Current through Register Vol. 54, No. 38, September 21, 2024
(a)
Power source. Electrical and internal combustion energy may be
utilized as a power source, under the requirements set forth in §
7.427(a)
(relating to terminals and stations).
(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 unload the line in the event of power
failure unless an exception is granted by the authority having jurisdiction.
Internal combustion engine exhaust shall be discharged in 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. All bearings, couplings, and shafting shall conform to the
provisions of § 7.427(d).
(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. The primary requirement is to
have means of preventing runaway speeds particularly when overhauling loads are
being carried. Specific provision other than brakes shall be made for
maintaining normal speed under overhauling loads. The power developed by such
overhauling load may be dissipated electrically, hydraulically, or
pneumatically. Provision shall also be made for slowing and stopping the
tramway drive automatically if the line velocity exceeds design values by more
than 15%. Drive equipment shall be designed to accelerate the line smoothly and
to avoid discomfort to passengers under any loading condition. When carriers
are detachable, they shall be accelerated and decelerated to and from the rope
speed at such rates as not to cause discomfort to passengers. When carriers are
fixed to the rope, there shall be an attendant to assist the passengers
mounting and dismounting. The drive shall be capable of rotating the unloaded
system at reduced speed for rope inspection. In the case of systems involving
detachable carriers, unbalanced loading shall be controlled by automatic car
counters or other suitable devices.
(g)
Brakes and stops. Every
chair lift, gondola lift and skimobile shall be provided with at least the
following:
(1)
Brakes. Every
such lift shall include the following brakes:
(i) An automatic brake to stop and hold the
system under maximum load when power is shut off or the lift is stopped for any
reason. Such brake shall be electrically released and applied by springs of
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. The brake shall be applied to a drive shaft so that
there is no clutch, V-belt or chain drive, or similar device between the brake
and the drive wheel. This restriction on the location of the brake is not
required in cases where the gear pitch or gear reduction is such that the lift
cannot overhaul with a capacity load plus 10% after the interruption of
power.
(ii) A manually-operated
brake on the main drive sheave with controls located near the
operator.
(iii) A backstop to
prevent reverse rotation of the tramway, unless the gearing will prevent
gravity reversal.
(2)
Stops. Electric switches affecting all power shall be
installed at all loading and unloading points and be so located as to be
immediately available to the attendants. The stop system shall be so arranged
that the lift cannot be started until the device that stopped the lift 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 the wind velocity reaches the established
maximum. When wind conditions, as determined by such a device or by observation
of an attendant or the operator, make operations dangerous, the tramway shall
be unloaded and stopped. The tramway shall be started only by the operator or
with his approval, unless the plan of operations set by the management of the
tramway permits other attendants to start the lift under certain specified
conditions. Reference should be made to subsections (f) and (t) of this section
and §
7.448(d)
(relating to line structures).
(h)
Machine rooms. Machine
rooms shall conform to the requirements specified in §
7.427(h), except
that a door with a suitable lock is not required for a cabinet type unit. In
all cases, all safety devices, such as backstops, brakes, relays, and the like,
shall be protected from the weather.
(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 wheel.
Bull wheel frames shall be so designed that they will retain the
wheel in the event of shaft breakage. If this is not feasible, shaft design
working stresses shall be not more than 60% of those otherwise allowable. The
minimum diameter for bull wheels shall be 72 times the diameter of the rope, if
no gripping device passes around the bull wheel. The minimum diameter for bull
wheels shall be 96 times the diameter of the rope in cases where the gripping
devices travel around the bull wheel. In such instances, 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 bull wheel mounting at all terminals
shall be supported from the ground by rigid structures. The mounting that
travels under the action of the counterweight shall be supported on rigid
straight rails by means of wheels. The available travel should be such that the
frame does reach either limit of motion during normal operation and until the
hauling rope needs to be resocketed or respliced for other reasons, or
replaced. On fixed-grip lifts, guides shall be provided to prevent the carriers
from excessive swinging while passing around the bull wheel. On skimobiles,
provision shall be made in the design of the turntable to prevent the car from
leaving the track.
(k)
Sheaves and bearings in terminals. All sheaves and bearings in
terminals shall conform to the following:
(1)
Drive sheaves. Drive sheaves shall be designed to withstand
static and dynamic loads. Sheave mountings and bearings shall satisfy the
recommendations of the manufacturers of the bearings. When sheaves are mounted
on vertical shafts, such shafts shall be equipped with bearings which
adequately resist the vertical thrust. Drive sheaves shall be so designed that
the hauling rope will not slip in the sheave groove which involves the friction
between the bull wheel or its groove liner and the rope, as well as the
relative levels of tensions of the rope entering and leaving the bull
wheel.
(2)
Hauling rope
sheaves. Guide sheaves shall be placed to prevent misalignment of the
rope entering and leaving the bull wheels. Sheaves shall meet the
specifications of §
7.448(d), and
carry no figured load from the rope. When necessary to prevent the rope from
leaving the sheaves, counter sheaves shall be installed adjacent to them.
Provision shall be made for grounding the wire rope to offset the effects of
static electricity and electrical storms. When deflecting sheaves are required
they shall also satisfy the requirements of § 7.427(k)(2).
(3)
Counterweight rope sheaves.
Counterweight rope sheaves are subject to the specifications
prescribed in paragraph (2) of this subsection, except that if antifriction
bearings are considered, they shall be selected to avoid a tendency for flat
spots to develop on the rollers or balls since counterweight sheaves are
subject to very little motion and often stand without moving for long periods
of time.
