What supposed errors did the US Army commit in the Overload operations?
The US Army coordinated with the USMC in writing amphibious doctrine for both services, the USMC had the lead.
The USMC helped train US Army units in amphibious operations.
So I am not sure what the US Army failed to learn from the "enemy"..
the Devil is in the details.
One of the brutal lessons learned earlier in the Pacific was the critical importance of fire support communications through the beach assault phase and general landing operation. Preparatory fires have limited value & brief preparatory attacks like the Allies thought they had to use are only good for momentary suppression. The leading assault companies absolutely must be able to direct supporting fires on the active defense points from the instant the first landing craft grounds. Actually in the 1980s we were training to do that as the first assault wave approached, but I digress. Usually the assault force was able to get away with ordinary or doctrinal fire support communications, but it would have been better in general if it had been at the same level as in the Pacific in 1943-44. & Occasionally the leading battalions of the assault forces got bit in the ass. On Omaha Beach communications with the fire support broke down for nearly two hours. Between 06:35 when the first boats grounded & approximate 08:20-30 there was no effective direction of naval gunfire or tactical airstrikes on the beach defenses. There were six NGF spotting teams assigned to the two regiments assaulting Omaha Beach & none were in action for a critical two hours. My training in the 1980s derived directly from the experience in the 1940s vs the Japanese & that was when attacking you absolutely had multiple & redundant communications for fire support. Any radio, any network, and frequency could be hijacked during the assault for directing fire support and all radio operators/supervisors at all levels had to know how to deal with such. Once the assault regiments on O Beach salvaged their NGF radio equipment and reconstituted the spotting teams the fire support worked. Bu, thing could have gone far better had they been as prepared for the problem of their communications teams being shot down in the opening minutes.
Assaulting bunkers. The strength and density of the defense on the Normandy beaches was something not previously encountered on African or European coasts. By comparison the beaches in the Mediterranean landings were lightly defended, and a some like at Anzio completely undefended. The enemy seldom had fortifications overlooking the beaches & did not make the same sort of waters edge stand as on the Normandy beaches. Numerous bunkers with interlocking fields of fire, mines, and wire were actually a bit new, even to veteran formations like the US 1st ID. The Commonwealth and US assault forces could have benefitted from a tutoring in tactics for this from the US Army and Marine veterans in the Pacific. On 6th June some did better than others, but everyone needed a through understanding of Corkscrew attacks and related matters.
The LVT. A lot of reasons are propped up why these things won't make a difference. In the Pacific the value of a assault vehicle/inf carrier for crossing the beach was seen by mid 1943. Their value was proven by any measure on Betio Island high months before the Normandy landing. The US Army used them eagerly in the Pacific. They should have been used in the ETO, and earlier than Operation Neptune.
I could go on, but there were a lot of other detains the US First Army got wrong 6th June. Fortunately the Germans got a lot more things wrong & lost the beach battle within couple hours. I suspect that had Mark Clark & 5th Army staff been brought to command the 1st Army some of the higher level problems would have not appeared. It would not have been a panacea, but Bradley & his staff lacked depth of experience in this sort of operation.
As a whole, US Army amphibious landings in the ETO were much larger in scale than USMC ops and were successful.
Yes they were successful, and by the standards of early 1943 they were pretty good at it. They could have done a lot better. Never mind the Marines, the US Army in the Pacific in 1944 was way better at amphibious ops than their counterparts in the MTO/ETO.
The problem with launching the DD tanks early at Omaha was definitely not a doctrine problem.
The sea state was much higher than the units were designed to handle, they should have been launched either much closer to shore or landed directly on the beaches which the British did on many of their beaches.
Never heard of any problems with DD tanks at Utah beach, almost all reached the beach safely.
IIRC thirty-six tanks did make it ashore on O Beach that morning. By noon eight or less were still operating. Between drowning when leaving the landing craft, mines, hanging up & detracting on the seawall, and the dozen AT guns covering the beach the tanks did not fare well. All of both battalions getting ashore that morning would have been helpful, but not a panacea.
The US Army coordinated with the USMC in writing amphibious doctrine for both services, the USMC had the lead.
The USMC helped train US Army units in amphibious operations.
The Joint Board of the 1920s was more concerned with strategic and operational matters. Walther Kruger, who also attended the Naval War College, was a member of the board in that era. This was a Army/Navy entity & Marines were a subset & concerned mostly with their lesser slice of the study. In terms of actual training the Army contributed observers & a few battalions in the 1920s. From 1932 through most of 1939 the Army does not seem to have participated in any amphibious training. this is a bit odd since the Army was supposed to contribute the bulk of forces for Pacific operations under WAR PLAN ORANGE. The Marines as they existed in that era were only capable of forming 3-4 brigades. When restarted in 1939 Joint training was conducted by the Navy. The Marines did not command the Amphibious Fleet/s did not operate the ships, did not run the support services of the amphibious forces. Their writ was in a important but narrow part of the whole of amphibious operations.
As a final random note; I'd point out the most successful amphib op in the MTO/ETO was Op DRAGOON & the landing force was commanded by a PTO veteran corps commander.
