Tag quantitative analysis

TDI Friday Read: Measuring The Effects of Combat in Cities

Between 2001 and 2004, TDI undertook a series of studies on the effects of urban combat in cities for the U.S. Army Center for Army Analysis (CAA). These studies examined a total of 304 cases of urban combat at the divisional and battalion level that occurred between 1942 and 2003, as well as 319 cases of concurrent non-urban combat for comparison.

The primary findings of Phases I-III of the study were:

  • Urban terrain had no significantly measurable influence on the outcome of battle.
  • Attacker casualties in the urban engagements were less than in the non-urban engagements and the casualty exchange ratio favored the attacker as well.
  • One of the primary effects of urban terrain is that it slowed opposed advance rates. The average advance rate in urban combat was one-half to one-third that of non-urban combat.
  • There is little evidence that combat operations in urban terrain resulted in a higher linear density of troops.
  • Armor losses in urban terrain were the same as, or lower than armor losses in non-urban terrain. In some cases it appears that armor losses were significantly lower in urban than non-urban terrain.
  • Urban terrain did not significantly influence the force ratio required to achieve success or effectively conduct combat operations.
  • Overall, it appears that urban terrain was no more stressful a combat environment during actual combat operations than was non-urban terrain.
  • Overall, the expenditure of ammunition in urban operations was not greater than that in non-urban operations. There is no evidence that the expenditure of other consumable items (rations; water; or fuel, oil, or lubricants) was significantly different in urban as opposed to non-urban combat.
  • Since it was found that advance rates in urban combat were significantly reduced, then it is obvious that these two effects (advance rates and time) were interrelated. It does appear that the primary impact of urban combat was to slow the tempo of operations.

In order to broaden and deepen understanding of the effects of urban combat, TDI proposed several follow-up studies. To date, none of these have been funded:

  1. Conduct a detailed study of the Battle of Stalingrad. Stalingrad may also represent one of the most intense examples of urban combat, so may provide some clues to the causes of the urban outliers.
  2. Conduct a detailed study of battalion/brigade-level urban combat. This would begin with an analysis of battalion-level actions from the first two phases of this study (European Theater of Operations and Eastern Front), added to the battalion-level actions completed in this third phase of the study. Additional battalion-level engagements would be added as needed.
  3. Conduct a detailed study of the outliers in an attempt to discover the causes for the atypical nature of these urban battles.
  4. Conduct a detailed study of urban warfare in an unconventional warfare setting.

Details of the Phase I-III study reports and conclusions can be found below:

Measuring The Effects Of Combat In Cities, Phase I

Measuring the Effects of Combat in Cities, Phase II – part 1

Measuring the Effects of Combat in Cities, Phase II – part 2

Measuring the Effects of Combat in Cities, Phase III – part 1

Measuring the Effects of Combat in Cities, Phase III – part 2

Measuring the Effects of Combat in Cities, Phase III – part 2.1

Measuring the Effects of Combat in Cities, Phase III – part 3

Urban Phase IV – Stalingrad

Urban Combat in War by Numbers

The Combat Value of Surprise

American soldiers being marched down a road after capture by German troops in the Ardennes, December 1944.
American soldiers being marched down a road after capture by German troops in the Ardennes, December 1944.

[This article was originally posted on 1 December 2016]

In his recent analysis of the role of conventional armored forces in Russian hybrid warfare, U.S. Army Major Amos Fox noted an emphasis on tactical surprise.

Changes to Russian tactics typify the manner in which Russia now employs its ground force. Borrowing from the pages of military theorist Carl von Clausewitz, who stated, “It is still more important to remember that almost the only advantage of the attack rests on its initial surprise,” Russia’s contemporary operations embody the characteristic of surprise. Russian operations in Georgia and Ukraine demonstrate a rapid, decentralized attack seeking to temporally dislocate the enemy, triggering the opposing forces’ defeat.

Tactical surprise enabled by electronic, cyber, information and unconventional warfare capabilities, combined with mobile and powerful combined arms brigade tactical groups, and massive and lethal long-range fires provide Russian Army ground forces with formidable combat power.

Trevor Dupuy considered the combat value of surprise to be important enough to cite it as one of his “timeless verities of combat.”

Surprise substantially enhances combat power. Achieving surprise in combat has always been important. It is perhaps more important today than ever. Quantitative analysis of historical combat shows that surprise has increased the combat power of military forces in those engagements in which it was achieved. Surprise has proven to be the greatest of all combat multipliers. It may be the most important of the Principles of War; it is at least as important as Mass and Maneuver.

