What was that engineering frat you mentioned?? Was it pi tau sigma? That's the current Greek society for engineers.
IIRC Alpha Phi Omega is a service organization open to all.
OT:
I'm not sure that engineers have a frat as such, but engineers have honorary society Tau Beta Pi which is the Phi Beta Kappa equivalent. If you look in front of the Hudson engineering bldg at Duke you'll see the "bent" which is the symbol of PBK.
The pledges are made to go out and polish the bent each year. It also leads to a lot of "let's get bent" jokes.
Electrical engineers have Eta Kappa Nu. The initiation ceremony is a hoot. Everyone assumes an identity: "Brother Ohm", "Brother Volt", etc. We could never do it without cracking up. Oops! I gave away the secret ceremony. I guess I'm out. The Civil Engineers have their own as do the Mech. E.'s, etc.
p.s. Pi Tau Sigma is the engineering honor society for Mech E.s