Search This Blog

Friday, January 31, 2014

Battlefield Interpretation 101-


The concept of Terrain and Line of Sight

  For the serious historian there seems to be a natural progression from the well-read enthusiast to the hardcore scholar. While the enthusiast gets caught up in the pomp, pageantry, heroics, and devastation wrought by war, the scholar looks deeper into the subject. He or she must be a student of not only events, but how different parts of a battle come together to determine the outcome. The scholarly historian must study not only strategy, but operational and tactical implementation of overall strategy. They must understand how an army, a regiment, a company, and indeed the common soldier preforms its individual function. To be a good military historian, especially one who is providing an interpretation of an individual battle, one must walk the ground to get the feel of what each soldier faced. You must have a thorough understanding of terrain and line of sight. Once you understand this concept, the historian must be able to visualize how it affected actions on the battlefield. It is with these concepts that we begin our study on how to properly interpret a battlefield.

I recently took a little trip east with my research partner Wayne Fielder and my son to visit some Civil War Battlefields. Several I had visited before, but our visit to the Bull Run (or Manassas) battlefield was a first for me. As we climbed Henry House Hill towards the position of Ricketts Battery, I was struck by how close Rickets position was to the Position of Stonewall Jacksons 1st Virginia.
Figure 1: Ricketts Battery at the Crest of Henery House

 As Ricketts crested the hill; the Virginians were out of sight and would remain so until the Federals began to unlimber their pieces (figure 1). Almost immediately,
the Battery was taking rifle fire. The Virginians advanced against the Federals on the hill pushing them away from the Henry house and eventually down the hill. The Confederate counterattack on Henry House Hill cost Rickets many men and more importantly a large number of horses. Without the ability to remove all his guns, several were abandoned to the Confederate onslaught.

  My initial reaction was one of wonderment at the obvious folly of trying to deploy the artillery battery under the concentrated fire of the Confederate infantry and artillery. After examining the situation however, Wayne and I came to the same conclusion. There is no way Ricketts either saw the Confederates or at a minimum did not appreciate the danger. As Ricketts Battery thundered up the hill from the ford, they stopped just short of the crest and swung their teams around brining the field pieces to bear. This was done very rapidly as they rushed to get into position. More than likely, the artillerymen did not even look to the far ridge where Jackson had posted his guns. They most certainly did not see Jackson’s brigade as it sheltered itself behind the ridge a few hundred yards away, or the Confederate infantry in the low ground immediately to their front. The Picture in Figure
2 is taken from the position of Ricketts Battery looking toward Jacksons Line which is marked by his monument and the artillery. The seemingly flat ground directly in front of the marker is deceiving. The ground slopes rapidly down into a draw where the tall grass now lies. Unless Ricketts was looking down, he probably did not notice the Infantry until it was too late.

Figure 2: Jacksons Position (stone marker and statue) as seen from Ricketts Battery Position.
What struck me most about this event was the fact that the Confederate troops and batteries were not purposely concealed by some elaborate rou├ęs, but by the masking effect of the surrounding terrain. The ebb and flow of the landscape kept Jackson’s men hidden until the battery had crested the hill and began to unlimber. The two lessons which must be learned from this is first, how terrain and specifically line of sight effected not only the overall strategic decision of Ricketts and how his tactical objectives were supported or disrupted by the terrain. Secondly, it is important for the battlefield or military historian to understand how a horse drawn artillery battery would go into action. How they unlimbered, where they positioned their caissons, how long it took to unlimber the battery and all the other details. It is important to appreciate that these guns did not just appear. The combination of these two factors created a situation where the battery commander was lulled to a false sense of security about his intended position.


Important Things to Consider

To fully understand why line of sight and terrain have such an impact on the battlefield through the eighteenth and nineteenth century’s one must understand a few key concepts. All artillery, up until the late (really late) 1800’s, were line-of-sight weapons. For field artillery to be effective the gunner must be able to see the target. Even shell and case shot, which exploded on or above the attacking enemy, had to have a visible target for the gunner to hit. Some elevation was possible. Early field and naval guns could be elevated by inserting or removing wooden wedges under the breach. Later, most guns were equipped with an elevating screw. Even with these devices, all artillery lacked an over the horizon ability. In other words, they could not fire over hills and drop shells onto concealed troops. Most guns had a maximum elevation of no more than five degrees which allowed them to shoot up hill or against fortifications. There were mortars available which could fire shells high over terrain and fortifications, but they were unwieldy and little used unless during a siege.

