Why Did Old Telephone Poles Have Lots of Cables?

Individual phone lines, for one (or such things as 32 parties being served with eight four-party lines with distinctive ring patterns for each party).

Basically it was about the same thing today, bandwidth capacity. More wires more signals.

These days telecom cables are usually underground and occasionally for long haul, optical fibre.

Also the interconnecting technology has improved significantly.

Back when Sylvester boards and Partylines were the vanguard all there was were analog telephones. Also some of the wires carried telegraphic signalling.

These digital days with multiplexing and tristate data signalling, connections need more than just a twist of copper..

Thanks for your good answer. I will look up sylvester boards now!

For each line for one phone it was required 2 wires in olden days, if 15 phones are served on that pole route it was required 30 wires minium.

Except when they used earth return.

One word: multiplexer. It's a device that made widespread phone service possible by allowing many conversations to be carried on one wire, then separated to serve each subscriber. It takes advantage of the fact that human speech occupies a very narrow bandwidth (and can tolerate further narrowing of the bandwidth).

There are still places in the Philippines where you can find hanks of "black spaghetti" and they still run individual wire pairs from the local exchange to each subscriber. Now that there is competition for local telephone service that is changing fast.

There is another issue that is not mentioned here as well. Multiple pair cables were not common back in the day because of reliability issues. It was difficult to manufacture a cable of any length that had a large number of pairs in it because invariably a large number of pairs had a break in one of the wires if the cable was of any reasonable length. And handling the cable, or ice or tree limb damage tended to break or short more of them due to internal chafing, and replacing a multi-conductor cable because a number wires broke or were shorted was cost prohibitive, so instead they used a number of cables with fewer pairs so that it was cheaper to replace/splice them. But as multi-conductor cable manufacturing and design matured, it was easier to get more pairs in a given cable. Then fiberoptics came along and changed everything.

Thankyou to everyone who posted a reply. I am thankful a forum like CR4 exists.