General Comparison of COD with Conventional Ducting System

Description of
comparison
C.O.D.
Conventional Method
Outer Duct
Inner ducts
Outer Duct
Inner ducts
Raw material

H.D.P.E
H.D.P.E

P.V.C.
H.D.P.E
Length

No limit
No limit

6 meters
(At maximum)
No limit
(Up to 500m or 1,000m)
Connection
No need (saves materials
and accessories)
In every 6 m
Insertion of inner ducts
No need
To insert
Intermediate Manhole
No need to build
To build in turning point
Horizontal alignment
of inner duct
Straight
Straight
Straight
twisted
Saves optic cable about 3 to 5%
.
Trench Dimension
(Volume)

(28mm inner ducts in
112mm outer duct)
(Dimension)
(No need man-working space:
vertical cut)

Up to 5 inner ducts
0.3m(W) x 0.6m(H)
(Slope cut to secure man-working space)

3 inner ducts only
0.5m(W) x 0.81m(H)
Trench Bedding
Rough bedding
(passes over/by hurdles)
Fine bedding