Another key concept that needs understanding is the tactical doctrine of the time. Unlike modern soldiers, troops of the eighteenth and nineteenth centuries fought standing in mass formations utilizing long battle lines to maximize the effect of their musket fire. In this respect, with the exception of men assigned as skirmishers, troops did not move stealthily up to the brow of a hill and snipe at the enemy. The assaulting forces would begin receiving incoming rifle fire as they began to expose their head and shoulders above the crest of a terrain feature. They would be unable to return the fire until they had crested the hill to an elevation where they could bring their arms to bear. A stark example of this situation occurred during the battle of Antietam. As the Federals advanced against the Confederates positioned along the Sunken Road, known also as Bloody Lane, they were initially exposed to rifle fire as they crossed a small ridge taking terrible casualties. As they continued to advance, they dropped into a draw which completely masked them. This intervening terrain feature allowed the Federals to reach a point directly above the lane and deliver terrible slaughter on the defenders. In this case, the terrain masked the attacking Federals long enough for them to reach a position with their attack largely intact.


Walking the Field

To truly understand the why’s and how’s of a battle, it is of critical importance the historian walk the terrain in the area of study. It is simple enough to read from historical sources that a certain position was here and what it did, but from a flat map or a textbook one cannot see how the terrain dictated the outcome of the defense or strength of the attack. It is important to understand what could be seen and when it could be seen. Sometimes this makes all the difference in understanding the historical record. Additionally, sometimes it is the historical record which can be called into question. If an account relates information that, after the examination of the ground, cannot possibly be seen, we are justified in calling that source and possibly its whole interpretation of the event into question.

 When examining terrain the historian must keep some information in mind. First, unless the trees are very large, they probably did not exist during the battle. Although the tree’s age is based on several factors such as the species and growing conditions we can make some generalizations about the age of the trees without cutting them down (figures 3 & 4). Let’s examine, for example, a Red Oak tree. If it is about ten inches in diameter it is probably only about seventy-five years old.

Figure 3: New Growth Trees at an Artillery Position on the Antietam Battlefield
If the same Oak tree has a diameter of thirty inches it could easily be over two-hundred years old. Battlefield interpretation can be particularly confusing when the view shed is blocked by new growth trees or even whole wood lots. It should be noted however, that the diameter of a tree must not completely eliminate it from the picture. The historian must make a careful comparison of the historical record and the terrain. Some wooded areas or tree lines may indeed be in their original position but the replacement of old growth by new growth may give a false impression of the age of the standing timber as it relates to the battle. Secondly, the locations of water course or streams can change over time. While these changes are usually subtle they can create a false impression and confuse the historian when attempting to align oneself along a critical event during the battle. Finally, farming, road construction, and construction of housing disturb the landscape in various ways. They change the terrain by grading and creating erosion runoff which will raise valleys and lower hills over time. It is therefore important for the historian to understand what the property has been used for since the event took place and any changes which have affected the line of sight

Figure 4: Tree Age based on Diameter


What if I can’t take a field trip?

While I cannot stress the importance of the field visit for understanding battlefields, one cannot always do so. If I were writing an article about the battle of Balaklava in the Crimea It would be cost prohibitive to catch a plane to Turkey for a quick walk. You do however have another option. While it is should not be substituted unless necessary, Google Earth with its street view feature can give you a good look at the view shed. It will allow you to look over the terrain from a view parallel to the ground and get an idea of what it is like without leaving your desk. Additionally, you can use it as a tool to confirm a hypothesis or as a method of doing reconnaissance prior to a site visit.

Another neat feature of Google Earth is the overlay function. While working on a recent project, I needed to reference a map drawn in 1862 to the actual terrain on the ground now. I needed this to reconcile between what I understood of the actions and the current layout of the area. To do this, first I pulled up Google Earth for the area I was working in. Then, using the overlay function, I placed the old map on top of the new one. After some positioning and lining up known landmarks, the old map draped over the terrain like a table cloth following the dimensional terrain displayed in Google Earth. With the overlay I could see exactly what the original map maker saw from the modern perspective. Figure 5: Google Earth with Historic Map Overlay

Figure 5: Google Earth with Historic Map Overlay
Regardless of your reason for studying a particular event, it is very important to understand the role terrain and line of site will play on the outcome of the event. Interpretation of the battle begins with reading and understanding as many of the available historical sources as possible. The second act is to visit the site either virtually or physically and walk the ground to find those key points and identify how the view shed impacted the actions of the actors. With the widespread availability of digital cameras it can be very useful to take as many pictures as you can from multiple angles. These photos can be used as a later date to refresh your memory or shore up a theory. Being good military historian requires more than a cursory study of primary source material. Unlike other historians, the military historian is required to understand how terrain and lines of sight affect the course of the battle. Without a serious study of terrain, it is difficult for a military historian to accurately convey the actions of the combatants in the proper light.