load their rubber boat; another was eliminated, after setting its charges, by well-placed mortar fire. The third was blown up after bringing in its rubber boat, when a direct hit set off the auxiliary explosives in it and somehow also the charges at the obstacles where men still were.) A freak accident caused the failure of another naval group; the officer was about to pull the twin friction-igniters, when a bit of shrapnel cut the two fuses and his finger as well. The enemy saved one naval team the trouble of pulling its igniters, when a bullet or fragment managed somehow to set off the primacord and all the charges!
Despite the casualties, surviving units continued working, with general disregard for personal safety. A notable example of courage was given by men who voluntarily placed charges on Tellermines atop obstacles, 10 or 12 feet above the beach; in the face of accurate rifle and machine-gun fire, they climbed on each others shoulders or shinnied up the pilings and ramps.
Support Teams, due on the beaches at H Plus 8 (0638), were all late by amounts varying from 20 to 60 minutes. Their LCMs had arrived late for loading at the LS[T] Princess Maud. Their task was made difficult by height of tide which in one case was reported above the landward obstacle (location indefinite).
The plans had provided for the marking of gaps. Two white triangular range-markers on poles to be stuck in the sand would show the centerline of each gap. Its extremities, to seaward, would be marked by a pair of can buoys holding green flags. Many buoys, because of their bulk, were left in the rubber boats. Among those brought ashore, the cans of several were pierced by bullets or shrapnel, leaving either one buoy of the pair or none. At least two units put out their single remaining buoy at the edge of their gap; but they seemed to serve little purpose; some coxswains apparently thought they were merely wreck markers, without knowledge to which side they should leave them.
The error that carried some teams to the extreme left of FOX RED may have been a very fortunate one. One all-Army unit and several combined A-N units blew and dozed gaps in this area on the afternoon of D-day and the morning of D-plus-1. Tanks and troops entered there, and passed inland over the unscheduled beach exit (at 697893) leading to Cabourg and Colleville. The presence of these gaps may therefore have been of incidental assistance in the capture of Colleville.
By the evening of D-day, 40 per cent of the obstacled area on Omaha had been cleared. 85 per cent had been cleared by D-plus-2 days. Work of course continued, by both explosive and mechanical means, on succeeding days, and by 1200 of D-Plus-4, Lt.-Cdr. Gibbons reported that the beach was clear of all enemy obstacles that constituted a hazard to craft.
The NCDUs of Force 'O' left for the U.K. on 27 June, 1944.
- Methods used.
Enclosure (5) is a table showing the amount and placement of charge for each different type of obstacle, and the results obtained, covering the work of both Forces. It refers primarily to methods of the Naval Combat Demolition Units but is generally applicable to Army Engineer technique also.
- The Mission of the NCDUs.
- Force UTAH.
- The Mission of the NCDUs.
- The following is quoted from the Demolition Plan,
which, forms Appendix Three to Annex George of Operation Order
No. 3-44, dated 15 May, 1944, (Enclosure (7)
- At the present time it is contemplated that all obstacles will be breached above water. As above-water demolition is primarily an Army function, the Naval Demolition Units are coordinated with the Army Demolition Units, under the supervision of the Commander of the Army units.
- The force will breach and destroy above-water obstacles on UTAH BEACHES in order to permit the unimpeded landing of personnel, vehicles, and equipment of the VII Corps, U. S. Army.
- (a) Naval Combat Demolition Units clear four gaps 50 yards wide at 250 yard intervals through the seaward band of obstacles on each beach. Widen gaps to the left until entire band of obstacles is cleared.
- Details of mission. Force 'U' made its entire landing
1500-odd yards south of the intended location. This accident
turned out to be very fortunate, as a glance at the Obstacle
Overprint map at Enclosure (4) [omitted] will show. The detailed
mission of the NCDUs here involved the clearance of the following
- scattered wooded ramps, some like those on OMAHA, others looking like a large letter 'A' the feet of which rest on the sand while the members slope upward, with the apex resting on a frame or a single leg; timbers were 10-24 inches diameter;
- three sparse bands of wooden piling, or wooden and concrete piles mingled; wooden piles were as met on OMAHA; concrete piles were reinforced with half-inch bars at each corner (square cross-section); pilings were irregularly spaced on about 35-foot centers;
- Eight unconnected "bays" of Element C, scattered to seaward of other obstacles;
- hedgehogs, of same dimensions as OMAHA, but some reported as welded throughout instead of partially bolted; these were mostly at northern end of actual assault area; in a well-defined band to landward, spaced about 15-20 feet apart; in some instances a single strand of wire was strung between each two hedgehogs, perhaps to foul screws of landing craft at high water;
- tetrahedra, made of six equal pre-formed, reinforced concrete limbs fitted so as to form four equilateral triangles, capable of resting on any of them; by having a pin thrust hinge-wise through the projecting loop-ends of the reinforcing bars at each end;
- tetrahedra, steel, standard anti-tank type;
- Tellermines were conspicuous by their absence in the actual assault area; they were fairly dense in the intended assault area.
