— 241 — 
ril Pture by bending there are aitxclied to the underside by countersunk rivets two 
an g】 e irons or plates bent into th) form o.' angle irons, the vertical legs being con- 
ne cteJ by countersunk rivets, wliich in the neighbourhood of the pin pass as nearly 
as ma y be through the neutral surface of the T beam, and elsewhere near tlie lower 
etl ges of the angles. 
As tlie axis of the pin is parallel to the lengtli of the bridge, they ertical legs 
也 Ust be transverse thereto. 
This detail will be readily understood from tlie accompanying diagram. 
To illustrate how to find the sizes of the stiffening plates, number of rivets re- 
&c, it will be well to design a beam hanger plate for a 24 f panel of a single 
tr ack bridge. 
The total weight on the four hangers is about; forty tons, and the centres of tlie 
arn hanger holes may be assumed to be situated on the corners of a six inch 
quaie. Uiig would make the bending moment on the plate thirty inch tons, which 
Mould be resisted by tlie T shaped section of the two bent plates combined with the 
portion of tlie beam hanger plate below the pin. Assuming the latter tliick- 
i ， and the plate stiffeners to be of G ff x G r, x angle iron would make the T 
0 ut 12" 父 6 务" x 1", tlie centre of gravity of which is about 5" above tlie bottom. 
The 
moment oi' inertia is thereibre ^ x 12 + 12 x (1.Ö) 2 + ^ (5.5) 3 + 5.5 x 
( 2 . 25 ) 2 =： 54 + 
丄 he resisting moment is given by the equation 
M: 
hi 
so taking E = 4 tons 
4x54 
M ■ 
5 
：43.2 
As the bending moment was 30 inch tons, the sizes assumed are ample. 
你 、 be well to use three quarter inch 031111 tersauk rivets (tlie largest pos- 
e ?’ so a[to make tho ditferent portions oi* the T head act together. 
( | e _ is a tendency to bend the plate iu a direction at angles to tlie one consi- 
res. ’ ’ 出 3 moi nent for wliicli is fifteen inch tons on oach side o：' the pin. This will be 
. e a couple whose forces acb as compression ou the top plate of tlie T and 
te 
at th e 
lo n on fclie riveks near the bottom of tlie angles. T ikiug the centre of moments 
of the top plate ami the distance therefrom to tlie horizontal centre 
ton ^ 1G r i ve t holes as 4 g inches, will make the tension on tho rivets = 3 42 
tli マ如玆 au intensity of only two and a half tans, bscause of the initial tension 
Uvefc、 will make the section required 1.37 square inches ; consequently two 
，1V ^ fcs wil l be sufficient. 
t L , ac 、 仏 s i ze of stiffened beam hanger plate may be adopted for all panels of single 
、 bridges， or tlie fchickaess of the angles may be retlueed to three eigliths of 
ani ^ for short p , nel , 'つ 
difftii’eiice in tlie total weight of iron per lineal foot caused by the use of* 
