North Africa Terrain Primer

[leakyD]

Been digging through some links. This one in particular:

http://www-cgsc.army.mil/carl/resources/csi/Toppe/toppe.asp

From the looks of it, we have some interesting terrain to deal with very shortly!

From the link:

Within the zone described, the following types of terrain obstacles were to be found:

a. Mountain Ranges

Three mountain ranges played an important part in the war in Africa, namely:

(1) The Cyrenaica Mountains. At points, these mountains reach a heiaht of 875 meters above sea level and intercept the moisture carried inland by the north wind. The heavier rainfall here is the reason why the chalky ground carries a growth of macchia in contrast to the desert or steppe-like areas. The mountains rise in two, high, steep terraces that can be traversed at only a few points and are intersected by numerous deep valleys, which make it impossible to conduct sizable operations except along roads. South of the topmost ridges, the mountains slope down gradually to the desert terrain, which is good for vehicular traffic. For this reason, the Cyrenaica region was vulnerable to attack from the south-a fact that Rommel recognized at once during his attack in the spring of 1941. For this reason, he delivered his main attack against Mechili, a desert fort designed to protect the southern approaches to the Cyrenaica. The fact that it was so easy to bypass is the reason why the Cyrenaica was never held with any degree of determination by either side during the entire campaign, although it could be called a natural fortress. During every retreat, every effort was made to pass through this region as rapidly as possible to avoid being intercepted.

(2) The Gebel Nefusa Mountains. These mountains protruded like a barrier between the coastal plains of Tripoli and those of Misurata. South of Tripoli, they rose to a height of 700 meters above sea level, the first 300 meters of which were a gigantic cliff. In the southeast, they descended in a gradual slope. At Homs, in the northeast toward the sea, their height was less than 200 meters above sea level. In the central part, this mountain range was extremely rugged, and motorized troops could only pass along the roads. The southeast slope was covered with a deep layer of wind-blown sandy loess that made vehicular traffic difficult. From the north, this mountain range formed an impregnable fortress. From the southeast, however, it was vulnerable to attack in spite of the mountainous and intersected nature of its approaches, since the attacking forces could find favorable assembly areas in the foothills and could approach under cover to the proximity of defense positions. Possibilities for bypassing the area existed and were taken advantage of by the British in the attack in January 1943.

(3) The Matmata Mountains. These mountains, a range in south Tunisia, had a steep drop of 100 to 200 meters in the east. In the west, they sloped down gradually to a high plateau, which was sandy in parts, while in other areas, the ground was good for motor traffic so that it could be crossed by motorized columns in spite of occasional difficulties. The steep, clifflike wall in the east and north was interrupted by numerous wadis, through some of which an ascent to the high plateau was possible.

The Matmata Mountains narrowed down the size of the coastal plains of southern Tunisia considerably so that it was possible to organize a defense line at the narrowest point, at Mareth. However, the steep mountainside was only a weak protection against flanking attacks, since it could be bypassed with little difficulty. Only if the German-Italian forces had been numerous enough to hold all passes and if they had had a mobile reserve available to repulse any enemy attempts at detouring the mountains would this range have constituted an important factor in the defense.

b. Steep Terraces

Most of the steep terraces in the steppe-like terrain were not high and followed a course parallel with the coast. Thus, they hardly interfered with troop movements. In the numerous caves, overhanging cliffs, and gorges, good opportunities could be found for troop shelters, for which purpose they were frequently used, since they were the most effective protection against air attacks that was to be found. Some of the steep terraces and other similar terrain features, however, became of outstanding importance, namely:

(1) The Northern Rim of the Qattara Depression, on which the Southern Flank of the El Alamein Line Was Based. This rim towered about 300 meters above the floor of the depression, which was 80 meters below sea level. Within the sectors held by the German-Italian forces, there were only three points at which motor traffic was possible, and even there, difficulties were encountered because of the deep sand. Throughout the entire campaign, no better protection for a flank was ever found than in the El Alamein line.

(2) The Steep Terrace at Sollum Between the Bardia-Capuzzo High Plateau and the Sollum Coastal Plain. There were two roads with numerous serpentine curves across the terrace, one from the Via Balbia-the tarred coastal road-the other from the Halfaya Pass road. During the period of positional warfare in the summer of 1941, the terrace was within the combat area.

(3) Large-Size Wadis. These were found in the Cyrenaica region and in the eastern approaches to the Tripolitanian Mountain and extended as far as the Bay of Sirte. Usually the bed of a wadi consisted of a layer of soft sand; less frequently, the beds were salty swamps with. a growth of camel's thorn. The banks were usually steep but not continuous, since they were cut by numerous intersecting wadis. On the whole, wadis could be considered as terrain obstacles-but as obstacles that could be overcome without difficulty unless obstinately defended.