- In general, obstacles varied from 'moderate' on the right flank to 'negligible' on the left flank. Obstacles were denser everywhere than May 30th overprint shows, and extended further south. As on OMAHA, Element C was usually interspersed with ramps. All obstacles were on very wide centers (25-35 feet), in poorly defined bands or singly. The commonest were reinforced concrete posts and wooden pilings, in about 2-1 ratio, the tops of wooden posts generally recessed for Tellermining; concrete tetrahedra were the next commonest.
- Lt. Smith reports the installation of fixed flamethrowers, remote-controlled, behind the beach seawall south of the exit at 452967 (La Grande Dune). Description given in Enclosure (5).
- The following is quoted from the Demolition Plan, which, forms Appendix Three to Annex George of Operation Order No. 3-44, dated 15 May, 1944, (Enclosure (7) hereof).
- Gap Clearance
A tabular and map summary of UTAH gap clearance work, similar to that given for OMAHA in Enclosures (1) and (2), is contained in Enclosures (3) and (4) [all omitted]. These must be read with the same reservations as were stated above for the OMAHA summary.
All the UTAH NCDUs touched down within one or two minutes of their scheduled times H+3. As is now well-known, they were all about 1500 yards south (left) of their intended assault area; and the units themselves were not in the order from right to left which had been planned, but they spaced themselves out, and allowed this fact to make no difference in their work.
The fact of landing so far south of their planned areas resulted in their finding only light opposing fire, and this fact must be taken as an important factor in the success of the demolitions operations. Officers report that with few exceptions they were hardly aware of the opposing fire till they were through work and took cover. (This does not alter the fact that machinegun, artillery, and rifle fire took toll of NCDU personnel leaving 6 dead and 11 wounded.
The navigational error further assisted NCDUs inasmuch as the obstacles were far lighter than where they should have landed. This is a second major factor in their success.
All units at once went to work laying charges, and all blew their first gaps, generally of more then fifty yards clear through from water-line to the barbed wire-at the seawall, in 5 - 8 minutes. They immediately wired and fired their second, and many of them their third shots, widening their gaps leftward (south) as per plan. By 0800 of D-day morning, Lt.Cdr. Peterson was able to see. that the entire beach in the assault area was clear of enemy obstacles.
The comparative lightness of the opposing fire was responsible for NCDUs here not being held up by the presence of the assault infantry pinned down among the obstacles. The infantry, which in all reported cases arrived right on schedule neither behind it nor ahead it, was able to go straight across the beach and over the seawall.
When the Support NCDUs arrived, about on schedule, they found in general that work was well in hand in their assigned areas, and were assigned other spots to work, including the extreme northern flank of the assault beach.
The Army Engineer Demolition Teams hit the beach a little late, and when they proceeded at once to work on the breaching of seawall exits and the clearance of the minefields behind it, progress was good enough. Some Army personnel remained on the beach, however, and breached gaps edge-to-edge with Navy gaps. Cooperation was excellent.
On subsequent days, large areas were cleared on the flanks of the assault beaches, and even in entirely separate areas (ROGER WHITE). All firing was electrical, preceded in each case by use of the planned warning signal, a purple smoke grenade. Shell-holes provided cover. There were few misfires, but of those which did occur, one cause was the cutting of primacord by infantry and vehicles coming through the gap after the setting of the charges.
Gap-marking gear was not used, since there were no gaps to mark. The plan was to use range markers, green flags, and red and black channel markers.
NCDUs left UTAH beach for the U.K. on 13 June, 1944.
- Methods used.
Enclosure (5) is a table showing the amount and placement of charge for each different type of obstacle found on either OMAHA or UTAH. It refers primarily to the work of the Naval Combat Demolition Units, but is generally applicable also to Army Engineer Demolition Technique.
The only major difference in practice between the two Forces is that on UTAH all firing was done electrically. The only other major difference affects the Army's work primarily: the absence of Tellermines on the obstacles in the assault area enabled dozer work to proceed without a mine-clearing party first. (Incidentally, almost all Army officers on OMAHA, felt that more dozers could have been used there; it is a question whether the same is true of UTAH in view of the lightness of the obstacles.)
- The Mission of the NCDUs.
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.
