High-speed vehicle pursuits are sometimes a perilous enterprise — some jurisdictions are even adopting controversial “no-pursuit” policies — so officers and agencies are always looking for ways to mitigate the dangers.
A number of years ago, a retired Utah Highway Patrol trooper named Donald Kilgrow and a design engineer devised the Stinger Spike Strip, now a well-known tire-deflation system that has certainly saved countless lives. But as great as they are, Spike Strips have their own inherent dangers.
According to ODMP, more than 20 officers have been killed and countless officers have been injured while deploying Spike Strips — thankfully, Danville (Ohio) Officer Chad Lishness is reported to be in good condition after being struck by a fleeing suspect’s vehicle just yesterday morning.
Inventors and officers are still partnering to build a better mousetrap. Late last year, I wrote about the End-X Systems PT1100, a patent-pending technology that enables officers to deploy Stop Sticks from within their squad car, and sometime soon I’ll investigate a product named NightHawk (previously called VIPER) from Pacific Scientific. Today, I want to let you know about the development of the DynaSpike, starting with the video below from their website, followed by some additional information I got from Eric Spencer, the engineer who invented this great new product.
A Précis on the Product
While “no-pursuit” policies might make sense make sense in certain neighborhoods — school zones immediately spring to mind — good guys are always going to chase bad guys. Thus the need for products like DynaSpike.
The patented DynaSpike system uses high-strength spikes that penetrate all types of tires — including self-sealing and run-flats — and is effective on all types of vehicles, including cars, trucks, and buses. The hollow spikes deflate tires in a regulated manner, slowing the violator’s vehicle and allowing him or her to make a controlled stop.
DynaSpike is powered by a self-contained tank of pressurized air (150-psi) connected to a double-acting pneumatic actuator. The wireless remote is programmed to control a solenoid valve that directs the flow of pressurized air to the pneumatic actuator.
When the open button on the wireless remote control is pressed, the solenoid valve directs the flow of pressurized air to the actuator, which extends the scissor mechanism of the spike strip out and into the path of the fleeing vehicle. When the close button on the wireless remote is pressed, the solenoid valve directs the flow of pressurized air to the actuator, which retracts the scissor mechanism.
In some ways, the DynaSpike system is very similar to current pursuit-termination products. They’re stored in the trunk of the squad car and can be very-quickly deployed along the shoulder of a road. It takes less than 10 seconds to turn the DynaSpike on and remove the safety interlocks, which are designed to prevent accidental deployment.
The officer then finds a safe location where he/she can see the DynaSpike and see the fleeing vehicle, but remain far enough away to ensure they’re not injured once the DynaSpike is deployed.
The operator can be up to 100 yards away, and still remotely control the strips — using what amounts to being a key fob — to extend 17.5 feet into the roadway, and then quickly retract them to allow the pursuing vehicle to safely pass.
The officer can then retrieve the DynaSpike from the side of the road, recharge the air supply, replace any missing spikes, and place the DynaSpike back in the cruiser’s trunk, ready to end the next pursuit.
All this from someone who was never a cop...
Aircraft Engineering and Street-Level Testing
“Development of the DynaSpike all started with an innocent conversation with my brother, who is a police officer for a small town in upstate New York,” Spencer told me. “I was so surprised when he told me how dangerous current ‘throw-type’ pursuit termination products are, and I immediately said there has to be a better way to solve this problem.”
Early in his engineering career, Spencer had worked on missile launchers for aircraft that used high pressure pneumatics to power scissor mechanisms, so it occurred to him that he could adapt some of that aircraft technology to extend and retract the scissor mechanism of a spike strip.
Once Spencer settled on the use of pneumatics, the rest of the system “fell into place pretty easily,” he said.
“First I built a rudimentary prototype just to confirm the basic concept would work. It took several iterations to get the right size of pneumatic components to get the system to work reliably and operate at a safe pressure. After a couple of redesigns, the prototype worked flawlessly, and I knew I had something that could be used to safely end high speed pursuits.”
Spencer then had a few prototype DynaSpikes fabricated by local machine shops, and was happy to learn that the Hillsborough County (Fla.) Sheriff’s Office agreed to field test the devices.
“After several months of field testing, and some redesigns as a result of feedback from the field, we finalized the design,” Spencer said.
One of the most interesting — and unique, as far as I can tell — aspects of the DynaSpike is the ability to extend and retract the spikes across almost two lanes of traffic using a wireless remote control. The spikes shoot into the road in about one second, and retract just about as quickly.
This, says Spencer, “ensures you will strike the fleeing car on the first attempt because the driver has no time to react and drive around the spikes. The rapid retraction time ensures that the spikes are quickly removed from the road so that the pursuit vehicles or general public is not accidentally spiked, which can cause hundreds of dollars of damage.
So, what does Spencer think of “no-pursuit” policies?
“If a child is kidnapped and officers can follow or track the vehicle, you want officers to have the ability to follow that vehicle and never lose sight of it,” he said.
“However, it doesn’t make sense for a 100 mile-per-hour chase through city streets to catch a shoplifter. There has to be some balance and intelligence to the policy.”
Well said, sir. Well said indeed.
