Naval Gun Support During Amphibious Landings.

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Sheldrake
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Re: Naval Gun Support During Amphibious Landings.

#61

Post by Sheldrake » 17 Mar 2015, 22:25

ChristopherPerrien wrote:
Graeme Sydney wrote: A lot of interesting comments some of which I knew and some of which I surmised. But I don't think I've had a definitive answer as "how effective was US Naval Gun bombardment".

My second question was "Did the US Navy make variation with trajectory and ammunition for Naval Gun bombardment" and I think the answer is basically 'no'. I'm fairly certain it is a 'no' for BB's but the others I'm not so certain.

I asked the question specifically about the Pacific but I'm also thinking of how it would apply to D day and even the Dardanelles in 1915.
If NGS suppresses the enemy and prevents fire on the landing forces, it is successful.
US NGS in WWII was very successful in most battles. Adjustments were made after Tarawa.
The 21 Army Group Operations Research Group study no 292 was a study of the effectivness of fire support on the two Us Beacvhes on D Day with the British Beaches, the subject of study 261.

The conclusions were that each German machine gun on Omaha beach inflicted about 16-17 casualties, about 1.5 times more than on the British beaches. This in itself meant that the machine guns were less than half as effective as should have been inflicted.

On Utah the casualties were only a quarter per Mg of those on the British beaches, which is attributed to a weight of fire three times greater than on the British beaches. Here the fire plan all worked.

The short answer is that the NGS worked. The assault was successful.

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Re: Naval Gun Support During Amphibious Landings.

#62

Post by RichTO90 » 18 Mar 2015, 00:16

Sheldrake wrote:The 21 Army Group Operations Research Group study no 292 was a study of the effectivness of fire support on the two Us Beacvhes on D Day with the British Beaches, the subject of study 261.
Indeed, but if you have done a careful reading of the two you will realize the limitations of the comparison, which the original writers certainly understood. The parameters for what was considered casualties in report No. 261 were carefully determined (in Report No. 264 actually, which is usually ignored) and assessed as only those incurred in the actual beach assault, i.e., the assault waves. However, such a careful delineation was not possible for the researchers WRT to OMAHA and UTAH, so the figures are not in fact direct comparisons.

Furthermore, slopping readings of the two reports have led to the ludicrously under-reported British and Canadian casualty figures that have now been repeated ad-nauseum by lazy historians for the last 70 years...and they took the report for the 4th ID casualties at UTAH as the total figure - also incorrect - which has also been repeated over and over again.
The conclusions were that each German machine gun on Omaha beach inflicted about 16-17 casualties, about 1.5 times more than on the British beaches. This in itself meant that the machine guns were less than half as effective as should have been inflicted.
Sorry, but that is a typical mixing up of correlation and causality. Other factors related to that causality are the terrain and siting of the German positions, the more effective sighting of the beach defense guns, more effective use of mortars and field artillery, and so on.
On Utah the casualties were only a quarter per Mg of those on the British beaches, which is attributed to a weight of fire three times greater than on the British beaches. Here the fire plan all worked.
Unfortunately that is an assumption based on poor data. The actual casualties were about three times that usually quoted due to a misapprehension of exactly what the figures reported. There is actually little evidence that the naval gunfire support worked significantly better or worse than anywhere else. Anecdotally, the medium bomber strike was much more effective and timely than at any other beach, but that is about it.
The short answer is that the NGS worked. The assault was successful.
Of course the gunfire "worked"...ammunition was expended after all. However, there is little evidence that it had much effect on the defenses it faced until the various close support craft, LCG and DD, closed to engage targets of opportunity...and the LCG fared pretty badly in the exchange. Certainly the LCT (R) were ineffective (except in sinking British DD at SWORD, IIRC), there is little evidence that the LCT (A) were worth the effort, and only one of the LCT (CB) that I can recall (I think on SWORD as well) did what it was supposed to. As far as the LCT (SP) go given the reality of howitzers firing from landing craft heaving up and down three to four feet for every three to four feet they advanced, I think that attributing suppression effects to them is charitable (you can argue that the British/Canadian beach suppression per brigade/regiment front was more effective than at OMAHA because there were 24 instead of 18 M7 105mm GMC firing, but I would beg to doubt it).

Cheers!


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Re: Naval Gun Support During Amphibious Landings.

#63

Post by Mil-tech Bard » 18 Mar 2015, 19:33

Rich,

I'd think it would be fair to say the fire support LCT (R), LCG, and LCT (CB) would have been better used as plain LCT landing more tanks....especially on Omaha and Utah beaches.