- General recommendations, for NCDU work under any circumstances.
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.
- 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.
- 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.
- 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[er] 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.
- 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.
- Sea Transport on operations to point where NCDUs will embark in small craft to go to beach should if possible be done in large vessels such as LSI or LST, rather than making a long trip like the channel crossing in LCT or even LCM.
- Landing Craft, taking NCDUs to beach should, if possible, be permanently assigned to that Unit, and be trained with it.
- Hagensen Pack is recommended for use in all future operations where obstacles at all similar to those in NEPTUNE are to be attacked with hand-placed charges. It has received universal endorsement from Naval and Army Demolition Officers.
- Recommendations specifically
for Operations similar to NEPTUNE.
- Enemy Fire. Experience in NEPTUNE bears out the statement
that hand-placed charges can be used successfully only if enemy
fire has been neutralized.
It is recommended that the Demolition Units, the tanks covering them, and the Assault Infantry be considered an inseparable Team, and the plan be so made that all the components of the Team will arrive on the beach together even if it is the wrong beach. Corollary recommendation is that the three elements of the team should be exercised together, and be personally acquainted, for a week or so before the operation.
It is also recommended that Assault Infantry be allowed more time, in the plan, to neutralize enemy fire before demolition begins. This would facilitate demolition work by (a) reducing casualties and (b) giving infantry time to get beyond obstacles.
- Technique of Ramming Obstacles. Obstacles encountered
so far can be rammed by LCT, and craft can retract and navigate
afterward. Greater hazard to craft are the Tellermines, or other
attached explosive devices. (These must therefore be neutralized
or countermined before ramming.)
It is recommended that ramming be considered for obstacle clearance in any further operations. It is quite possible that the enemy will put obstacles below water hereafter, having seen that we chose to attack them above-water in NEPTUNE; and in this case ramming (preceded by mine clearance) might be the only possible method.
- Explosive Devices. Whether ramming-technique is used or not, there should be a fixed rule that demolition parties will either countermine or remove Tellermines, artillery shells, and other explosive devices attached to obstacles. (As mentioned earlier, vehicles were damaged by mines apparently fallen from obstacles; and some NCDUs did not actually put a charge on the mines on their obstacles, but relied on shock of blowing obstacles to detonate mine.)
- Rubber Boat. Under the conditions met by Force 'O',
the use of a rubber boat for auxiliary explosives is undesirable.
It is easily bullet-holed, it is awkward above the water line,
and it forces the men off-loading it from landing craft to gather
and stay in one spot, a perfect target. (NCDU 141 virtually wiped
out by machine gun fire while unloading [a] rubber boat; NCDU
23 wiped out by shell-hit on explosives in rubber boat.)
Under the conditions met by Force 'U', the rubber boat was satisfactory.
It is recommended, however, that an amphibious or wading vehicle, such as jeep or weasel, be used as the carrier for auxiliary explosives.
- Army M-1 Ammunition-Bag.I t is recommended that charges and other demolition gear be packed in these bags. Those NCDUs having them report their men were far more free to run, use their hands, and hit the deck than if they had ordinary packs.
- Short-burning detonating assemblies. If non-electric firing is to be used, each unit should be equipped with shorter-burning, lengths of fuse then the 2 minute fuses generally used. These enable Units to Clear their gaps of personnel and vehicles, and fire their charges before others infiltrate the gap.
- Dozers for NCDUs. It is recommended dozers be assigned to NCDUs as they were to Army Demolition Teams. Then Naval units will not have to cease mechanical clearance work when Army dozers go inland, as they must very early in any operation. (On OMAHA, NCDUs had to borrow dozers from Seabees; arrangement was mutually unsatisfactory because each group needed dozers at same times, especially at low tides.) OMAHA units feel more dozers could have been used; UTAH units feel enough were on hand.
- Gap Marking should not be the duty of the NCDU. A separate party should be trained and equipped for it, working closely with beach-marking groups. They should be exercised and embarked with NCDUs, however.
- Gap Markers should be lighter, and harder to puncture, than the can buoys used in NEPTUNE. In several cases in NEPTUNE one can of a pair was punctured by bullets or shrapnel. The plan to use black & red channel markers should also be further considered. Or perhaps black-and-white striped mid-channel markers could be used. Whatever colors & markers are used, the highly vulnerable can-construction should be avoided.
- Coxswain's Briefing.
- In future operations, coxswains should be briefed to expect demolitions explosions continuing on the beach after D-day, Some coxswains in this operation apparently mistook the demolition for shelling, (an easy mistake to make), and were afraid to approach the beach.
