# Supply Lines | Big Mech Energy Idle Wiki

Unlocked by scrapping **Sir Pent**. You beat a train; you keep the rails. Every cleared 10-wave segment becomes a **depot** on the logistics map, and Scrap lays track between adjacent depots.

- **+1 percent Scrap per linked depot, +2 percent per completed loop**, hard-capped at +25 percent. A management toy with a low ceiling, on purpose.
- **Derailments:** now and then a track goes down. One click re-rails it instantly; left alone, the crews fix it in about ten minutes. Idle players lose pennies, not progress.
- Track gets pricier the deeper the depot, anchored to that segment's Scrap income, so the network grows with your frontier.