700 
MR. FAIRBAIRN’S EXPERIMENTAL INQUIRY 
but in boilers and similar vessels, where the rivets require to be close to each other, 
the edges of the plates are weakened to'that extent. In this estimate we must however 
take into consideration the circumstances under which the results were obtained, as 
only two or three rivets came within the reach of experiment : and again, looking at 
the increase of strength which might be gained by having a greater number of rivets 
in combination, and the adhesion of the two surfaces of the plates in contact, which 
in the compressed rivets by machine is considerable, we may fairly assume the follow- 
ing relative strengths as the value of plates with their riveted joints : — 
Taking the strength of the plate at 100 
The strength of the double-riveted joint would then be . . 70 
And the strength of the single-riveted joint 56 
These proportions may therefore in practice be safely taken as nearly the standard 
value of joints, such as used in vessels where they are required to be steam- or water- 
tight, and subjected to pressure varying from 10 to 100 lbs. upon the square inch. 
Since the above was written, I have ascertained, on a recent visit to Bristol, that the 
large steam-ship* now building there is double-riveted, the plates being three-fourths 
of an inch thick over the bottom and bilge, and five-eighths thick up to the water- 
line. These plates are joined together with double rivets of 1 inch diameter, and in- 
serted at distances of 3 inches apart. The proportions appear to be good ; and con- 
ceiving the workmanship to be equally so, I should infer that this fine vessel would 
fairly establish the principle, that iron, in all the ramifications of ship-building, is 
an article of paramount importance to the war as well as to the mercantile navy. 
In the pursuit of the foregoing inquiry, I was naturally led to the consideration of 
the best proportions and best forms of riveting plates together. I investigated this 
subject with great care, and from my own personal knowledge and that of others, 
I have collected a number of practical facts, such as long experience alone could 
furnish. From these data I have been enabled to complete the following Table, 
which for practical use I have found highly valuable in proportioning the distances 
and strength of rivets in joints requiring to be steam- or water-tight. 
Table exhibiting the strongest forms and best proportions of riveted joints as deduced 
from the experiments and actual practice. 
Thickness of 
plates in inches. 
Diameter of 
rivets in inches. 
Length of rivets 
from the head in 
inches. 
Distance of rivets 
from centre to 
centre in inches. 
Quantity of lap 
in single joints in 
inches. 
Quantity of lap in double-riveted 
joints in inches. 
•19=A 
•25=-A 
' •31=Ar 
•38=A 
•50— 
•63=i^ 
•75=i| 
•38' 
•50 
•63 
•75 J 
•811 
•94 
M3 J 
•88'' 
M3 
1-38 
1- 63 
2’25 
2 - 75 
3 - 25 
^ 
1-251 
1-50 
1-63' 
1- 75 J 
2- 00' 
2- 50 
3- 00 
r 
1-251 ^ 
1-50 
1- 88 J 
2- OO'f 5-5 
2-251 
2- 75 >4-5 
3- 25 J 
For the double-riveted joint, 
add two-thirds of the depth of the 
single lap. 
* The Great Britain steam-ship. 