- They should also be briefed very forcefully on the effect of and similar explosive devices upon their craft. It is believed that many craft, especially among the LCTs, after being holed by could have been retracted successfully (at the very least to deep water) instead of being abandoned to obstruct the beach.
- Post Assault Work of the NCDUs.
Work in the post-assault period for the Demolition Units should be definitely provided for in the Operation Order. Either NCDU should be withdrawn at a specified date, or else definitely included in plans for wreck dispersal, channel-blasting, etc.
The position of Bomb-Disposal and Mine-Disposal Officers in the NCDUs, with respect to post-assault work in those special fields, should be clarified. It is recommended that regular U.S.N. Bomb and Mine Disposal Officers, who have been spending full time on these highly technical specialties, be put in a position to take over U.S. Naval responsibilities in this field, early after the assault, calling on B.D. and M.D. Officers within NCDU for assistance, as a sort of reserve.
- Enemy Fire. Experience in NEPTUNE bears out the statement that hand-placed charges can be used successfully only if enemy fire has been neutralized.
METHODS -- Charges used, placement of charges, results.
- Explosive Methods.
Element "C" 18 2-lb Hagensen packs, placed to cut face from rear-frame, & to flatten rear-frame as well. Extra charges used when possible. Obstacle cleared. Ramps One 2-lb Hagensen pack at. base of each leg, unless timbers over 18-20 inches diam., or wood very green. If so, 2 packs. Also one 2-lb. pack underside of apex of legs. Legs cut off at bases, blown apart at top. Obstacle cleared. Piling Single Hagensen pack at base, as with ramp timbers; if extra thick, or green, 2 packs (4 lbs.) Obstacle cleared. Steel hedgehogs 3 Tetrytol blocks; 2 on one side of central gusset plate, 1 on the other side. (Not necessarily placed for shearing effect.) Obstacle cleared, but much shrapnel projected. Steel hedgehogs 2 Hagensen packs; 1 each side of gusset. Obstacle not always cleared. Sometimes members merely bent, leaving hazard to light craft. Concrete tetrahedra (members wired or pinned together at the joints) 1 Hagensen pack at apex each triangle. Obstacle demolished. Concrete posts (reinforced) 2 Hagensen packs at base. Obstacle demolished. Concrete posts (reinforced) 1 Hagensen pack at base. Concrete cleared but reinf. bars left. obstacle could be pushed over by hand afterwards. Tellermines - 35, 42, 43 1 Hagensen pack, or 1 Tetrytol Block, or 1½-lb. block TNT Tellermine countermined. Tellermines - 35, 42, 43 1 Number Eight Cap placed in detonator Tellermine detonated.
- Non-Explosive Methods.
All the above obstacles were successfully removed with caterpillars, dozers, tank dozers, or tanks, if the 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.
- 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 ½ 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.
WESTERN NAVAL TASK FORCE
ASSAULT FORCE "O"
(TASK FORCE ONE TWO FOUR)
NAVAL COMBAT DEMOLITION GROUP
31 May 1944; 1200
No. 1 - 44
|(a)||Naval Combat Demolition Section No. ONE- Lt.(jg) Heideman, USNR, (LCM 25)|
NCDU No. 11 - LCM 1
LCMs 25, 28, 29 30, 31
|(b)||Naval Combat Demolition Section No. TWO- Lt.(jg) V. Cooper, USNR, (LCM 26)|
NCDU No. 44. - LCM 9
LCMs 26, 32, 33, 34, 36
- 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.
- 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.
- (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.
Serial No. of Gap
I - Assault Units 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 WHITE 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
(b) NCDU Section No. TWO land as directed by Commander Assault Group O-1, and clear eight gaps through the seaward band of obstacles on Beaches EASY RED and FOX GREEN in accordance with the table set forth below.
Serial No. of Gap
I - Assault Units 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
- Land at H plus three minutes, each unit clearing a gap fifty yards or more in width through the seaward band of obstacles. Upon completion of clearing the initial gap, each unit widen and extend the gap as time permits until the entire seaward band of obstacles is removed. If the seaward band of obstacles is Element "C", ten men from the Army section of the Gap Team will reinforce the NCDU to assist in removal of the obstacle. The two powder men of each NCDU launch the rubber boat with reserve explosives from the LCM at the time of debarking and tow it ashore. One man remain with the boat while the other proceeds inshore to the highwater mark with a white, triangular range marker, two feet wide at the base, and eight feet high. The man proceeding inshore with the marker, place it on the beach above the highwater mark on the center line of the gap cleared by the combined Army and Navy team.
- When the depth of water prevents further clearance of the seaward band of obstacles, mark the extremities of the cleared gaps by green flags mounted on buoys, then assist the Army team clearing obstacles in the inshore bands.
