Ed Halper from the University of Georgia wrote:
I had thought that one could ride any elevator on Shabbos, as long as it did not make a special stop for you. Then someone recently told me that Shabbos Elevators are specially constructed. Is this correct? How does one construct a Shabbat Elevator?
A Shabbat elevator is essentially an automatic elevator which operates according to a preset program, and is not influenced by the passenger(s) in any way. Such an elevator stops for a fixed predetermined time at each floor. A buzzer sounds to warn the passenger(s) not to interfere with the doors when they are about to close because it would influence the program.
Note, however, that not all automatic elevator systems are Shabbat elevators, per se. Because there are many Halachic issues surrounding the use of elevators on Shabbat, one should familiarize oneself with all of them before the particular elevator in question can be used.
One of the common misconceptions about how elevators work, is that they are moved by a powerful motor which works equally hard no matter how many passengers have boarded, or even if no passengers have boarded at all. If this were the case, then the added weight of the passenger is not a contributing factor in any of the functions of the elevator and he wouldn't be considered responsible for those violations of Shabbat caused by use of the elevator. This assumption though, is false.
The assumption is false because elevator motors do not use the same amount of power regardless of the number of passengers or weight. The following is an explanation of how the majority of elevators work, illustrating just a small number of Halachic issues surrounding the use of elevators on Shabbat:
- Most elevators are the traction type: consisting of a car and a counterweight on opposite ends of a cable hanging from a pulley;
- The pulley raises or lowers the car by using a motor, and stops by using a mechanical brake;
- The motor only requires enough power to lift the difference between the counterweight and the car, and to overcome friction;
- The weight is equal to half capacity of the car, thus the motor operates to counteract the pull of the weight when the elevator is less than half full, and does not operate when the elevator is more than half full, when the car is descending.
Since the weight of the passenger is partly responsible for the motion of the elevator, he becomes liable for any infractions caused by the elevator's descent. In a typical non-Shabbos elevator, these are some of the many problems that one could encounter:
- Letting your weight trigger the mechanism that slows the elevator down and stops it at the next floor.
- Causing the light that indicates the floor that the elevator is presently on to illuminate.
- Activating the system (resistance sensitive pads, photoelectric device, or proximity detector) that opens the elevator doors.
The Institute for Science and Halacha has spent many years working out the various Halachic problems and have designs for Shabbat elevators that meet the most rigorous Shabbat standards. Don't just use any automatic elevator - check with a Local Halachic Authority and find out whether it really is Shabbat safe.
Speaking of elevators, I heard a story several years ago about two Israelis who boarded an elevator in New York. The elevator operator - who was Israeli and recognized his fellow compatriots by their Hebrew conversation - asked "Yordim?" Stunned at hearing the Hebrew words, they quickly answered: "No! No! We're only tourists!"
Note: "Yordim" is a Hebrew word which can be translated either as 'descending' flights in an elevator, or as 'emigrants from Israel."
- D.R. Bannett - The Sabbath Elevator Question, Elevators and Shabbat, The Institute for Science and Halacha.
- Rabbi L.Y. Halperin - Shabbat and Electricity, The Institute for Science and Halacha.