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Re: Naval Gun Support During Amphibious Landings.

#64

Post by RichTO90 » 18 Mar 2015, 19:39

Mil-tech Bard wrote:Rich,

I'd think it would be fair to say the fire support LCT (R), LCT (A), and LCT (CB) would have been better used as plain LCT landing more tanks....especially on Omaha and Utah beaches.
Yep. A lot of it was based upon the assumption that landing tanks from LCT in the initial assault waves would be problematic and the fixation with the "beach drenching" suppressive fire, which is what led to the development of the DD tank and then all the ancillary supporting LCT. Except that it didn't work out that way. There is simply little or no evidence to show that the beach drenching had any effect whatsoever and the DD tank proved an unneccessary innovation.

OTOH, the problem with putting more tanks onto OMAHA is that there was limited ground on which they could maneuver and landing more effectively in the 116th sector than in the 16th sector didn't seem to make a lick of difference. :(

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Re: Naval Gun Support During Amphibious Landings.

#65

Post by Mil-tech Bard » 18 Mar 2015, 19:45

RichTO90 wrote:
Carl Schwamberger wrote:No. I was refering to the AAR in the web site linked. those concerned Pacific events 1944-45.
Sorry Carl, I guess I remain confused then? Sixth Army did not engage much in extensive naval gunfire support operations in New Guinea before the NEPTUNE operations and neither did Eighth Army, which wasn't activated until 10 June 1944. So where is the experience that should have been a lesson learned?
We discussed this specific subject once before, but if you have any further information I am eager to see it. Thanks
Sorry, I will get to it as soon as I can, but I'm off again, this time to Savannah, for a family emergency.

The Sixth Army made extensive use of heavy and medium bombers in the beach preparation role in New Guinea because they lacked a BB battle line until Leyte.

Neptune attempted the same thing with marked lack of success. Primarily because the 8th Air Force insisted on using H2X radar sited bomb runs rather than the available Gee-H. Gee-H's "Cat and Mouse" flight path would have required a much longer bomb run over German Heavy Flak sites than H2X that was used, which came in perpendicular to the beach for better radar target contrast.

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Re: Naval Gun Support During Amphibious Landings.

#66

Post by Carl Schwamberger » 19 Mar 2015, 00:26

binder001 wrote:The issue of the destroyers in supporting Neptune has several interesting stories. In Amrose's book he mentions that the destroyers' fire control optics were excellent, but many reports comment on poor visibility on D-Day, any comments?
I used to take photos of the gunnery ranges where I trained as a FO & have a few of those remaining. Comparing those to photos of Omaha Beach suggests the haze, smoke, camoflage, & general concealment prevented much identification of anything from anything over 800 meters, or less. There were probably exceptions, but... If I were depending on my failing memory of my experience at that sort of thing I'd say target identification on O Beach from 1500 meters or beyond 'Sucked', whatever optics you had.

Identification of major landmarks would be better, and attacking known points from those looks practical. But spotting a AT gun embrasure among the rubble and brush, through the haze/smoke looks beyond difficult.
There are also reports about the surviving armor on Omaha engaging enemy positions and some of the destroyers would observe the tanks and look at what they firing at. This target designation was unplanned by reportedly effective. Any comments?
Seen that one any times. Either it is many versions of one incident. Or, maybe it happened a few different times. I have found similar descriptions of tanks or MG or mortars using smoke rounds or tracers to indicate targets to artillery FO in multiple wars. It was a technique in the books in my era, tho I dont recall actually practicing it. It is not beyond belief someone sucessfully used the technique. Since this event is to have occured when the destroyers came in close to the beach I'd guess there were not many tanks remaining in action & it is more likely all the stories are based on the same tank/destroyer.

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Re: Naval Gun Support During Amphibious Landings.

#67

Post by Carl Schwamberger » 19 Mar 2015, 00:38

RichTO90 wrote:[.... As far as the LCT (SP) go given the reality of howitzers firing from landing craft heaving up and down three to four feet for every three to four feet they advanced, I think that attributing suppression effects to them is charitable (you can argue that the British/Canadian beach suppression per brigade/regiment front was more effective than at OMAHA because there were 24 instead of 18 M7 105mm GMC firing, but I would beg to doubt it).

Cheers!
Leaving aside the motion of the boats, the quantity of ammunition aboard them was no where near "drenching" quantities. If all the ammo aboard each boat had been expended on a single MG or AT gun embrasure it would not have come close to the book quantity for simple suppresion. That assumes the desired target were clearly seen no camoflage, concealment in enfilade, haze, smoke, water spray on your gun sights... or vomit.


