A railway project should be implemented in different stages, as described below:
Justification of Constructing New Line
When the question of constructing a new railway line between some places arises due to public demand or some other reason, an intensive study is carried out as regards viability of the project.
- The following points should be kept in mind while considering the justification of constructing a new line
- Total population of the villages, towns, industrial places, etc, coming –under the project, should be recorded.
- The standard of living and habits of the population, and the economic conditions of the locality, should be thoroughly studied as it will be a source of revenue for the department.
- The amount of agricultural, natural and industrial resources should be recorded.
- Information regarding religious places, religious fairs of festivals, business centers, etc. should be noted.
- The amount of revenue that may accrue from passengers, agricultural goods, industrial goods, natural resources, etc. should be estimated.
- A topographical map should be studied to determine the number of culverts, bridges, level crossings, tunnels, etc.
- An agricultural map should also be studied so that too much valuable land is not affected.
- A contour map should be studied in order to ensure economical alignment, avoiding unnecessary cutting or filling and maintaining a permissible gradient.
- An Industrial map should be studied to find the shortest route to connect industrial areas.
Marking of Tentative Alignment
After the decision to set up a new railway line is taken, tentative alignments of alignments are marked on the contour map and topographical map for the area concerned. While marking the tentative alignment, the following points should be kept in mind:
- The route should be the shortest possible.
- As far as possible, it should follow the ridge line to avoid unnecessary earth work in filling.
- It should cross rivers perpendicularly.
- It should not pass through religious places, such as temples, mosques, churches etc. or burial grounds, burning ghats, and so on.
- The route should not pass through the centres of villages, towns, valuable structures, etc. where the compensation payable is likely to be more.
- It should not be too zigzag, so that the number of curves is minimized.
- It should not cross large depressions or valleys, high summits or ridge lines, to avoid huge earth fillings in areas of depression and tunneling in regions including summits.
- The tentative alignments of two routes should be marked for comparing costs of construction, feasibility, advantages, etc.
Along the tentative alignments. The survey should be conducted for collecting the following data:
- The magnetic bearings of the lines of the alignment are measured by prismatic compass, and the distances are measured by pacing (i.e stepping) and noted in a field book.
- Approximate positions of different objects and the nature of the ground are noted in the field book, for a strip of land covering above 100 m on both sides of the alignment,
- A soil survey should be conducted along the alignment
- Boring should be done along the alignment to know the nature of the water table.
- The slope or undulation of the ground should be determined by Abney level or hand level.
- The number of crossing points, like roads, rivers, canals, etc. should be noted. Detailed information regarding these points should be recorded, so that it is possible to design suitable structures to cross them.
- The number of curves and difficulties in curve setting , if any, should be clearly noted.
- The number of culverts or bridges should be noted along with detailed information pertaining to span, HFL, discharge, etc.
- Rainfall records of the area and the discharge records (for the past 10 years) of big rivers should be collected.
- Large depressions and high summits should be avoided as far as possible to minimize the cost of earth work or tunneling. Where they are unavoidable, detailed information regarding these obstacles should be recorded.
- Availability of construction material and the possible route for their collection should be noted.
- Availability of labor, suitable places for labor colonies, etc. should be recorded.
- A project report should be prepared accompanied with an index map of alignment, approximate longitudinal section, number of curves, culverts, bridges, etc. to select a suitable alignment for preliminary survey.
- A preliminary record of properties for which compensation is to be paid along with such details as the name of the owner, quantity of land, present valuation, etc. should be prepared.
Selection of Good Alignment
After reconnaissance survey, a good alignment or alignments are selected for preliminary detailed survey.
Detailed Preliminary Survey
After selection of suitable alignment of alignments, a detailed preliminary survey is conducted. Such survey should be extremely accurate as selection of the final alignment depends on it.
Preparation of Estimate:
- Earth work required in cutting and banking is estimated.
- A mass diagram is prepared fro balancing the cutting and banking operations.
- An approximate estimate is done for culverts, bridges, levels crossings, etc. (A final estimate is prepared after the design.)
- A compensation list is prepared showing full details.
- A detailed costing of the project is then prepared for inclusion in the project report.
Final location Survey
Of the alignments considered in the preliminary survey, the most economical is selected. Before the approval of the project, the final location survey is completed in all respects. This survey helps the engineers in charge of construction projects.
After completion of all survey work, a project report should be prepared and submitted for approval.
- Cadastral Survey
- GPS, RTK, DGPS Survey
- Final Location Survey
- Contour Survey
- Drawing Digitization
- Engineering Survey
- Pipeline Survey
- Topographical Survey
- Land Survey
- Road Survey
- Railway Survey
- Airport Road Survey
- Dam Survey
- Bridge Survey
- Hill Survey
- River Survey