That weapon name is: "tur_bldg_recoilless_lg"
Located in data_ABC/Side/tur/odf
Open ZE and load your .wld file and go into "object" edit mode.
Then click browse, and browse to,
and find and click on, tur_bldg_recoilless_lg
Then place them on your map wherever you want them.
Then save and close ZE.
Now open your ABCc or g_con.lua and scroll down to:
add the line, "tur_bldg_recoilless_lg"
Then save and munge your "tur" side and "common" together, then go play.