In addition to acting as combat power multiplier, Dupuy observed that surprise decreases the casualties of a surprising force and increases those of a surprised one. Surprise also enhances advance rates for forces that achieve it.

In his combat models, Dupuy categorized tactical surprise as complete, substantial, and minor; defining the level achieved was a matter of analyst judgement. The combat effects of surprise in battle would last for three days, declining by one-third each day.

He developed two methods for applying the effects of surprise in calculating combat power, each yielding the same general overall influence. In his original Quantified Judgement Model (QJM) detailed in Numbers, Predictions and War: The Use of History to Evaluate and Predict the Outcome of Armed Conflict (1977), factors for surprise were applied to calculations for vulnerability and mobility, which in turn were applied to the calculation of overall combat power. The net value of surprise on combat power ranged from a factor of about 2.24 for complete surprise to 1.10 for minor surprise.

For a simplified version of his combat power calculation detailed in Attrition: Forecasting Battle Casualties and Equipment Losses in Modern War (1990), Dupuy applied a surprise combat multiplier value directly to the calculation of combat power. These figures also ranged between 2.20 for complete surprise and 1.10 for minor surprise.

Dupuy established these values for surprise based on his judgement of the difference between the calculated outcome of combat engagements in his data and theoretical outcomes based on his models. He never validated them back to his data himself. However, TDI President Chris Lawrence recently did conduct substantial tests on TDI’s expanded combat databases in the context of analyzing the combat value of situational awareness. The results are described in detail in his forthcoming book, War By Numbers: Understanding Conventional Combat.

Measuring the Effects of Combat in Cities, Phase III – part 1

Now comes Phase III of this effort. The Phase I report was dated 11 January 2002 and covered the European Theater of Operations (ETO). The Phase II report [Part I and Part II] was dated 30 June 2003 and covered the Eastern Front (the three battles of Kharkov). Phase III was completed in 31 July 2004 and covered the Battle of Manila in the Pacific Theater, post-WWII engagements, and battalion-level engagements. It was a pretty far ranging effort.

In the case of Manila, this was the first time that we based our analysis using only one-side data (U.S. only). In this case, the Japanese tended to fight to almost the last man. We occupied the field of combat after the battle and picked up their surviving unit records. Among the Japanese, almost all died and only a few were captured by the U.S. So, we had fairly good data from the U.S. intelligence files. Regardless, the U.S. battle reports for Japanese data was the best data available. This allowed us to work with one-sided data. The engagements were based upon the daily operations of the U.S. Army’s 37th Infantry Division and the 1st Cavalry Division.

Conclusions (from pages 44-45):

The overall conclusions derived from the data analysis in Phase I were as follows, while those from this Phase III analysis are in bold italics.

  1. Urban combat did not significantly influence the Mission Accomplishment (Outcome) of the engagements. Phase III Conclusion: This conclusion was further supported.
  2. Urban combat may have influenced the casualty rate. If so, it appears that it resulted in a reduction of the attacker casualty rate and a more favorable casualty exchange ratio compared to non-urban warfare. Whether or not these differences are caused by the data selection or by the terrain differences is difficult to say, but regardless, there appears to be no basis to the claim that urban combat is significantly more intense with regards to casualties than is non-urban warfare. Phase III Conclusion: This conclusion was further supported. If urban combat influenced the casualty rate, it appears that it resulted in a reduction of the attacker casualty rate and a more favorable casualty exchange ratio compared to non-urban warfare. There still appears to be no basis to the claim that urban combat is significantly more intense with regards to casualties than is non-urban warfare.
  3. The average advance rate in urban combat should be one-half to one-third that of non-urban combat. Phase III Conclusion: There was strong evidence of a reduction in the advance rates in urban terrain in the PTO data. However, given that this was a single extreme case, then TDI still stands by its original conclusion that the average advance rate in urban combat should be about one-half to one-third that of non-urban combat/
  4. Overall, there is little evidence that the presence of urban terrain results in a higher linear density of troops, although the data does seem to trend in that direction. Phase III Conclusion: The PTO data shows the highest densities found in the data sets for all three phases of this study. However, it does not appear that the urban density in the PTO was significantly higher than the non-urban density. So it remains difficult to tell whether or not the higher density was a result of the urban terrain or was simply a consequence of the doctrine adopted to meet the requirements found in the Pacific Theater.
  5. Overall, it appears that the loss of armor in urban terrain is the same as or less than that found in non-urban terrain, and in some cases is significantly lower. Phase III Conclusion: This conclusion was further supported.
  6. Urban combat did not significantly influence the Force Ratio required to achieve success or effectively conduct combat operations. Phase III Conclusion: This conclusion was further supported.
  7. Nothing could be determined from an analysis of the data regarding the Duration of Combat (Time) in urban versus non-urban terrain. Phase III Conclusion: Nothing could be determined from an analysis of the data regarding the Duration of Combat (Time) in urban versus non-urban terrain.

