A new late-game vacuum belt tier that transports items very quickly, 3x as fast as express belts. Inspired by the belts vs bots Reddit thread.

The drawback of these belts is that you can't directly connect them to other belts, nor have inserters able to directly interact with the items on top. A splitter is required as an intermediary.

The mod also includes settings to change the speed of the belts, remove the restriction, and simplify the crafting recipe by removing the pump ingredient.

The intention of this mod is to act as a prototype for a future belt type, an enclosed and non-intractable belt that has to go through a machine first before the contents are intractable. It's pretty rudimentary and uses a fair amount of workarounds, but should be fine for at least experimenting.

I had originally planned to make the belts look like vacuum tubes, but that appears to be very hard if not impossible due to the belts being hardcoded to always be rendered under the items.

For an in-universe explanation for why the belts are called vacuum belts beside me just being lazy with renaming, is that they use special vacuum suction in order to keep items in place. Allowing super-fast speeds at the cost of flexibility.

Credit for the idea goes to https://www.reddit.com/r/factorio/comments/7oddab/friday_facts_224_bots_versus_belts/ds8vgdb/ and https://www.reddit.com/r/factorio/comments/7oddab/friday_facts_224_bots_versus_belts/ds8pb32/