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83:, sending an indication that the fence is intact. If a rock slide occurs, one or more of the wires is broken, interrupting the current. This allows the relay to open, indicating that a slide has occurred thus causing the approaching signals to display a stop or slow aspect. Restoring normal operation requires splicing the broken fence wires back together after the
55:
The mechanical slide fence parallel to the rails consists of a series of tensioned wires strung about 10 inches (25 cm) apart on poles. When a rock slide occurs, one or more of the wires may break, allowing heavy weights attached to either end to drop. This triggers the protecting signals to the
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to proceed slowly, watching for a dangerous rock slide. If the train is able to successfully pass through the slide area (that is, there is no remaining danger), that train will then be allowed to proceed normally. However, once the slide fence has been activated (even if in error), all trains must
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Used extensively throughout French Alps, where passenger trains routinely travel at speeds in excess of 200kph through areas prone to rock slides. In many locations, structures have been installed as a roof over the tracks to allow rock falls to occur without effect, but in many others these fences
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When a train approaches a slide fence area and the signal displays a restrictive aspect, the train is not permitted to proceed normally because a rock slide may have occurred. However, the slide may not prevent the safe passage of the train. For example, a large rock may have fallen off the cliff,
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A slide fence is typically found in a rock-cut area, where rocks could fall on the track and present a danger to approaching trains. The length of the fence may range from 100 feet (30 meters) to several miles (kilometers), depending on the length of the rock cut and the area being protected. The
110:, thus indicating that the fence is in place. When a rock slide occurs, the fence moves laterally, causing a plug to pull out. This breaks the circuit, allowing the relay to denergize thus preventing the approaching signals from displaying unrestricted aspects.
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The structural fence is a physical barrier designed to stop falling rocks from reaching the tracks. Several methods are used, including steel I-beams, wooden barriers, and galvanized fencing. Alternatively, netting can be installed directly against the rock.
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when activated. This causes signals on either side of the slide fence to display a restricting indication, requiring trains to travel at a speed enabling them to stop within one-half the range of vision. On lines formerly operated by the
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Another type of slide fence is similar except that the wires do not have to break and thus it is easier to maintain and reset. This slide fence consists of a series of fence sections, typically as shown in the SLIDE FENCE DETAIL drawing
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One type of electrical slide fence consists of a series of parallel conductive wires strung about 8 inches (20 cm) apart on poles that create a fence parallel to the rails. An
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Hand-written slide protection placard on a PRR Pedestal type signal at CP-SOUTH FERRY indicates to engine crews that this signal is connected to a slide detector.
184:, signals connected to a slide detector have an 'SP' placard, reminding engineers to watch for slides when governed by any restrictive speed signal.
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traverse the area with caution until the fence is repaired by maintenance personnel. This may result in several hours of delay in train service.
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broken through the slide fence, and continued to fall away from the track. After stopping, the train may obtain permission from the
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102:). Each fence section is held in place by strong springs. At each end are electro-mechanical plugs, which maintain a continuous
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is a structural fence designed to physically stop falling rocks from reaching the tracks. The fence is designed to retain a
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that is monitored by signaling equipment. In normal operation, the current through the plugs energizes a
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There are two types of electrical slide fences in operation, as described in section 5.1.12 of the
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Railway
Rockfall Electromagnetic Field Disturbance Sensing System Development and Test Results
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Several alternative technologies have been tried to solve the rock slide problem, including:
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In North
America slide fences are typically connected in such a way as to shunt the
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Structural fence designed to physically stop falling rocks from reaching the tracks
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slide fence is usually located on the uphill side of the track in the slide area.
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through these wires is monitored by signaling equipment. In normal operation, the
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US Patent 6216985 Railway hazard acoustic sensing, locating, and alarm system
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Weir-Jones
Engineering RockFall - Seismic RockFall Detection System
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The
American Railway Engineering and Maintenance of Way Association
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if possible, but if it is displaced by such it also can cause the
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371:"Railway-News eMagazine Issue 4 2023 by a2b Global Media - Issuu"
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Railway
Signalling and Operations, Glossary of Signalling Terms
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107:
80:
622:
153:
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On approach to Aix-les-Bains on banks of Lac du
Bourget
42:
to display a restrictive aspect to approaching trains.
