Section 7.468. Line structures

(a) Towers. The design of towers shall satisfy the requirements of § 7.427(p) (relating to terminals and stations) and all of the following:

(1) A minimum clearance of 36 inches shall be maintained between the base of a tower and the vertical plane of the upward traveling cable. With respect to the downward traveling cable a minimum clearance of 24 inches shall be provided between the towing outfit in its normal position and the tower.

(2) If guyed towers are used and the guys intersect the ground within or near ski runs, the guys shall be marked for visibility, preferably with boards painted with black and yellow strips.

(3) Means shall be provided for ready access from the ground to all tower tops. This requirement is fulfilled if the tower structure is such that it is safe to climb. Otherwise, means such as permanent or light, portable ladders shall be provided. The latter, if used shall be in at least sufficient quantity to be available at each point where attendants are stationed.

(4) All towers should be grounded by individual grounds, by buried ground wires connecting all towers, or by tying all towers into a suspended ground wire, which may also be used as a ground for the signal system, and is itself grounded. The ground shall satisfy all national and local codes. The local electric power company is a good source of information regarding such code requirements.

(5) Towers shall be clearly identified with successive numbers.

(6) When towers are designed to permit variations in rope height, sheave unit supports shall be attached so as to prevent misalignment by rotation during normal operation.

(b) Foundations. Foundations shall comply with the provisions of § 7.428(b) (relating to line structures).

(c) Guards. Guards shall comply with the provisions of § 7.428(c).

(d) Sheaves and mounts. Sheaves and mounts shall conform to § 7.427(k)(1), except that this application is that of a tower roller, not a large-angle deflection sheave. The following shall also apply:

(1) The provisions of § 7.428(d)(1),(3)—(6).

(2) Sheave grooves shall be designed with deep flanges to discourage the rope from leaving the sheaves. In addition, suitable guards shall be installed to prevent the rope from falling into dangerous positions within the tower structure in case it does leave the sheaves, and suitable devices shall be installed to stop the tramway in the event the cable leaves the sheave on either side.

(3) When, under the most adverse loading conditions, the load on a group of support sheaves at a tower may become less than 1/2 the permissible load on the sheave, depression sheaves shall be installed to ensure that the rope will not lift out of the support sheaves. The reverse requirement shall apply to depress towers.

(4) The sheaves for return ropes shall be installed in a manner which will prevent a passenger from contacting the rope or being hit by one of the returning towing outfits.

(5) Line sheaves shall be so guarded that towing devices or attachments cannot become entangled in sheaves or sheave supports. If unloading is permitted ahead of any intermediate tower, the layout of the unloading area shall satisy the requirements of § 7.467(q) (relating to terminals and stations), and the tower shall be so guarded as to prevent the released towing devices from becoming entangled with it.

Notation

Cross References

This section cited in 34 Pa. Code § 7.461 (relating to definitions); 34 Pa. Code § 7.462 (relating to applicability); and 34 Pa. Code § 7.467 (relating to terminals and stations).