Tag Measuring the Effects of Combat in Cities study

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

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

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.