Enhances Coal Output at Coal Mine
| Level | Prerequisites | Research Cost | Time | Bonus | Power |
|---|---|---|---|---|---|
| 1 |
Research Center 13 Iron Mining I 1 |
|
00:25:00 |
Coal Output: 5.50% |
1430 |
| 2 |
Research Center 14 |
|
00:37:30 |
Coal Output: 5.50% |
1430 |
| 3 |
Research Center 15 |
|
01:40:00 |
Coal Output: 7.00% |
1820 |