So, in Phase I we compared 46 urban and conurban engagements in the ETO to 91 non-urban engagements. In Phase II, we compared 51 urban and conurban engagements in an around Kharkov to 49 non-urban Kursk engagements. On Phase III, from Manila we compared 53 urban and conurban engagements to 41 non-urban engagements mostly from Iwo Jima, Okinawa and Manila. The next blog post on urban warfare will discuss our post-WWII data.

P.S. The picture is an aerial view of the destroyed walled city of Intramuros taken on May 1945

Are There Only Three Ways of Assessing Military Power?

military-power[This article was originally posted on 11 October 2016]

In 2004, military analyst and academic Stephen Biddle published Military Power: Explaining Victory and Defeat in Modern Battle, a book that addressed the fundamental question of what causes victory and defeat in battle. Biddle took to task the study of the conduct of war, which he asserted was based on “a weak foundation” of empirical knowledge. He surveyed the existing literature on the topic and determined that the plethora of theories of military success or failure fell into one of three analytical categories: numerical preponderance, technological superiority, or force employment.

Numerical preponderance theories explain victory or defeat in terms of material advantage, with the winners possessing greater numbers of troops, populations, economic production, or financial expenditures. Many of these involve gross comparisons of numbers, but some of the more sophisticated analyses involve calculations of force density, force-to-space ratios, or measurements of quality-adjusted “combat power.” Notions of threshold “rules of thumb,” such as the 3-1 rule, arise from this. These sorts of measurements form the basis for many theories of power in the study of international relations.

The next most influential means of assessment, according to Biddle, involve views on the primacy of technology. One school, systemic technology theory, looks at how technological advances shift balances within the international system. The best example of this is how the introduction of machine guns in the late 19th century shifted the advantage in combat to the defender, and the development of the tank in the early 20th century shifted it back to the attacker. Such measures are influential in international relations and political science scholarship.

The other school of technological determinacy is dyadic technology theory, which looks at relative advantages between states regardless of posture. This usually involves detailed comparisons of specific weapons systems, tanks, aircraft, infantry weapons, ships, missiles, etc., with the edge going to the more sophisticated and capable technology. The use of Lanchester theory in operations research and combat modeling is rooted in this thinking.

Biddle identified the third category of assessment as subjective assessments of force employment based on non-material factors including tactics, doctrine, skill, experience, morale or leadership. Analyses on these lines are the stock-in-trade of military staff work, military historians, and strategic studies scholars. However, international relations theorists largely ignore force employment and operations research combat modelers tend to treat it as a constant or omit it because they believe its effects cannot be measured.

The common weakness of all of these approaches, Biddle argued, is that “there are differing views, each intuitively plausible but none of which can be considered empirically proven.” For example, no one has yet been able to find empirical support substantiating the validity of the 3-1 rule or Lanchester theory. Biddle notes that the track record for predictions based on force employment analyses has also been “poor.” (To be fair, the problem of testing theory to see if applies to the real world is not limited to assessments of military power, it afflicts security and strategic studies generally.)

So, is Biddle correct? Are there only three ways to assess military outcomes? Are they valid? Can we do better?

Measuring the Effects of Combat in Cities, Phase II – part 2

There was actually supposed to be a part 2 to this Phase II contract, which was analysis of urban combat at the army-level based upon 50 operations, of which a half-dozen would include significant urban terrain. This effort was not funded.

On the other hand, the quantitative analysis of battles of Kharkov only took up the first 41 pages of the report. A significant part of the rest of the report was a more detailed analysis and case study of the three fights over Kharkov in February, March and August of 1943. Kharkov was a large city, according to the January 1939 census, it has a population of 1,344,200, although a Soviet-era encyclopedia gives the pre-war population as 840,000. We never were able to figure out why there was a discrepancy. The whole area was populated with many villages. The January 1939 gives Kharkov Oblast (region) a population of 1,209,496. This is in addition to the city, so the region had a total population of 2,552,686. Soviet-era sources state that when the city was liberated in August 1943, the remaining population was only 190,000. Kharkov was a much larger city than any of the others ones covered in Phase I effort (except for Paris, but the liberation of that city was hardly a major urban battle).

