Thursday, July 16, 2015

D-Day Conclusions and Lessons

This is a wrap up of the previous posts based on the book, D-Day June 6, 1944: The Climatic Batle of World War II, by Stephen Ambrose. 

Here are some overall conclusions and lessons from the D-Day assault.  Note that these are my own interpretations of the book’s lessons.  The author did not present an itemized list, as such.  Also, these are not meant to be all-encompassing.  These are just some of the lessons emphasized by the readings in the book.


·        Almost nothing went right.
·        Naval gunfire from destroyers was instrumental in aiding initial infantry progress.
·        Numbers were our biggest advantage and, ultimately, ensured success.
·        The Germans failed to pick the right defensive strategy.
·        The Germans failed to pick a single defensive strategy and wound up distributing their assets among multiple commanders with multiple strategies for defense, thus diluting their capabilities.
·        Mines were devastating.
·        Airborne assault troops were effective only by staying within physical proximity of the main assault force, thereby able to link up within 24 hours, and accomplished their missions, to the degree they did, through sheer, overwhelming numbers.
·        The US lack of specialized engineering vehicles proved costly.
·        The lack of tanks in the initial assault waves proved costly.

Unsurprisingly, the conclusions and lessons mirror each other.


·        Mines are a devastatingly effective weapon against an amphibious assault.  We need to vastly increase our MCM capability and our offensive mine warfare (mine laying) capability.
·        Naval gunfire is mandatory.  Naval guns will be the only source of high explosive available during initial phases of an assault.  The Navy’s doctrine of standing off 25-50 miles, out of range of the few 5” guns we have, is unsatisfactory and will leave the Marines without support.
·        Numbers matter and are the most important factor in the success of an assault. 
·        Everything will go wrong.  Our arrogance regarding our faith in complex networks of data, communications, shared sensors, GPS, etc. is breathtaking.  None of those will work and we need to train for loss of the electromagnetic spectrum and we need to develop many more old-fashioned weapons that work without external input and communications.
·        Inland airborne assault forces are unsustainable beyond 24 hours and will become combat ineffective after that period if not relieved.
·        We will need orders of magnitude more supplies and equipment than are currently allocated for an assault

The overwhelming conclusion from an examination of D-Day is that the US military is totally incapable of conducting an assault anywhere near this scale today.  That’s not necessarily surprising or even disappointing – it took the Allies a couple of years to build up the strength to conduct the assault.  What is disappointing is that we have lost the ability to conduct even a small scale assault against a peer defender. 

Consider just the mine aspect of an assault.  The Allies used hundreds of minesweepers for one operation.  The Navy has 11 minesweepers and some helos available today.  A relative handful of mines can absolutely paralyze and negate our assault options.

Reading the book conveys a stunning appreciation for the tonnage of supplies and equipment that were thrown at the assault.  Tons were destroyed before they could get a hundred feet beyond the shore and yet untold tons more kept coming.  Today, we have an utterly unrealistic view about the amount of weapons and supplies needed to conduct high end combat.  We have neither the tonnage of supplies nor the means to transport them to support and sustain even a minor assault involving high end combat.

D-Day saw the use of over 5,000 vessels including over 1,000 warships.  Today, the entire Navy consists of only 280 ships.  The Navy has nowhere near the numbers or types (LCT, LST, LSM, LCVP, MCM, etc.) of ships to support an assault.

While the technology has changed, the lessons involving amphibious assault have not.  We’ve lost the institutional memory of those lessons but that does not mean that the lessons do not still apply.  They do and we will relearn those lessons when the time comes and will pay in blood to do so.

(4)Second Line of Defense, “Closing the US Navy’s Mine Warfare Gap”, Scott Truver, 20-Jun-2015


  1. Another thing missing is direct fire support from the landing craft and vehicles. If you look at WW2 landing the number and size of direct support weapons used by the landing force was going up. They started with machine guns, then went to some with 37mm tank turrets, then with 75mm howitzers, then 75mm guns and at the end of the war were researching 76mm guns. Also even after the war the firepower went up until the LVTP-5 had a 105mm howitzer

    Today all they have is machine guns and a few auto grenade launchers.

    And while its true that they will try to avoid any heavily defended beach, they won’t be lucky all the time and it would be nice if the landing force had something more then machine guns and 40mm grenades to fire back if they run into a opposing force on the beach. Even a enemy infantry battalion could tear up a landing force on the beach with mortars, anti-tank rockets/missiles and machine guns

    1. "Another thing missing is direct fire support from the landing craft and vehicles."

