Understanding Survey Lines and Their Purpose

In surveying, various types of lines are established to create a framework for measuring and mapping an area. Each type of line serves a specific purpose in the surveying process. The question asks about the line used specifically to collect details of objects within the surveyed area. Let's examine the options provided to determine which line fits this description.

Analyzing Different Types of Survey Lines

We are given four types of lines commonly used in surveying: base line, check line, main line, and tie line. Understanding the function of each is crucial to answering the question.

• Base Line: This is the fundamental and longest line in a chain surveying process. It acts as the reference line for the entire survey framework. It is measured with high precision because errors in the base line affect the accuracy of the whole survey. The primary purpose of a base line is to establish a control framework, not directly collect details of individual objects off the line itself.
• Check Line: Also known as a proof line, a check line is run to check the accuracy of the framework triangulation. It connects the apex of a triangle to some point on the opposite side or connects two main survey stations. Its length is measured in the field and compared with its calculated length based on the triangle geometry. This line is used for verification, not for collecting details of objects.
• Main Line: Main survey lines connect the main survey stations that form the skeleton of the survey. These lines divide the area into large sections or triangles. While objects along or near these lines might be located, the primary purpose of main lines is to form the main framework, similar to the base line.
• Tie Line: A tie line is a line that connects two main survey lines or a main survey line to a check line. It is used to locate the details of objects (like buildings, trees, fences, etc.) that are situated off the main survey lines. Measurements are taken from the tie line to these objects to fix their positions relative to the main survey framework. This is precisely the line used to "collect the details of the objects in an area" by referencing them to the established survey lines.

Identifying the Line for Collecting Details

Based on the functions described above:

• The base line establishes the main reference.
• The check line verifies accuracy.
• The main lines form the primary framework.
• The tie line is specifically used to locate and collect details of objects positioned away from the main survey lines.

Therefore, the line used to collect the details of the objects in an area is the tie line.

Revision Table: Survey Lines Overview

Additional Information: Surveying Techniques and Detail Collection

Collecting details of objects, also known as plotting the details or filling in the details, is a crucial part of chain surveying. Once the main survey stations are established and connected by main lines, and the framework is checked, the surveyor needs to locate all the features and objects in the area that need to be shown on the map. This is done by taking measurements (offsets and ties) from the established survey lines (including main lines, base lines, and particularly tie lines) to the corners or key points of the objects. Tie lines provide convenient reference lines within or across larger sections to facilitate the accurate location of these details. The selection and measurement of appropriate tie lines are essential for ensuring that all necessary details are collected efficiently and accurately for the final map or plan.