diff --git a/mods/d2k/rules/structures.yaml b/mods/d2k/rules/structures.yaml
index c7f566a706..5d4d10990a 100644
--- a/mods/d2k/rules/structures.yaml
+++ b/mods/d2k/rules/structures.yaml
@@ -255,6 +255,8 @@
 	ProductionBar:
 	ProvidesCustomPrerequisite:
 		Prerequisite: Heavy
+	WithIdleOverlay@WELDING:
+		Sequence: idle-welding
 
 ^RADAR:
 	RequiresPower:
diff --git a/mods/d2k/sequences/structures.yaml b/mods/d2k/sequences/structures.yaml
index 7a026fefeb..7a82476b6c 100644
--- a/mods/d2k/sequences/structures.yaml
+++ b/mods/d2k/sequences/structures.yaml
@@ -634,10 +634,12 @@ heavya:
 	damaged-idle-top: DATA.R8
 		Start: 2520
 		Offset: -48,80
-	active: DATA.R8 # TODO: not wired up
+	idle-welding: DATA.R8
 		Start: 4674
 		Length: 47
 		Offset: -48,80
+		Tick: 200
+		BlendMode: Additive
 	bib: bib3x
 		Start: 0
 		Length: *
@@ -922,10 +924,12 @@ heavyh:
 	damaged-idle-top: DATA.R8
 		Start: 2680
 		Offset: -48,80
-	active: DATA.R8 # TODO: not wired up
+	idle-welding: DATA.R8
 		Start: 4674
 		Length: 47
 		Offset: -48,80
+		Tick: 200
+		BlendMode: Additive
 	bib: bib3x
 		Start: 0
 		Length: *
@@ -1198,10 +1202,12 @@ heavyo:
 	damaged-idle-top: DATA.R8
 		Start: 2840
 		Offset: -48,80
-	active: DATA.R8 # TODO: not wired up
+	idle-welding: DATA.R8
 		Start: 4674
 		Length: 47
 		Offset: -48,80
+		Tick: 200
+		BlendMode: Additive
 	bib: bib3x
 		Start: 0
 		Length: *