Comparing Containment: The Sizzler

To illustrate the relationship between restraint fit and containment, let's look at a popular and profitable amusement ride that met all industry standards and continued to pass regulatory inspections despite a decade-long history of serious ejection accidents involving young children.

Photo of 6-year-old riding the Sizzler alone provided by telegram.com

The Wisdom Sizzler - Ride Summary

• The Wisdom Sizzler was designed in the 1970s as a teenage/adult thrill ride. In 1999, the manufacturer was asked to issue a height requirement instead of the 11-year-old limit to ride alone documented in the ride manual. A mandatory bulletin was issued instructing ride owners to post signs stating that riders 52"-tall may ride alone and children 36"-tall may ride with someone else. The change effectively reduced the minimum age of unaccompanied riders from 11-years-old to 6 years-old and encouraged parents to bring toddlers on board a highly dynamic ride with restraints fitted for teens and adults.
• The Sizzler is considered a major ride with scrambling-type motion, where groups of cars spin clockwise around the central mast, and each individual car spins counter-clockwise around its own mast. The ride lasts approximately 1.5 minutes. Riders feel like they're moving around in a triangular pattern, accelerating rapidly then slowing almost to a stop, then accelerating again.
• The sleek, low-profile containment system increases the thrill potential, but also reduces its ability to contain smaller riders. The ride generates lateral acceleration (y-axis) that pushes the rider to the side, and generates negative acceleration in the x-axis, which pushes the rider forward and away from the seat back. The front of the car has little to hold riders inside except a fixed restraint bar positioned more than nine inches above the seat.

Safer Seating Arrangements

The following photos show safer use of the Sizzler. On the left, you see three teenage girls riding together. Note the difference in the way their larger bodies fit securely within the car's containment system. On the right, you see a family riding together. The smaller child is approximately the same age/size as the little girl riding solo in the first picture, but the potential for sliding is reduced because the seat is filled up. Notice the difference, though, between the way the ride fits him compared with his older brother and mom. A ride with individually-adjustable lap bars would be a safer choice.

Photo of 13 & 14-year-old girls riding the Sizzler provided by TheOlympian.com		Photo of adult riding with two children, ages 9 and 6 provided by pictopia.com

Child Containment

• The motion of the ride requires that riders brace themselves with their feet and hands to resist the ride forces pushing them to the outside of the car, yet engineering analyses conducted by federal and state authorities following child ejection accidents found that 52" riders are too short to reach the floor with their feet, and therefore cannot properly brace themselves.
• Ejections accounted for 32% of the Sizzler accidents reported to state regulatory agencies, and two thirds of the ejected riders were under the age of 10. As comparison, ejections account for less than 10% of accidents reported for scrambler-style rides and less than 4% of accidents reported for all amusement rides.
• In 2006, the manufacturer issued a mandatory bulletin requiring owner/operators to fill in the largest gap in the center of the fixed lap bar. (The first photo shows the gap; the bottom two photos show Sizzlers with the lap bar filler piece.)
• More children were ejected from this ride during the 2007 season, sparking another manufacturer bulletin, this one non-mandatory, authorizing ride owners to install supplemental lap belts in the Sizzler. Parents should note that, although the ride is approved for use by children as small as 36", one of the engineering reports found that a child under 42" in height who is sharing the single lap belt with an adult rider would not be adequately restrained due to the difference in their sizes.