Your Pro Citizen Newsletter 51 - Types of Obstacles; Weekly Discount Code

Emplacing obstacles to impede the movement of a threat is as old as warfare itself. Ditches, rubble, moats, and abatis are all ancient methods of putting something between an organization and a threat. We will save the employment or purpose of the different types of obstacles for another time, this is a quick overview of some options available to use.

There are existing and reinforcing obstacles. Reinforcing obstacles are used by both friendly and enemy forces to tie together, anchor, strengthen, and extend existing obstacles. Careful evaluation of the terrain to determine its existing obstructing or canalizing effect is required to achieve maximum use of reinforcing obstacles. Installation time, type of heavy equipment available, and manpower usually are the most important factors.

The reinforcing obstacles are (two in bold are probably most applicable to us):

• Landmines.

• Constructed obstacles

• Demolition obstacles

• Improvised obstacles

Land Mines. Land mine is a munition on or near the ground or other surface area that is designed to be exploded by the presence, proximity, or contact of a person or vehicle. The Ottawa Treaty (eliminating anti personnel mines other than on Korean Peninsula) is not followed by China, Russia, or the US. The US has a contradictory stance on it, the current administration claims they are abiding by it but in Nov 2024 they committed to sending anti-personnel mines to Ukraine in violation of the treaty. This treaty does not apply to the M18A1 Claymore as they are command detonated (tripwire rigging of a claymore is a gray area…on paper anyway. Supposedly it is good to go as long as it is recovered or “used” each time). Pretty irrelevant for our purposes, just mentioning for doctrine's and neat to know sake.

Constructed Obstacles. Units create constructed obstacles with manpower or equipment without the use of explosives.

Examples of constructed obstacles include:

Ditches. Ditches across roads and trails are obstacles. Large ditches in open areas require heavy equipment and a lot of time but can be very effective at keeping vehicles out of an area.

Log hurdles. Log hurdles act as "speed bumps" on roads. They are installed easily and are most effective when used in conjunction with other obstacles. Log hurdles can be constructed using logs greater than 10 inches in diameter. The size of the logs will dictate if the hurdles should be constructed of single logs or multiple logs tied together. On level ground, log hurdles will not stop tracked vehicles or off some road optimized vehicles, but will cause them to slow down. Hurdles will improve the effectiveness of other obstacles by slowing enemy vehicles and making them more vulnerable to friendly weapon fire. (Red arrow indicates direction of opposing force movement)

Log cribs. A log crib is constructed of logs, dirt, and rocks. The logs are used to make rectangular or triangular cribs filled with dirt and rock. These are used to block narrow roads and defiles. Rectangular or triangular log cribs are used effectively as roadblocks where standing timber is available, and where such an obstacle cannot be readily bypassed. Unless substantially built, obstacles of this type are not effective against heavy-tracked vehicles. Cribs are strengthened by filling them with earth. It is preferable to obtain the earth by digging a shallow ditch in front of the obstacle. Log hurdles in front of a log crib will force vehicles to reduce speed and add to the effectiveness of the roadblock.

Log posts. Think of these as fence posts planted in a roadway. Log posts embedded in the road and employed in-depth can stop tracked vehicles. If they are not high enough to be pushed out of the way, posts can cause a tracked vehicle to throw a track if it tries to climb over. If employed with wire and mines, they also can slow enemy Infantry. Posts are among the best antivehicular obstacles because each post presents breaching problems to the attacker. There are no fast methods of breaching a belt of posts. Normally, the attacker will try to bypass such an obstacle. Therefore, post obstacles should be placed where bypass requires much time and effort. Posts should be hardwood with a minimum diameter of 40 centimeters (15.8 inches). All posts are buried 1.5 meters (5 feet) in the ground, either vertically or at a slight angle toward the enemy, and project between 75 to 120 centimeters (30 to 48 inches) above ground level. The height should vary from post to post. The minimum acceptable density for posts is 200 per 100 meters (328 feet) of front. The spacing should be irregular, with at least 1 meter (3.3 feet), and not more than 2 meters (6.6 feet), between posts. The effect of post type obstacles can be improved, and the obstacles made more difficult to breach, by weaving spirals of barbed wire among the posts.

Wire entanglements. Wire entanglements impede the movement of dismounted enemy Infantry, and in some cases, tracked and wheeled vehicles. Triple standard (not “triple strand”) concertina is a common wire obstacle as 11 row concertina. However, there are other types, such as double apron, tanglefoot, and general-purpose barbed-tape obstacles. The materials used in constructing wire entanglements are relatively lightweight (compared to other obstacles) and inexpensive, considering the protection they afford. Standard barbed wire from a farm supply store can be effective if emplaced properly, but it cannot be used in place of coiled concertina. So don’t think for a second you are going to get a triple standard or 11 row out of a roll of TSC barbed wire. The second challenge is personnel; proper wire obstacles are labor and time intensive. They take a lot of people working together to construct / emplace; even fully trained and manned combat engineer platoon capabilities can be challenged by obstacle emplacement. Be realistic in your thinking.

Abatis. An abatis is a tangle of felled trees, leaving a 1 or 2 yards (0.9 or 1.8 m) stump in such a manner as the trees fall interlocked pointing at a 45-degree angle towards the direction of approach of the enemy. Try to leave the trees remain connected to the stumps and the length of roadway covered be at least 80 yards (75 m). Abatis are only effective if large enough trees, telephone poles, or other similar objects are available to stop the opposing force. An abatis is an obstacle created by cutting down trees so their tops are crisscrossed and pointing toward the expected enemy direction. It is most effective for stopping vehicles in a forest or narrow movement routes.

Constructed wire and log obstacles are a combination of the two. They are time consuming and need to be built deliberately but can be effective at stopping a threat.

Demolition Obstacles. Army and USMC units create demolition obstacles by detonating explosives. There are many uses for demolitions, but some examples are road craters and abatis. Road craters are obstacles on roads or trails if the areas on the flanks of the crater are tied into steep slopes or mined areas. Road craters can compel the opposing force to use earthmoving equipment, blade tanks, or mechanical bridging assets.

Improvised Obstacles. Improvised obstacles are designed with imagination and ingenuity when using available materiel and other resources. Improvised obstacles include rubble from selected masonry structures and buildings in a built-up area will limit movement through an area and provide fortified fighting positions. Another “category” is battle damage by using damaged or junked vehicle hulks or other debris as roadblocks. Flooded areas are created by opening floodgates or breaching levees are another improvised obstacle.

Summary. The combat engineers among our readers are having a great newsletter morning, they always love this kind of stuff. The takeaway is not only the doctrinal overview of the types of obstacles, but also the mental process and creativity that can be applied to adapt these to a crisis. Denying access to a neighborhood or even a section of town to keep groups of criminals and rioters (“peaceful protestors”) is always a good thing to consider. While you may not necessarily be sinking posts in the local highway you may need to construct temporary barriers to keep mobs from encroaching. As always be realistic and understand just how labor intensive any obstacle is…the easier it is to emplace the easier it is to breach.

Today’s Discount Code (only good ‘til midnight)