diff --git a/core/assets-raw/sprites/blocks/defense/build-tower-base.png b/core/assets-raw/sprites/blocks/defense/build-tower-base.png
new file mode 100644
index 0000000000..c404b9c886
Binary files /dev/null and b/core/assets-raw/sprites/blocks/defense/build-tower-base.png differ
diff --git a/core/assets-raw/sprites/blocks/defense/build-tower.png b/core/assets-raw/sprites/blocks/defense/build-tower.png
new file mode 100644
index 0000000000..cc06efaf34
Binary files /dev/null and b/core/assets-raw/sprites/blocks/defense/build-tower.png differ
diff --git a/core/src/mindustry/content/Blocks.java b/core/src/mindustry/content/Blocks.java
index 9ff4968c88..3040ddc0ce 100644
--- a/core/src/mindustry/content/Blocks.java
+++ b/core/src/mindustry/content/Blocks.java
@@ -1159,7 +1159,7 @@ public class Blocks implements ContentList{
         }};
 
         buildTower = new BuildTurret("build-tower"){{
-            requirements(Category.effect, with(Items.lead, 40, Items.beryllium, 50));
+            requirements(Category.effect, with(Items.graphite, 40, Items.beryllium, 50));
             consumes.power(0.2f);
             range = 200f;
             size = 3;
@@ -1412,7 +1412,7 @@ public class Blocks implements ContentList{
         }};
 
         beamNode = new BeamNode("beam-node"){{
-            requirements(Category.power, with(Items.graphite, 1, Items.lead, 3));
+            requirements(Category.power, with(Items.graphite, 1, Items.beryllium, 3));
             consumesPower = outputsPower = true;
             consumes.powerBuffered(1000f);
             range = 10;
@@ -1420,7 +1420,7 @@ public class Blocks implements ContentList{
 
         //TODO requirements
         beamTower = new BeamNode("beam-tower"){{
-            requirements(Category.power, with(Items.graphite, 10, Items.lead, 30, Items.beryllium, 30));
+            requirements(Category.power, with(Items.graphite, 10, Items.beryllium, 30));
             size = 3;
             consumesPower = outputsPower = true;
             consumes.powerBuffered(40000f);
@@ -1520,7 +1520,7 @@ public class Blocks implements ContentList{
 
         //TODO work on sprite, green bits?
         turbineCondenser = new ThermalGenerator("turbine-condenser"){{
-            requirements(Category.power, with(Items.graphite, 35, Items.lead, 50, Items.beryllium, 25));
+            requirements(Category.power, with(Items.graphite, 35, Items.beryllium, 25));
             attribute = Attribute.vent;
             displayEfficiencyScale = 1f / 9f;
             minEfficiency = 9f - 0.0001f;
@@ -2375,12 +2375,12 @@ public class Blocks implements ContentList{
         //region payloads
 
         payloadConveyor = new PayloadConveyor("payload-conveyor"){{
-            requirements(Category.units, with(Items.graphite, 10, Items.lead, 10));
+            requirements(Category.units, with(Items.graphite, 10));
             canOverdrive = false;
         }};
 
         payloadRouter = new PayloadRouter("payload-router"){{
-            requirements(Category.units, with(Items.graphite, 15, Items.lead, 15));
+            requirements(Category.units, with(Items.graphite, 15));
             canOverdrive = false;
         }};
 
diff --git a/core/src/mindustry/content/UnitTypes.java b/core/src/mindustry/content/UnitTypes.java
index e0856d3ff9..d92283cae5 100644
--- a/core/src/mindustry/content/UnitTypes.java
+++ b/core/src/mindustry/content/UnitTypes.java
@@ -2415,6 +2415,7 @@ public class UnitTypes implements ContentList{
         spark = new UnitType("spark"){{
             defaultController = BuilderAI::new;
             isCounted = false;
+            envDisabled = 0;
 
             lowAltitude = false;
             flying = true;
diff --git a/core/src/mindustry/maps/planet/ErekirPlanetGenerator.java b/core/src/mindustry/maps/planet/ErekirPlanetGenerator.java
index 789447da55..d55c8c63a0 100644
--- a/core/src/mindustry/maps/planet/ErekirPlanetGenerator.java
+++ b/core/src/mindustry/maps/planet/ErekirPlanetGenerator.java
@@ -197,7 +197,7 @@ public class ErekirPlanetGenerator extends PlanetGenerator{
         }
 
         //not allowed
-        state.rules.hiddenBuildItems.addAll(Items.copper, Items.titanium, Items.coal);
+        state.rules.hiddenBuildItems.addAll(Items.copper, Items.titanium, Items.coal, Items.lead);
 
         //it is very hot
         state.rules.attributes.set(Attribute.heat, 0.8f);
diff --git a/core/src/mindustry/type/UnitType.java b/core/src/mindustry/type/UnitType.java
index 2969a80997..c7d1ec306b 100644
--- a/core/src/mindustry/type/UnitType.java
+++ b/core/src/mindustry/type/UnitType.java
@@ -54,8 +54,8 @@ public class UnitType extends UnlockableContent{
     public int envRequired = 0;
     /** The environment flags that this unit can function in. If the env matches any of these, it will be enabled. */
     public int envEnabled = Env.terrestrial;
-    /** The environment flags that this unit *cannot* function in. If the env matches any of these, it will be *disabled*. */
-    public int envDisabled = 0;
+    /** The environment flags that this unit *cannot* function in. If the env matches any of these, it will explode or be disabled. */
+    public int envDisabled = Env.scorching;
 
     public float speed = 1.1f, boostMultiplier = 1f, rotateSpeed = 5f, baseRotateSpeed = 5f;
     public float drag = 0.3f, accel = 0.5f, landShake = 0f, rippleScale = 1f, riseSpeed = 0.08f, fallSpeed = 0.018f;