What is Chain Surveying? How Chain Surveying Works
What is Chain Surveying?
What is Chain Surveying
Chain surveying is a type of surveying in which distances are measured between points using a chain. A chain is a metal bar with evenly spaced markings that are used to measure distances.
Chain surveying is often used to survey large areas, such as towns and cities.
Chain surveying is a technique used to measure distances between two points. A surveyor measures a distance with a chain and then marks the location of the first point with a peg.
The surveyor then walks to the second point and measures the distance between the two points. The surveyor then marks the location of the second point with a peg.
This process is repeated until the surveyor reaches the end of the chain. The distance between the two points is calculated by adding the lengths of the individual links in the chain.
Chain surveying is a technique that helps to minimize errors in production and surveying because you take measurements over many points instead of only one.
The idea behind chain surveying is that when you steadily progress from point to point without irregularity, the chance of error at each stage will be minimized.
How Chain Surveying Works
Chain surveying is a type of surveying in which a chain is used to measure distances between points. The chain is stretched out between two points and the distance is measured using a measuring wheel or tape. The chain is then moved to the next point and the process is repeated.
Chain surveying works by assigning a number for each measurement taken, then connecting each number with a straight line to create what’s called a “chain”. The chain can then be used to make sure the measurements are taken correctly for future use.
Chain surveying is often used to survey small areas, such as a property line or a building site.
Chain Survey Principle
The basic principle of chain surveying is to split the entire region into a number of triangles with appropriate sides.
The creation of triangles must be done with great care so that the chain surveying procedure runs well. To the greatest extent feasible, the triangles generated should have the shape of an equilateral triangle.
The created triangle should be a well-conditioned triangle. Ell conditioned triangles are triangles that are extremely nearly equilateral.
Chain Survey Importance
- The process of chain surveying guarantees the user knows where he’s at and how far away he is from the endpoints.
- The process of chain surveying helps to be in control of your production from start to finish since the measurements have a huge bearing on the final product.
- Chain surveying helps you travel anywhere without the need for stops or measured distances, which means more freedom for exploration, adapting, and changing behavior without having to draw exact positions or paths beforehand.
- Chain surveying means that you can take one chain of measurements and use it to obtain an unlimited number of results. Chain surveying enables the user to make accurate decisions based on measurements, giving the user huge operational efficiency and freedom.
- Chain surveying makes the process of surveying flexible, allowing for quick changes without having to redraw a whole chain survey.
- Chain surveying eliminates the need for maps since information regarding positions and distances can be obtained from one chain survey.
- Chain surveying enables the user to find out their current position at any time, without having to make new measurements. Studying and developing chain surveying is one of the most important tools for any kind of production, paving the way for a new realm of possibilities in history.
Chain Survey types
1. Metric chain- The chain which is used all over the world, also called an “international chain” or decimal chain.
2. Engineer’s chain- Metric chain with a conversion chart, which shows the distance between two units in the chain.
3. Revenue chain- A long tape that is used in surveying for land surveying and other purposes.
Gunter’s chain to surveyor chain- When the chain was invented by Edmund Gunter in 1620, it measured 66 feet. Later in the nineteenth century, it was divided into 100 links to be used by surveyors.
Chain Survey is Suitable when:
- The terrain is rather flat and straightforward
- Large-scale plans, such as fields, are necessary.
- When the area to be surveyed is tiny,
Chain surveying is ineffective in:
- Large Areas with Undulating Surfaces
- When a great deal of information is necessary
- Forested nations
Chain Survey Procedure
- Reconnaissance refers to the preliminary inspection of the region to be surveyed. The surveyor inspects the area to be surveyed and creates an index sketch or key plan.
- Marking Station: The surveyor sets the needed no stations at locations where the greatest number of stations are achievable.
Some of the marking methods are as follows:
Putting up ranging poles
If the ground is firm, draw a line across it.
A stone is being dug and repaired.
Pegs for driving
- Then he chooses a route for crossing the mainline that is as horizontal and clean as possible and passes roughly through the center of work.
- Then, on the stations, range roads are installed.
- Chaining might begin when the stations were repaired.
- Make adjustments as needed.
- Calculate the difference and offset.
- Fill in the blanks with the title of the book.
Chain Survey Instrument
1. The chain: The chain is the most important instrument used to take measurements and make notes in a chain surveying method.
