a fastener is used to attach the rib to the rib rail it is important to note that rib 28 is of a hypothetical design not currently commercially available and is considered to be cost prohibitive and is essentially employed herein as a construct to demonstrate by contrast the features of the current embodiment specifically note the spacing a and b between the ends of adjacent ribs wherein waste material would be left by this hypothetical design as illustrated in fig5 a nest or grouping of ribs 29 of the present embodiment with mounting surfaces 24 u2032 25 u2032 oriented essentially in line with the immediately proximate segment of rib can be arranged on a sheet of raw plate material in a manner to best utilize the raw material when cutting ribs therefrom this requires the mounting surfaces 24 u2032 25 u2032 to not be oriented essentially parallel it will be noted this arrangement allows for more efficient usage of the raw material than the rib shown in fig2 and 4 by eliminating the waste shown at a and b of fig4 thus allowing the possibility for more ribs to be cut from a similar sized sheet of raw material and reducing the amount of raw material wasted furthermore the ribs are oriented such that the width of the rib is defined as the raw material thickness albeit prior to subsequent machining processes the outline or profile of the rib as seen in this view will be cut in.