NOTES ON RIVETS AND SPACING OF RIVETS FOR OIL-TIGHT WORK. 67 
British 
Admiralty 
American Bureau 
1919-20 rules 
Martell, 
1894 
Lloyd’s 
1919-20 rules 
U. S. Navy | 
On: | ON: | 2. | O. T. | w | O. T. | we | (0), te hae 
Shell plating seams........ 3 34 4 33 4h 3h 3355 4 4-41 
eck plating seams........ 3 33 43 33 4h 34 34-5 4 4-43 
Bulkhead plating seams... . 3 34 43 32 41 34 34-5 4 4-43 
D. B. plating seams....... 3 34 4 32 43 3h 34-5 4 4-4} 
Tunnel plating............ 3 34 4h 32 43 4 4-43 
Frames to shell........... 6 6 7 6 * 8 4 7-14 
Decksbarss (eis) jis) la): 5 45 45 4 43 
Bulkhead bounding bars... 3 5 5 5 5 5 53 4 4t 
Bulkhead stiffeners........ 6 6 7 T T 6 6 6 vi 
Tunnel stiffeners.......... 6 6 7 7 7 6 8 
Shaver joyeqaise, we Gh oceecadons 3 37 3% 33 43 3H 43 45 43-5 
Decl buttsy eee ae 3 33 4 33 4h 3h 4n 4h | 44-5 
Bulkhead butts........... 3 33 43 33 43 33 43 4 43-5 
DB utiseeaie ae sas aroelen. 3 Se 4 34 43 3} 43 4 43 
* 7 up to 27-inch frame spacing. +7 generally. 
6 above 27-inch frame spacing. 53 deep tanks. 
53 inch deep tanks. 4 for 15 per cent length each end. 
strength, and therefore the riveting should not be so closely spaced that more 
material is punched out of the plating than allowed in the calculations, without 
compensation. If, however, these bulkheads form boundaries of oil tanks, it 
becomes a matter of importance, when transverse bulkheads join the longitudinal 
strength bulkheads, to avoid too close spacing in the bounding bars. If the 
strength bulkhead is designed for a spacing of six diameters for rivets in stiffeners 
and oil tightness demands five diameters at a transverse bulkhead, it becomes 
necessary to introduce compensating liners which add to the weight and, on 
account of the extra thickness of plating, increase the difficulty of making the 
structure tight. 
The Hull Division of the Philadelphia Navy Yard recently made a test on an 
experimental box to determine if a six-diameter spacing of rivets would be sat- 
isfactory under the conditions as stated above. It may naturally be expected that 
a wider spacing for oil-tight work can be used where the bulkheads are close to- 
gether, where the stresses due to swash are not severe, and where alternating 
stresses are of secondary consideration. Six diameters might be quite suitable on 
a deck near the neutral axis but unsuitable for parts subject to stresses resulting 
from the vessel working in a seaway or from shocks of gun-fire or explosion. In 
this test it was found that the caulking of bounding bars to heavy bulkheads was 
satisfactory under a 60-foot head with a six-diameter spacing in the connection of 
