We know everyone has heard this tip before but maybe don’t understand how much it can affect the outcome. Here’s an example: One day at the test site we wanted to see empirically how much a little resistance made on the tension. A MaxCell rep walked to the feed end and grabbed the cable with one hand while having the contractor on the other end report the tension increase. We were roughly half-way into a 1640ft (500m) pull and the tension was running roughly 200lbs (90kg’s). When the cable was grabbed slightly, the tension spiked 50-60lbs or 25%. Imagine now if a heavy reel of cable were being fed without being let-off, the negative impact could be much higher.
The photo is an example of proper cable slack during let-off.
One other note, some maintenance holes are deep and that can really impact the tension. Most good cable installers will have a guy in the bottom assisting the cable when it makes the turn into the MaxCell. Some may not man this assist point which can cause greater tension by acting like an additional 90o sweep with a very tight turn radius.