SURVEYS”. In this survey data regarding the growth of traffic is collected the existing facilities are evaluated the possibilities of optimizing them and new alternative schemes are examined. An estimate is prepared based on such investigation should under ordinary circumstances be sufficiently accurate to permit commencement of examinations straight way.
The various kinds of surveys, which are carried out as part of investigation of Railway project, are indicated below
CLASSIFICATION OF SURVEYS –
- TRAFFIC SURVEY: – This is a detailed study to make a forecast of traffic prospects to facilitate the projection of most promising routes and category of line to be constructed in the case of new lines and to assess the quantum of traffic to determine the traffic facilities to be provided on existing lines. These surveys are to be undertaken in conjunction with the Reconnaissance or Preliminary engineering survey. The technical feasibility and cost of alternative proposals should be taken into account while formulating the recommendations. This is a detailed study of traffic prospects, technical feasibility of alternative proposals and the cost of alternative lines.
- RECONNAISSANCE SURVEY: – This term should apply to all rough and rapid investigations of an area with a view to determine the technical feasibility and approximate cost of one or more routes for a projected Railway line from the general or some what hasty examination with the help of counter survey map of India and other available material without a more careful investigation in the field and with the use of only those instruments that will rapidly give approximate distance and heights such as prismatic compass, clinometer and similar other instruments.
- PRELIMINARY SURVEY: – This consists of a detailed instrumental examination of the route or routes selected as a result of reconnaissance survey in order to obtain a close estimate of the probable cost of projected line under this survey. However stacking of the alignment with a theodalite is not required. Whether a line is to be built or not will usually be decided on the result of this survey considered in consultation with traffic survey. The Railway board may however require the submission of an estimate based on final location survey before sanctioning the commencement of construction.
- FINAL LOCATION SURVEY: – A final location survey will generally be a post investment decision, investigation to prepare working details and to make accurate costing in all cases. The principal difference between the work required in final location survey and that in a preliminary survey is that the alignment finally selected during a final location survey is fully stacked on the ground with a theodolite or techometer, the report should be full and detailed plans and sections should be submitted.