      DJF, that's a point worthy of further discussion and it covers more than just that. Your more generic point is (I'll take the liberty of putting words in your mouth) the issue of initial assault wave explosive support. How do we support the infantry as they first step onto the beach? Is it with landing craft mounted weapons? Is it with tanks? If so, how do we land tanks in the initial wave? Is it with naval gunfire? If so, how do we provide that given that the Navy's doctrine is to stand 25-50 miles out, well beyond range of 5" guns. Is it with aircraft? If so, where will the aircraft come from given that the fleet's aircraft will be prioritized with establishing local air superiority and defending the carriers? And so on. I've got some posts in the pipeline addressing some of this issue.

      Good comment.

    2. The interesting thing is that the PLA seems to be doing a better job learning from the lessons of World War II and preparing for modern amphibious operations. They are developing modern LPD and LHD type amphibs, but continue to build and use LST’s, LCT’s, and LSM’s in large numbers. They recognize the need to be able to land heavy armor and large numbers of vehicles, infantry, engineers and supporting units over the beachhead from the first wave onwards.

      The Chinese are also equipping their marine brigades and army amphibious divisions (the PLA Ground Force has no fewer than four mechanized infantry divisions specifically trained and equipped for amphibious assaults) with modern amphibious assault vehicles and the like. While the USMC’s EFV program was canceled due to cost overruns, the PLA has had an equivalent design in service for several years

      As DJF and others have pointed out, one of the lessons from World War II is the need for heavy direct fire support that can go ashore with the first wave, including tanks landed from LCT’s and LST’s and amphibious tanks that can swim ashore with the amphibious assault vehicles.

      The Chinese developed a light tank version of their EFV clone precisely because they realized the need to provide heavy direct fire support for their infantry and combat engineers that can go ashore with the first wave. The PLA has long built both MBT’s and light tanks, and they have even developed an upgraded version of their Type 63 light tank (Chinese derivative of the old Soviet PT-76) with a 105 mm tank cannon. The ZTD-05 has the same 105mm turret as the upgraded Type 63 and can travel at speeds of up to 25 knots on water and 40 knots on land. The troop carrier version (the ZBD-05) has a 30mm autocannon and anti-tank missiles and is certainly no slouch in the fire support department. The PLA also has an amphibious self-propelled howitzer based on the good old Soviet 2S1, so they also have artillery that can come ashore quickly to provide heavy direct and indirect fire support. If the Chinese can do it, why can’t we? Has our military industrial complex really become that incompetent?

  2. Hi CNO,
    Nice serious of posts. I have a few overarching comments.
    1. Ambrose’s book addresses the American portion of the Normandy invasion: it is easy to forget that we were part of a much larger Allied effort with the UK, Canada and other providing the majority of troops, ships and aircraft; and they were responsible for three of the five landing beaches and arguably they key initial objectives (e.g. the Orne river bridges).
    2. On the whole, the British and rest of our allies got it right. Utah beach was also “done right” (even though they landed in the wrong spot). Surprise at all levels was achieved, the troops got ashore, key bridges were seized and defended, and the German counter-attacks (limited though they were) were defeated, aerial interdiction of the invasion beaches effectively isolated the German defenders. Finally, the all important logistics efforts were initiated.
    3. Naval gunfire support was significantly more effective in the British sector including the preparatory bombardment. There is little to suggest that the British insistence on neutralization fires was incorrect. This doctrinal employment of naval gunfire was effective in all major landings in the ETO: Dieppe and Omaha were the exceptions. Much credit for the success of these fires can be laid in effective reconnaissance of targets. Plainly stated, the UK did better recce and was better able to prioritize and hit assigned targets, including the preparatory fires.

    I highly recommend “Gators of Neptune: Naval Amphibious Planning for the Normandy Invasion” by Christopher Yung as an excellent source.


  3. I wonder what a series of large (MOAB) fuel air bombs would do to defenders both in the open and in bunkers, Over pressure instead of a long term high caliber bombardment might be where new technology could be a better solution.

    Try before you buy though!

    1. Like any conflagration bomb of its size, the MOAB would wreck the defenders in the open.
      However, it wouldn't do much to the bunkers.

      The overpressure wouldn't make it inside the bunker, otherwise the entire crew of the Yamato would have been turned into paste every time the ship fired a full broadside. (Concrete does a better job at reflecting overpressure than steel, IIRC)

      You'd need to get into Mega-FOAB territories to get through the bunker, so you'd be better off just throwing bunker busters at it (cheaper, more accurate).

