"A giant who towered four inches over six feet. He weighed fully two fifty. His face was severe, his mouth thin and grim, and compressed tightly, as though he has just finished uttering a disapproving, "tsk! tsk! sound. His features had a most puritanical look. His arms were enormous, his fists bony monstrosities. His favorite act was to slam his great fists through the solid panel of a heavy door. He was known throughout the world for his engineering accomplishments, also."
(from Doc Savage, The Man Of Bronze, by Kenneth Robeson)

Holy Cow! booms Renny. His voice sounds like the deep rumbling of a lion roaring in a cave. World famed Engineer Renny Renwick is known for two things- his association with Doc Savage, and his ability as an Engineer. He has a long puritanical face and if its expression is any indication, he has not a friend in the world. It is a peculiar trait of Renny's that he registers his emotions inversely. The happier he is, the more gloom is on his face. He stands 6'-4" tall and weighs in at 250 lbs. He knows every rough and tumble fighting trick in the book. His huge fists are composed of slightly less than a gallon each of bone, gristle and leathery hide and are as effective in a fight as two concrete blocks. Renny's favorite pastime is to use his monstrous fists to smash the panels out of doors. His boast is that his fists can plow through the panels of any wooden door made.

As part of his association with Doc, Renny serves as the group's construction manager. Renny handled the design and construction of all of the structures that Doc uses. This includes the Empire State Building (from Spook Hole), the Hidalgo Trading Company warehouse/hanger, the Crime College and Doc's Fortress Of Solitude. These structures were custom-built to Doc and early on Doc's father's requirements, and incorporate secrets that could not be revealed to the public. Renny, with his contacts in the construction industry was able to hand pick the men that worked on these jobs, men he knew he could trust to secrecy.

 The stories told us that none of Doc's aides knew where the Fortress Of Solitude was, but that really wasn't the case. Renny knew because he and Doc and Clark Sr. designed it, and Renny got it built. He was under strict orders from Doc and his father never to reveal the location to anyone including the other members of Doc's aids. This was tough on Renny when Doc was at the Fortress and trouble broke out. In fact, that was where Doc was when word of his father's death came to the group. Renny waited until Doc showed up again. Renny is strong and dependable that way.

 In addition to Doc's lairs, Renny oversees construction of the untold hundreds of hospitals that Doc charitably finances everywhere he goes. On top of all that, Renny is in such demand for his design and construction managenent skills that he is doing projects all over the globe. He has built hydroelectric dams, tunnels, bridges, airports and hospitals to name a few.

 It is no wonder that Renny is often missing from Doc's adventures. This is a busy guy. He is constantly moving around. He has never been able to have a permanent home like some of the other aids. But that is the way Renny likes it. He loves to go to new places, stay for a year or so, build something big, and go on to the next one.

 Regardless, Renny's greatest love is the kind of adventure he gets from his association with Doc Savage, and as much as he likes to build things, he hates it when he misses out on an adventure because he cannot leave a job he has in progress.