APPENDIX 3 

 SUBMERGENCE PRESSURE TESTS ON THE TMB PLANING FLOAT 



PURPOSE AND SCOPE OP THE TESTS 



Subsequent to the tests of the hydrodynamlc properties of the TMB 

 planing float, It was requested that external pressure tests be made In or- 

 der to determine the maximum depth of submergence that the hollow metal 

 float could withstand without collapse. 



The submergence tests were made In the decompression chamber of the 

 Naval Gun Factory, Washington, D.C. A sketch of the model used In these tests 

 Is shown In Figure 41 . The float was airtight when Introduced into the de- 



-7TE **-5 



.— 5^ 



J^« 



-57 



It 

 II 



II 



-1^'— . ,_i' 



z: 



•f- Sheet Steel 



Air 

 Check 

 Valve 



=-|« 



--[00 ^ 



<c =_ 





Ssiis 



-IS 



I * i 



^ II 



-^+4- 

 II 

 II 

 II 

 ■ :'\f I I 

 [I 



tt=--i-.ife 



n 

 II 



Weldment of 

 Reinforcing Rods 



Figure kl - Principal Dimensions of TMB 4l-Inch Planing Float 



compression chamber. The vertical and transverse rods are Introduced only as 

 simple tension members to reinforce the float against the prestressing pres- 

 sure of 8 pounds per square Inch, corresponding to l8 feet of sea water. 

 During the pressure tests, however, no Initial Internal pressure was applied. 