- Support NCDUs land as directed by NCD Section Commanders to assist, or augment the assault NCDUs. Unload reserve explosives from the support craft. Retract and remain on call, to be unloaded as directed by NCD Section Commanders.
- Reserve craft remain afloat on call, to be unloaded as directed by NCD Section Commander.
- Indicate intention to explode charges by a violet smoke grenade lighted when the fuze to the charge is ignited.
- Unless otherwise directed use a two minute delay fuze for all charges.
- Rations. Each individual will land with one type "K" and one type "D" rations.
- Water. All individuals land with one full canteen. Canteens will be refilled only from supplies of Allied troops.
- Arms and equipment. Each man will carry arms and ammunition and equipment as separately indicated.
- Life belts. Life belts will be worn high up under the arms.
- Additional equipment of NCDUs will be brought forward in LCMs of Convoy O-5, arriving in the Assault Area D plus 1 day.
- Communications as outlined in Communication Plan,
Annex H, to Commander Assault Force "O" Operation Order
Use Zone minus Two Time.
All units synchronize watches with ships time prior to embarking in LCMs.
Commander Naval Combat Demolition Group initially in LCT(R) 464.
During the assault he will be embarked in LCM 27.
A. LCM Movement and Approach Plan
B. Deployment and Landing Plan.
JOSEPH H. GIBBONS,
Lieutenant Commander, U.S.N.R.
Commander Naval Combat Demolition Group
|Commander Assault Force O-1||(3)|
|Commander Assault Force O-2||(3)|
|Commander Assault Force O-3||(3)|
|Commander Assault Force O-4||(3)|
|Comdr. LST Flotilla TWELVE||(3)|
|Comdr. LCI(L) Flotilla TEN||(3)|
|Comdr. LCT Flotilla TWELVE||(3)|
|Comdr. LCT Flotilla EIGHTEEN||(3)|
|Comdr. LCT Flotilla NINETEEN||(3)|
|Comdr. Gunfire Support Craft||(45)|
|Demolition Units & LCMs||(40)|
|CG V. Corps||(5)|
|CG 1st Inf. Div.||(5)|
|Col. Comdg. 16th R.C.T.||(3)|
|Col. Comdg. 18th R.C.T.||(3)|
|Col. Comdg. 115th R.C.T.||(3)|
|Col. Comdg. 116th R.C.T.||(3)|
|Prov. Eng. Spec. Brig. Grp.||(5)|
|5th Eng. Spec. Brig.||(3)|
|6th Eng. Spec. Brig.||(3)|
|CO 6th Beach Battalion||(3)|
|CO 7th Beach battalion||(3)|
|Comdr. Far Shore Service Group (OMAHA)||(3)|
|Col. Comdg. Army Eng. Demolition Group||(30)|
|ComLanCrab 11th Phib||(5)|
WESTERN NAVAL TASK FORCE
ASSAULT FORCE "O"
(TASK FORCE ONE TWO FOUR)
NAVAL COMBAT DEMOLITION GROUP
|31 May 1944: 1200|
MOVEMENT, APPROACH, DEPLOYMENT, & LANDING PLAN
- Assault and Command Craft - Lt (jg) Orr, USNR. (LCM
LCMs 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 25, 26, 27 19 LCMs
- Support Craft - Ens. Williams, USNR. (LCM 17).
LCMs 17, 18, 19, 20, 21, 22, 23, 24. 8 LCMs
- Reserve Craft - Ens. Edelfelt, USNR. (LCM 30).
LCMs 28, 29, 30, 31, 32, 33, 34, 35, 36. 9 LCMs
- (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.
- 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
- (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.
(b) Support Craft . -- LCMs 17-24 inclusive, proceed from POOLE to the Assault Area in tow of Gunfire Support Craft in Convoy Group TWO in accordance with Appendix 1 to this Annex. Upon arrival of the towing craft at Point KING, LCMs cast off lines, assemble by sections on the senior boat division officer of their section, and proceed to LSI(S) Princess Maude to embark support demolition teams. When demolition teams are embarked, Support Craft of each section proceed via route prescribed by the Commanders of Assault Groups O-1 and O-2 respectively, to the line of departure, and deploy as indicated in Appendix 2 to this Annex. Leave line of departure when despatched by control vessels about H - 5 minutes and land on assigned beaches at H + 8.
