1. PLANE TABLE SURVEYING
NUST Institute of Civil Engineering/Engr Muhammad Ammar

2. PLANE TABLE SURVEYING
Plane Tabling is a graphical method of surveying in which the field work and plotting are done simultaneously.
Useful to fill in details between stations fixed by triangulation or theodolite traversing.
Particularly adapted for small scale or medium scale mapping in which great accuracy in detail is not required.
The plane table consists essentially of:
A drawing board mounted on a tripod and
A straight edge called an alidade.
NUST Institute of Civil Engineering/Engr Muhammad Ammar

3. NUST Institute of Civil Engineering/Engr Muhammad Ammar

4. THE DRAWING BOARD Made of well-seasoned wood such as teak or pine.
Size varies from 40cm x 30cm x 75cm x 60cm or 50cm to 60 m square.
It is mounted on a tripod in such a manner that it can be leveled, and revolved about a vertical axis and clamped in any position.
NUST Institute of Civil Engineering/Engr Muhammad Ammar

5. PLAIN ALIDADE
Consists of a metal (brass or gunmetal) or boxwood straight edge or ruler about 50 cm long.
The beveled (ruling or working) edge of the alidade is called the fiducial edge.
It consists of two vanes at the ends, the vanes are hinged and can be folded when the alidade is not in use.
One of the sight vanes is provided with a narrow slit and the other with a central vertical wire or hair.
One of the vanes known as sight vane is provided with a narrow slit with three holes, one at the top, one at the bottom and one in the middle.
NUST Institute of Civil Engineering/Engr Muhammad Ammar

6. PLAIN ALIDADE SURVEYING – I (CE- 128)
The other vane which is known as object vane, is open and carried a hair or a fine thread or a thin wire stretched between the top and bottom of the slit.
With the help of the slit, a definite line of sight may be established parallel to the ruling edge of the alidade.
The length of the ruling edge should be equal to the smaller side of the plane table.
A plane alidade can be used only when the elevations of the of the objects are low.
NUST Institute of Civil Engineering/Engr Muhammad Ammar

7. PLAIN ALIDADE Sight Vane Object Vane Fiducial Edge
NUST Institute of Civil Engineering/Engr Muhammad Ammar

8. NUST Institute of Civil Engineering/Engr Ahmed Rasheed Mirza
PLAIN ALIDADE
NUST Institute of Civil Engineering/Engr Ahmed Rasheed Mirza
NUST Institute of Civil Engineering/Engr Muhammad Ammar

9. TELESCOPIC ALIDADE
The alidade which is fitted with a telescope is known as a telescopic alidade.
It is used to take inclined sights.
It increases the range and accuracy of the sights.
It consists of a small telescope with a level tube.
A graduated scale is mounted on the horizontal axis.
One side of the metal ruler is used as the working edge along which lines are drawn.
The angles of elevation or depression can be read on the vertical circle.
NUST Institute of Civil Engineering/Engr Muhammad Ammar

10. NUST Institute of Civil Engineering/Engr Ahmed Rasheed Mirza
TELESCOPIC ALIDADE
NUST Institute of Civil Engineering/Engr Ahmed Rasheed Mirza
NUST Institute of Civil Engineering/Engr Muhammad Ammar