5:14A-7.4        Patron clearance envelope design criteria

 (b)  The shape and size of the required clearance envelope shall be based on the appropriate patron model and the design of the patron containment system, if any.  The minimum patron model shall be based on Dreyfuss Human Scale 4/5/6, 7/8/9 or SAE J833, or CDC 95th percentile with an additional (extended) arm and leg reach of three inches (effectively a 99.9th percentile) male, adult or child, as appropriate.  The following shall be considered:

1.  The intended patron size and height and any specified restriction for minimum or maximum patron height; 2.  The shape(s) and configuration of the patron containment system including:

i.  Seats, armrest, seat back and sides, foot well or other.

ii.  Associated restraint system(s), if provided, for example, lap bar, seat belt, shoulder restraint, cage, or other; and

iii.  The ability, as limited by the patron containment, of the rider to extend any part of their body, for example, arms and legs outward beyond the perimeters of the vehicle;

3.  The physical nature of surrounding objects or surfaces that might otherwise be contacted, for example sharp, hard, rough or abrasive, ability to snag or trap and hold, or other attributes that may produce undesirable contact for the riders of the ride or device;

4.  The relative speeds and directions that contact might take place;

5.  The reasonably foreseeable changes that are likely to occur in the location or nature of the surroundings, for example, other adjacent moving vehicles or objects and their physical nature and speeds; and

6.  The possibility of variations in the position or orientation of the patron carrying device (for example, angular movement, side movement, unrestrained or undampened motion or free swinging).

(c) The Patron Clearance Envelope Analysis shall be in accordance with N.J.A.C. 5:14A-7.4.  These formats and the following definitions may be used as a guideline for determining minimum patron clearance envelope for amusement rides and devices: 

1.  The reach distance shall be the maximum reach limited only by the vehicle and seat geometry and restraint system.  The possibility of a patron extending arms or legs through vehicle openings or beyond the reasonably foreseeable reach shall be considered.  The Ride Analysis performed in accordance with N.J.A.C. 5:14A-7.2 may modify these requirements.

2.  Where the design of an amusement ride or device allows contact within the clearance envelope between patrons and surrounding surfaces or objects, the manufacturer shall take reasonably appropriate measures to ensure that those surfaces or objects are configured to avoid hostile features such as splinters, sharp or sharply angled features or edges, protruding items, pinch points or entrapment areas.  This requirement is especially important in a ride or device load/unload area where patron control and assistance devices are provided.

3.  When the design of an amusement ride or device allows patron-to-patron contact, appropriate steps shall be taken to ensure that the potential contact is appropriate for the amusement ride's or device's intended use and the intended patron experience.  Patron safety shall be addressed as dictated by the Ride Analysis.

1.  The specified means shall include points from which measurements shall be taken. The locations of these points shall be illustrated with appropriate drawings in the manufacturer provided instructions or they may be physical markers on the amusement ride or device. 

2.  The determined means and clearance distances shall be shown in a convenient form and illustrated both graphically and numerically.  Illustrations similar to Figures 3 and 4 below are one acceptable method.

Figure 3

Sample Rider Clearance Envelope – Front View

Figure 4

Sample Rider Clearance Envelope – Side View

(e)  Any moveable system or device designed to encroach on the clearance envelope, that is, loading/unloading platforms, decks or other devices, shall be designed in a failsafe manner in order to prevent undesirable contact.

(f)  The design shall include advisory signs or warning signs based on the attributes of the amusement ride or device.  The recommendations included with the design shall be clear and concise, but are not intended to be the final wording of the signs that may be generated and displayed at the ride or device. 

(g) Secondary safety devices such as latching belts, straps or other devices that limit the travel of a primary restraint device are acceptable.

5:14A-7.5        Acceleration limits

(a)  Amusement rides and devices shall be designed such that the accelerations are within the limits specified in this subchapter.  Any ride submitted for type certification/amended type certification or individual approval/supplemental modification certification with g’s in excess of 75 percent of the limits of this subchapter shall be tested in accordance with ASTM F 2137-01.  Any ride that has peaks greater than 75 percent of any value in the pulse width of less than 60 seconds in Figures 5 through 9 below, no matter how long its total run time, requires a Department-witnessed accelerometer test at the time of the acceptance inspection. For a carnival ride, this test may be performed at the factory by a third party testing agency.   

(b)  Amusement rides and devices or modifications that are designed to operate outside the acceleration limits herein shall include justification in the Ride Analysis.  The justification shall include a review by a biodynamic expert.

(c)  Acceleration can vary greatly depending on the type and design of the amusement ride or device and the effect of these accelerations is dependent on many factors that may be considered in the design. Accelerations shall be coordinated with the intended physical orientation of the patron during the operating cycle.  Rides and devices with patron containment systems shall be designed such that the patron is suitably contained and positioned to accept these accelerations.  The Patron Restraint and Containment Analysis shall consider cases related to patron position within the restraint as determined by the Ride Analysis.  Figure 1 in N.J.A.C. 5:14A-7.2 illustrates the coordinate system utilized.

