Escalators may be used as exits in lieu of interior stairs provided they comply with all of the requirements of subchapter eighteen of this chapter and with the applicable requirements for enclosed interior stairs, except as modified below:
(a) Capacity. The capacity of escalators as listed in table 6-1 shall be based on the following:
Minimum Width (in.) at:
Step | Balustrade
1
| Enclosure
2
| Units of Exit Width |
24 | 32 | 52 | 1 1/2 |
40 | 48 | 68 | 2 1/2 |
Notes for Table:
1
Measured twenty-seven inches above front edge of tread.
2
Clear width above handrails.
(b) Acceptable exits. Only escalators moving in the direction of exit travel may be credited as exits, except that any escalator may be credited when it is connected to an automatic fire detection system that will cause it to stop simultaneously with the detection of fire. The detection system shall comply with the construction provisions of subchapter seventeen of this chapter. Where an escalator provides exit facilities from only one floor of a building, the automatic detection system shall be located on that floor. Where escalators provide exit facilities from more than one floor, the detection system shall be located on all floors so served, and shall cause escalators on all floors of the section of the building that they serve to stop operating. The stopping mechanism shall operate to bring the escalator to a gradual, rather than an abrupt stop.
(c) Escalators not used as exits. Escalators that do not serve as exits, and that connect more than two stories of a building, shall be completely enclosed with noncombustible construction having a three-quarter hour fire-resistance rating, except that in buildings completely protected by an automatic sprinkler system complying with the construction requirements of subchapter seventeen of this chapter, such escalators may, alternatively, be protected by one of the methods specified in subchapter eighteen of this chapter.