The Man of Bronze by Lester Dent (AKA Kenneth Robeson) (1933)
Clark "Doc" Savage, Jr and his five companions Monk, Ham, Long Tom, Renny and Johnny are mourning the sudden death of Doc's father from a mysterious tropical illness. However, things become complicated when a sniper tries to kill Doc by shooting at him through the window of his study on the 86th floor of the Empire State Building. This and other attempts on his life lead Doc and his friends on a chase to the Central American country of Hildalgo where they discover a lost Mayan civilisation and Doc's incredible legacy.
In 1933, Street & Smith were flush with the success of The Shadow magazine, a pulp spin-off of the popular radio series of the same name. Hoping to keep the trend going, they thought up a new hero, Doc Savage, who would be to the Shadow what Superman would be to Batman. Where the Shadow is mysterious and potentially deadly character of the city, Doc Savage would be a larger than life superman who roamed the world battling evil in exotic locales. Throw in Doc's stalwart "brain trust" of simian chemist Monk, dapper lawyer Hamm, electrical wizard Long Tom, Engineer Renny and archaeologist Johnny; add a formula of our heroes on the trail of a mysterious treasure while fighting baddies and you have a recipe that would keep boys coming back to the news stand until the bottom fell out of the pulp market in the 1950s.
Boys is the operative word here. The prolific Lester Dent, who wrote under the house name of Kenneth Robeson so that the magazine would always seem to be written by the same man even if Dent quit, understood his audience and their parents. The Man of Bronze is filled with blood and thunder of fights, shoot outs, escapes and tight spots galore. However, to please worried mothers, Doc Savage and his friends were always virtuous to a fault, never killed anyone–at least, not directly–and Doc method of maintaining his incredible mind and physique were explained in a way that encouraged readers to study and exercise daily.
As to characters, what you see in The Man of Bronze is exactly what would be there for the next twenty years with all the character work being repeated literally word for word from one issue to the next. And while there are women in the story, the reader is assured time and again that there won't be any "mushy stuff".
Dent knew his audience.