Detail Surveying and Plotting

Abstract

The two previous chapters dealt with the various methods by which networks of control points can be established. In engineering surveying, such a network is required for one of two purposes. Either to use as a base on which to form a plan of the area in question or to use as a series of points of known coordinates from which to set out a particular engineering construction. Often, these two purposes are linked in a three-stage process. First, using the control points, a contoured plan of the area is produced showing all the existing features. Second, the project is designed and superimposed on the original plan. Third, the designed points are set out on site with the aid of the control points used to prepare the original plan. While the design stage may be undertaken by any of the engineering team, the production of the original plan and the setting out of the project are the responsibility of the engineering surveyor. Consequently, it is essential that correct surveying procedures are adopted to ensure that these two activities are carried out successfully. The purpose of this chapter, therefore, is to describe the various methods by which accurate contoured plans at the common engineering scales of between 1:50 and 1:1000 can be produced from control networks. The techniques by which control networks are used to set out engineering projects are covered in depth in chapter 14.