I believe that if you make any antenna with “fatter” elements it becomes more broadbanded. I wonder if the Double Bazooka any more broadband than if you used wire the diameter of the coax used to make the antenna?
If the G5RV didn’t stay up at the city EOC that is a fault in the mechanical design/installation of that particular antenna, not a fault of the G5RV type.
Were both ends of the antenna attached to something rigid? What kind of spring was used with the antenna to prevent whiplash failures? If one or more of the ends weren’t very rigid, what kind of pulley and counterweight was used? Exactly what caused that G5RV to fail?
One issue I see at the city EOC is the antenna “tuner” is in the wrong place. Tuning an non-resonant dipole at the far end of coaxial cable except a very short piece introduces a lot of loss in the coax. At my tower in my backyard I tune my non-resonant antennas with a remote operated automatic coupler feeding the antennas through about three feet of LMR-400 coax and out through a Unun at the antennas. My coax run from my tower to my station is about 140′.
Most any antenna we put up at an EOC is likely to be a compromise antenna/installation.
I prefer antennas that resonate close enough to each HF band of interest to use the built-in tuner in the radio.
Perhaps something like this?
https://www.alphadeltaradio.com/dx-series/model-dx-cc
Or
https://palomar-engineers.com/rfi-kits/broad-band-terminated-dipoles
Every antenna is going to have its pluses and minuses, we may have to use what will physically fit.
73,
Charles WA5VHU