diff --git a/src/engine/gameManager/ForgeManager.java b/src/engine/gameManager/ForgeManager.java
index 9dd7dd67..efd2cbc2 100644
--- a/src/engine/gameManager/ForgeManager.java
+++ b/src/engine/gameManager/ForgeManager.java
@@ -140,18 +140,20 @@ public enum ForgeManager implements Runnable {
 
     public static long calcRollingDuration(WorkOrder workOrder) {
 
-        long rollingDuration;
-        float rate = (float) 2.5 * (workOrder.vendor.getBuilding().getRank() - 1);
-        float baseTime = (20 - rate) * 60000;
+        float rollingDuration;
+
+        rollingDuration = workOrder.vendor.getBuilding().getRank() * 5L + 40;
+        rollingDuration *= 60000;
+        rollingDuration *= Float.parseFloat(ConfigManager.MB_PRODUCTION_RATE.getValue());
+
         ItemTemplate template = ItemTemplate.templates.get(workOrder.templateID);
 
         // Bane circles
 
         if (template.item_bane_rank > 0)
-            baseTime = template.item_bane_rank * 60 * 60 * 3 * 1000;
+            rollingDuration = (long) template.item_bane_rank * 60 * 60 * 3 * 1000 * Float.parseFloat(ConfigManager.MB_PRODUCTION_RATE.getValue());
 
-        rollingDuration = (long) (baseTime * Float.parseFloat(ConfigManager.MB_PRODUCTION_RATE.getValue()));
-        return rollingDuration;
+        return (long) rollingDuration;
     }
 
     public static int calcAvailableSlots(WorkOrder workOrder) {