During the German-Italian retreat from El Alamein to Tunis, only one defense position was based on a wadi, namely the Buerat line, which extended along the Zem-Zein wadi south of the Via Balbia. After careful deliberation, however, the line was developed east of the wadi to prevent an approach by the enemy under cover and not on the low-lying west bank, since the west bank was dominated by the higher opposite bank.

The Buerat line could be bypassed easily. It was therefore evacuated by the infantry before the attack began and held only for a short while in a delaying action by mobile units.

(4) Dune Terrain. Large sandy areas were found close to the coast, near larger wadis, and in the desert proper, where the ergs* present barriers that were impenetrable for traffic.

*Large areas of shifting sand dunes (translator).

Big dunes along the coast that interfered with traffic were found around Agedabia, on the shores of the Bay of Sirte south of Misurata, and in the neighborhood of Tripoli, thus mostly in western Libya. These dunes seriously impeded traffic off the roads, and even the roads were affected, since the dunes shifted constantly. After severe storms, the roads became so deeply covered with sand that they had to be cleared. For this reason, a constant road-maintenance service was necessary where the roads crossed dune areas.

A large area of dunes was also found north of the El Fareh wadi, between El Agheila and Marada along the shores of the Bay of Sirte. These dunes protected the German Marsa el Brega position against flanking attacks and forced the British to make a wide detour through the region south of the El Fareh wadi, where vehicular traffic was possible.

The big dunes of the desert proper were all south of the zone of operations, and only a section of them along the border between Libya and Egypt played a role of some tactical importance, since they afforded protection for the south flank of the German Alamein positions. The dunes in the desert proper were not crescent shaped like the dunes along the coast but formed continuous ridges between four and fifty meters high that usually extended from north to south. A number of these ridges, driven by the wind, formed a labyrinthian confusion of dune ridges with completely encircled hollows in which the firm ground could be seen. This enormous ocean of dunes formed what might be called a collection of honeycomb dunes. To cross them, it was necessary to have the best cross-country vehicles available and to drive at top speed at the first dune, breaking through its crest, and on driving down the opposite slope, to gather speed for the next dune. While driving in this way, vehicles were enveloped in a dense cloud of dust that reduced visibility to practically nil. In this way, one to two kilometers might be covered per day. Serious losses in personnel and materiel were unavoidable.

The Great Eastern Erg, a similar large dune area, extended from south Tunisia to south Algeria, close to the western border of Libya. If adequate German manpower had been available to extend the Mareth position across the Matmata Mountains and Fort Le Boeuf to this dune area, the German flank would have been as well protected as was the case in the Alamein line.

(5) Salt Swamps. These swamps developed at those points where the water in the subsoil of the desert rose to the surface. Owing to the constant evaporation that takes place in the desert, the salts carried by the water were deposited, and the resultant brine formed either a lake or, when mixed with sand and clay, a patch of thick, tough mud on which salt-marsh vegetation could take root. Once a person was caught in a salt swamp, it was impossible for him to escape without help. Vehicles sunk in salt marshes could be recovered but only on terrain that was not too swampy. In really soft, swampy ground, the vehicle had to be pulled out by another vehicle, which was often extremely difficult and could only be done if the latter was on firm ground and had a strong engine. Most of the salt marshes were crossed by fords that were known to the natives. Many of the fords could carry vehicular traffic so that any salt marshes within a defensive position should always be kept under observation, and all fords crossing it must be carefully reconnoitered with the aid of native guides. Frequently, the salt marshes dried out completely and then presented no obstacle at all.

The biggest salt marsh in the Libyan and Egyptian deserts was the Qattara Depression, the surface of which was eighty meters below sea level. This depression and its northern rim protected the flank of the El Alamein line. The swamp itself was skirted by a zone of soft sand varying between one and two kilometers in width, on which a few vehicles could travel with some difficulty. All other ground outside of the actual swamp, but within the Qattara Depression, was also soft and difficult to cross with vehicles. The salt marsh that was within the German zone of operations in the Marsa el Brega line was considerably smaller. Nevertheless, in conjunction with the sandy patches and dune areas, it provided good protection against a frontal attack, in spite of the fact that it had numerous fords. The salt marshes of southern Tunisia, called Schotts, were of more importance. The Schott el Djerid was the terrain feature that led to the decision to construct the Gabes line, which served as a rear line for the Mareth line. In most parts, the Schott el Djerid was considered an impassable obstacle, but its eastern part, the so-called El Fedjad Schott, had numerous good fords that could be crossed without difficulty by vehicles.