When Pforzheimer House residents step onto their elevators, they expect to be dropped off on their floor. But according to several House residents, they have been taken for a ride by malfunctions in the buildings' aging elevators.

Pforzheimer residents said in the past few weeks, at least four incidents in the Comstock and Holmes Hall elevators have trapped students for periods ranging from 10 minutes to two hours.

The most serious incident to date trapped residents Ellen Harkavy '01 and Erin E. Conroy '01 for more than two hours last week. According to Harkavy, the Harvard maintenance operator was unable to release them or fix the elevator, and two hours passed before an elevator company technician arrived.

According to Pforzheimer House Superintendent Milton Canjura, the elevators had been fixed since the incidents.

Canjura added that occasional elevator troubles "happen in every House" from time to time, and that the slated replacement of the Comstock elevator during the summer of 2001 should fix "99 percent" of the difficulties.

According to Michael N. Lichten, director of the Faculty of Arts and Sciences' Office for Physical Resources, the maintenance of Harvard's elevators is contracted to Thyssen Dover Elevator, which performs a "regular preventative maintenance program" of monthly inspections, as well as interventions during breakdowns.

In addition to the checkups by Thyssen Dover, Cambridge building inspectors test the elevators monthly and the state of Massachusetts certifies them yearly.

The elevator company is not always called in to solve technical problems--Harvard staff are often able to resolve the problem on their own.