TESTS OF WOODEN BARRELS. 5 



GENERAL OBSERVATIONS OF NATURE OF FAILURES. 



In each kind of test the first water to appear on the outside of the 

 barrel was usually from the seepage through the pores of the wood 

 at the chime. The first leak usually occurred either between the 

 staves and the head or between the staves at the chime. In all the 

 tests except the internal pressure the first leak was usually coincident 

 with the slipping of the staves. 



In the internal-pressure test there were two general classes of 

 failures: (1) By springing and breaking of the head; and (2) by 

 leaking between the staves at the bilge. 



In the diagonal-compression test the failure was a general failure 

 of the head combined with the slipping of the staves. In the com 

 pression-perpendicular test the failure was a general leaking at the 

 heads and slipping of the staves followed by the breaking of the 

 staves at the bilge. 



In the side-drop test the slipping of the staves caused loosening of 

 the hoops and leakage at the heads. This was followed by breaking 

 of the staves at the bilge. In three of the six tests the failure of the 

 barrels was due to the heads being broken or forced out by the 

 internal pressure produced by the impact. 



The lower heads of all barrels tested by dropping on the chime were 

 broken or forced out by the pressure due to the impact. 



CHANGES IN DESIGN AS INDICATED BY THE CHARACTER OF THE 



FAILURES. 



A slight increase in the length of the chime from croze to the end of 

 the stave would lessen the amount of seepage without any marked 

 increase of liability to breakage at the croze by dropping the barrel 

 on the chime. The chimes of the test barrels were made exceptionally 

 short (three-fourths of an inch from outer side of croze to end of stave) 

 to reduce the danger of breakage when dropped on the chime. Chimes 

 1 inch long would probably have given better results. 



The internal-pressure test and the side-drop test indicated that the 

 bilge hoops were too wide apart. A spacing of not more than 8 inches 

 between the bilge hoops would have materially strengthened the bar- 

 rels for the internal pressure without any weakening for the other tests. 



The weakest parts of the barrels were the heads. The first leak in 

 most of the tests was due either to the springing of the head or to the 

 slipping of the staves at the head, or to both these causes. 



The ultimate failure of a large per cent of the barrels was at the head. 

 It appears that a head much thicker than the staves would give mate- 

 rially better results. Heads should probably be made about one and 

 one-half times as thick as the staves. 



The heads appeared to be materially weakened by the dowel holes 

 and not infrequently the flagging was forced out. It would seem that 

 these head joints could be improved. 