- Plumb Bob- It is used to determine the vertical direction. The plumb bob hangs from the end of a long string, which is then dangled from a pole, cylinder or staff. As you move around the work area and move vertically up and down, the plumb bob helps you judge your vertical position relative to your last point.
- Cross-staff: It is a rod that has an L-shaped instrument on one end to help you measure horizontal angles of features and distances between points.
- Arrows- It is mainly used to measure the height and width of objects.
- Offset- A device made up of a tripod, a measuring rod and strings is used to measure horizontal intervals.
- Ranging Rods- It is used to determine horizontal distances.
- Distance measuring tape- It is used to measure the distance of objects by making triangles, echelon and parallel lines with the measurements of a chain.
- Hammer- It is used to mark trees, posts, etc.
- Pegs- Pegs are used for marking positions and for the construction of level surfaces, etc.
Chain Survey Examples
This is how to survey the lands by a chain, which is based on the formula of lengths, coordinates, and angles.
The French engineer established a system using a reduced number of measurements that were truly revolutionary compared to all previous methods in use.
This system was a great improvement on the previous methods in that it allowed the surveyor to determine a point’s location based on only two measurements.
Chain Surveying Errors
- Personal Errors- One error in surveying is a person’s personal errors. For example, if someone estimates that the distance between two points is twice their actual distance and they are close, they then move the point closer to cover up their mistake. This makes them confused and loses efficiency in their work.
2. Compensating Errors- A compensating error is a surveyor’s inability to make a correction due to personal errors.
For example, if you are inaccurate in measuring the distances between points and then correct that error so that you are not off your mark, the end result will still be inaccurate because of the error in your measurements.
3.Cumulating Errors- An accumulative error is what happens when the errors of several people in a survey team add together to make their survey result inaccurate.
For example, say that three people are measuring the same area with their chains. The first person reads their distance as 100 meters, the second as 100.3 meters, and the third as 99.4 meters.
Line types in Chain Survey
1. Tie or Subsidiary lines- It connects two places on the chain line that are fixed. When testing surveying accuracy in detecting interior elements such as houses and walkways, the advantage of tie-line becomes apparent.
2. Baselines- It is the main and longest line from which all measurements to show the work’s details are taken. The base line runs through the center of the field.
3. Checklines-It connects the apex of a triangle to certain fixed spots on any two sides of a triangle. It is used to test the framework’s accuracy. The length of the check line measured on the ground must be consistent with the length shown on the plan.
4. Chain (Main Survey) lines-Chain lines or major survey lines are the lines that connect key stations.
Advantages of Chain Survey
1. The great thing about chain surveying is that it is fast, effective, and convenient to use as a survey method.
2. It can be used on small areas with undulating surfaces or large areas with even terrain. It avoids the consequence that surveying is expensive and slow in large areas of arid or mountainous countries where the land is rugged in structure and the measurement must be accurate for manipulation purposes.
3. It is a quick method of surveying using only three basic components: compass, chain and pencil. It is not known to be difficult to use.
4. It can be used in most landforms and may be used in almost any weather condition.
5. The system of measurement is already known, so it makes surveying easy and convenient.
6. The equipment needed for surveying is very simple, less expensive, and compact compared to other methods such as theodolite, laser levels, etc.
Disadvantages of Chain Survey
1. It has its disadvantages as well. It does not have as many uses as other methods do. The most significant disadvantage is the lack of ability for someone to calculate the measurements of a point using only three measurements and compass, chain, and pencil.
2. It is not a perfect method, like a normal surveyor’s level, which can be used to determine the points on a line or surface so that it will be exactly horizontal and perpendicular to its surroundings.
3. The chain has no ability to measure vertical or horizontal distances. Therefore, it is a not a complete survey method.
4. Like any other method of surveying, it is not capable of being used in any situation where the measurements are marked on every surface, especially when they are not marked in every spot.
5. The chain has a problem measuring small spaces because the distances that must be measured don’t allow for smaller spaces to be measured accurately.
6. It cannot be used in places where the land is not flat and even.
7. People with little experience have a difficult time using chain because they are unfamiliar with their use. It is easy to become confused and make errors.
8. It may be difficult to meet the standards of accuracy that are required in the chain survey’s methods if it is not done with a level, which is known as leveling chain.
Chain Survey Errors
- Erroneous Length of the Chain or the Tape.
- Errors due to Inefficient Ranging.
- Errors due to Careless Holding and Markings.
- Error due to Sag in Chain.
- Personal Errors
- Errors caused by Pull Variation
- Errors Caused by Temperature Variation
Different Chains used in Surveying
- Metric Chains-Used for measuring areas.