      - Ray D.

  4. Doesn't the USMC expect to insert its airborne forces by helicopter, rather than parachute? That seems to offer a significant advantage: a 'copter's worth of troops and their stuff arrives as a coherent unit, rather than being scattered. That has considerable potential to improve effectiveness.

    Expecting unsupported troops in enemy territory to continue being effective after about 24 hours is probably too much, though. The lack of rest will wear men down.

    1. John, yes, the Marines would insert via helos and MV-22s (Army still has paratroops), however, you may have missed the overall point which is the utter confusion and disorganization that results from combat, in general, and aviation assaults, in particular. While it is true and fair to say that the element within the individual helo/22 would land intact (if they land alive), the helos and MV-22s would not land in a neat parade at the precise landing spot. Instead, in an opposed assault, half will be shot down on the way in, the chosen landing spot will be obscured by weather and smoke, some aircraft will consider the LZ to be too hot and opt to land elsewhere, some aircraft will become disoriented and lost and not land or land elsewhere, vital equipment will be destroyed before it lands, leadership ranks will be killed on the way in, and so on.

      What does history offer on this point? While the paratroops at D-Day stole the headlines, there was also a massive, follow on glider landing. The gliders are kind of the functional equivalent of today's helos in that they were landing an intact element (if they landed alive) from the air to a designated spot. The reality is that the glider landings were a disaster. The gliders were scattered far and wide and destroyed in large numbers. Again, only massive numbers allowed them to succeed to the extent that they did.

      Consider the experience of helo assaults in Viet Nam. In only lightly opposed landings (meaning the helo transit was not contested), the LZs often became slaughter zones. Many, many helos were lost on insertion. Alternate often had to be spontaneously assigned. And this would be the best case scenario of a nearly unopposed assault (other than at the point of the LZ and then only with small arms).

      We play our wargames and run our simulations but the utter confusion of actual combat is ignored. The lessons are ignored.

      If we want a realistic training scenario, we should have the Marines land randomly within a 20 mile radius of the actual LZ and with half the helos and MV-22s randomly removed from the landing as kills and have half the Marines immediately pinned down by roving enemy units and then start the land warfare portion of the exercise and see how it goes.

  5. your reference to airborne drop's limited effectiveness. in dday , are fully realized in arnhem , where british 1st para got slaughtered by german forces..

    read the Bridge to Far book , it is documenting the hilarious mistake upon mistakes and hubris/arrogance in the planning stage , that resulted in the destruction of british para..

  6. Consider that:

    -The only reason D Day was possible was because of prepositioning forces ahead of time, in very close proximatey to the landing zones, it would therefore not have been possible to have conducted the operation, if all the materials were required to be moved by sea, in one go, like the USMC operate.

    -That without the nearby location to preposition resources, the USN would not have had the aerial support they had on D Day, and even if they managed to perform a much smaller landing (at a much greater cost due to the extra ships needed than D Day cost IRL), they likely would have been in major problems because of German Air Power which would have been largely unchallanged.

    -That in other examples During WW2, Naval forces often opted to pick landings away from fortified areas, and then drive/walk to and encircle, then assault the targets. As opposed to attacking them from the direction they were best fortified. In this case, the USMC today for instance, would likely seek to bypass enemy hard-points, and conduct landings away from such targets, and then seek to move to their objectives and/or approach those hardpoints from a less defended perspective, after they have fully landed.

    -That much of the ships involved, were very cheap, very basic ships, quickly constructed, built to a low-spec, and designed with a requirement to last a few years at most. The very opposite of many of the current USN ships associated with the role of such landings. Noting that this was the only way to field enough ships, to support such a landing, even with the ability to preposition forces very close to the landing zones.

    1. Anon, your first, second, and fourth points are good. In particular, the role of low end, purpose built ships is one that begs consideration today.

      Your point about landing in some other location and fighting/moving to the real objective is highly suspect. I've covered this previously. Consider our logistics issues alone. Do you believe we have enough transport craft to get the required supplies ashore? Do you believe we have enough helos/trucks/whatever to move the supplies from the landing spot to a front line combat unit that is moving ever further away from the landing spot? Given the hundreds of mile range of modern artillery, rockets, and missiles, how do you envision defending the continual flow of sustainment fuel, munitions, etc that would have to cross the landing site once the main combat unit has moved along towards their ultimate objective? How many helos/trucks does a MEU/MEB have to draw on?