The Sixth Army made extensive use of heavy and medium bombers in the beach preparation role in New Guinea because they lacked a BB battle line until Leyte. ...
BB are nice to have, but most NGF fire support is from the 12 to 20 cm guns of the destroyers and cruisers. There are trade offs between the different calibers and often the smaller are preferable. those in the 15 to 20 cm range being the most desirable if you have to choose.
I recomend that you download General Weller's report "NAVAL GUNFIRE SUPPORT OF AMPHIBIOUS OPERATIONS:
PAST, PRESENT, AND FUTURE" available at http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA051873. General Weller was the Naval Gunfire Officer, Fleet Marine Force, Pacific in WWII. The report covers NGFS in both the Pacific and ETO in WWII and Korea. It includes CEP and rounds per hit tables for all American naval gun systems used for NGFS.
Skimmed & then read again the Weller document. It refreshed my memory on the NGF discussion underway in the USN/MC back in the 1980s. Really useful for context on the last three decades of the 20th Century. I'd have to look it over further to judge it as a WWII analysis. There seemed to be more than a few errors, or clear disagreements with other documents/books.

RichTO90 wrote:
RichTO90 wrote:
We discussed this specific subject once before, but if you have any further information I am eager to see it. Thanks
Sorry, I will get to it as soon as I can, but I'm off again, this time to Savannah, for a family emergency.
Hey Carl,

I've been through the various combat interviews compiled by Forrest Poague about two weeks after D-Day and there were none that I can find with personnel of the gunfire support parties. Neither reports of the 116th and 16th Infantry directly mention the NSCFP either.

The Action Report for TF 124 is also ambiguous WRT the problems encountered. They give a recommendation for the future, but dwell little on the specifics of the lessons learned. Each infantry battalion and each of the RCT FA battalions had assigned a NSFCP consisting of a FO Section (one officers and seven EM) and a Liaison Section (one officer and five EM). It turns out only one FO Section was attached to the airborne forces rather than an entire NSFCP. Each FO and Liaison Section was to have an SCR 609 FM voice set for primary comms, backed up by SCR 284 sets.

Part of the problem was that they had to provide for a joint (USN, RN, FFN, etc) capability, so modified the standard TTP as expressed in CSP 2156(A) (the USN SOP) in an attempt to compensate. However, critically, the USN support ships were unable to participate in the full-dress OMAHA rehersal exercise at Slapton Sands.

The NSFCP of the assault battalions landed at H+30 and none of them were initially able to establish communications, except for the party with Rudder's Ranger group on Pointe du Hoc. It is difficult to determine how many of the eight teams landed with the 116th and 16th Infantry ever established communications, but at least one (unidentified which unit it was attached to) remained in its LCV(P) and was able to direct fire from just off shore. Reading between the lines of the various accounts, it looks like it wasn't until later in the afternoon before any of the others gained contact. All firing was otherwise from aerial spotting or direct observation of targets of opportunity.
Rich... thanks for locating that info. Very useful for the details. Context is everything.

The one item that jumps out, & I have to ask if it is certain is this:
The NSFCP of the assault battalions landed at H+30 ...
Made a bad situation worse. While the survival of the spotting teams landing in the first minutes would have been problematic, landing them 30 minutes after the first elements was not the best course. It leaves the leading edge of the attack without directed heavy fire support for a bit too long. Add in time to cross the beach, orient, make contact with the associated infantry leaders & under the very best circumstances the start of directed fire support is delayed to H+ 35 to 40 minutes. Realistically longer.

As it was some sort of contact seems to have come around 08:20, more or less. I'll have to drag out another book and run those items past you.

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Re: Naval Gun Support During Amphibious Landings.

#68

Post by RichTO90 » 19 Mar 2015, 03:43

Carl Schwamberger wrote:Leaving aside the motion of the boats, the quantity of ammunition aboard them was no where near "drenching" quantities. If all the ammo aboard each boat had been expended on a single MG or AT gun embrasure it would not have come close to the book quantity for simple suppresion. That assumes the desired target were clearly seen no camoflage, concealment in enfilade, haze, smoke, water spray on your gun sights... or vomit.
Yep. The plan actually remarked on the big problem...where does the ammo go? They noted that it would be necessary to preserve the basic load on the assault vehicles by stacking ammo in the LCT...but acknowledged that had its own problems, not least of which was getting the Navy to agree. In the end the plan allowed for a 1/2 U/F to be expended on D-Day for the 105mm SP...all day.
Rich... thanks for locating that info. Very useful for the details. Context is everything.

