706 
MR. FAIRBAIRN’S EXPERIMENTAL INQUIRY 
of the length of the ship ; c, c, angle-iron of the same strength is riveted along the 
edge of each rib for the purpose of stiffening the sides of the ship and giving in- 
creased resistance to those parts, also to receive interior plates, some of which, in 
large vessels, are riveted diagonally to the interior angle-irons c, c, &c., forming 
stringers and braces from the kelsons round the bilge to the upper decks. 
Other kinds of frames might be used with double 
angle-iron, as shown at d, d, &c. in the annexed 
sketch, but they are more expensive, and from 
the increased complexity of construction, the 
extra strength obtained does not compensate for 
the difference of cost. Altogether, the frames recorded in fig. 15 have come into 
general use as the most effective and easy of construction. Those experimented upon 
were of different kinds, as shown in Plate LVIII. fig. 17, 18, &c., and in sections given 
in the Tables, and from which the following results were obtained : — 
Table XVI. Experiments to ascertain the strengths of uniform wrought-iron beams 
of different forms to support the sides and other parts of vessels, the beams having 
their ends placed upon props and being loaded in the middle. 
No. 
of 
exp. 
Description and form of the beam. 
Weight 
laid on 
middle. 
Deflections 
with these 
weights. 
Breaking 
weight of 
the beam 
of 7 feet 
between 
the sup- 
ports. 
Weight of 
the beam 
of 7 feet 
6 inches 
long. 
Oak beams. 
Remarks. 
Side of 
square of 
oak beams 
of equal 
strength 
with the 
iron one. 
Weight of 
such beams 
of 7 feet 
6 inches 
long and 
specific 
gravity 900. 
1. 
Beam formed from two 2^ angle-irons, 
riveted together with rivets 6 inches 
asunder, and a plate a f inch thick 
riveted to the back, with rivets 4 
inches asunder. Distance between the 
supports 7 feet, and whole length 7 feet 
6 inches, its weight being 109 lbs. 
^ Thickness. 
° - n AB =5 inches, 
g g agj CD =2-6 inches. 
'-5 b aa = ’5 inch. 
- i * ~ inch. 
•S cc = "64 inch. 
bJ ee = '25 inch. 
The part C was downwards during the 
experiment, the weight being laid upon 
the part D. 
lbs. 
lbs. 
3.'i55 
lbs. 
109 
inches. 
3*6324 
lbs. 
38-65 
The weight 3355 lbs. 
was laid on at once, and 
the beam almost immedi- 
ately sunk -with it ; a 
weight something less 
would have done it. 
2. 
The beam last used, cut in two ; di- 
stance between supports 2 feet 3 inches ; 
vertical rib downwards, that it might 
be stretched as before ; weight of 3 
feet 9 inches =541hs. 
4,039 
5,383 
6,0.55 
6,727 
7,399 
7,735 1 
sunk J 
•18 
•30 
•43 
•64 
•88 
2486 
109 
3-287 
31-80 
With 7735 Ihs. it sunk, 
by stretching and tearing 
at a rivet-hole. 
3. 
The other half of the beam (exp. 1.) 
cut in two. Distance between the sup- 
ports 2 feet 3 inches ; weight of 3 feet 
9 inches =55 lbs. ; vertical rib upwards 
thus, _L that fracture might take place 
by the compression of that rib. 
4,039 
5,383 
6,055 
6,727 
7,399 
8,071 
8,743 
9,415 
10,087 
10,423 
10,759 1 
sunk/ 
•17 
•23 
•26 
•34 
•47 
•63 
•85 
MO 
1- 95 
2- 90 
3458 
109 
3-6692 
39-44 
With 10,7591bs. it sunk ; 
the vertical rib becoming 
twisted. 