            1.  For roller coasters, the maximum pitch, roll, and yaw design acceleration rates on the rider are (1 rev/sec²) or (2∏r/sec²). Higher values may be used if demonstrated to be safe in the Ride Analysis.  These are not to be used to exceed maximum acceleration rates from Figures 5 through 9 below.

(d)  Sustained acceleration limits are shown in Figures 5, 6, 7, 8 and 9 below.  The following definitions apply:

1.  Acceleration units are “g’s” (32.2 ft/sec/sec or 9.81 m/sec/sec).

2.  The limits are based on low pass filtered data with a cutoff frequency of five Hz.  The filter to be applied shall be either a 2 pole Butterworth applied in both the forward and reverse directions, or a 4 pole Butterworth applied in the forward direction conforming to SAE J 211.  Cutoff frequency is defined to be that frequency where the magnitude response of the filter is the square root of 1/2.

3.  Impacts are not addressed by this section.

4.  Acceleration limits herein are for patrons 48 inches in height and above.  The Ride Analysis shall determine whether more restrictive limits are appropriate for an amusement ride or device that accommodates patrons under 48 inches in height.  This determination shall consider biodynamic effects on the patrons. 

5.  The coordinates and measurement point for the acceleration limits are in accordance with ASTM F 2137-01 Section 12 “Standardized Amusement Ride Characterization Test” (SARC Test).  

6.  The limits specified for all axes are for total net acceleration, inclusive of earth’s gravity.  A motionless body would therefore have a magnitude of one g measured in the axis perpendicular to the earth’s surface, and a zero g magnitude in the axes parallel to the earth’s surface.

7.  Steady state values in the charts are not limited in time unless otherwise specified.  Sustained exposure shall not exceed 90 seconds in a single event.

            i.   Sustained exposure in +Gz shall not exceed 40 seconds in a single event.

8.  The Patron Restraint and Containment Analysis shall be used to determine the type of restraint.  The type and performance of the restraint system selected may require a reduction in the acceleration limit. These limits are provided for the following basic restraints types: 

  i.  Base Case (Class 4 or 5 Restraint):   For the purpose of acceleration limits the class 4 restraint used as the base case herein also provides support to the lower body in all directions and maintains patron contact with the seat at all times.

 ii. Over-the-Shoulder (Class 5 Restraint)

iii. Prone Restraint:  A prone restraint is one in which the patron is oriented face down at a point or points during the ride cycle.  A prone restraint is a restraint designed to allow the patron to accept higher acceleration in the –Gx (eyes front) as compared to the Base Case and Over-the-Shoulder restraints.

 (e)  Simultaneous combinations of single axis accelerations shall be limited as follows: 

1.  The instantaneous combined acceleration magnitude of any two axes shall be limited by a curve that is defined in each quadrant by an ellipse.  The ellipse is centered at (0,0) and is characterized by major and minor radii equal to the allowable 200 millisecond (msec) g limits x 1.1.  Graphical illustrations of this requirement are presented in Figure 10 below.  (Note:  For a given ride, only three of the illustrations will apply.)

(f)  Reversals in X and Y accelerations are shown in Figure 10.  The following criteria shall apply:

1.  The peak-to-peak transition time between consecutive sustained events in X and Y accelerations shall be greater than 200 msec, as measured by the time between the peaks of the consecutive events.  When the duration between consecutive sustained events is less than 200 milliseconds, the limit for the peak values shall be reduced by 50 percent.

2.  The following examples illustrate such reversals (Figure 10):

(g)  Transitions in Z

1.  Transition directly from negative (eyes up) limits to positive (eyes down) limits is restricted.  If patrons are exposed to a negative Gz environment for more than three seconds, then the limits are reduced as shown in the +Gz limit chart for six seconds after the transition to positive Gz.  After the six-second period, the limits may be increased to the normal chart levels.

2.  Other transitions in Z accelerations are shown in Figure 11 below.  The following criteria shall apply: When transitioning from sustained weightless (0G) and more negative levels to two g and more positive levels, the effective onset of positive g’s shall be less than 15 g/sec.  Figure 11 below illustrates such transitions.

(h)  Measurement and analysis of acceleration on amusement rides and devices shall be performed in accordance with ASTM F 2137-01, “Measuring the Dynamic Characteristics of Amusement Rides and Devices.”  The design acceleration levels of the final operational assembly of a newly developed amusement ride, device, or modification shall be verified at commissioning.  The manufacturer may verify acceleration limits herein by using either manual or automatic procedures. 

(i)  Illustrations for simultaneous acceleration combinations between axes follow: 

  Illustration 1 of 8

Illustration 3 of 8

Illustration 4 of 8

Illustration 5 of 8

Illustration 6 0f 8

Illustration 7 of 8

Illustration 8 of 8

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