Letter Re: Anti-Vehicular Barriers for Retreat Defense

Jim,
This video is rather impressive. The video description reads: “How many times have you wondered how strong those cement barriers are that you see in front of military base entrances?
From time to time someone asks what the concrete barriers are in front of controlled and secure buildings. When they are told that the barriers will stop traffic, even trucks, from approaching the secure building, they usually get a look of disbelief. In the test, the following parameters were used:

Truck weight = 65,000 pounds.
Speed at impact = 50 m.p.h.
Kinetic Energy = 5.5 Million foot-pounds.
Stopping distance = 24 inches.”

I thought that you might find this interesting. Keep of the GOOD work. Best Regards, – R.E.in Oklahoma

JWR Replies. That is indeed an impressive video. Something as simple as a three foot tall berm with a near-vertical face , or a two foot tall concrete “planter” with a vertical face can be almost as effective as the barrier shown in the video.

We live in a highly mechanized society, so in addition to intruders on foot, think in terms of how you would stop intruders that are in wheeled vehicles. Ideally, they should be stopped at a distance where they could then be engaged by rifle fire. And never forget the old military adage that any obstacle that is not in view of armed sentries is only a delay–not a real obstacle.

Stopping tracked vehicles is much more difficult, but thankfully the risk of being attacked by someone in a tracked vehicle is relatively low, and an armored tracked vehicle is even lower. Few of us have the means to construct obstacles to stop those! Depending on terrain, however, most of us can afford to erect barriers to wheeled vehicles. (Flat “plains” country is problematic.)