Ss report 2

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SCHOOL OF ARCHITECTURE, BUILDING & DESIGN!
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BACHELOR OF QUANTITY SURVEYING (HONOURS)
QSB 60103 - SITE SURVEYING
Fieldwork Report 2
Traversing
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NAME STUDENT ID NO. MARKS
NG WAI KHONG 0317980
PAN LEK VUN! 0323164
PANG KHAI SHUEN 0318423
SHERLYN ANG TSE YUN 0317977

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Table of Contents
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Contents
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Page No.
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Cover Page
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1
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Table of Contents
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2
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Introduction to Traversing
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3 - 6
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Apparatus Used
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7 - 8
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Field Data
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9 - 10
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Adjusted Field Data
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11 - 13
Adjusted Course Latitudes and
Departures & Graph
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14 - 15
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Discussion
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2

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Introduction to Traversing
Traversing is a method in surveying that involves using length and directions of connected lines.
The lines connect a series of connected points called traverse stations. The angles and distances
between points are measured using different types of measuring equipment. The angles are often
measured using total station or theodolite while the distances are often measured using steel tape,
total station or electronic distance measurement (EDM) instrument. The measurements then are
used by surveyors to compute the relative positions of the traverse stations on a system of
coordinates.
Traversing is used in control survey to determine a network of horizontal reference points called
control points. Control points are used as fixed reference points for other surveying measurements
later on in preparation of maps and plans, and required for setting out of site in construction.
Types of Traversing:
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a) Open traverse
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Figure 1
An open traverse (Figure 1) is a series of connected lines that do not intersect or form a loop. It
ends at a station whose relative position is not known before. It is normally not used as there is no
check on fieldwork or starting data. Because of that, the planning of a traverse often tries to
provide for closure of the traverse. As long as the condition permits, traverses are closed in all
cases.
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3

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b) Closed traverse
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Figure 2
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A closed traverse (Figure 2) is connected lines that start at a point and ends at the same point or at
a point whose relative position is known. The errors during measurement are minimised and
adjusted to get accurate data. Closed traverse is the primary method used in checking surveying
field work.
There are two types of closed traverse:
i) Loop traverse:
It starts and ends at the same point, forming a loop or a polygon.
ii) Connecting traverse:
It looks similar to open traverse, however it starts and ends at points of known
position at every end of traverse.
Suitability
While open traverse is generally not used, it can be used in route surveys for roads or coast line.
Closed traverse are normally used in surveying and is suitable for determining the boundaries of
areas like construction site or large areas. We are using loop traverse of closed traverse in our field
work.
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4

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Bearing and Azimuth
The direction or angle of the lines can be described by its azimuth or bearing. Azimuth are usually
used by surveyors in surveying as it helps to simplify work by providing a simple way of
calculations or computations.
Bearings required two letter symbols that indicate the quadrant of the line and a numerical value
that indicate the angle. Bearings are often used to mark out the direction of boundary lines in legal
land descriptions.
Azimuth
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The azimuth of a line is the clockwise horizontal angle between the line and a meridian or a given
reference direction. North is normally used as the reference direction, however south also can be
used for large area surveying. All azimuth angles will have a positive value between 0 and 360°.
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Bearing
The bearing of a line is the angle from the north (N) or the south (S) end of the meridian. It can
belong to one of four quadrants: northeast (NE), northwest (NW), southeast (SE) and southwest
(SW). Depending on which quadrant the line is in, bearing can be measured in clockwise or
counter clockwise direction. A bearing angle is always equal to or less than 90°.
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5
Figure'3'Azimuth Figure'4'Bearing

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Compass Rule and Transit Rule
There are two ways of adjusting the course latitude and departures during traversing. This is to do
correction to the data to enable accurate result. They are the Compass Rule and the Transit Rule.
For this field work, we are using the Compass Rule.
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Formula of Compass Rule
Correction = – [ΣΔy] / P × L or – [ΣΔx] / P × L
Where
ΣΔy and ΣΔx = the error in latitude or in departure
P = the total length or perimeter of the traverse
L = the length of a particular course
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Corrections are done to the latitudes and departures of each course so the total results are
accurate and the course loop can be closed.
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6

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Apparatus Used
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Theodolite
Theodolite is a basic surveying instrument that is
commonly used in traversing. It is used to measure
horizontal and vertical angles. In its modern form now, it
consists of a telescope mounted to swivel both
horizontally and vertically. Levelling is accomplished
with the help of a spirit level; crosshairs in the telescope
allow accurate alignment with the object sighted. After
the telescope is adjusted accurately, the two
accompanying scales, vertical and horizontal, are read.
We are using the stadia method for calculation in our
field work.
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Tripod
A tripod is a device used to support any one of a
number of surveying instruments, such as
theodolites, total stations, levels or transits during
surveying. They provide a level base to easily mount
and securely hold the instrument. This allows for
accurate readings and data. 
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7

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Plumb Bob
The plumb bob or plumb line uses the law of gravity to
establish what is “plumb”. A string suspended with a
weight at the bottom will be both vertical and
perpendicular to any level plane through which it
passes. The plumb bob is the vertical equivalent of the
line level. Precisely machined and balanced bobs have
pointed tips, and can be made of brass, steel, or other
materials, including plastic.
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Levelling Staff
A levelling staff or levelling rod is a
graduated rod or staff having rectangular
cross section. It is used with a levelling
instrument for measuring differences of
level between points. The lower end of the
rod is shod with metal to protect it from
wear. Many of them are sectional and can
be shortened for storage and transport or
lengthened for use. For example, aluminium
rods can be shortened by telescoping
sections inside each other.
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8

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Field data
C
B
94°'10''20"'
97°'16''50"'
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86° 43' 50" 86° 43' 50"
D A
(not to scale)
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9

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Adjusted data
C
B
94°'02''57"'
97°'09''28"'
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82°'11''07" 86° 36' 28"'
D A
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12

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Final Coordinates
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Sta$on Coordinates
A (100.000,'0.000)
B (98.961,'20.269)
C (86.584,'21.089)
D (83.875,'0.008)
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Discussion
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This traversing we have done is a closed loop traverse. The equipments that we utilized overall are
the theodolite, tripod and plumb bob. The fieldwork was carried out at Taylor’s University Lakeside
Campus staff’s car park, near Academic Block E. Each group was required to mark at least four
points so that the traversing work can be done. Furthermore, we were required to measure the
horizontal and vertical angles at the four points which are then labelled as point A,B,C and D.
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One of the apparent obstacles in doing the fieldwork was to balance the air bubble in the spirit level
in order to get accurate results. We realised that the 4-person count in each group is the optimal
head-count to get our job done quickly and smoothly, as each person was assigned to one specific
task throughout the fieldwork. In addition, with guidance from our lecturer, Mr Chai, we were able to
identify the important steps of the fieldwork and also the proper way to operate the theodolite.
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However, after repeating the fieldwork twice, we were unable to obtain an accurate and acceptable
result. We realised that even the slightest error in taking the readings can result in final readings
that stray off too much from the acceptable error. We took our second set of readings are it is more
accurate than the first set, even though both of them are off the acceptable range of error.
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In conclusion, practical experience in surveying is very important aside from everything we have
learnt in the classroom.
16

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