Enhances Coal Output at Coal Mine
| Level | Prerequisites | Research Cost | Time | Bonus | Power |
|---|---|---|---|---|---|
| 1 |
Research Center 18 Iron Mining II 1 |
|
01:40:00 |
Coal Output: 7.00% |
1820 |
| 2 |
Research Center 19 |
|
02:30:00 |
Coal Output: 6.50% |
1690 |
| 3 |
Research Center 20 |
|
06:40:00 |
Coal Output: 9.00% |
2340 |