      Once a Marine unit begins its cross country trek to the real desired objective, it becomes a slow moving, semi-fixed target. Given the Marine's lack of armor, artillery, and other heavy combat equipment, how do you envision the combat going when they encounter increasing armored resistance as they approach their ultimate objective given that the element of surprise would have long since vanished?

      I can go on but you get the idea that simply hand waving and saying that we'll land where there is no resistance runs the risk of ignoring the realities of both combat and logistical support. I'm not saying that we can't land where there is less resistance but I am saying that it won't be as simple an exercise as many would like to believe.

      The Marines simply don't have the combat power or logistical support to engage in an extended overland campaign just to reach their real objective.

      Do you know how many days worth of combat supplies an embarked MEU carries? Check it out. You'll be surprised.

    2. Regarding the third point, I am a little rusty so can't point out any good specific examples, they did sort of do this in the battle of Singapore, where they positioned their soldiers in nearbye malaysia, where they can land much more soldiers, much quicker than in a naval assault. In the theatre Japanese islands were often completely bypassed, and instead cutoff.

      I don't think we will see the USMC assaulting through a very defensible, and well defended and mined landing zone. I think it makes more sense for instance to find locations several kilometers away and on either side of the port city for example, so that you can land a great deal more of your forces before they meet opposition, and then assault towards the port city and attempt to encircle it.

      I just dont see how a few MEBs are going to fight against a well entrenched Heavy IFV based Brigade with artillery support and maybe a few light infantry Brigades, when they are landing a few at a time, on a beach protected by that IFV Brigade. If they can't fight the enemy when they are somewhat deployed, I don't see how the first wave, and it's landing crafts, your only landing crafts, are going to survive. Therefore they are going to need to either gain air supperiority and clear the beaches first, or go in and land away from the objective, and fight towardss it.

  7. I think that there are other matters to discuss:

    - Germany had been blockaded too, leading to fuel shortages and other problems. The bombings may have also affected production, although the extent is debated even today.

    - Loss of the best pilots from attrition with Allied air forces over Germany.

    - The fact that the bulk of the German might was on the Eastern front, where they were very hard pressed. Had they been able to direct their full might to the West, it would have been much harder.

    1. Alt, all valid points. As I mentioned in the posts, this was just a collection of some of the points made obvious in the book rather than an attempt at a comprehensive military analysis of the operation. The book itself was not a comprehensive analysis either. Instead, it was more of an oral history collection although the lessons were clearly there to be had.

      People can, and have, written volumes on D-Day!

      Are there particular lessons that would apply to, and impact, today's amphibious operations that you think deserve more examination?

    2. Yes, I think if germany was not at war with the soviet union, even though germany was vastly outclassed economically and in terms of manpower, and availability of resources, I think that the US and the British Empire would not have been in able to conduct the landing.

      In the same way, I believe the USN will have a hard time conducting a landing on any well armed 2nd world country.

    3. The other big one I should note is that the Germans were losing the Battle of the Atlantic. Had the German submarines fared better, it's likely that the UK would have been far more hard pressed.

      Although years of sanctions I suppose can perhaps get a similar effect, sanctions may not work against a more powerful enemy.

  8. when the last time US ground soldier ever face enemy that can lob massive altilery bombardment ? the last time i remember was the DMZ battles in vietnam where north vietnamese slaughter US marines , disregarding the cost of their own soldiers..

    now you have a ground force that never got bombarded with anything bigger than few mortar shell and RPG.. what do you think their morale will be if US ground force got bombarded routinely by Grads or bigger rockets ? calling your air support / CAS and watching them got shot down by MANPADS / SAMS will be just another morale breaker..

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    1. Absolutely! Now, do you think we can achieve it? Shrinking air wings. Vast distances from AF bases. Modern enemy aircraft. Modern enemy air defenses.

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  10. What few understand that it will take many months (if not a year) to position tons of supplies for months of combat in the region, known as staging. We are not going to load up in San Diego with 30 days of supplies and head for shore in Asia. This is why keeping amphibs at Sasebo is nuts. Yes, the MPF ships add another 30 days, but then what? We'll run out of parts and ammo at D+60 and surrender?

  11. One other issue - in order to make an amphibious landing, you must have overwhelming naval superiority.

    It simply is not going to happen if the enemy can use submarines at your landing craft, has a viable surface fleet still, etc. They could counterattack or disrupt supply lines.

    I think that looking forward, an amphibious landing is going to be harder to do.


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