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tunnel engineering – будівництво тунелів;
at the foot of the shafts – у підніжжі шахти;
piece of surveying equipment – обладнання для геодезичної
зйомки;

expensive – дорогий;
It takes considerable time – Це потребує доволі багато
часу;

to become experienced and competent – стати досвідченим
та компетентним;
to have access to – мати доступ до;
to become proficient – стати вмілим, вправним;

a gyroscope – гіроскоп;
to locate the meridian direction – визначити напрямок

меридіана;
mine surveying – маркшейдерське знімання;
tunnel engineering – будівництво тунелей;
to enable – давати змогу;

external connection – зовнішній зв'язок;
power supply – джерело енергії;
to distinguish from – відрізняти від.

Text 2 Gyrotheodolite

A gyrotheodolite is a surveying instrument composed of a
gyroscope mounted to a theodolite. It is used to determine the

orientation of true north by locating the meridian direction. It is the
main instrument for orientating in mine surveying and in tunnel
engineering, where astronomical star sights are not visible.

A gyrotheodolite can be operated at the surface and then again at
the foot of the shafts to identify the directions needed to tunnel
between the base of the two shafts. Unlike an artificial horizon or
inertial navigation system, a gyrotheodolite cannot be relocated while

it is operating. It must be restarted again at each site.
The Gyrotheodolite is an expensive special piece of surveying
equipment. It takes considerable time to become experienced and

competent in its operation. Most surveyors don`t have access to
Gyrotheodolites and yet when they have to use them will spend much
time becoming proficient, prior to becoming productive.

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