- Surveyor’s chain- Used for measuring heights of land for buildings and other structures, as well as for measuring horizontal distances.
- “Gunter’s” chain: used in the measurement of horizontal distances and vertical heights. It consists of 100 links, each link being 1 ft long and weighing 1 lb., so that a chain weigh 100 lb. and measures 100 ft.
- Magic chain- Used for measuring horizontal distances. It consists of 100 links, each links being 1 ft long and weighing 1 lb.
- Watt and Robertson’s chain
- Rigg’s chain: a special form of the metric chain used in surveying, in which the distance between extremities is not measured twice but three times at “consecutive” points on the line over which one travels, so that it measures to half an inch (1/4″).
- Engineers chain- Used for measuring vertical heights and angles, it consists of a special chain and tape with a weighted bob at the end of the line.
The chain and weight are equally divided in length so that if the distance between two points is measured, each part of the measuring instrument will have an equal surface laid out on which to read. The length of the chain is pre-marked before starting work.
Is chain surveying legal?
Yes, chain surveying is legal as long as it is plotted according to government standards.
What are the differences between chain, tape, and line?
Chain- It is a measuring tool that has been used for mapping since the 18th century. With this tool, which has a 100-meter tape attached to it, the surveyors note their readings by placing pins at every ten meters.
The pins are placed in a way where they remain at an equal distance from one another. The chain is tied to the points in such a way that the intervals between them remain constant¬¬with their own direction.
Tape- It is a tape measure that has a mark on it from 0 to 100 meters. It does not have any pins or marks placed on it, but it does have a marking to show the distance between two points.
Line- It is a form of measuring stick made of wood with markings on its surface that measure distances according to length, width, and height.
What is a simple chain survey?
Simple chain survey is a type of chain surveying that uses a 100-meter tape to measure distances between points. It can be used in land that has great horizontal distances and uneven terrain where it is difficult to determine the exact measurement.
How is simple chain survey accurate?
Simple chain survey is not as accurate as several other forms of surveying, but it is simple and easy to use, which makes it popular among surveyors and those who perform minor works.
How long does simple chain survey take?
Simple chain survey takes less than an hour.
What kind of equipment is needed to perform simple chain survey?
Primary and secondary chains and pencils are enough equipment to perform simple chain survey. Pencils are used to note measurements on the 100-meter tape.
What is a primary chain?
Primary chains are the lines that connect two points on the field that serve as reference points. Primary chains use 100-meter tapes to measure distances between them at every ten meters.
What is chain surveying plot?
Chain surveying plot is a map that is made according to a certain measurement system. In this method of surveying, the primary chains are plotted, and then the secondary chains are connected to them in order to decrease the number of errors that may occur.
What is the purpose of chain surveying?
Chain surveying is a method of surveying that uses solely linear measurements in the field. The fundamental idea behind chain surveying or chain triangulation is to offer a framework made up of a number of well-conditioned triangles or nearly equilateral triangles.
It is used to determine the size of the field.
What is the need of chain surveying?
Chain surveying is required because linear measurements are required. Its benefit is its simplicity, as well as the fact that it may be particularly useful in regions with rocky terrain.
How long is a survey chain?
The chain is a length unit equal to 66 feet (22 yards). It’s separated into 100 links or four rods.
Who invented chain survey?
It was invented by the British engineer William Playfair in 1789.
How many points does a chain have?
A 100-meter chain has 20 measuring points making it a 20-point chain.
How do you ensure good booking in chain survey?
A good surveyor has to first ensure that he is in a space that is flat and level before starting the work. He should mark spots on the ground with points, which have pins at every ten meters.
If the sides are longer than 100 meters, then they should be used to measure the lengths of things, such as bridges and tunnels.
Are there any applications of chain survey?
There are many applications of chain surveying. Chain surveying is used in the hospital, building design and construction, and police work.
What is the purpose of a chain surveyor?
A chain surveyor’s duty is to verify the accuracy and quality of his measurements that are done using a 100-meter tape. Since most of the people will be taking measurements using this method, it is important that they be accurate because they need good lines.
How can we avoid errors in chain survey?
There are several ways to avoid errors in the chain survey. It is possible to avoid error by merely reading the 100-meter tape to find out whether measurements can be taken accurately.
How much does chain survey cost?
It costs about $500 for a 100-meter chain, which may include its cost of purchase, labor, and shipping.