Obstacle to chaining and ranging - Obstacle to chaining but not ranging

Unit 1- Surveying

Obstacle to chaining and ranging
Obstacle to chaining but not ranging
There are two types of obstacle in this case
  • When it is possible to chain round the obstacle. E.g., pond.
  • When it is not possible to chain round the obstacle. E.g., river
When it is possible to chain round the obstacle
Fig1
Select two points A and B on either side (Fig(a)). Set out equal perpendiculars AC and BD. Measure CD; then CD=AB.

II Method
Set out AC perpendicular to the chain line (Fig(b)). Measure AC and BC. The length AB is calculated from the relation.
Fig2

Fig2
Last modified: Friday, 29 April 2011, 8:39 AM