M-25188-F 



Testing the strength o£ a glued laminated 

 wood arch. 



Development of wood prefabricated house 

 construction. 



M-28751-F. M-26006-F 



sitate more efficient use of material 

 from smaller trees. These conditions 

 give constantly increasing importance 

 to Laboratory investigations and tests 

 of laminated and plywood construction 

 in all its phases, from simple veneer 

 samples to built-up wall and floor sec-A 

 tions and laminated wood arches sub- 

 jected to loadings of thousands of 

 pounds. Tests are made to determine 

 the strength of plywood of different 

 combinations of species, the effect of 

 increasing the number of plies, of vary- 

 ing the ratio of core thickness to total 

 panel thickness, and of joining with 

 various kinds of glues. Possibilities of 

 spliced, laminated, and composite con- 

 struction of beams, panels, columns, 

 and arches built up by both nailing and 

 gluing are under investigation with a 

 view to increasing the economy of wood 

 construction through the utilization of 

 small pieces and material of low grades. 

 New types of construction embodying 

 these principles are demonstrated, such 

 as the utility building of plywood 

 supported by glued arches, now under- 

 going service tests on the Laboratory 

 grounds. 



Shipping containers 



An essential service performed by 

 wood in commerce and daily life is in 

 the form of containers for commodity 

 shipments. The work of the Labora- 

 tory in improving the strength and 

 serviceability of boxes and crates has 

 promoted the more efficient utilization 

 of billions of board feet of lumber, and 

 has led to savings to the consuming^ 

 public, in freight handling charges, * 

 losses, and damage to goods, amounting 

 to millions of dollars a year. 



It is frequently possible to redesign 

 a container so as to reduce the amount 



