Global Guerrillas: Caltrops & System Disruption


For educational purposes only.

Remove clothing before ironing.

Do not taunt Happy Fun Ball.


UPDATE 1055EST 27 NOV 2014: H/t to the WRSA commenter who pointed to this related piece from SWJ.


35 responses to “Global Guerrillas: Caltrops & System Disruption

  1. Reblogged this on Starvin Larry and commented:
    Nice technique…

  2. Human ingenuity at its very best.

    Thanks for that.

  3. Those improvised spikes might work against 1960s tires, but not against modern tires.

    • I’m looking at the steel mesh which is on top of my oil-burner. Tough as old boots … 3mm stainless steel.

    • Anyone know how they work against modern combat boots?

    • Not true at all. They were enough of a hazard from 2011-2013 in Texas from cartel drug runners (over 20 vehicles disabled) that special laws were enacted banning their possession. Check out the analysis from small wars journal about their use, its pretty interesting.

      • The ones shown in SWJ are significantly superior in construction to those created from a wire fence.

    • “Those improvised spikes might work against 1960s tires, but not against modern tires.”

      Finally! Solid proof that you ain’t Detroit…no innovation.

  4. Run-Flat tires.

  5. A little dirt brown spray paint would be a nice finishing touch.

  6. Stainless steel tubing cut and bent at the appropriate angles and welded would produce a caltrop able to defeat all but the most sophisticated run flat tires.,

  7. I have some first hand field exp with these caltrops, more commonly known as “jackrocks”. The concept presented is excellent. The execution is deficient as the “gauge” of the metal would have to be greater than presented to be of use as anti vehicle. As presented they may be effective anti personnel and certainly effective anti critter. Much respect for the concept. Lately I have been toying with ideas re: repurposing trail cams and those road signs that have built in radar and display your speed.

    • Yeah, maybe lower gauge and maybe stronger foundation. Lucky thing FREEFOR has tens of thousands of engineers and fabricators. Ha, imagine how many riflemen, and there must be millions of untrained scouts.

  8. Slightly off-topic…

  9. At least the officers went home safely at the end of their shift. Imagine the collateral damage of typical cop gunfighting had they caught them. Dead citizens everdamnwhere.

  10. At least all the officers went home at the end of their shift. Can you imagine the collateral damage of all that police gunfire, to citizens, had they caught them?

    File this under Tactics, Techniques, and Procedures.

  11. In my ute I was engaged in a high speed pursuit on dark country roads. The shitbirds in the vehicle in front of us deployed a full quart bottle of beer which landed dead on the windshield base like a fucking explosion, scared the shit out of us as we were momentarily blinded barreling down a dark tree lined road. Our driver calmly switched on the wipers and we were GTG. We never did catch them which was fortunate for them. I imagine quart bottles have quite a bit of utility in a SHTF scenario. They are so useful and can be filled with almost anything.


    During the union troubles at Kerr-McGee in Trona, CA, the union people used caltrops to flatten the tires of the semi-trucks/trailers whiched crossed the picket lines to make deliveries to the plant. They kept a huge barrel of them in the union office. They were fabricated from rebar. I would imagine if you know how to weld and have access to rebar, you are only limited by your imagination.

  13. revjen45 is right. You use small diameter steel pipe, it does not have to be stainless, and you cut out half moon shapes. Tack weld back to back so that a point is always up. You can turn out hundreds of them fast. And yes, they work on modern tires.

  14. A Non E Mouse

    Outstanding share on Narcotics Armor!

    Hog panel fencing makes heavy duty caltrop material.

  15. NightWatcher

    Typical feedlot panels are made of 4Ga galvanized steel. The cut edges will rust over time, but a good bolt cutter will leave an almost razor edge.

    The bend angle (i.e. bonding angle for a tetrahedon) is 109.5 degrees. In other words, bend until almost perpendicular.

    N.B. Steel tubing works best, but negates the ease of fabrication.
    N.B. (2) Goat panels are more expensive (4 inch mesh) but give you twice as many “crossings”.
    N.B. (3) These will not work on regroovable tires (most military vehicles unless fitted with aftermarket tires).

  16. Use 3″ square mesh x 7 ga.(3/16″) steel. About $60 for a 4′ x 8′ sheet. Cut at 45° and bend at about 95° to 100°. Good on heavy duty tires. Small diameter tubing does not bend without kinking and will need to be welded. I have seen tubing used with a square metal base that was drilled through on all sides and the tube stuffed into the holes. Excellent for fast air bleed out of the tires but too much work to mass produce, unless you invest in all the tooling. The mesh works great and is plenty heavy for truck tires. Also laser cut sheet metal then bent to form the caltrops. These are available online and are antipersonnel mostly. Very sharp and unfriendly.

  17. I know a DOT cop who recently told me about making a U-turn across the median. He said a CALTROP took a 1/2 inch diameter plug out of his tire. Almost pursuit ended quicker than expected. I guess a hollow tube works great to make a big enough hole that a self-sealing tire won’t self seal ever again. Yankee ingenuity at it’s finest.

  18. Caltrops have a long history, and are particularly effective against vehicle tires on hard surfaces, but there are other similar devices that one might wish to contemplate-

    • A chop saw set to a very sharp angle and a couple of teenagers=mass production.

      A 4′ or so piece of pointed rebar with a T handle and a sack full of stakes would allow rapid emplacement. Make hole, insert stake.


  19. robroysimmons

    One news show I watched back in the day was about some union coal miners up in W. Virginia making these out of bent nails welded at the center for use against semi-truck tires

  20. Pingback: Global Guerrillas: Caltrops & System Disruption | From the Trenches World Report

  21. We have a III Patriot (professional machinist) working on caltrops – hollow stainless of sufficient sidewall to be reliable. Non-hollow caltrops and spikes tend to fill the hole they punch in rubber tires. Hollow lets the air out.

    For educational purposes only. Don’t put them in your slippers. Etc…

    • See if a U or channel profile will work, it’ll be easier to make.

      Stainless will last, but consider cleaning up. Magnet can make it easy, but also makes it easier for the other side. How big does a caltrop need to be for the heavy tires on a stryker?

  22. Avoid welding, it adds an extra step. Consider an arbor press. What gage of sheet or strap do you want, and how much pressure do you need? You’re gonna use the cnc at the patriot space to make a simple die that will let you just stamp them out by the hundred, assuming someone doesn’t have access to a proper automatic press.

    I’ve Considered a similar setup for stamping ar mags, but those are much more sensitive to too many variables.

  23. HHH Old Vet.

    1/2″ water pipe, from the scrap yards, old houses, etc. cut ends like a big Ol hypo needle tip and weld up. Chop saw helps speed them along.