The one item that jumps out, & I have to ask if it is certain is this:
The NSFCP of the assault battalions landed at H+30 ...
Made a bad situation worse. While the survival of the spotting teams landing in the first minutes would have been problematic, landing them 30 minutes after the first elements was not the best course. It leaves the leading edge of the attack without directed heavy fire support for a bit too long. Add in time to cross the beach, orient, make contact with the associated infantry leaders & under the very best circumstances the start of directed fire support is delayed to H+ 35 to 40 minutes. Realistically longer.

As it was some sort of contact seems to have come around 08:20, more or less. I'll have to drag out another book and run those items past you.
Yes that is correct. But as you say, context is everything. The reason for that was the "attack" actually was at H+30. Up to that point the only thing supposed to be landed were the DD tanks and the leading infantry companies who were only supposed to cover the operations of the obstacle clearance teams. It is important to remember that the big dilemma for the planners was the seaward obstacle belt. It was believed that until they were cleared massed landings would be impossible. So practically speaking the assault proper was to begin at H+30 when the bulk of the infantry battalions landed with the deep-wading tanks and SPs to execute the attack on the strongpoints at the beach exits. Then the reserve battalions were to land with the regimental elements to exploit forward onto the bluffs.

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Re: Naval Gun Support During Amphibious Landings.

#69

Post by Mil-tech Bard » 19 Mar 2015, 16:54

Carl Schwamberger wrote:
BB are nice to have, but most NGF fire support is from the 12 to 20 cm guns of the destroyers and cruisers. There are trade offs between the different calibers and often the smaller are preferable. those in the 15 to 20 cm range being the most desirable if you have to choose.
Not when you are dealing with heavy shore guns in concrete embrasures.

The AAR of the Iwo Jima bombardment made that clear.

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Re: Naval Gun Support During Amphibious Landings.

#70

Post by Carl Schwamberger » 24 Mar 2015, 05:28

RichTO90 wrote:
Rich... thanks for locating that info. Very useful for the details. Context is everything.

The one item that jumps out, & I have to ask if it is certain is this:
The NSFCP of the assault battalions landed at H+30 ...
Made a bad situation worse. While the survival of the spotting teams landing in the first minutes would have been problematic, landing them 30 minutes after the first elements was not the best course. It leaves the leading edge of the attack without directed heavy fire support for a bit too long. Add in time to cross the beach, orient, make contact with the associated infantry leaders & under the very best circumstances the start of directed fire support is delayed to H+ 35 to 40 minutes. Realistically longer.

As it was some sort of contact seems to have come around 08:20, more or less. I'll have to drag out another book and run those items past you.
Yes that is correct. But as you say, context is everything. The reason for that was the "attack" actually was at H+30. Up to that point the only thing supposed to be landed were the DD tanks and the leading infantry companies who were only supposed to cover the operations of the obstacle clearance teams. It is important to remember that the big dilemma for the planners was the seaward obstacle belt. It was believed that until they were cleared massed landings would be impossible. So practically speaking the assault proper was to begin at H+30 when the bulk of the infantry battalions landed with the deep-wading tanks and SPs to execute the attack on the strongpoints at the beach exits. Then the reserve battalions were to land with the regimental elements to exploit forward onto the bluffs.
The more I understand this plan the less I like it. Setting aside the context of a beach crossing for the moment, consider this stripped down to a obstacle clearing phase: Clearing teams & a covering force is sent in, without a link to any heavy, or even medium fire support. This is not a matter of experience at amphibious assaults. Its basic fire support 101, a class that had been around since at least 1917-18.

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Re: Naval Gun Support During Amphibious Landings.

#71

Post by RichTO90 » 24 Mar 2015, 13:35

Carl Schwamberger wrote: The more I understand this plan the less I like it. Setting aside the context of a beach crossing for the moment, consider this stripped down to a obstacle clearing phase: Clearing teams & a covering force is sent in, without a link to any heavy, or even medium fire support. This is not a matter of experience at amphibious assaults. Its basic fire support 101, a class that had been around since at least 1917-18.
Oh, I agree completely Carl, the fundamental problem with the basic NEPTUNE assault plan, which was implemented on all the beaches, was the ad hoc and poorly conceived obstacle clearance plan. It drove everything and yet was just an afterthought added to the existing plan at the last moment. I can find no evidence that any consideration was ever given to landing the NSFCP assigned to the assault battalions with the first rifle company landed to cover the clearance teams. Instead, the planners allowed themselves to be seduced by the idea that the preliminary bombardment by the heavy bombers and naval heavies would silence any coast defense artillery, while the beach drenching program (LCG, LCT (R), LCT (A), LCT (SP), and LCT (CB)) would adequately suppress the actual beach defenses (the anti-boat artillery, machine guns, and mortars).

