Brass Tunnel

A Brass Tunnel is a machine that can only be placed on Mechanical Belts. It can be decorative or it can be used to split, sort, or combine streams of items fed by belts.

Obtaining

Crafting

Name	Ingredients	Crafting Recipe
Brass Tunnel	Electron Tube + Brass Ingot + Dried Kelp	2

Usage

Brass Tunnels may be used on mechanical belts for four functions: 1) purely decorative, 2) splitting streams of items to multiple destinations, 3) sorting streams of items, and 4) combining multiple streams of items. Each tunnel can have an input or output portal on each of its four sides in a variety of combinations. The status of being an input or output depends purely on the direction of the belt touching a given side. A tunnel must straddle a belt, thus forcing at least one input and one output on opposite sides. The other two sides may have belts abutting the tunnel forming either input or output portals.

Tunnels which are placed immediately next to each other are automatically treated as a group, in most cases collecting from all inputs and distributing to all outputs. The way that items are distributed is controlled by the tunnels' value setting. Item stacks from different inputs will not be combined prior to distributing.

Value Settings

The Value Settings Screen can be accessed from the top of a tunnel. It is only viewable if the tunnel has more than two portals or is connected to other tunnels. All tunnels connected as a group will have the same value setting.

Setting	Split Stack?	Pause when blocked?	Function
Split	Yes	No	Each item stack will be split evenly between available outputs.
Forced Split	Yes	Yes	Each item stack will be split evenly. All output is paused when any output is blocked.
Round Robin	No	No	Keeps input stacks together and routes each successive stack to the next available output in turn. Successive outputs progress clockwise.
Forced Round Robin	No	Yes	Keeps input stacks together. Alternates among the available outputs pausing at any blocked output until it is cleared.
Prefer Nearest	No	No	Chooses the output nearest to the input for as long as it is available. If there are multiple inputs, each input is routed separately to its nearest output. If a tunnel receiving an input has multiple outputs then the output on the right side is considered nearest, followed by the output on the left and finally the output across from the input.
Randomize	No	No	Output is randomized.
Synchronize Inputs	No	No	Takes inputs simultaneously from all available input ports. If any of the ports do not have an item ready to be taken, all inputs will pause. Each tunnel routes its input separately to its nearest output.

Splitting Item Streams to Multiple Destinations

The Split, Forced Split, Round Robin, Forced Round Robbin, and Randomize modes can be used to split one or more item input streams into multiple output streams. For example, a stream of logs may be split with half going to the fuel chamber of a furnace and half going to the smelting chamber. The Forced Split mode causes the output streams to have a nearly equal number of items while the Forced Round Robbin causes the output streams to have nearly equal numbers of stacks. The Split and Round Robin will also keep the items or stacks evenly distributed as long as none of the outputs become obstructed. If that happens, the output will continue at the unobstructed ports. If single items rather than stacks enter a tunnel, the Split and Forced Split will default to Round Robin and Forced Round Robbin behavior.

Item Sorting

Brass Tunnels can be Filtered to only allow certain items to pass. By placing different filters on the outputs of individual tunnels in a group, the cumulative input can be sorted. All items matching a filter will only pass through an output with that matching filter. They will not pass through an unfiltered output. Unfiltered outputs will pass all items that do not have a matching filter. If a particular filter is set on multiple tunnel outputs, then the distribution of the applicable items among the matching outputs will follow the value setting mode. Each group of outputs with common filters will apply the value setting mode independently.

Combining Multiple Item Streams

Brass Tunnels can be used to combine items from different input streams forming a mixed output to one or more output portals. If there is only one output portal, then any value setting mode will work. If there are multiple outputs, then Prefer Nearest and Synchronize Inputs will not result in mixed outputs.

A combination of tunnels and funnels can be used to create item streams with a particular ratio of item types. For example, forming brass ingots in a mixer requires an equal number of copper ingots and zinc ingots. This equal mix can be provided by feeding the copper and zinc ingots from individual chests through brass funnels set to the same stack size. The ingots are then fed by belt to two tunnels forming a group set to Synchronize Inputs. All outputs but one need to be filtered to reject copper and zinc ingots. The remaining output will have a properly balanced blend to feed into the mixer.

History

• 0.5.1:
  • Brass tunnels with no distribution behavior no longer show the mode switcher
  • Added Config entry for brass tunnel distribution cooldown
• 0.3.2:
  • Now show an Engineer's Goggles tooltip of contained items within their group.
  • Right-clicking brass tunnels now retrieves all contained items from their group.
• 0.3:
  • Renamed to Brass Tunnels.
  • Splitting, Sorting, and distribution functionality for Brass Tunnels.
• 0.2: Introduced as Belt Tunnels