1. Light rail: 30 pounds per linear foot (maximum load limit per foot evenly distributed).

2. Light rail maximum point load: 125 pounds.

3. Joist light rail support points, maximum point load (providing other loads are attached to any light rail sections being supported by same support point). Load: 386 * pounds

Explanation: There are approximately 66 points where the 4 ½' and 10' light rails are attached to the overhead supporting joists. Since there is a total of 850 feet of light rails @ 30 pounds per linear foot the total maximum load that may be supported is 30 x 850 = 25,500 pounds. 25,500 divided by the 66 support points = 386 pounds per support point.

Note #1 *Important: All light rail sections with their respective ends attached to the specific joist light rail support point that is to be used to support a special light truss, etc. must be left unused (clear) of any other loads for their entire length (to the other end of each where the next support point occurs 4 ½' or 10' away depending on location).

Note #2 All special devices to be supported by attaching at the joist light rail connection points must hang straight down. That is no special device may be placed parallel to and slung between two parallel joists in such a manner as to divide the load because this would also create a side pull (angle) that the structure was not designed to properly accommodate.

#1 Example: A 50' special light or speaker equipment truss may be supported every 10' left to right over the stage with a total of 6 joist light rail support points provided:

a). that no other loads are attached to any light rail the end of which is attached to any of the 6 joist light rail support points being used to support the special truss, and

b). the special truss is properly secured at each of the light rail joist connection points to evenly distribute the weight and to allow the truss to hang straight down underneath same. The maximum load would therefore be 6 x 386 = 2,316 pounds for a special 50' truss supported every 10' and at each end.

#2 Example: A special light or speaker equipment 50' truss may be supported every 4 ½' over the stage from the front of the stage to the rear of the stage with a total of 11* joist light rail support points provided:

a). that no other loads are attached to any light rail the one end of which is attached to any of the 11* joist light rail support points being used to support the special 50' truss, and

b). the special truss is properly secured at each of the light rail joist connections points to evenly distribute the weight and to allow the truss to hang straight down underneath same. The maximum load with 11 support points would therefore be 11 x 386 = 4,246 pounds for a 50' truss supported every 4 ½ feet and at each end.

*The first 4 ½' of the overhead grid is cantilevered up approximately 23 degrees and protrudes over the covered audience area. Therefore using this support point for a 50' special truss creates a need for a different length of attachment device compared to the other 10 support points.

Note #3: Any proposed system that departs from the above procedures in any manner must receive on site approval from the Metropolitan Park Manager.