HOW IT ALL WORKS - All Aboard: The Complete North American Train Travel Guide - page 166

tives now have AC (alternating current) traction motors because
they use less electricity and are therefore more fuel efficient. AC
locomotives also have more pulling power—three AC locomo-
tives can replace five DCs—and they require less maintenance.
Unlike with automobiles or airplanes, the engineer sits on the
right side of the cab when he's operating the locomotive. A sec-
ond engineer occupies the left-hand seat. This second engineer is
fully capable of operating the locomotive and, in fact, frequently
relieves the engineer at the controls. Short-haul trains often have
only one engineer.
The only set of controls is on the right side of the locomo-
tive cab in front of the engineer. There's a throttle to increase or
reduce power to the traction motors, a control for the air brakes,
and a little handle or button that blows the whistle. Of course
there are a number of gauges that allow the engineer to monitor
all the machinery, the fuel reserves, and the train's speed.
The engineer blows the whistle as the train approaches grade
crossings where automobile traffic crosses the tracks. On many
locomotives, the loudness of the whistle can be adjusted accord-
ing to how hard the handle is pulled. Engineers will often ease up
a bit at night when passing through a residential area, when they
can clearly see that there is no traffic near the grade crossing, or
when the train is moving at slow speeds. Pull that handle all the
way, however, and the whistle will make your ears ring!
A built-in device called an alerter is found in all locomotives.
If, over a period of 20-25 seconds, the engineer doesn't adjust
the throttle, apply the brakes, or blow the whistle, a loud horn
sounds and a bright light starts flashing in the cab. It pretty well
guarantees that the engineer won't become distracted from his
duties or fall asleep. If the engineer fails to respond by touching
one of those controls after the horn and light have been acti-
vated for a few seconds, the brakes will be applied automatically
and the train will come to a safe stop. These devices are in place