The report then does a day-by-day review of the urban fighting in Kharkov. Doing a book or two on the battles of Kharkov is on my short list of books to write, as I have already done a lot of the research. We do have daily logistical expenditures of the SS Panzer Corps for February and March (tons of ammo fired, gasoline used and diesel used). In March when the SS Panzer Corps re-took Kharkov, we noted that the daily average for the four days of urban combat from 12 to 15 March was 97.25 tons of ammunition, 92 cubic meters of gasoline and 10 cubic meters of diesel. For the previous five days (7-11 March) the daily average was 93.20 tons of ammunition, 145 cubic meters of gasoline and 9 cubic meters of diesel. Thus it does not produce a lot of support for the idea that–as has sometimes been expressed (for example in RAND’s earlier reports on the subject)–that ammunition and other supplies will be consumed at a higher rate in urban operations.

We do observe from the three battles of Kharkov that (page 95):

There is no question that the most important lesson found in the three battles of Kharkov is that one should just bypass cities rather than attack them. The Phase I study also points out that the attacker is usually aware that faster progress can be made outside the urban terrain, and that the tendency is to weight one or both flanks and not bother to attack the city until it is enveloped. This is indeed what happened in two of the three cases at Kharkov and was also the order given by the Fourth Panzer Army that was violated by the SS Panzer Corps in March.

One must also note that since this study began the United States invaded Iraq and conducted operations in some major urban areas, albeit against somewhat desultory and ineffective opposition. In the southern part of Iraq the two major port cities Umm Qasar and Basra were first enveloped before any forces were sent in to clear them. In the case of Baghdad, it could have been enveloped if sufficient forces were available. As it was, it was not seriously defended. The recent operations in Iraq again confirmed that observations made in the two phases of this study.

P.S. The picture is of Kharkov in 1942, when it was under German occupation.

Measuring the Effects of Combat in Cities, Phase II – part 1

Our first urban warfare report that we did had a big impact. It clearly showed that the intensity of urban warfare was not what some of the “experts” out there were claiming. In particular, it called into question some of the claims being made by RAND. But, the report was based upon Aachen, Cherbourg, and a collection of mop-up operations along the Channel Coast. Although this was a good starting point because of the ease of research and availability of data, we did not feel that this was a fully representative collection of cases. We also did not feel that it was based upon enough cases, although we had already assembled more cases than most “experts” were using. We therefore convinced CAA (Center for Army Analysis) to fund a similar effort for the Eastern Front in World War II.

For this second phase, we again assembled a collection of Eastern Front urban warfare engagements in our DLEDB (Division-level Engagement Data Base) and compared it to Eastern Front non-urban engagements. We had, of course, a considerable collection of non-urban engagements already assembled from the Battle of Kursk in July 1943. We therefore needed a good urban engagement nearby. Kharkov is the nearest major city to where these non-urban engagements occurred and it was fought over three times in 1943. It was taken by the Red Army in February, it was retaken by the German Army in March, and it was taken again by the Red Army in August. Many of the units involved were the same units involved in the Battle of Kursk. This was a good close match. It has the additional advantage that both sides were at times on the offense.

Furthermore, Kharkov was a big city. At the time it was the fourth biggest city in the Soviet Union, being bigger than Stalingrad (as measured by pre-war population). A picture of its Red Square in March 1943, after the Germans retook it, is above.

We did have good German records for 1943 and we were able to get access to Soviet division-level records from February, March and August from the Soviet military archives in Podolsk. Therefore, we were able to assembled all the engagements based upon the unit records of both sides. No secondary sources were used, and those that were available were incomplete, usually one-sided, sometimes biased and often riddled with factual errors.

So, we ended up with 51 urban and conurban engagements from the fighting around Kharkov, along with 65 non-urban engagements from Kursk (we have more now).

The Phase II effort was completed on 30 June 2003. The conclusions of Phase II (pages 40-41) were similar to Phase I:

.Phase II Conclusions:

  1. Mission Accomplishment: This [Phase I] conclusion was further supported. The data does show a tendency for urban engagements not to generate penetrations.
  2. Casualty Rates: This [Phase I] conclusion was further supported. If urban combat influenced the casualty rate, it appears that it resulted in a reduction of the attacker casualty rate and a more favorable casualty exchange ratio compared to nonurban warfare. There still appears to be no basis to the claim that urban combat is significantly more intense with regards to casualties than is nonurban warfare.
  3. Advance Rates: There is no strong evidence of a reduction in the advance rates in urban terrain in the Eastern Front data. TDI still stands by its original conclusion that the average advance rate in urban combat should be one-half to one-third that of nonurban combat.
  4. Linear Density: Again, there is little evidence that the presence of urban terrain results in a higher linear density of troops, but unlike the ETO data, the data did not show a tendency to trend in that direction.
  5. Armor Losses: This conclusion was further supported (Phase I conclusion was: Overall, it appears that the loss of armor in urban terrain is the same as or less than that found in nonurban terrain, and in some cases is significantly lower.)
  6. Force Ratios: The conclusion was further supported (Phase I conclusion was: Urban combat did not significantly influence the Force Ratio required to achieve success or effectively conduct combat operations).
  7. Duration of Combat: Nothing could be determined from an analysis of the data regarding the Duration of Combat (Time) in urban versus nonurban terrain.

