Decoding the FMB sketch: what those lines and numbers mean
Those lines and numbers on your Field Measurement Book actually mean something. Learn to read the G-line, the F-line, and the measurement 'ladder' on the side.
An FMB (Field Measurement Book) sketch can look like a maze of lines and figures. Once you know what each part means, it reads clearly. This guide walks through the main parts so you can read your own FMB sketch with confidence.
The G-line and the F-line
The G-line (Gramam line) is the village boundary — the outer edge of the village. The F-line (field line) marks the boundary of an individual field or survey number. Together they tell you where your plot sits and where the village ends.
The measurement 'ladder'
Down the side of the FMB sketch you'll see a table of measurements — often called the ladder. It lists the distances along each boundary so the plot can be reconstructed exactly on the ground.
Subdivision numbers inside the field
Inside the field boundary you'll see the survey number and any subdivision numbers (like 12/1, 12/2). Each subdivision is a separate parcel with its own owner in the A-Register, even though they share one survey number.
Why the ground may differ from the FMB
Small differences between the FMB and the physical measurements are normal. Surveys allow for an error margin, and old measurements were taken with chains and theodolites. If the difference is large, that's when you ask for a fresh survey.
Frequently asked questions
What is the G-line in an FMB sketch?+
The G-line (Gramam line) is the village boundary — the outermost line on the sketch that separates one revenue village from the next. It is different from the F-line, which is the boundary of an individual field or survey number inside the village.
What does the measurement ladder on the side show?+
The ladder is a table of distances measured along each boundary of the field. Surveyors use it to plot the exact shape of the plot on the ground, so it's the part you check when verifying an area.
Why doesn't the FMB match my ground measurement exactly?+
A small error margin is normal because older surveys used chains and theodolites. Only a large mismatch is a reason to apply for a fresh survey through the taluk survey office.