Dead End Poles and Double Dead End Poles

This double line insulator attaches the wire to the pole to relieve the strain on the wire...

...and would have guy wires supporting the load on the opposite sides...

Are you talking about power lines, telecom. lines, or, something else?

define pOLES - Search (bing.com)

How are dead end poles and double dead end poles defined? - Search (bing.com)

I spent around 20 years in the electric pole industry, but have been retired for about 18 years, so terminology may have changed. We supplied single-tube poles as opposed to lattice structures, but the connection terminology should be the same.

Dead-end or suspension types would depend on how the conductor is attached to the pole (arm.) In DE types the conductor is attached directly to the pole or arm through the insulator.. In the suspension type, the conductor is attached to the insulator, which hangs from the arm, and the pole doesn't see the tension load. I didn't design the line itself, just the poles used to hold the conductors, which can have very large tensions. An interesting thing about the suspension type: if the conductor on the left side fails, the suspension insulator swings to the right to add its length to the catenary; this reduces the tension drastically.

A double dead-end (I don't recall us using that term) would have the DE connection going in each direction from the pole; it does not mean 2 poles. (but there are other types such as H-Frames, and V-structures which would require multiple poles.)

The line design would have to incorporate a DE pole, you said every 10 poles, to prevent the whole system from having a cascade (domino) failure in case of a broken conductor. This would be to limit the damage. We also had to evaluate high wind and ice loading conditions.

Hope I have answered what you need.