---
title: "Field procedure of chain surveying"
subject: "Surveying I"
chapter: 3
key: "semester_3/surveying_i:field-procedure-chain-survey"
source: https://www.bctengineer.com/q/semester_3/surveying_i/field-procedure-chain-survey
site: BCT Engineering
---

# Field procedure of chain surveying

Surveying I · Chapter 3: Chain Survey

- Asked in: 2064 Jestha, 10 marks; 2057 Chaitra, 10 marks; 2069 Chaitra, 4 marks; 2072 Chaitra, 4 marks (asked 4 times)
- Video: [Procedure of Chain Surveying](https://www.youtube.com/watch?v=P70bPZ58-jM) — Learn Civil Tech & Tricks
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_3/surveying_i/field-procedure-chain-survey
- Whole chapter: https://www.bctengineer.com/md/semester_3/surveying_i/chapter-3

## Question

With the help of neat sketches, explain the field procedure of chain surveying.

## Short answer

After reconnaissance and station marking, a key sketch is made. Lines are ranged and chained; offsets (perpendicular and oblique) are taken and recorded in the field book from bottom upward. Check lines and tie lines ensure accuracy before plotting and area computation.

## Answer

The field procedure of chain surveying follows these steps.

#### 1. Reconnaissance
The surveyor walks over the area, observes its shape, details and obstacles, and plans the survey lines.

#### 2. Selection and marking of stations
- Select main stations so that the main lines form well-conditioned triangles (angles $30^\circ$ to $120^\circ$).
- Select the **base line** (the longest, on level ground), the **check lines** and the **tie lines**.
- Mark stations with pegs or ranging rods, and tie them to permanent objects so they can be found again.

#### 3. Index (key) sketch
A neat freehand sketch (not to scale) shows the whole area, the stations, the lines and the main details. Station names (A, B, C ...) are written on it.

```text
        C
       /|\ 
      / | \ 
     /  |D \     A, B, C = stations
    A---+---B    D = check line CD
```

#### 4. Ranging and chaining the lines
- Each line is **ranged** between its end stations with ranging rods so that the chain stays in a straight line.
- The leader and follower pull the chain. The follower stands at the starting station, and the leader carries 10 arrows, sticking one into the ground at the end of each chain length.
- The follower picks up each arrow as he reaches it; the number of arrows collected gives the number of whole chain lengths, and the last part length is read on the chain. All the main lines are chained in this way.

#### 5. Taking offsets
- Perpendicular offsets are set with a cross-staff, optical square or the 3-4-5 tape method and measured with the tape.
- Oblique offsets or ties are used for far or hidden objects.

#### 6. Booking
All chainages and offsets are written in the field book **from the bottom of the page upwards**, with the objects sketched. The left and right offsets are placed on either side of the chain line column.

| Left offset | Chainage (m) | Right offset |
|---|---|---|
| | 90 (B) | |
| 6 (fence) | 70 | |
| | 40 | 12 (tree) |
| | 0 (A) | |

#### 7. Checking
- Measure **check lines** (for example, a line from the apex to a point on the opposite side) and **tie lines**; compare the measured length with the length scaled from the plot.
- Measure each line twice, forward and backward.

#### 8. Office work
Plot the triangles to scale using arcs, plot the offsets, draw the details and ink the plan, then compute areas.

Chain surveying is best for small, open and fairly level areas.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. First step is
   A. reconnaissance
   B. booking
   C. plotting
   D. ranging
   Answer: A. Walk over area. (Key point: Order)

2. Well-conditioned triangles have angles
   A. 0 to 30
   B. 30 to 120 deg
   C. 120 to 180
   D. exactly 60 only
   Answer: B. Stated. (Key point: Triangles)

3. Check lines are used to
   A. tie
   B. plot
   C. verify accuracy by comparing measured and plotted length
   D. range
   Answer: C. Check. (Key point: Check lines)

4. Base line should be
   A. shortest
   B. steep
   C. anywhere
   D. the longest, on level ground
   Answer: D. Stated. (Key point: Base line)

## Related in Surveying I

- [Principle of chain surveying](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Aprinciple-of-chain-survey) — Surveying I, chapter 3, asked 3×
- [Principle of chain surveying; well-conditioned triangle](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Achain-principle-well-conditioned-vs-error) — Surveying I, chapter 3
- [Field book and obstacles in chain survey](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Afield-book-and-obstacles) — Surveying I, chapter 3
- [Chain survey principle and operations](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Achain-principle-and-field-procedure) — Surveying I, chapter 3, asked 2×
- [Field procedure of compass traversing](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Acompass-traverse-field-procedure) — Surveying I, chapter 4
- [Field books and reference sketch](https://www.bctengineer.com/question.md?key=semester_3%2Fsurveying_i%3Afield-book-chain-survey) — Surveying I, chapter 3, asked 2×

## Related in other subjects

- [Field procedure of aerial photogrammetry, relief displacement](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Aaerial-photogrammetry-field-procedure-relief-displacement) — Surveying II, chapter 7, asked 2×
- [Traverse field procedure between two known stations](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Atraverse-field-procedure-between-known-stations) — Surveying II, chapter 1
- [Three-wire stadia field procedure for topo map](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Athree-wire-stadia-field-procedure) — Surveying II, chapter 2
- [Stadia principle and field procedure](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Astadia-principle-field-procedure-topo) — Surveying II, chapter 2