Munck was just one vendor of traveling gantry cranes, and Johnson Line just one of several ship lines to put them on their early container ships. The very first Sea-Land cellular conversions of 1957 had traveling gantries for self loading/unloading, as did most Sea-Land conversions through 1965 and even some lengthened in 1969. The very first new-built cellular ship, the KOORINGA, had gantries. Other lines that used gantries on at least some of their early container ships included APL, American Export-Isbrandtsen, Grace, Hamburg Sud's Columbus Line, K-Line/Pheonix Container Line/OOCL (same three ships), and British Yukon Navigation.
Other lines used a pivoting crane mounted on a traveling gantry, including Ben Line, DAL, Maersk, Nedlloyd, Woermann, and the CAROL Line ships of Hapag-Lloyd, Harrison Line, CGM, and KNSM.