§ 7.427. Terminals and stations.
(a) Power source. Electrical and internal combustion energy may be utilized as a power source, as follows:
(1) Electrical. Exposed electrical transmission wiring shall be so located that in case of collapse or breakage of the power line it will not come in contact with cars, cables or passengers. All electrical work shall comply with the American Standard National Electrical Code, C1-1959 and the American Standard National Electrical Safety Code, C2 (R 1947). Transformer stations and other electrical equipment shall be so protected as to prevent unauthorized persons from entering the area or coming in contact with any portion of the equipment or wiring. Power equipment shall be protected against overloads by proper circuit breakers or fuses.
(2) Internal combustion. Fuel tanks shall be of adequate capacity to permit uninterrupted operation during normal operating hours. In any event, the tank shall be refilled while there is still enough fuel in such tank to bring the fuel to the stations. Fuel tanks shall be buried or so located as to be free of fire hazard. The engine shall always be shut down during refueling. The fuel entry opening shall be capped and located to avoid toxic fumes and fire hazard during refueling. Liquid fuels shall be stored and handled in accordance with the standards of the National Board of Fire Underwriters as outlined in Pamphlet No. 30, Flammable Liquids, June 1959. Also, liquefied petroleum gas installations shall be made in accordance with the standards of the National Board of Fire Underwriters, as outlined in Pamphlet No. 58, Liquefied Petroleum Gases, as amended through 1959.
(b) Prime movers. Prime movers shall have the capacity to handle the most unfavorable design loading conditions. An auxiliary power unit with an independent power source shall be provided which may readily be used to move the cabins to the terminals in the event of power failure, unless other means are provided to return the cabin to the terminal. Internal combustion engine exhaust shall be discharged into the atmosphere.
(c) Speed reducers and gears. Speed reducers and gears shall comply with accepted standard practices, and have the capacity for starting the tramway under the most unfavorable design load conditions.
(d) Bearings, couplings and shafting. Shafting shall be designed in accordance with accepted standard practices. Provision shall be made for the adjustment and lubrication of all bearings and couplings when required. Bearings and couplings shall be selected on the basis of the published recommendations of the manufacturer for the particular use in question. If published data are not available to cover the use, the approval of the manufacturer shall be obtained for the intended use. Bearings and couplings of special design, when used, shall have the approval of a competent mechanical engineer.
(e) Clutches. Any clutch device used between the prime mover and the drive sheave shall meet the requirements for bearings and couplings specified in subsection (d).
(f) Acceleration and speed control. Acceleration and speed controls are required to avoid discomfort to passengers caused by undue longitudinal swinging of the cabin or by excessive acceleration or deceleration and in order to start and stop the cabins smoothly and safely. The following points shall be considered in the design:
(1) Provision shall be made for smooth deceleration of the tramway prior to the actuation of one of the automatic motor brakes specified in subsection (g).
(2) Cabins shall be brought to a stop for loading and unloading, and provision made to make the tramway immobile during loading and unloading periods. The control room shall contain, in full view of the operator, indicators which show the location of the cars at all times.
(3) Provision shall be made for an overhauling load so that the system always operates at a controlled speed not exceeding the rated speed by more than 10%. The power developed by the overhauling load shall be automatically dissipated electrically, hydraulically or pneumatically.
(g) Brakes and stops. Each tramway system shall have brakes and manual stops as follows:
(1) Brakes. Each tramway system shall include the following brakes:
(i) An automatic brake to stop and hold the tramway system under maximum load when power is shut off or the tramway is stopped for any reason. Such brake shall be applied to a drive shaft such that there is no clutch, V-belt, chain drive or similar device between the brake and the drive wheel. The brake shall be electrically released and applied by springs or gravity, except in cases where another type of brake is specifically approved by the authority having jurisdiction. In all cases the brake shall normally be in the applied position. It shall be held open for operation of the tramway by a device which is automatically cut out if power is shut off or the tramway stopped. Such device shall, without exception, be placed in operation before the tramway is started.
(ii) An automatic overspeed device which actuates the brake specified in subparagraph (i) or a similar independent brake when the speed of the prime mover exceeds its rated value by more than 10%.
(iii) A manually-operated brake on the main drive sheave with controls located near the operator.
(iv) On bicable tramways, an automatic track cable brake. Reference should be made to § 7.429(b)(3)(ii) (relating to line equipment).
(2) Stops. Electric switches to stop tramways shall be installed on both terminal platforms. One shall also be installed on the control board of the conductor in each cabin, unless no conductor is required. The stopping system shall be so arranged that the tramway cannot be started until the device that stopped the tramway is reset and the operator obtains clearance from the point at which the device is actuated. It is desirable that a wind gage be installed on the most exposed point along the tramway line. In such case, a conspicuous warning device shall function to alert the operator when wind velocity reaches the established maximum. When wind conditions make operations dangerous, as determined by such a device or by observation of an attendant or the operator, the tramway shall be unloaded and stopped. The tramway shall never be started except by the operator. Reference should also be made to subsections (f) and (t) and § 7.428(d) (relating to line structures).
