Answer: Cable Packing
Today, we secure our cables with Velcro straps and the all-in-one plastic straps (also called cable ties). However, in an age before zip bands, the cables were more organic and handmade.
How organic and handmade? Although there are small variations in cable locking techniques across geographic areas and applications, the core of technology is consistent. The cables are carefully tied using coils of wax-impregnated cotton or lineband ̵1; a kind of heavy dental floss if you wish. Flatband band of modern materials such as nylon, polyester, Teflon, fiberglass and Nomex with a variety of coatings to improve knot retention is also sometimes used now.
At regular intervals along the cable tie, the string is stretched around. It uses a simple knot (or a combination of two types of knots in some cases). This continues throughout the length of the cableway, and repeats even when a new cable connects. The finished product, even in comparison with modern cable protection technology, has some advantages. The characteristics of roughly deforming or grinding the cable insulation are almost zero and the cable connection itself gives so little bulk to the bundle of wires that the sliding bundle through wires is easy because there are little or no advancements to hook the conductor.
Amateur radio operators, electronics hobbyists, NASA engineers and more have all used a technology called "cable locking" to ensure permanent cableways. When we set a man on the moon, hundreds of meters of cables were deep inside the moon landers carefully and nicely secured with NASA's exact cable locking technique.
Although the method has largely fallen out of favor, it is still practiced by NASA in specific applications (as specified in NASA Technical Standard NASA-STD-8739.4-Crimping, Connecting Connectors, Harnesses and Wiring). On the picture here you can see traditional cable locking used on curious rowers on Mars. The technology has undergone some revival in recent years, and a short-term internet search will pop up dozens of tutorials that show you how to tip your cables as it is 1969.
Image licensed by NASA.