These are the plugins of librecad for the use of civil department.
Dependencies-
Librecad
Qt
For creating a new plugin run the PluginGenerator.sh in your LibreCAD/Plugins/ folder.
edit plugins.pro add the plugin name in SUBDIRS and save the changes.
now run the librecad project in QT.
For including these plugin in your librecad replace the tank.h and tank.cpp files with those of new generated plugin.