diff --git a/projects/openttd_vs100.vcxproj b/projects/openttd_vs100.vcxproj
index a7abe4d1ab..35c2a47e56 100644
--- a/projects/openttd_vs100.vcxproj
+++ b/projects/openttd_vs100.vcxproj
@@ -1272,6 +1272,13 @@
     <ClCompile Include="..\src\os\windows\win32.cpp" />
     <ClInclude Include="..\src\thread\thread.h" />
     <ClCompile Include="..\src\thread\thread_win32.cpp" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_container.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_map.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_set.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_map.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_set.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="..\media\openttd.ico" />
diff --git a/projects/openttd_vs100.vcxproj.filters b/projects/openttd_vs100.vcxproj.filters
index d996963c06..f43ab3b04f 100644
--- a/projects/openttd_vs100.vcxproj.filters
+++ b/projects/openttd_vs100.vcxproj.filters
@@ -100,6 +100,9 @@
     <Filter Include="Threading">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000032}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Btree containers">
+      <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000033}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\airport.cpp">
@@ -3045,6 +3048,27 @@
     <ClCompile Include="..\src\thread\thread_win32.cpp">
       <Filter>Threading</Filter>
     </ClCompile>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_container.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_map.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_set.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_map.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_set.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\media\openttd.ico" />
diff --git a/projects/openttd_vs140.vcxproj b/projects/openttd_vs140.vcxproj
index 67acda0402..9c720b87b5 100644
--- a/projects/openttd_vs140.vcxproj
+++ b/projects/openttd_vs140.vcxproj
@@ -1289,6 +1289,13 @@
     <ClCompile Include="..\src\os\windows\win32.cpp" />
     <ClInclude Include="..\src\thread\thread.h" />
     <ClCompile Include="..\src\thread\thread_win32.cpp" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_container.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_map.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_set.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_map.h" />
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_set.h" />
   </ItemGroup>
   <ItemGroup>
     <None Include="..\media\openttd.ico" />
diff --git a/projects/openttd_vs140.vcxproj.filters b/projects/openttd_vs140.vcxproj.filters
index d996963c06..f43ab3b04f 100644
--- a/projects/openttd_vs140.vcxproj.filters
+++ b/projects/openttd_vs140.vcxproj.filters
@@ -100,6 +100,9 @@
     <Filter Include="Threading">
       <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000032}</UniqueIdentifier>
     </Filter>
+    <Filter Include="Btree containers">
+      <UniqueIdentifier>{c76ff9f1-1e62-46d8-8d55-000000000033}</UniqueIdentifier>
+    </Filter>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="..\src\airport.cpp">
@@ -3045,6 +3048,27 @@
     <ClCompile Include="..\src\thread\thread_win32.cpp">
       <Filter>Threading</Filter>
     </ClCompile>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_container.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_map.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\btree_set.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_map.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
+    <ClInclude Include="..\src\3rdparty\cpp-btree\safe_btree_set.h">
+      <Filter>Btree containers</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <None Include="..\media\openttd.ico" />
diff --git a/projects/openttd_vs80.vcproj b/projects/openttd_vs80.vcproj
index fcd9c0e3a3..7809491c40 100644
--- a/projects/openttd_vs80.vcproj
+++ b/projects/openttd_vs80.vcproj
@@ -4487,6 +4487,38 @@
 				>
 			</File>
 		</Filter>
+		<Filter
+			Name="Btree containers"
+			>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_container.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_map.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_set.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree_map.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree_set.h"
+				>
+			</File>
+		</Filter>
 		<File
 			RelativePath=".\..\media\openttd.ico"
 			>
diff --git a/projects/openttd_vs90.vcproj b/projects/openttd_vs90.vcproj
index cd5eea9d4e..f3946b13c6 100644
--- a/projects/openttd_vs90.vcproj
+++ b/projects/openttd_vs90.vcproj
@@ -4484,6 +4484,38 @@
 				>
 			</File>
 		</Filter>
+		<Filter
+			Name="Btree containers"
+			>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_container.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_map.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\btree_set.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree_map.h"
+				>
+			</File>
+			<File
+				RelativePath=".\..\src\3rdparty\cpp-btree\safe_btree_set.h"
+				>
+			</File>
+		</Filter>
 		<File
 			RelativePath=".\..\media\openttd.ico"
 			>
diff --git a/source.list b/source.list
index 59b2824ad0..25dfd357e5 100644
--- a/source.list
+++ b/source.list
@@ -1194,3 +1194,12 @@ thread/thread.h
 #else
 	thread/thread_none.cpp
 #end
+
+# Btree containers
+3rdparty/cpp-btree/btree.h
+3rdparty/cpp-btree/btree_container.h
+3rdparty/cpp-btree/btree_map.h
+3rdparty/cpp-btree/btree_set.h
+3rdparty/cpp-btree/safe_btree.h
+3rdparty/cpp-btree/safe_btree_map.h
+3rdparty/cpp-btree/safe_btree_set.h