The ppt is related to the calculation of volume of logs. It was delivered to the frontline staff of Forest department of Jammu & Kashmir, India.

1. Jammu & Kashmir Forest Department
Kashmir Forest Training School Chitternar
Bandipora, J&K
ONLINE CLASSES
Forest Mensuration
TOPIC:
Calculation of volume of logs
By
Dr. Imtyaz Ali Khan

2. Volume of Logs
Examples : Calculate the volume of logs having following
dimension: (Solution is given in the last slide)
1. Girth = 9 ft. , Length = 20 ft.
2. Girth = 5 ft. 9 in, Length = 32 ft
3. Girth = 40 in, Length = 144 in.

3. Volume of Logs
Volume of Logs or round wood is calculated by Quarter Girth Formula which
is also known as Hoppes Rule.
Quarter Girth
V = (g/4)2 X l
Where g is a girth of log and l is a length of a log

4. Here we have:
Ꙥ = 3.14
Radius (r) = 0.8 feet
Height = 4 feet
V = Ꙥr2 h
Volume = 3.14 X 0.8 X 0.8 X 4
= 8.04 cft
=4 ft.
= 60 ‘’= 0.8 ft. (d= g/Ꙥ = 60/3.14
= 19.11 = 19.11/12 = d=1.59
= 1.59/2 = 0.8 ft.

5. Length of log = 4 ft. Girth of log = 60 inch

6. Log

8. Volume of scantling ( Cuboid)
= Length x width x height
= 4 x 1.25 x 1.25
= 6.25 cft.
Length of log = 4 ft, Girth = 60 in.
Volume of Log using Q.G formula/Hoppes rule
Volume = (g/4)2 X L
= 60 X 60 X 4 = 14400 = 6.25 cft.
16 x 12 x 12 2304
Length of
log = 4 ft.
Girth of
log = 60
inch
If we consider log as a cylinder, then volume will be calculated by the formula
V = Ꙥr2 h = 8.04 cft
% volume difference in full volume (cylinder) and Q.G/Hoppes volum is equal to
= 6.25 X 100 = 78 % , the difference will be = 100-78 = 22 %
8.04

9. Calculate the volume of logs having following dimension:
1. Girth = 9 ft. , Length = 20 ft.
By Quarter girth formula Volume (V) = (g/4)2 X L
Volume (V) = 9 x 9 x 20 = 101.25 cft
4 X 4
2. Girth = 5 ft 9 in , Length = 32 ft.
By Quarter girth formula Volume (V) = (g/4)2 X L
Volume (V) = 5.75 x 5.75 x 32 = 66.13 cft
4 X 4
3. Girth = 40 in , Length = 144 ft.
By Quarter girth formula Volume (V) = (g/4)2 X L
Volume (V) = 40 x 40 x 144 = 230400 = 100 cft.
4 X 4X12x12 2304