Where do I get a rope that is that long and that thick?
I always find ropes on the web that are either too short or too thin, but they all have in common that they’re fucking expensive.
May be a slim chance but if you have a Marine complex or training camp anywhere near by they use rope for bridge building, you could go ask. I got some scrap off of them, 60ft 2" thick.
Check a shipping yard or something. I snagged a massive nautical rope near my local ship channel. Or google industrial shipping supplies, most tug boats use them.