There is a part 2 to this effort that I will pick up in a later post.

Measuring The Effects Of Combat In Cities, Phase I

“Catalina Kid,” a M4 medium tank of Company C, 745th Tank Battalion, U.S. Army, drives through the entrance of the Aachen-Rothe Erde railroad station during the fighting around the city viaduct on Oct. 20, 1944. [Courtesy of First Division Museum/Daily Herald]

In 2002, TDI submitted a report to the U.S. Army Center for Army Analysis (CAA) on the first phase of a study examining the effects of combat in cities, or what was then called “military operations on urbanized terrain,” or MOUT. This first phase of a series of studies on urban warfare focused on the impact of urban terrain on division-level engagements and army-level operations, based on data drawn from TDI’s DuWar database suite.

This included engagements in France during 1944 including the Channel and Brittany port cities of Brest, Boulogne, Le Havre, Calais, and Cherbourg, as well as Paris, and the extended series of battles in and around Aachen in 1944. These were then compared to data on fighting in contrasting non-urban terrain in Western Europe in 1944-45.

The conclusions of Phase I of that study (pp. 85-86) were as follows:

The Effect of Urban Terrain on Outcome

The data appears to support a null hypothesis, that is, that the urban terrain had no significantly measurable influence on the outcome of battle.

The Effect of Urban Terrain on Casualties

Overall, any way the data is sectioned, the attacker casualties in the urban engagements are less than in the non-urban engagements and the casualty exchange ratio favors the attacker as well. Because of the selection of the data, there is some question whether these observations can be extended beyond this data, but it does not provide much support to the notion that urban combat is a more intense environment than non-urban combat.

The Effect of Urban Terrain on Advance Rates

It would appear that one of the primary effects of urban terrain is that it slows opposed advance rates. One can conclude that the average advance rate in urban combat should be one-half to one-third that of non-urban combat.

The Effect of Urban Terrain on Force Density

Overall, there is little evidence that combat operations in urban terrain result in a higher linear density of troops, although the data does seem to trend in that direction.

The Effect of Urban Terrain on Armor

Overall, it appears that armor losses in urban terrain are the same as, or lower than armor losses in non-urban terrain. And in some cases it appears that armor losses are significantly lower in urban than non-urban terrain.

The Effect of Urban Terrain on Force Ratios

Urban terrain did not significantly influence the force ratio required to achieve success or effectively conduct combat operations.

The Effect of Urban Terrain on Stress in Combat

Overall, it appears that urban terrain was no more stressful a combat environment during actual combat operations than was non-urban terrain.

The Effect of Urban Terrain on Logistics

Overall, the evidence appears to be that the expenditure of artillery ammunition in urban operations was not greater than that in non-urban operations. In the two cases where exact comparisons could be made, the average expenditure rates were about one-third to one-quarter the average expenditure rates expected for an attack posture in the European Theater of Operations as a whole.

The evidence regarding the expenditure of other types of ammunition is less conclusive, but again does not appear to be significantly greater than the expenditures in non-urban terrain. Expenditures of specialized ordnance may have been higher, but the total weight expended was a minor fraction of that for all of the ammunition expended.

There is no evidence that the expenditure of other consumable items (rations, water or POL) was significantly different in urban as opposed to non-urban combat.

The Effect of Urban Combat on Time Requirements

It was impossible to draw significant conclusions from the data set as a whole. However, in the five significant urban operations that were carefully studied, the maximum length of time required to secure the urban area was twelve days in the case of Aachen, followed by six days in the case of Brest. But the other operations all required little more than a day to complete (Cherbourg, Boulogne and Calais).

However, since it was found that advance rates in urban combat were significantly reduced, then it is obvious that these two effects (advance rates and time) are interrelated. It does appear that the primary impact of urban combat is to slow the tempo of operations.

This in turn leads to a hypothetical construct, where the reduced tempo of urban operations (reduced casualties, reduced opposed advance rates and increased time) compared to non-urban operations, results in two possible scenarios.

The first is if the urban area is bounded by non-urban terrain. In this case the urban area will tend to be enveloped during combat, since the pace of battle in the non-urban terrain is quicker. Thus, the urban battle becomes more a mopping-up operation, as it historically has usually been, rather than a full-fledged battle.

