We’ve all seen movies where a strip of retractable spikes at a checkpoint tears up a vehicle’s tires, or where a roadside cop throws a chain of linked spikes across the highway in front of a car. While such devices are pretty effective, there’s always room for improvement. That’s where the Pit-BUL and NightHawk car-stopping devices come into play. Both devices are based on a single other existing product, known as the Safe, Quick, Undercarriage Immobilization Device ... or SQUID, for short.

The SQUID was developed in 2010 by the Engineering Science Analysis Corporation and manufacturing partner Pacific Scientific Energetic Materials Company, with funding from Homeland Security's Science & Technology Directorate.

It launches spiked arms attached to strips of heavy webbing into the underside of a vehicle. The result is that the arms and webbing get tangled up in the axles, causing the vehicle to stop. Although it gets the job done, feedback from law enforcement officials indicated that it was too big and heavy. The solution? Divide it into two devices.

The first device, the Pit-Ballistic Undercarriage Lanyard (Pit-BUL), is placed at a checkpoint and looks like a speed bump. Should a driver try charging through that checkpoint, however, spikes attached to netting are launched from the Pit-BUL and into the vehicle’s tires.

Not only does this flatten the tires, but the rotation of the car’s wheels pulls the netting up into the axles. Within milliseconds, the front wheels seize up completely. A car that simply had flat tires could conceivably still be driven for some distance, although not with a great deal of control – potentially making it more dangerous.

Pit-BUL can be remotely activated manually, or can be set to automatically deploy in response to a triggering mechanism. It can be seen in action in the video below.

The second device, NightHawk, serves the same purpose as the spike chain being thrown by hand. In this case, however, no one is required to stand at the side of the road, potentially in the altered path of a fast-moving vehicle.

Instead, the suitcase-like device is placed beside the road, then its human operator retreats to a safe distance of up to 180 feet (55 meters). Just before the vehicle reaches the NightHawk, the operator remotely triggers it to shoot a spike chain across the road. As soon as the vehicle has run over the chain, the user once again activates the device, this time to pull the chain back in. This keeps other vehicles, such as pursuing police cars, from also running over it.

The NightHawk can be seen in the following video – note how much the ejected, covered chain looks like one of those joke snakes that jumps out of a fake can of peanuts.

Source: Homeland Security