(c) Reserve Craft -- LCMs 28-36 inclusive, proceed from POOLE to the Assault Area in tow of Gunfire Support Craft as set forth in Appendix 2 of this Annex. Upon arrival of towing craft at point KING, LCM cast off tow line. Assemble by sections on the senior boat division commander of each section and proceed to the point about 1,000 yards inshore from Point KING where assault demolition teams are embarking in assault craft. Replace any missing assault craft with LCMs from the Reserve Group. From this point, proceed to LSI(S), Princess Maud, and embark any Support demolition teams whose LCMs did not arrive. From Princess Maud, remaining Reserve Craft proceed toward line of departure via route prescribed by their respective Assault Group commanders and deploy as indicated in Appendix 2 to this Annex. Leave line of departure when despatched by control vessels in time to arrive approximately 1,000 yards off their assigned beaches at H + 20 minutes. Lie to in these positions on call.
- (x)(1) LCMs berth alongside their respective towing craft
when directed by the Commander Convoy Group TWO.
(2) LCMs nominally in tow enroute to the Assault Area will run engines at sufficient speed to preserve a slack tow line. See that the tow line is tended carefully, however, in order to prevent it fouling the screws of the towing vessel.
(3) In the event of engine failure or other casualty while on passage during daylight, adjacent LCM take necessary action to take the casualty in two and place it in tow of an LCT of low priority at the rear of the convoy. In the event of casualties during darkness, LCM crews embark on towing craft and set the LCM adrift to leeward, if necessary to maintain convoy speed.
- Use reserve fuel to replenish tanks prior to arrival at the Assault Area.
- LCMs when released by Naval Combat Demolition Group Commanders, report for duty to Ferry Control Subordinate Command Number ONE in LCI(L) __, one mile off Beach CHARLIE, displaying International flag hoist FOX EASY ROGER, Numeral ONE.
- (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.
JOSEPH E. GIBBONS
Lieutenant Commander, U.S.N.R.
Commander Naval Combat Demolition Group
1. Loading and Towing assignments.
2. Deployment Diagram. [omitted]
3. Assault Area Diagram. [omitted]
WESTERN NAVAL TASK FORCE
ASSAULT FORCE "O"
(TASK FORCE ONE TWO FOUR)
NAVAL COMBAT DEMOLITION GROUP
TO OPERATION ORDER 1-44
LOADING AND TOWING ASSIGNMENTS
|C.O. NCDU||Towed By||Beach||
|1||1||11||40||Freeman C.G.M.||2124(A)||Dog G||O-2|
|2||2||24||40||Culver Lt(jg)||2227(A)||Dog G||O-2|
|3||3||27||40||Holtman Lt(jg)||2273(A)||Dog W||O-2|
|4||4||41||40||Nichols Lt(jg)||2275(A)||Dog W||O-2|
|5||5||42||40||Thompson Carp.||2050(HE)||Dog R||O-2|
|6||6||43||40||Jenkins Lt(jg)||2075(HE)||Dog R||O-2|
|7||7||140||40||Hill Carp.||2229(HE)||Easy G||O-2|
|8||8||137||40||Blein Ens.||2307(HE)||Easy G||O-2|
|9||9||44||40||Reymer Carp.||2339(HE)||Easy R||O-1|
|10||10||45||40||Karnowski Ens.||2425(HE)||Easy R||O-1|
|11||11||46||40||Bassell Ens.||2049(HE)||Easy R||O-1|
|12||12||22||40||Barbour ACOM||2287(HE)||Easy R||O-1|
|13||13||23||40||Vetter Lt(jg)||2037(A)||Easy R||O-1|
|14||14||141||40||Guinlock Ens||2228(A)||Easy R||O-1|
|15||15||138||40||Allen Ens.||2043(A)||Fox G||O-1|
|16||16||142||40||Stocking Ens.||2008(A)||Fox G||O-1|
Gibbons, Lt Cdr
O'Neill, Lt Col
|SUPPORT CRAFT - DEPART POOLE|
|17||A||133||40||Mitchell, Ens.||LCG(L) 424||Dog G||O-2|
|18||B||130||40||Cheney, Ens.||LCG(L) 426||Dog W||O-2|
|19||C||Army||35||LCG(L) 449||Dog R||O-2|
|20||D||128||40||Duquette, Ens||LCT(L) 687||Easy G||O-2|
|21||E||Army||37||LCT(L) 811||Easy R||O-1|
|22||F||131||40||Inman, Ens.||LCT(R) 366||Easy R||O-1|
|23||G||Army||37||LCT(R) 423||Easy R||O-1|
|24||H||129||40||Peterson, Ens||LCT(R) 447||Fox G||O-1|
|28||LCT(R) 473||O-2||DOG GREEN|
|29||LCT(R) 482||O-2||DOG WHITE|
|30||LCF 3||O-2||DOG RED|
|31||LCF 5||O-2||EASY GREEN|
|32||LCP 6||O-1||EASY RED|
|33||LCF 7||O-1||EASY RED|
|34||LCF 9||O-1||EASY RED|
|35||LCF 11||O-1||FOX GREEN|
|36||LCF 12||O-1||FOX GREEN|
ENCLOSURE ( 7 )
|BIGOT - NEPTUNE||15 May 1944|
APPENDIX THREE TO ANNEX "GEORGE" to
- 125.2.3 Naval Demolition group Lt. Comdr.
