2013 Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG)

4.6 Telescopes and Periscopes

4.6.1 General.

Where telescopes or periscopes are provided, no fewer than two telescopes or periscopes shall be provided at each distinct viewing location in a viewing area. At least one telescope or periscope for each viewing location shall comply with 4.6. The other telescopes shall be usable from a standing position. Telescopes or periscopes at different heights can be mounted separately or on a single pedestal.

Exception. In alterations, where a condition for exception in section 1.1 prohibits full compliance with a specific requirement for clear floor or ground space surface, slope, size, or location, the clear floor or ground space shall comply with requirements to the extent practicable.

4.6.2 Operable Parts.

Controls and operating mechanisms for telescopes and periscopes that are useable from a seated position shall comply with the operable parts requirements in sections 308 and 309.4 of the ABAAS. 

4.6.3 Eyepiece.

The eyepiece for the telescope or periscope that is usable from a seated position for viewing each point of interest shall be positioned 43 inches (1090 mm) minimum and 51 inches (1295 mm) maximum above the floor or ground surface.

4.6.4 Clear Floor or Ground Space.

The clear floor or ground space for telescopes and periscopes shall be at least 36 inches (915 mm) by 48 inches (1220 mm) positioned for forward approach to the telescope or periscope, and be located adjacent to an ORAR. Knee and toe clearance complying with ABAAS section 306 shall be provided under the telescope or periscope. Clear floor or ground space shall be positioned so that the eyepiece of the telescope or periscope is centered on the space.

4.6.5 Slope.

The slope of the clear floor or ground space required by section 4.6.4 shall not exceed 1:48 (2 percent) in any direction.

Exception. When the surface is not paved or is not elevated above the natural ground, slopes not steeper than 1:33 (3 percent) shall be permitted where necessary for drainage. 

4.6.6 Surface.

The surface of the clear floor or ground space required by section 4.6.4 shall be firm and stable. The type of surface should be appropriate to the setting and level of development. 

4.6.7 Openings.

Openings in the clear floor or ground space surface shall not allow passage of a sphere more than 1/2 inch (13 mm) diameter. Where possible, elongated openings should be placed perpendicular, or as close to perpendicular as possible, to the dominant direction of travel.