diff --git a/src/engine.h b/src/engine.h
--- a/src/engine.h
+++ b/src/engine.h
@@ -262,84 +262,6 @@ static inline const RoadVehicleInfo* Roa
 	return &_road_vehicle_info[e - ROAD_ENGINES_INDEX];
 }
 
-/************************************************************************
- * Engine Replacement stuff
- ************************************************************************/
-
-struct EngineRenew;
-/**
- * Memory pool for engine renew elements. DO NOT USE outside of engine.c. Is
- * placed here so the only exception to this rule, the saveload code, can use
- * it.
- */
-DECLARE_OLD_POOL(EngineRenew, EngineRenew, 3, 8000)
-
-/**
- * Struct to store engine replacements. DO NOT USE outside of engine.c. Is
- * placed here so the only exception to this rule, the saveload code, can use
- * it.
- */
-struct EngineRenew : PoolItem<EngineRenew, EngineRenewID, &_EngineRenew_pool> {
-	EngineID from;
-	EngineID to;
-	EngineRenew *next;
-	GroupID group_id;
-
-	EngineRenew(EngineID from = INVALID_ENGINE, EngineID to = INVALID_ENGINE) : from(from), to(to), next(NULL) {}
-	~EngineRenew() { this->from = INVALID_ENGINE; }
-
-	inline bool IsValid() const { return this->from != INVALID_ENGINE; }
-};
-
-#define FOR_ALL_ENGINE_RENEWS_FROM(er, start) for (er = GetEngineRenew(start); er != NULL; er = (er->index + 1U < GetEngineRenewPoolSize()) ? GetEngineRenew(er->index + 1U) : NULL) if (er->IsValid())
-#define FOR_ALL_ENGINE_RENEWS(er) FOR_ALL_ENGINE_RENEWS_FROM(er, 0)
-
-
-/**
- * A list to group EngineRenew directives together (such as per-player).
- */
-typedef EngineRenew* EngineRenewList;
-
-/**
- * Remove all engine replacement settings for the player.
- * @param  erl The renewlist for a given player.
- * @return The new renewlist for the player.
- */
-void RemoveAllEngineReplacement(EngineRenewList *erl);
-
-/**
- * Retrieve the engine replacement in a given renewlist for an original engine type.
- * @param  erl The renewlist to search in.
- * @param  engine Engine type to be replaced.
- * @return The engine type to replace with, or INVALID_ENGINE if no
- * replacement is in the list.
- */
-EngineID EngineReplacement(EngineRenewList erl, EngineID engine, GroupID group);
-
-/**
- * Add an engine replacement to the given renewlist.
- * @param erl The renewlist to add to.
- * @param old_engine The original engine type.
- * @param new_engine The replacement engine type.
- * @param flags The calling command flags.
- * @return 0 on success, CMD_ERROR on failure.
- */
-CommandCost AddEngineReplacement(EngineRenewList *erl, EngineID old_engine, EngineID new_engine, GroupID group, uint32 flags);
-
-/**
- * Remove an engine replacement from a given renewlist.
- * @param erl The renewlist from which to remove the replacement
- * @param engine The original engine type.
- * @param flags The calling command flags.
- * @return 0 on success, CMD_ERROR on failure.
- */
-CommandCost RemoveEngineReplacement(EngineRenewList *erl, EngineID engine, GroupID group, uint32 flags);
-
-/** When an engine is made buildable or is removed from being buildable, add/remove it from the build/autoreplace lists
- * @param type The type of engine
- */
-void AddRemoveEngineFromAutoreplaceAndBuildWindows(VehicleType type);
-
 /* Engine list manipulators - current implementation is only C wrapper of CBlobT<EngineID> class (helpers.cpp) */
 void EngList_Create(EngineList *el);            ///< Creates engine list
 void EngList_Destroy(EngineList *el);           ///< Deallocate and destroy engine list