- Green Beach Demolition Party - Lt.(jg) E. P. Clayton
Unit #24 Lt.(jg) Clayton Unit #26 Lt.(jg) Jeter Unit #127 Ensign Padgett Unit #136 Ensign Roloff
- Red Beach Demolition Party - Lt. R. C. Smith
Unit #28 Lt. R. C. Smith Unit #29 Ensign L. H. Bohne Unit #30 Lt. (jg) Hagansen Unit #132 Carp. Noyes
- Reserve Demolition Units
Unit #134 Ensign Phillips Unit #135 Carp. Sprouse Unit #139 Ensign Itzkowitz
- Information . The Intelligence Plan, Annex "ABLE" contains latest data available on beach obstacles at the time of Its preparation. There are positive indications that the number and/or type of obstacles in UTAH beaches is being increased. Additional information on beaches obstacles can be expected as data from later reconnaissance becomes available.
- Green Beach Demolition Party - Lt.(jg) E. P. Clayton
At the present time, it is contemplated that all obstacles will be broached above water . As above water demolition is primarily an Army Function, the Naval Demolition Units are coordinated with the Army Demolition Units under the supervision of the Commander of the Army Units.
Eight Engineer Demolition Units consisting of one officer and 25 men will embark on LCT(4)s and will transfer to LCM(3)s upon arrival in Transport Area. LCT(4)s tow LCM(3)s as follows:
|Red Beach||Green Beach|
|LCT 797 tow LCM 91||LCT 518 tow LCM 95|
|LCT 691 tow LCM 92||LCT 837 tow LCM 96|
|LCT 836 tow LCM 93||LCT 1050 tow LCM 109|
|LCT 801 tow LCM 94||LCT 646 tow LCM 110|
"LCM(3)s towed by LCT(4)s will be preloaded with two tons of explosives prior to departure from near shore. In the event LCM is inoperative upon arrival in transport Area, LCT(4) furnishing tow signal flagship for replacement LCM. Demolitions personnel embarked on LCT(4) will each carry an additional explosive pack for a reserve in the event an LCM is lost.
Reserve engineer demolition personnel will be embarked on U.S.S. Dickman and are to be landed when lift becomes available. Then reserves will embark on transport with only individual explosive packs. Reserve explosives are available on LCMs towed by LCT(4)s.
- The Assault will be so timed that all beach obstacles will be above water.
- The attack on obstacles will be made after the initial assault infantry have infiltrated the obstacles and proceeded toward the seawall.
- Naval Demolition Units will assist the Army Demolition Units in the broaching of above water obstacles.
- Naval Demolition Units are embarked with their Demolitions
material for passage to the Transport Area as follows:
RED BEACH GREEN BEACH
28, 29 282 25, 26 48 30, 132, 135 230 127,136 47 134,139 281
- Upon anchoring of LSTs in transport area each demolition unit will embark personnel and material in an LCVP assigned from LST in, which they are embarked. When loaded in LCVPs, proceed to rendezvous area and proceed with designated assault wave in accordance with Attack Landing Plan, Appendix Two to Annex "George."
- Navy Combat Demolition Units clear four gaps 50 yards wide
at 250 yard intervals through the seaward band of obstacles on
each beach. Widen gaps to the left until entire band of obstacles
is cleared. Clear gaps in obstacles as follows:
- Green Beach Demolition Party .
Unit #25 clear gap a right flank of beach.
Unit #26 clear cap at 250 yards from right flank.
Unit #127 clear gap at 500 yards from right flank.
Unit #136 clear gap at 750 yards from right flank.
- Red Beach Demolition Party .
Unit #28 clear gap at right flank of beach
Unit #29 clear gap 250 yards from right flank.
Unit #30 clear gap 500 yards from right flank.
Unit #132 clear gap 750 yards from right flank.
- Reserve Demolition Units are assigned to demolition parties
Units #139 and #134 are to assigned to Green Beach Demolition Party.
Unit #135 is assigned to Red Beach Demolition Party.
"Naval Combat Demolition Units assigned as Red and Green Beach demolition parties in task organization land with wave 2 at H + 5 minutes. Reserve NCDU's land with wave 4 at H + 17 minutes on beaches designated In para 3(c(3).