(h) Machine rooms. Motive power shall be housed in a well-ventilated machine room in a manner which permits proper maintenance and keeps the public away from the machinery. Adequate lighting and protection against lightning and static electricity shall be provided. A minimum of 18 inches clearance shall be provided between machinery and machine room enclosures, and passageways between units of machinery shall have the same minimum width. A fireproof room is preferable, but in any event, fire prevention measures and fire fighting devices shall be installed. A door with a suitable lock shall be installed on all machine rooms.
(i) Protection against moving parts. Moving machine parts which may normally be within reach of personnel shall be fitted with safety guards conforming to American Standard B15.1-1953.
(j) Bull wheels. Bull wheel frames shall be so designed that they will retain the wheel in the event of shaft breakage. The minimum diameter for bull wheels shall be 72 times the diameter of the rope, provided that no gripping device passes around the bull wheel. The minimum diameter for bull wheels shall be 96 times the diameter of the rope if gripping devices travel around the bull wheel. In the latter instance, the angle formed by the cable as it enters and leaves the grip body when passing around the bull wheel shall not exceed seven degrees. The mounting that travels under the action of the counterweight shall be supported on rigid straight rails by means of wheels. The available travel shall be such that the frame does not reach either limit of motion during normal operation and until the hauling rope needs to be resocketed or respliced for other reasons, or replaced.
(k) Sheaves and bearings in terminals. Sheaves and bearings in terminals shall conform to the following:
(1) All drive sheaves. All drive sheaves shall meet the requirements of this subsection.
(2) Hauling rope deflecting sheaves. Hauling rope deflecting sheaves in terminals shall be designed to withstand static and dynamic loads. The tread diameter shall be not less than that recommended by the manufacturer of the hauling rope for the intended use. Standard recommendations are as follows:
Rope Construction Sheave Diameters Category Condition A Condition B 6 x 7 72d 42d 6 x 19 45d 30d 6 x 37 27d 18d (i) For the purposes of this section, the following words and terms shall have the following meanings:
Condition A—Where bending over sheaves is of major importance.
Condition B—Where bending over sheaves is important but some sacrifice in rope life is acceptable to achieve reduction in weight, economy of design, and the like.
d—Nominal diameter of rope.
(ii) When unlined grooves are used they shall be V-shaped with rounded bottoms having a radius equal to 55% of the rope diameter. Sheave mountings and bearings shall satisfy the recommendations of the manufacturers of the bearings.
(iii) Provision shall be made for grounding the wire rope. When such rope is used as a conductor in the communication system, lightning protection shall be provided and the rope grounded when the tramway is not in operation.
(3) Counterweight rope sheaves. Counterweight rope sheaves are subject to the requirements set forth in paragraph (1), except that antifriction bearings shall be selected to avoid a tendency for flat spots to develop on the rollers or balls.
(4) Track cable deflecting sheaves. Track cable deflecting sheaves in terminals shall be designed to withstand static and dynamic loads. Their tread diameter shall be not less than that recommended by the manufacturer of the track cable for the particular installation and shall also satisfy the allowable bearing load limits of the material with which their grooves are lined. When unlined grooves are used they should be V-shaped with rounded bottoms having a radius equal to 55% of the cable diameter. Sheave mountings and bearings shall satisfy the recommendations of the manufacturers of the bearings. Provision shall be made for grounding the cable. When the cable is used as a conductor in the communication system, lightning protection shall be provided, and the cable shall be grounded when the tramway is not in operation.
(l) Track cable saddles. The requirements for track cable saddles are the same as those set forth in § 7.428(e), except that if saddles in the terminals are located so that the carriage wheels do not pass over them, § 7.428(e)(1)(ii) and (iv) need not apply.
(m) Anchor connections for hauling ropes, track cables, counterweight ropes, tower or station anchor cables or guys, and the like. Rope and cable sockets shall be designed so that they will not be stressed beyond the yield point of the material used when the ropes or cables which they anchor are under tensions equal to their catalog breaking strength. Anchor connections shall be above ground. Any part of the anchorage below ground shall be protected against loss of strength due to corrosion.
(n) Counterweight ropes. Counterweight ropes shall have a minimum factor of safety of six, when new, based on their catalog strength. A copy of the specifications of the wire rope manufacture shall be available to the authority having jurisdiction. Such specifications shall include size, grade rope, construction, type of core, and breaking strength, based on values as published in United States Department of Commerce, National Bureau of Standards Simplified Practice Recommendations 198-50. Before installation the manufacturer shall test to destruction a sample of the rope furnished, and submit a certified report of the results. In the case of ropes of foreign origin, a test shall be made by a reputable testing agency approved by the authority having jurisdiction in order to obtain adequate proof. No splices are permitted in counterweight ropes. Counterweight ropes should be lubricated regularly with a lubricant specifically recommended for this type of service to avoid corrosion. They shall be adjusted so that the counterweight will reach the end of its travel when the corresponding bull wheel carriage comes within not less than 6 inches of the end of its travel.
