201 OF ENGINEERING FOBMULÆ.
Repost ok German Railway Union—continned.
For ascending steep gradients, an auxiliary engine should
be placed behind the train.
A tire is considered unsafe as soon as the rounded part of
the flange is worn away.
Examination in colour blindness is necessary for rail-
way servants whose duty it is to watch coloured signals.
Communication between passenger and guard is not
successful.
Sleeping carriages with one tier are preferred by passengers
to those with two tiers.
SIGNALS.
Telegraph wires through tunnels should be well insulated,
and protected with casing.
For block system, " Siemens’ ” is preferred; the Morse
system with independent optical signals also recommended.
Distant signal wires to be compensated.
Jn distant signals actuated by electricity, the induced
current is preferred to a constant current.
Signals are unnecessary on sidings, but should be retained
on the main line.
Signals recognized by form are better than those shown by
colour.
INCREASE TO GAUGE ON SHARP CURVES.
R = Radius of curve in feet.
x — Increase to be given to gauge if in eighths of an inch.
y = „ „ „ if in inches.
z— „ „ „ in terms of radius R,
4500 562'5 46'8’75
The increase is in no case to exceed inch.
No increase is to be made on curves the radius of which
exceeds 1600 feet.