- Green Beach Demolition Party .
- Each man will carry a 50 pound pack of prepared explosives ashore. After landing demolition units, LCM(3) and LCVPs return to the line 1000 yards beyond the line of departure, keeping clear of other waves, reform into wave formation as in first landing, and again proceed to beach to arrive at H + 65 minutes unless directed to do so earlier, or otherwise directed. On second beaching, demolition units unload all explosives remaining in landing craft. Landing craft remain under control of Senior Demolition Officer for use as directed. Landing craft will be released on order of Senior Demolition Officer when no longer needed.
- Tow by tank dozers or bull dozers obstacles which cannot be completely destroyed. Concentrate into piles on beach. Naval Beach Parties will buoy, as navigational hazards, piles of obstacles and scrap if within tidal area. If water approaches obstacles before arrival of beach party, demolition parties will buoy existing channels.
- Close coordination must be exercised between Naval and Engineer Demolition teams to insure alignment of gaps in the various bands of obstacles. Engineer and Naval Demolition Teams will be mutually supporting as necessary.
- Naval Demolition teams are entirely responsible for clearing any underwater obstacles which may be encountered.
- Naval Demolition Units report to Commander 2nd Beach Battalion after initial demolitions have been effected."
THIS MUST BE ACCOMPLISHED AS EXPEDITIOUSLY AS POSSIBLE
LCT 522 and LCT 524 each embark six (6) tons of reserve explosives for Green Beach Units. LCT 810 and LCT 855 each embark five (5) tons of reserve explosives for Red Beach Units.
In the event that either LCT is lost, the other will serve as a common source of supply for all units of its beach. LCT's designated to carry Navy Demolition explosives fly "ANSWERING" pennant "BAKER" flag for quick identification. LCT's carrying reserve explosives beach as scheduled in Attack Landing Plan, Appendix Two to Annex "George", unless otherwise directed. (It is quite likely that reserve explosives will be required before regular beaching time.)
Navy Demolition explosives will be unloaded and placed in beach dumps. Senior Demolitions Officer delegate an Officer to supervise unloading of explosives belonging to Naval Demolition Group and note Location of beach dump in which explosives are placed.
Demolition Units diving gear for use in emergency Units take rations and water for 24 hours ashore. Further, billeting and supply will be from Shore Party Sources.
Communications between units by SCR 536; between demolition parties on Red and Green Beaches and Flagship by SCR 609. (See Report Plan, Appendix One, Annex Able.)
Communications will be in accordance with Communication Plan Annex "Love"; use Zone BAKER time.
Please refer to file:
UNITED STATES FLEET
UNITED STATES NAVAL FORCES IN EUROPE
20 GROSVENOR SQUARE
|Serial:001782||AUG 12 1944|
End-l to CTF 122 Ltr.
A16-3, Ser. 844 dated
19 July, 1944.
|From:||Commander, U.S. Naval Forces in Europe.|
|To:||Commander-in-Chief, U.S. Fleet.|
|Subj:||Naval Combat Demolition Units, Report on.|
(1) As shown in basic letter.
(2) Revised copy of Report on Combat Demolition Units in Invasion of Normandy.
- Lt. (jg) Blackwell was ordered from the Readiness Division of this command to temporary duty under Commander, Task Force One Two Two just prior to D-day, in order to collect and correlate the data used in preparation of enclosures (1) and (2).
- Enclosure (2) is forwarded herewith to replace the text of enclosure (l) of basic letter; further review of this material has shown the necessity for correcting some technical details in the text of the original report, enclosure (1).
- Particular attention is invited to the following recommendations
for future operations in enclosure (2).
- Urgent necessity for further work in developing methods of eliminating obstacles actually under water, in assault conditions.
- Necessity for giving any large group of N.C.D. Units a formal organization, to facilitate pre-assault training and procurement.
- The value of the "Hagensen Pack" Charge (described in ComNavEu secret report SX-2330, dated 9 June, 1944) in obstacle-demolition involving hand-placement.
- The need for improved gap-marking gear, including non-sinkable buoys.
- It is further suggested that attention be given to reinforcing landing craft so as to permit them to ram obstacles (especially those with attached explosive devices) without being impaled or sunk.
- By copy of this endorsement, C.T.F. 122 is directed to classify his basic letter A16-3, Serial 844 dated 19 July, 1944, and all enclosures thereto, as TOP SECRET. This is necessitated by the fact that enclosures (6) and (7) of subject report are classified TOP SECRET.
GEO. B. WILSON
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, 8601 Adelphi Road, College Park, MD 20749