The alternate scenario is that created by an urban area that cannot be enveloped and must therefore be directly attacked. This may be caused by geography, as in a city on an island or peninsula, by operational requirements, as in the case of Cherbourg, Brest and the Channel Ports, or by political requirements, as in the case of Stalingrad, Suez City and Grozny.

Of course these last three cases are also those usually included as examples of combat in urban terrain that resulted in high casualty rates. However, all three of them had significant political requirements that influenced the nature, tempo and even the simple necessity of conducting the operation. And, in the case of Stalingrad and Suez City, significant geographical limitations effected the operations as well. These may well be better used to quantify the impact of political agendas on casualties, rather than to quantify the effects of urban terrain on casualties.

The effects of urban terrain at the operational level, and the effect of urban terrain on the tempo of operations, will be further addressed in Phase II of this study.

More on the QJM/TNDM Italian Battles

Troops of the U.S. 36th Infantry Division advance inland on Red Beach, Salerno, Italy, 1943. [ibiblio/U.S. Center for Military History]

[The article below is reprinted from December 1998 edition of The International TNDM Newsletter.]

More on the QJM/TNDM Italian Battles
by Richard C. Anderson, Jr.

In regard to Niklas Zetterling’s article and Christopher Lawrence’s response (Newsletter Volume 1, Number 6) [and Christopher Lawrence’s 2018 addendum] I would like to add a few observations of my own. Recently I have had occasion to revisit the Allied and German records for Italy in general and for the Battle of Salerno in particular. What I found is relevant in both an analytical and an historical sense.

The Salerno Order of Battle

The first and most evident observation that I was able to make of the Allied and German Order of Battle for the Salerno engagements was that it was incorrect. The following observations all relate to the table found on page 25 of Volume 1, Number 6.

The divisional totals are misleading. The U.S. had one infantry division (the 36th) and two-thirds of a second (the 45th, minus the 180th RCT [Regimental Combat Team] and one battalion of the 157th Infantry) available during the major stages of the battle (9-15 September 1943). The 82nd Airborne Division was represented solely by elements of two parachute infantry regiments that were dropped as emergency reinforcements on 13-14 September. The British 7th Armored Division did not begin to arrive until 15-16 September and was not fully closed in the beachhead until 18-19 September.

The German situation was more complicated. Only a single panzer division, the 16th, under the command of the LXXVI Panzer Corps was present on 9 September. On 10 September elements of the Hermann Goring Parachute Panzer Division, with elements of the 15th Panzergrenadier Division under tactical command, began arriving from the vicinity of Naples. Major elements of the Herman Goring Division (with its subordinated elements of the 15th Panzergrenadier Division) were in place and had relieved elements of the 16th Panzer Division opposing the British beaches by 11 September. At the same time the 29th Panzergrenandier Division began arriving from Calabria and took up positions opposite the U.S. 36th Divisions in and south of Altavilla, again relieving elements of the 16th Panzer Division. By 11-12 September the German forces in the northern sector of the beachhead were under the command of the XIV Panzer Corps (Herman Goring Division (-), elements of the 15th Panzergrenadier Division and elements of the 3rd Panzergrenadier Division), while the LXXVI Panzer Corps commanded the 16th Panzer Division, 29th Panzergrenadier Division, and elements of the 26th Panzer Division. Unfortunately for the Germans the 16th Panzer Division’s zone was split by the boundary between the XIV and LXXVI Corps, both of whom appear to have had operational control over different elements of the division. Needless to say, the German command and control problems in this action were tremendous.[1]

The artillery totals given in the table are almost inexplicable. The numbers of SP [self-propelled] 75mm howitzers is a bit fuzzy, inasmuch as this was a non-standardized weapon on a half-track chassis. It was allocated to the infantry regimental cannon company (6 tubes) and was also issued to tank and tank destroyer battalions as a stopgap until purpose-designed systems could be brought into production. The 105mm SP was also present on a half-track chassis in the regimental cannon company (2 tubes) and on a full-track chassis in the armored field artillery battalion (18 tubes). The towed 105mm artillery was present in the five field artillery battalions present of the 36th and 45th divisions and in a single non-divisional battalion assigned to the VI Corps. The 155mm howitzers were only present in the two divisional field artillery battalions, the general support artillery assigned to the VI Corps, the 36th Field Artillery Regiment, did not arrive until 16 September. No 155mm gun battalions landed in Italy until October 1943. The U.S. artillery figures should approximately be as follows:

75mm Howitzer (SP)

2 per infantry battalion

28

6 per tank battalion

12

Total

40
105mm Howitzer (SP)

2 per infantry regiment

10

1 armored FA battalion[2]

18

5 divisional FA battalions

60

1 non-divisional FA battalion

12

Total

100
155mm Howitzer

2 divisional FA battalions

24
3″ Tank Destroyer

3 battalions

108

Thus, the U.S. artillery strength is approximately 272 versus 525 as given in the chart.

