Indeed I don't (it IS a brute though). I've never seen a serpentine system without a powerful spring loaded tensioner - the one on my wife's minivan requires a breaker bar to unload the tension. How is tension maintained on the belt on the system you describe?
Yes automotive serpentine belts require a loaded tensioner, the ones used on marine engines employing large case alternators do not. The belt goes around ALL the drive pulleys, but underneath the idler pulley. The tension is loaded with the alternator adjusting arm. The main reason it's done this way is that marine diesel engines don't operate at variable and higher engine RPMs (therefore no backlash that causes the belt to "jump") like automotive engines. Hope that helps.