diff --git a/src/common/ai_strategy/naval_production.txt b/src/common/ai_strategy/naval_production.txt
index 0db38ce..26c549b 100755
--- a/src/common/ai_strategy/naval_production.txt
+++ b/src/common/ai_strategy/naval_production.txt
@@ -421,7 +421,7 @@ naval_unit_role_ratios_GER_prewar_late = {
 	ai_strategy = {
 		type = role_ratio
 		id = vnr_naval_submarine
-		value = 200
+		value = 400
 	}
 }
 
diff --git a/src/common/scripted_effects/_add_never_built.txt b/src/common/scripted_effects/_add_never_built.txt
index 7817ed9..352af2d 100755
--- a/src/common/scripted_effects/_add_never_built.txt
+++ b/src/common/scripted_effects/_add_never_built.txt
@@ -34,7 +34,7 @@ ENG_never_built_blueprints = {
       fixed_ship_anti_air_slot = ship_anti_air_1_h
       fixed_ship_fire_control_system_slot = ship_fire_control_system_0
       fixed_ship_radar_slot = empty
-      fixed_ship_engine_slot = heavy_ship_engine_2
+      fixed_ship_engine_slot = super_heavy_ship_engine_1
       fixed_ship_secondaries_slot = ship_secondaries_2
       fixed_ship_armor_slot = ship_armor_shbb
       fixed_ship_armor_scheme_slot = ship_scheme_all_or_nothing
diff --git a/src/common/technologies/MTG_naval.txt b/src/common/technologies/MTG_naval.txt
index 412fe25..006806c 100755
--- a/src/common/technologies/MTG_naval.txt
+++ b/src/common/technologies/MTG_naval.txt
@@ -790,6 +790,7 @@ technologies = {
 			}
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_destroyer_and_modules
 		}
@@ -817,6 +818,7 @@ technologies = {
 			}
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_destroyer_and_modules
 		}
@@ -844,6 +846,7 @@ technologies = {
 		}
 
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_destroyer_and_modules
 		}
@@ -874,6 +877,7 @@ technologies = {
 			}
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_screen_ship_and_modules
 			mio_cat_tech_all_capital_ship_and_modules
@@ -908,6 +912,7 @@ technologies = {
 			}
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_screen_ship_and_modules
 			mio_cat_tech_all_capital_ship_and_modules
@@ -932,6 +937,7 @@ technologies = {
 			factor = 2
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_screen_ship_and_modules
 			mio_cat_tech_all_capital_ship_and_modules
@@ -959,6 +965,7 @@ technologies = {
 			factor = 1
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_screen_ship_and_modules
 			mio_cat_tech_all_capital_ship_and_modules
@@ -985,6 +992,7 @@ technologies = {
 			factor = 1
 		}
 		categories = {
+			naval_equipment
 			dd_tech
 			mio_cat_tech_all_screen_ship_and_modules
 			mio_cat_tech_all_capital_ship_and_modules