But the beach drenching didn't work nearly as well as was supposed, on any of the beaches. Only on UTAH, where the low-level medium bombing run was fortuitously effective, were the beach defenses really suppressed (and it helped that the defenses weren't as dense). To varying degrees all four of the others were not suppressed well for one reason or another. The LCT (R) and 105mm howitzers on the LCT (SP) had zero effect as did the 75mm and 95mm-armed tanks firing from the LCT (A). The LCT (CB) were not used on the American beaches, but on the five brigade sectors on the British/Canadian beaches I could find evidence that only one of the ten-odd deployed had any effect either. The LCG tried, but where they were most needed on OMAHA they got hammered themselves. The Commonwealth forces were fortunate that on GOLD one of the 88mm guns was abandoned by its crew very early, which may have been a suppression result, but otherwise they were even more fortunate that the fields of fire, terrain, and defenses on SWORD, JUNO, and GOLD didn't combine as well as on OMAHA.

OTOH, I am not at all sure that landing the NSFCP with the forlorn hope at H Hour would have had any effect either. Their communications gear - and themselves - were simply too vulnerable and isolated a target if they landed then and they likely all would have been neutralized anyway. Perhaps the best thing to have done would have been to put them on fire control vessels with additional radios, an LCS (S) or (M) might have made a good platform. Except, again, I can find no evidence that such an idea was ever raised. Instead, everyone hoped really hard that the existing plan would work.

Cheers!

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Re: Naval Gun Support During Amphibious Landings.

#72

Post by Mil-tech Bard » 24 Mar 2015, 21:07

Carl,

Also remember that Gen. Bradley was counting on the 8th Air Force heavy bombers to deliver part of that drenching fire a'la Monetcasino Italy.

The 8th Air Force tried to use H2X radar pathfinders rather than Gee-H radio navigation Pathfinders. The latter of which the 8th Air Force were using for the Crossbow attacks on the V-1 sites before (starting Jan 1944) during and after D-Day.

The Gee-H was 1/4 as accurate as pure visual attacks on a 1-10th cloudy visual day attack and 20 times as accurate as H2X radar on a 8-to-10 10ths cloudy day.

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Re: Naval Gun Support During Amphibious Landings.

#73

Post by ChristopherPerrien » 25 Mar 2015, 02:42

I am puzzled to where the Overlord landings were "stopped" or even held up for more than a few hours , and how that is attributable at all to NGS or lack there-of. By all standards Overlord was a hammer on an eggshell. Whether or not the NGS plan could have been better THAN IT WAS, doesn't seem to mean anything. Does it matter if the US Army gets past Omaha beach in 1 hour instead of 3-4 , if the British don't take Caan for 1+ months .

What is better NGS and bombing gonna do? Blow up Caan worse? , Maybe the Brits will be held up by another EXTRA month, if Caan was vaporized to a finer grade of rubble.

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Re: Naval Gun Support During Amphibious Landings.

#74

Post by Mil-tech Bard » 25 Mar 2015, 16:18

Christopher Perrien,

The delay off the Beach at Omaha caused the local fleet there to ditch all its ship mounted barrage balloons because they were being used as aim points for German artillery that American troops trapped on the beach could not push back.

This ditching of barrage balloons didn't happen at Utah, Sword, Juno or Gold.

What this meant was the Luftwaffe could fly low at night off Omaha for weeks after the landing sowing the shipping lanes with their secret weapon for the Normandy landing -- the then unsweepable pressure fuzed sea mine.

The Allies lost 30 ships to these mines over the next few weeks until their SCR-584 gun laying radars tracked a air delivered mine dropped in the shallows that divers recovered. A sweep was quickly developed after technical analysis of the fuze.

That German fuze was duplicated by the US Navy and later used against the Japanese in the Operation Starvation B-29 mining campaign.

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Re: Naval Gun Support During Amphibious Landings.

#75

Post by Mil-tech Bard » 25 Mar 2015, 17:47

See this video at about 6:20 for the German pressure-influence mine problem off Omaha Beach.

World War II The Minehunters Part II
http://www.liveleak.com/view?i=c64_1371578794

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