The British artillery figures are also suspect. Each of the British divisions present, the 46th and 56th, had three regiments (battalions in U.S. parlance) of 25-pounder gun-howitzers for a total of 72 per division. There is no evidence of the presence of the British 3-inch howitzer, except possibly on a tank chassis in the support tank role attached to the tank troop headquarters of the armor regiment (battalion) attached to the X Corps (possibly 8 tubes). The X Corps had a single medium regiment (battalion) attached with either 4.5 inch guns or 5.5 inch gun-howitzers or a mixture of the two (16 tubes). The British did not have any 7.2 inch howitzers or 155mm guns at Salerno. I do not know where the figure for British 75mm howitzers is from, although it is possible that some may have been present with the corps armored car regiment.

Thus the British artillery strength is approximately 168 versus 321 as given in the chart.

The German artillery types are highly suspect. As Niklas Zetterling deduced, there was no German corps or army artillery present at Salemo. Neither the XIV or LXXVI Corps had Heeres (army) artillery attached. The two battalions of the 7lst Nebelwerfer regiment and one battery of 170mm guns (previously attached to the 15th Panzergrenadier Division) were all out of action, refurbishing and replenishing equipment in the vicinity of Naples. However, U.S. intelligence sources located 42 Italian coastal gun positions, including three 149mm (not 132mm) railway guns defending the beaches. These positions were taken over by German personnel on the night before the invasion. That they fired at all in the circumstances is a comment on the professionalism of the German Army. The remaining German artillery available was with the divisional elements that arrived to defend against the invasion forces. The following artillery strengths are known for the German forces at Salerno:

16th Panzer Division (as of 3 September):

14 75mm infantry support howitzers
11 150mm SP infantry support howitzers
10 105mm howitzers
8 105mm SP howitzers
4 105mm guns
8 150mm howitzers
5 150mm SP howitzers
5 88mm AA guns

26th Panzer Division (as of 12 September):

15 75mm infantry support howitzers
12 150mm infantry support howitzers
6 105mm SP howitzers
12 105mm howitzers
10 150mm SP howitzers
4 150mm howitzers

Herman Goring Parachute Panzer Division (as of 13 September):

6-8 75mm infantry support howitzers
8 150mm infantry support howitzers
24 105mm howitzers
12 105mm SP howitzers
4 105mm guns
8 150mrn howitzers
6 150mm SP howitzers
6 150mm multiple rocket launchers
12 88mm AA guns

29th Panzergrenadier Division

106 artillery pieces (types unknown)

15th Panzergrenadier Division (elements):

10-12 105mm howitzers

3d Panzergrenadier Division

6 150mm infantry support howitzers

Non-divisional:

501st Army Flak Battalion (probably 20mm and 37mm AA only)
I/49th Flak Battalion (probably 8 88mm AA guns)

Thus, German artillery strength is about 342 tubes versus 394 as given in the chart.[3]

Armor strengths are equally suspect for both the Allied and German forces. It should be noted however, that the original QJM database considered wheeled armored cars to be the equivalent of a light tank.

Only two U.S. armor battalions were assigned to the initial invasion force, with a total of 108 medium and 34 light tanks. The British X Corps had a single armor regiment (battalion) assigned with approximately 67 medium and 10 light tanks. Thus, the Allies had some 175 medium tanks versus 488 as given in the chart and 44 light tanks versus 236 (including an unknown number of armored cars) as given in the chart.

German armor strength was as follows (operational/in repair as of the date given):

16th Panzer Division (8 September):

7/0 Panzer III flamethrower tanks
12/0 Panzer IV short
86/6 Panzer IV long
37/3 assault guns

29th Panzergrenadier Division (1 September):

32/5 assault guns
17/4 SP antitank
3/0 Panzer III

26th Panzer Division (5 September):

11/? assault guns
10/? Panzer III

Herman Goering Parachute Panzer Division (7 September):

5/? Panzer IV short
11/? Panzer IV long
5/? Panzer III long
1/? Panzer III 75mm
21/? assault guns
3/? SP antitank

15th Panzergrenadier Division (8 September):

6/? Panzer IV long
18/? assault guns

Total 285/18 medium tanks, SP anti-tank, and assault guns. This number actually agrees very well with the 290 medium tanks given in the chart. I have not looked closely at the number of German armored cars but suspect that it is fairly close to that given in the charts.