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Transport Canada
Seismic Rail line rockfall monitoring
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293:
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406:
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718:Interoperable Communications Based Signaling
79:in the fence wires continuously energizes a
653:Automatic Train Protection (United Kingdom)
329:"Rockslide detectors are a critical device"
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618:Advanced Civil Speed Enforcement System
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154:Consequences of slide fence activation
778:Train Protection & Warning System
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511:Integrated Electronic Control Centre
773:Train automatic stopping controller
693:Continuous Automatic Warning System
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24:
453:Communications-based train control
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25:
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127:
935:Westinghouse Brake & Signal
698:Contrôle de vitesse par balises
564:North American railroad signals
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793:Transmission balise-locomotive
758:Sistema Controllo Marcia Treno
668:Automatische treinbeïnvloeding
554:Application of railway signals
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327:Lustig, David (May 28, 2023).
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13:
1:
743:Punktförmige Zugbeeinflussung
463:European Train Control System
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232:Pass of Brander stone signals
221:Visual sensing, using cameras
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59:
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683:Chinese Train Control System
473:Radio Electronic Token Block
217:Distributed acoustic sensing
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7:
448:Centralized traffic control
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10:
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648:Automatic train protection
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940:Westinghouse Rail Systems
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806:
798:Transmission Voie-Machine
643:Automatic train operation
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595:Track circuit interrupter
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443:Automatic block signaling
438:Absolute block signalling
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1123:Train protection systems
738:Pulse code cab signaling
663:Automatic Warning System
569:Railway semaphore signal
531:Solid State Interlocking
638:Automatic train control
204:Electromagnetic sensing
814:Level crossing signals
733:Positive Train Control
728:Linienzugbeeinflussung
458:Direct traffic control
210:buried parallel to ROW
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536:Westlock Interlocking
526:Rail operating centre
488:Train order operation
483:Track Warrant Control
182:Pennsylvania Railroad
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658:Automatic train stop
66:AREMA C&S Manual
56:'danger' position.
498:Signalling control
422:Railway signalling
314:2008-12-03 at the
282:2007-09-29 at the
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104:electrical circuit
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87:has been cleared.
73:electrical circuit
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920:Smith and Yardley
334:Trains Newsletter
200:Avalanche control
16:(Redirected from
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986:Transport Canada
870:General Electric
807:Crossing signals
688:Cityflo 650 CBTC
610:Train protection
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834:Wayside horn
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678:Catch points
585:Axle counter
516:Interlocking
468:Moving block
379:. Retrieved
377:. 2023-10-31
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342:. Retrieved
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272:
245:
208:Fiber optics
191:
188:Alternatives
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150:are in use.
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85:right of way
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31:
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1092:Switzerland
1067:New Zealand
1062:Netherlands
768:Slide fence
521:Lever frame
32:slide fence
18:Slide fence
1000:By country
783:Train stop
748:RS4 Codici
506:Block post
381:2024-01-04
238:References
123:Where used
60:Electrical
51:Mechanical
1007:Australia
860:AŽD Praha
819:Crossbuck
723:Crocodile
375:issuu.com
46:Operation
36:rockslide
1117:Category
1097:Thailand
905:Safetran
895:Magnetic
880:Griswold
829:E-signal
339:Kalmbach
312:Archived
280:Archived
226:See also
1042:Germany
1032:Finland
1017:Belgium
1012:Bavaria
915:Siemens
890:Hitachi
865:Federal
850:Adtranz
753:SelTrac
600:Treadle
546:Signals
344:May 30,
1087:Sweden
1082:Poland
1077:Norway
1047:Greece
1037:France
1022:Canada
925:Thales
855:Alstom
824:Wigwag
703:EBICAB
673:Balise
137:Europe
1057:Japan
1052:Italy
1027:China
961:AREMA
910:Saxby
763:SACEM
708:IIATS
633:ATACS
478:Token
108:relay
81:relay
981:IRSE
976:HMRI
885:Hall
628:ASFA
623:ALSN
346:2023
991:UIC
971:FRA
966:ERA
956:AAR
875:GRS
1119::
373:.
337:.
331:.
290:^
256:^
68:.
30:A
414:e
407:t
400:v
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98:(
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
