The minimum radius a cable may be bent around, set by the manufacturer for two conditions: under pulling tension and installed at rest. The usual rule of thumb is 20 times the cable diameter while pulling and 10 times once in place. Bending tighter causes macrobend loss right away and can crack fibers or stress them so they fail later.
That cable's half an inch, so keep the corner pulley at least ten inches radius or you'll be shooting it again tomorrow.
Also heard as
- minimum bend radius
- MBR
Do not mix it up with
- Macrobend: Bend radius is the installation limit; a macrobend is an actual bend tight enough to leak light, the usual result of violating that limit.
Related terms
Macrobend
A bend in a fiber tight enough to see, which lets light escape the core and causes loss.
Bend-insensitive fiber
Fiber designed to lose very little light when bent tightly, used in drops, apartment wiring and dense patching.
Snowshoe
An oval aerial bracket, shaped like a snowshoe, used to store slack loops of fiber cable on the strand.
Pull
A cable pulling operation, from setup at the feed end to the cable arriving at the far vault.