In general it appears that the original QJM Database got the numbers of major items of equipment right for the Germans, even if it flubbed on the details. On the other hand, the numbers and details are highly suspect for the Allied major items of equipment. Just as a first order “guestimate” I would say that this probably reduces the German CEV to some extent; however, missing from the formula is the Allied naval gunfire support which, although negligible in impact in the initial stages of the battle, had a strong influence on the later stages of the battle.

Hopefully, with a little more research and time, we will be able to go back and revalidate these engagements. In the meantime I hope that this has clarified some of the questions raised about the Italian QJM Database.

NOTES

[1] Exacerbating the German command and control problems was the fact that the Tenth Army, which was in overall command of the XIV Panzer Corps and LXXVI Panzer Corps, had only been in existence for about six weeks. The army’s signal regiment was only partly organized and its quartermaster services were almost nonexistent.

[2] Arrived 13 September, 1 battery in action 13-15 September.

[3] However, the number given for the 29th Panzergrenadier Division appears to be suspiciously high and is not well defined. Hopefully further research may clarify the status of this division.

Dupuy’s Verities: The Power Of Defense

Leonidas at Thermopylae, by Jacques-Louis David, 1814. [Wikimedia]

The second of Trevor Dupuy’s Timeless Verities of Combat is:

Defensive strength is greater than offensive strength.

From Understanding War (1987):

[Prussian military theorist, Carl von] Clausewitz expressed this: “Defense is the stronger form of combat.” It is possible to demonstrate by the qualitative comparison of many battles that Clausewitz is right and that posture has a multiplicative effect on the combat power of a military force that takes advantage of terrain and fortifications, whether hasty and rudimentary, or intricate and carefully prepared. There are many well-known examples of the need of an attacker for a preponderance of strength in order to carry the day against a well-placed and fortified defender. One has only to recall Thermopylae, the Alamo, Fredericksburg, Petersburg, and El Alamein to realize the advantage enjoyed by a defender with smaller forces, well placed, and well protected. [p. 2]

The advantages of fighting on the defensive and the benefits of cover and concealment in certain types of terrain have long been basic tenets in military thinking. Dupuy, however, considered defensive combat posture and defensive value of terrain not just to be additive, but combat power multipliers, or circumstantial variables of combat that when skillfully applied and exploited, the effects of which could increase the overall fighting capability of a military force.

The statement [that the defensive is the stronger form of combat] implies a comparison of relative strength. It is essentially scalar and thus ultimately quantitative. Clausewitz did not attempt to define the scale of his comparison. However, by following his conceptual approach it is possible to establish quantities for this comparison. Depending upon the extent to which the defender has had the time and capability to prepare for defensive combat, and depending also upon such considerations as the nature of the terrain which he is able to utilize for defense, my research tells me that the comparative strength of defense to offense can range from a factor with a minimum value of about 1.3 to maximum value of more than 3.0. [p. 26]

The values Dupuy established for posture and terrain based on historical combat experience were as follows:

For example, Dupuy calculated that mounting even a hasty defense in rolling, gentle terrain with some vegetation could increase a force’s combat power by more than 50%. This is a powerful effect, achievable without the addition of any extra combat capability.

It should be noted that these values are both descriptive, in terms of defining Dupuy’s theoretical conception of the circumstantial variables of combat, as well as factors specifically calculated for use in his combat models. Some of these factors have found their way into models and simulations produced by others and some U.S. military doctrinal publications, usually without attribution and shorn of explanatory context. (A good exploration of the relationship between the values Dupuy established for the circumstantial variables of combat and his combat models, and the pitfalls of applying them out of context can be found here.)

While the impact of terrain on combat is certainly an integral part of current U.S. Army thinking at all levels, and is constantly factored into combat planning and assessment, its doctrine does not explicitly acknowledge the classic Clausewitzian notion of a power disparity between the offense and defense. Nor are the effects of posture or terrain thought of as combat multipliers.

However, the Army does implicitly recognize the advantage of the defensive through its stubbornly persistent adherence to the so-called 3-1 rule of combat. Its version of this (which the U.S. Marine Corps also uses) is described in doctrinal publications as “historical minimum planning ratios,” which proscribe that a 3-1 advantage in numerical force ratio is necessary for an attacker to defeat a defender in a prepared or fortified position. Overcoming a defender in a hasty defense posture requires a 2.5-1 force ratio advantage. The force ratio advantages the Army considers necessary for decisive operations are even higher. While the 3-1 rule is a deeply problematic construct, the fact that is the only quantitative planning factor included in current doctrine reveals a healthy respect for the inherent power of the defensive.