Transactions . -Glear-span=66-^- lClarks Beam. beam, and Clark assumes this value to hold good for theactual girder composed of two 3- by 12-inch pieces of 20 feetspan. In the tests to be described, white pine was used for side-struts in some of the beams, and selected Norway pine in theothers. Diagram 4 shows deflections. No. 1. Two pieces of white pine, each inches deep inches wide. Side-struts of white pine thick,secured by 2-inch steel wire nails. No bolts used. Span, 66inches. (See Fig. 15.) Weight of beam, 42 pounds. Brokeat 7500 pounds. Check-pieces: A weighed 17 p
Transactions . -Glear-span=66-^- lClarks Beam. beam, and Clark assumes this value to hold good for theactual girder composed of two 3- by 12-inch pieces of 20 feetspan. In the tests to be described, white pine was used for side-struts in some of the beams, and selected Norway pine in theothers. Diagram 4 shows deflections. No. 1. Two pieces of white pine, each inches deep inches wide. Side-struts of white pine thick,secured by 2-inch steel wire nails. No bolts used. Span, 66inches. (See Fig. 15.) Weight of beam, 42 pounds. Brokeat 7500 pounds. Check-pieces: A weighed 17 pounds, broke * In the case under discussion, two 8- by 12-inch pieces of Georgia pine wereto be built into a compound beam,f Building Superintendence, page 91. THE EFFICIENCY OF BUILT-UP WOODEN BEAMS. 755 Diagram Clarks Beam. Each horizontal space -Hs inch deflection. 756 THE EFFICIENCY OF BUILT-UP WOODEN BEAMS. at 2700 pounds; D weighed 18 pounds, broke at 2600 of built beam, per cent. No. 2. Exactly the same as No. 1, except that the beamweighed 38 pounds. Broke at 5200 pounds. Check-pieces :A weighed 16 pounds, broke at 1880 pounds; D weighed 16pounds, broke at 1980 pounds. Efficiency of built beam, cent. No. 3. Exactly the same as No. 1, except that the beamweighed 42 pounds. Broke at 7800 pounds. Check-pieces:B weighed 18 pounds, broke at 2400 pounds; C weighed 18pounds, broke at 3500 pounds. Efficiency of beam, per cent. No. 4. Exactly similar to No. 1, except that side-struts wereof selected Norway pine thick, and beam weighed 37pounds. Broke at 6180 pounds. Check-pieces: A weighed
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Keywords: ., bo, bookcentury1800, bookdecade1870, booksubjectmineralindustries
