— • 206 
For portal struts the jaw plates will have to be from i" to 音 ’’ thick and from 
three to four feet long. If there be no portal vibration rods, the width of plate may 
be made equal to the depth of the portal strut channels, otherwise it should be about 
four inches greater. 
The thickness for any shoe or roller plate is given in Chapter VI. The widtli 
of shoe plate should bo about four inches greater than that of the batter brace plate, 
and the length three inolies or more longer than twice the depth of the batter brace 
channels. 
The width of a roller plate should be about six inches greater than that of the 
shoe plate, and its length eight or nine inches greater than the length of the same. 
Track stringer and plate girder bed plates should be about thick and 14 
square. 
Beam hanger plates should be about 1 各 ” thick and large enough to provide 
full bearing for the hanger nuts. 
The sizes for latticing and lacing bars for all cases are given in Tables XX. and 
Trussing bars should vary iu section from x 3 f, to x 3 士 
The sizes for all truss pins can be interpolated from the diagrams of stresses ， 
and those for vertical pins attaching single lateral rods to jaws can be taken from tli 0 
following table. 
SIZE OF ROD OR BAR 
DIAMETER OF 
IRON PIN 
Round 
Square 
if 
5" 
ir 
3F 
i か 
iH" 
2 ° 
ず 
3^ 
iir 
ず 
ぼ / 
少 
2 嘉 " 
J-K" 
3!" 
2 が 
2 ふ " 
3i" 
dj" • 
It seems almost unnecessary to state tliut the diameter of the greater of the two 
lateral rods attached to the pin is to be used in determining the size of the latter. 
• When double lateral rods aro employed, the sizes of vertical pins through tliß 
jaws can be obtained from the following table. Tlie bending moments are so g rea 
that it will generally be found necessary to employ steel pins. • 
SIZE OF ROB OE BAR 
DIA. OF 
STEEL PIN 
: DIA. OF 
Round 
Square 
IKON PIN 
HP 
i& f/ 
3r 
sr 
ir 
】r 
sr 
3!" 
iU r, 
ir 
3}" 
3r 
4" 
4r 
成 ， 
ふ 
i 始 " 
ir 
sr 
3r 
4r 
4i y， 
他 
3l" 
ボ 
4" 
才 
ず 
aV 
4r 
