NOTES ON RIVETS AND SPACING OF RIVETS FOR OIL-TIGHT WORK. 73 
CONNECTIONS. READING. DIAS. 
UndersSpoundssaaee eee roe 4 
Angles to plates, including staples. Tea eae GURe ORE HO BA a Da DSH Eto ae 2 
1S) poundsjandioverans serene eee 5% 
RISER Cae SER Rol BEE cae GUTS OIELEGe 3% 
Under 4 pounds eee ae area eee 3% 
Seam laps and seam straps........ Or over, 14 pounds to 20 pounds excl........ 4 
Or over, 20 pounds and over................ 4% 
Fo SE opes Me RIS Ch HEI MET A  iee nET ENG LAGiee hua 3144 
. LU fas sea ey OU OA a Reta MBNA A UL eae aie 34% 
Single butt straps and butt laps... Or over, 14 pounds to 20 pounds excl........)| 4 
Or over, 20 pounds and over................ 44 
evh ats poten oe aa mui eam mera ven rot 3% 
mad enw 4 Mounds pesos ces cwyaty es elrere eter spe ee 34% 
Double butt straps.............. Or over, 14 pounds to 20 pounds excl........) 4 
Or over, 20 pounds and over................ 4144 
With reference to the use of T bars no special difficulties have been encountered as 
yet, although the design does not call for their use to replace double bounding bars. 
The only riveting troubles have been due to bevels in the T rather than to spacing of 
rivets. 
Mr. Harotp P. Norton, Member:—Mr. Frear’s paper is a very excellent one, 
because it points out most of the matters under discussion and brings out all of the 
arguments pro and con, but makes very few attempts at definite recommendations. 
It has been our experience at Newport News, in connection with oil-tight work, 
that perhaps as much depends upon the riveting and caulking conditions as upon theo- 
retical considerations. For that reason we are a little inclined to favor the double 
bounding bars for bulkheads, but we do believe that it is only necessary to have the 
rivets countersunk, head and point, in one of these bars. We believe that the panhead 
rivet on the rough side of the bulkhead makes the best job, because the panhead rivet 
draws up the work better and gives a tighter joint. The reason we favor the double 
bar is because the bar on the other side backs up the caulking of the bar on the smooth 
side, and it seems to us that therein lies very largely the secret of success of oil-tight 
work—to see that all of the caulking is properly backed up. That is largely the reason 
why in naval work six-diameter spacing is considered sufficient in a bar at least a half- 
inch thick, against a good, thick bulkhead, such as a longitudinal torpedo protection 
bulkhead, and why a five-diameter spacing is used for the lighter plating of the adjacent 
transverse bullheads. 
It seems to us that it would be to the advantage of the classification societies to 
examine this class of work of the Navy Department, in connection with which the 
investigations mentioned in the paper were made, with a view of perhaps permitting 
some slightly wider spacing in connection with certain merchant work. 
The matter of the double-riveted seam is one in which there seems to be considerable 
difference of opinion, and we suggest that the principal advantage of the double riveting 
is in the bolting up of the work. The work can be bolted up better with the double- 
riveted lap than with the single-riveted lap, and perhaps that is the secret of the advan- 
tage of the latter. But right in this connection there is another possibility, and that is 