(4)
Track cable
deflecting sheaves (bicable lifts only). Track cable deflecting
sheaves in the 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. If 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)(1)-(5)
of this Title (relating to line structures), except that if saddles in the
terminals are so located that the carrier wheels do not pass over them,
subparagraphs (ii) and (iv) of paragraph (1) of that subsection need not
apply.
(m)
Anchor
connections for 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 conform to the
specifications prescribed in § 7.427(n).
(o)
Counterweights.
Counterweights shall conform to the specifications prescribed in §
7.427(o), except
that reference shall be made to subsection (j) in regard to bull
wheels.
(p)
Structures. The structures of chair lifts, gondola lifts, and
skimobiles shall conform to the specifications prescribed in §
7.427(p).
(q)
Foundations.
The foundations of chair lifts, gondola lifts, and skimobiles shall
conform to the specifications prescribed in § 7.427(q).
(r)
Loading and unloading areas.
All loading and unloading areas shall conform to the following:
(1)
Chair and monorail lifts.
Loading and unloading areas shall have sufficient level length to
load and unload passengers safely and, in the case of unloading, to clear them
from the platform. The minimum length shall be 16 feet, which shall be level
except for unloading areas for skiers, which may be inclined so that passengers
may ski away from the lift. Handrails, safety nets, or ramps shall be provided
on all sides of each platform for the protection of passengers. Attention
should be given to intermediate and upper unloading areas for double chair
lifts. Since there may be a hazard involved in attempting to disembark both
passengers from a carrier to the same side of the lift, this should be overcome
either in the design or operation of the lift. Towers adjacent to loading
points shall be covered with guards to prevent ski tips of starting passengers
from becoming entangled in the towers. The outer ends of unloading platforms
shall be fitted with inclined guards to prevent the ski tips of unwary
passengers from being caught under the edges of such platforms. The distance
between hauling rope supports on either side of each loading area shall be such
that the distance between chair and ground does not diminish excessively under
the impact of loading passengers. The same distance shall be used between
hauling rope supports at unloading areas.
(2)
Detachable chair and gondola
lifts. Sufficient terminal floor space shall be provided so that
passengers may board and leave the carriers without being crowded. Carriers
shall be secured or controlled to prevent excessive swinging during loading and
unloading. Provision shall be made at all stations for the separation of
incoming and outgoing passengers. Stations shall be so arranged that the
carriers can enter and leave safely even when swinging laterally. Beyond the
points of attachment and detachment of the grips, devices shall be installed to
avoid damage to equipment or injury to persons in the event of faulty
detachment or attachment. Such devices shall support the grip and carrier
safely as it travels the distance necessary to stop the lift after the
operation of a safety stop, to which 50% should be added as a safety margin.
The devices shall include bumpers wherever the carriage or carrier could become
freewheeling on an openend or deadend track. Switches in the track system shall
be provided with safety devices to prevent malfunction. Reference shall also be
made to §
7.449(b)(2)(i)
(relating to line equipment).
(3)
Skimobiles. Loading and unloading terminal platforms shall
have a minimum level length of 30 feet and the surface shall be maintained in a
nonslippery condition. There shall be a guardrail between incoming and outgoing
tracks. At intermediate stations used for unloading only, the slope of the
platform shall be the same grade as the track.
(s)
Attendants. Attendants
shall be provided as follows:
(1)
Chair lifts and skimobiles. There shall be a minimum of one
attendant at each station when it is being used for loading and unloading. One
attendant shall also be placed in charge of the operating crew. Primary tramway
controls and communication systems shall be immediately available to him. He
shall have enough time from other duties to discharge this responsibility and
keep the operation under observation at all times. At least one attendant shall
be available to service each carrier to be loaded or unloaded. At times of peak
load on double chair lifts with minimum interval between chairs, it may be
necessary for safe operation to have two attendants available for each
chair.
(2)
Detachable chair
and gondola lifts. The requirements for detachable chair and gondola
lifts are the same as those prescribed in paragraph (1), except that additional
attendants may be required to handle the carriers in the stations. When
carriers are not mechanically controlled in the stations, one or more
additional attendants may be required, one to handle incoming cars and the
other to handle outgoing cars during peak periods of operation.
(3)
All installations. All
personnel subject to the provisions of this subsection shall be carefully
instructed in tramway operation, including the acquisition of a knowledge of
possible emergency situations and methods of handling them.
(t)
Safety stops.
Safety stops shall be provided as follows:
(1)
Chair lifts and monorail lifts.
When danger to passengers or equipment may result if a passenger
remains on the carrier while it travels around a bull wheel, a safety stop
shall be provided at each such terminal to stop the lift before exposure to
such danger. The distance from such stop to the first obstruction shall not be
less than the distance travelled by the unloaded lift operating at maximum
speed after application of such a stop, to which should be added a safety
margin of 50%.
(2)
Detachable chair and gondola lifts. Automatic safety stops
shall be provided in each terminal to stop the lift in the event a carrier does
not properly disengage from, or reattach to, the hauling rope. The provisions
of subsection (r)(2) shall also be complied with.
(3)
All installations. Limit
switches shall 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 case of power failure or of malfunction of
the stop switch, the system will fail safe. The circuit 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, and the safety stop reset. Safety stop circuits shall not be bypassed
during passenger operation. In the case of such stops, the tramway shall never
be started except by the operator. Reference should also be made to subsections
(f) and (g) and § 7.448(d).
This section cited in 34 Pa. Code §
7.441 (relating to definitions);
34 Pa. Code §
7.442 (relating to applicability);
34 Pa. Code §
7.449 (relating to line
equipment); 34 Pa. Code §
7.453 (relating to operation); and
34 Pa. Code §
7.462 (relating to
applicability).