(o) Counterweights. Counterweights shall be provided for all hauling ropes and be so arranged as to move freely up and down. Enclosures for counterweights shall be provided when necessary to prevent snow or ice from accumulating under and around such counterweights and interfering with their free movement. When snow enclosures are not required, guard rails or enclosures shall be provided to prevent unauthorized persons from coming in contact with or passing under the counterweights. Counterweights shall have sufficient travel to take care of all normal operating changes in loading and temperature. Furthermore, it should preferably have a travel equal to that of the bull wheel carriage, as described in subsection (j), which moves in response to it. If this amount of travel is not available, means shall be provided to shorten the counterweight ropes so that the counterweight will be in full suspension at all times. When counterweights are used for track cables, the same provisions shall apply.
(p) Structures. With respect to static loads, terminal structures shall be designed on the basis of the following:
(1) Steel. American Standard A57.1-1952; American Welding Society Standard Code for Arc and Gas Welding for Building Construction; American Standard for Testing and Materials (ASTM) A6-57T; American Standard for Testing and Materials (ASTM) A7-58T.
(2) Timber. National Lumber Manufacturers Association Wood Structural Design Data.
(3) Concrete. American Standard A89.1-1957 (ACI 318-56).
(4) All structures. The following apply to all terminal structures subject to this subsection:
(i) Applied design loads include dead, live, snow and wind loads, plus impact, and earthquake loadings. They shall satisfy the requirements of American Standard A58.1-1955.
(ii) Attention shall be paid to those portions of the structure which are subject to vibration from moving parts. In such cases, the governing criterion may be deflection or natural period of vibration. The design shall be made or reviewed by an engineer competent to handle such problems.
(iii) Terminals located in snow creep areas shall be designed for such loads or be protected by snow breakers or shears.
(iv) Pressure due to snow creep may be approximated by use of the following:
(A) Formula.
(B) For the purposes of this section, the following symbols shall have the following meanings:
Ps—Total pressure on the object in pounds.
W—Width of snow in pounds per cubic foot.
B—Width of object in feet.
D—Vertical depth of snow in feet.
—Angle between horizontal and slope of ground surface.
(v) All terminals should be grounded so as to satisfy all national and local codes. The local electric power company is normally a good source of information regarding such code requirements.
(q) Foundations. Foundations for vertical loads shall satisfy the design requirements of subsection (p). For foundations for inclined or horizontal loads the structure of the anchorage shall satisfy the design requirements of subsection (p). In determining the resistance of the earth to motion of the anchorage, the subsoil conditions at the site shall be considered, including any buoyancy due to ground water which may be present. If the resistance of the soil is not practically determinable, the anchorage should be designed as a gravity anchor, using a coefficient of friction appropriate to the general character of the soil. Reference should also be made to § 7.428(b).
(r) Loading and unloading platforms. Steps should be avoided in all loading and unloading areas if possible. Platforms should be as level as practical and there shall be sufficient space for passengers waiting to ascend and descend. Railings shall be provided to guide passengers safely to and from cabins. Deadman controls shall be provided to stop the tramway in case the operator suddenly becomes incapacitated. Guide rails with curved ends shall be provided so that entrance and exit of cabins to and from platforms may be accomplished smoothly and without impact when the cabins are deflected from the vertical by ten degrees.
(s) Attendants. At least one trained platform attendant shall be present each time a cabin enters or leaves a terminal. The car conductor may serve as such an attendant if no loading passengers are permitted on the platform until it is cleared of all unloading passengers. There shall be a conductor who has knowledge of normal and emergency duties in each car having a capacity of more than six passengers during each trip. Reference should be made to § 7.429(b)(4) (relating to line equipment). The tramway operator shall be located where he has the best possible view of the tramway. His controls and communicating devices shall be within his reach without leaving his position.
(t) Safety stops. Limit switches or equivalent devices shall be installed to take over the operation of the drive automatically if the operator fails to decelerate the tramway when the cabin enters the terminal area. A further limiting device shall be installed to cut power and stop the tramway before the cabin reaches its limit of travel. An adequate bumper system shall also be installed. Limit switches may be installed to stop the tramway before any counterweight or bull wheel carriage reaches either end of its travel. Electrical stop circuits shall be closed circuits so that, in the event of power failure or of malfunction of a stop switch, the system will fail safe. Circuits shall be all metallic and ungrounded, unless otherwise approved by the authority having jurisdiction. After any actuation of a safety stop, the cause shall be determined and removed. The safety stop shall be reset. Safety stop circuits shall not be bypassed during passenger operation. The tramway shall never be started except by an experienced operator. Reference should be made to subsections (f) and (g) of this section and § 7.428(d).
Cross References This section cited in 34 Pa. Code § 7.421 (relating to definitions); 34 Pa. Code § 7.422 (relating to applicability); 34 Pa. Code § 7.428 (relating to line structures); 34 Pa. Code § 7.431 (relating to signs); 34 Pa. Code § 7.447 (relating to terminals and stations); 34 Pa. Code § 7.448 (relating to line structures); 34 Pa. Code § 7.453 (relating to operation); 34 Pa. Code § 7.467 (relating to terminals and stations); and 34 Pa. Code § 7.468 (relating to line structures).
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