Chain survey is suitable in the following cases:
(i) Area to be surveyed is comparatively small
(ii) Ground is fairly level
(iii) Area is open and
(iv) Details to be filled up are simple and less. In chain surveying only linear measurements are made i.e. no angular measurements are made.
Since triangle is the only figure that can be plotted with measurement of sides only, in chain surveying the area to be surveyed should be covered with a network of triangles. scheme of covering an area with a network of triangles.
No angle of the network triangles should be less than 30º to precisely get plotted position of a station with respect to already plotted positions of other station. As far as possible angles should be close to 60º. However, the arrangements of triangles to be adopted depends on the shape, topography, natural and artificial obstacles in the field.