Tornado Intercept Vehicle

The Tornado Intercept Vehicle 1 (TIV 1) and Tornado Intercept Vehicle 2 (TIV 2) are vehicles used to film with an IMAX camera from inside a tornado. They were designed by film director Sean Casey. On May 27, 2013 the TIV2 filmed the inside of a tornado in Kansas with Sean Casey inside.

TIV 1
The Tornado Intercept Vehicle 1 (TIV 1) is a heavily modified 1997 Ford F-450 truck used as a storm chasing platform and built by IMAX director Sean Casey. This heavily armored vehicle can drive into a relatively weak tornado (EF0 to EF3) to film it and take measurements. Work began on the TIV in 2003 and took around eight months to finish, at a total cost of around US$81,000. TIV's armored shell consists of 1/8–1/4 inch steel plate welded to a two inch square steel tubing frame. The windows are bullet resistant polycarbonate, measuring 1 1/2 inches thick on the windshield and 1/2 inch thick on the sides. The TIV weighs approximately 16,500 pounds fully loaded and is powered by a 7.3-liter Ford Power Stroke turbocharged Diesel engine manufactured by Navistar-International, giving it a top speed of 80 mi/h. The TIV has a fuel capacity of 60 USgal, giving it a range of around 500 mi. The TIV is featured in a series called Storm Chasers which began airing on the Discovery Channel in October 2007. TIV was succeeded in 2008 by TIV 2, but returned to service to finish out the 2008 storm chasing season after TIV 2 suffered mechanical problems. In a June 2011 interview with NPR's All Things Considered, Casey said that TIV is still in service and is designated as the backup vehicle in the event TIV 2 breaks down during a shoot.

TIV 2
Casey and his team developed and built the second Tornado Intercept Vehicle, dubbed "TIV 2", to be featured in their next IMAX movie and the Storm Chasers series. Work began in September 2007 by 40 welding students at the Great Plains Technology Center in Lawton, Oklahoma and was completed in time for the 2008 tornado chase season. TIV 2 was designed to address some of the problems experienced with the original TIV, namely its low ground clearance, lack of four-wheel drive, and low top speed. It is based on a Dodge Ram 3500 that was strengthened and converted to six-wheel drive by adding a third axle. After season two the six-wheel drive system was modified to four-wheel drive. It is powered by a 6.7-liter Cummins turbo charged Diesel engine, modified with propane and water injection to produce 625 hp. This gives TIV 2 an estimated top speed of over 100 mi/h. Its fuel capacity is 95 USgal, giving TIV 2 an approximate range of 750 mi. The body of TIV 2 is constructed of a 1/8-inch steel skin welded over a 2 in square tubing steel frame. The windows in TIV 2 are all bullet-resistant 1.63-inch interlayered polycarbonate sheets and tempered glass. TIV 2 also features an IMAX filming turret similar to the one on the original TIV. The original TIV's somewhat cumbersome hydraulic claws were not used on TIV 2 in favor of six hydraulic skirts that drop down to deflect wind over the TIV to stabilize it and protect the underside from debris, and four hydraulically operated anchoring spikes.

TIV 2 debuted on the second season of Storm Chasers, which began airing on the Discovery Channel in October 2008. Its initial performance did not go well, as it was plagued by mechanical failures, including several broken axles, which forced Casey to abandon TIV 2 and return to chasing in the original TIV until TIV 2's issues could be resolved. Although Casey hoped he would be back in TIV 2 before the end of the season, repairs and modifications on TIV 2 took longer than expected and Casey was shown on Storm Chasers ending the season in the original TIV.

In the fall of 2008, TIV 2 received several modifications, mostly focused on reducing the vehicle's 16,500-pound weight. To achieve this, certain less crucial areas of TIV 2's armor were converted from steel to aluminum while more vital areas were reinforced with supplemental composite armor consisting of thin layers of steel, Kevlar, polycarbonate and rubber. In all, the weight reduction measures brought TIV 2's weight down to 14,300 pounds. The safety systems were also improved, with the three front wind skirts being consolidated into one and new hydraulic stabilizing spikes to further increase stability in high winds. Other modifications included additional doors that provided every seat position with an exit (wind skirts up or down), and a redesigned IMAX turret with 50% more windows. The third axle was disconnected from the drive train, thus changing TIV2 to 6×4 from its 6×6 design. The third axle now acts as a brace for the vehicle's weight.

The TIV 2 appeared again in the fourth season of Storm Chasers, and also in an episode of another Discovery Channel series, Mythbusters, wherein both the TIV 2 and the SRV Dominator vehicle operated by Reed Timmer of TornadoVideos.Net were tested to determine their endurance to storm-force winds by being parked behind a Boeing 747 with the engines at full throttle. When tested at a wind speed of 160 MPH, the TIV 2 had the driver's door pulled open, though this was due to human error, as Casey had forgotten to lock the door prior to the test. When tested again at 250 MPH (equivalent to an EF5 tornado), the TIV 2 suffered no ill effects other than the anchoring spikes being slightly bent; the Dominator ended up getting blown approximately 50 ft, although it remained upright.

In 2011, a siren was added to the vehicle to allow the TIV 2 to act as a mobile warning system for civilians in the path of incoming tornadoes, after several incidents earlier that year where the TIV team was unable to effectively warn locals of the imminent danger of the tornadoes they were tracking.

Casey removed the rear flap in early 2012 and built a new set of two hydraulic spikes that go into the ground during an intercept.

On May 27, 2013, TIV 2 intercepted a large tornado near Smith Center, Kansas. The vehicle was struck by large debris from a nearby farm and suffered damage to the roof-mounted anemometer and at least two breaches of the crew compartment when the roof hatch and one of the doors were compromised. Before the anemometer was disabled, it recorded winds of 150 to 175 MPH, placing the tornado in the EF3 to EF4 range on the Enhanced Fujita scale.

TIV 3
Casey plans to build a TIV 3 that has the frame like a Baja racer with great suspension with a smaller cab, still using skirts to drop to the ground and more spikes for help holding up against wind. The TIV 3 has not been built yet, but is in the process.