\fdO'^ - Old Forge Coal Mines

304 TRACK WORK.
(1008) 8 ft. G in. = 102 in. 15 ft. 3 in. = 183 in. 183
in. — 102 in. = 81 in. 81 in. h- 48 = 1.69 in. = 1|| in. Ans.
(1009)
See Art. 1698.
(1010) We find the crotch frog distance as follows:
From the table of Tangent and Chord Deflections, we find
the tangent
deflection of a 100-ft. chord of a 10° curve is
8.72 ft. One-half the gauge is 2.35 ft. Calling
frog distance x^ we have the proportion
8.72 : 2.35:: 100' : .jr*;
the crotch
, 100-^ , X 2.35 - .__ ,
-i- whence, = — = 2,695, nearly,
8. < 2
and X = 51.9 ft. Ans.
The central angle for a chord of 51.9 ft. is 6' X 51.9 =
311.4' = 5° 11.4', and the angle of the crotch frog is 5° 11.4' x
2 = 10° 22.8'. Ans.
(lOll)