Supercharger Wagon
The supercharger wagon raises the effective level of nearby wagons by 1 level while active. The range of the boost begins at 1 (directly adjacent wagons) and increases by +1 per additional upgrade of the supercharger, up to a maximum of 3 wagons distance in either direction. This effective level can increase the storage capacity of other wagons beyond their normal maximum, including the number of tracks held by the crafting wagon, and the wood and iron stack size of the storage wagon. This effective level also applies to passive wagon benefits, such as the Ghost wagon.
The supercharger wagon requires iron to be loaded to operate, and gradually consumes the iron. The supercharger wagon will not be automatically loaded by other wagons. If the supercharger wagon is inactivated, boosted wagons will not eject excess commodities above their normal maximum.
The supercharger wagon will not operate or consume iron if wagons within its range are inactive. For example, if the supercharger wagon is at its first level and adjacent to a crafting wagon and storage wagon, and both wagons are full and incapable of producing additional tracks, then the supercharger wagon will turn off and cease using iron.
Note: A supercharged level 3 crafting wagon appears to craft tracks almost instantly. It may not be possible to complete the quest to keep the crafting wagon occupied for any amount of time, even with an auto-pickup wagon, as the crafting wagon will fill with new tracks too rapidly to use and allow further crafting, and/or the resources in the storage wagon will immediately exhaust.
PLEASE VERIFY THE FOLLOWING: The supercharger wagon appears to give benefits beyond level 3 if other wagons are already maximally upgraded. In other words, maximally upgraded wagons craft instantly instead of rapidly, hold additional commodities, have range increased, etc. beyond their normal maximum tier 3 stats.