606.2 Guard Cable - Revision history

Hoskir: /* 606.2.4 Maintenance and Repair */ minor change to splices per email from DB(CM)

2024-08-30T13:44:01Z

606.2.4 Maintenance and Repair: minor change to splices per email from DB(CM)

← Older revision		Revision as of 08:44, 30 August 2024
Line 112:		Line 112:
	'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.		'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.

	'''Splices.''' Cable repair splices for low-tension systems will be no closer than 400 feet per cable within a 2000-foot run. When a repair to a low-tension cable would require splices closer than 400 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 400’.		'''Splices.''' Cable repair splices for low-tension systems will be no closer than 400 feet per cable within a 2000-foot run (anchor to anchor). When a repair to a low-tension cable would require splices closer than 400 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 400’.

	Cable repair splices for high-tension systems will be no closer than 200 feet per cable within a 1000-foot run. When a repair to a high-tension cable would require splices closer than 200 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 200’.		Cable repair splices for high-tension systems will be no closer than 200 feet per cable within a 1000-foot run (turn buckle to turn buckle). When a repair to a high-tension cable would require splices closer than 200 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 200’.

	==606.2.5 Maintenance Planning Guidelines for Guard Cable==		==606.2.5 Maintenance Planning Guidelines for Guard Cable==

Hoskir: /* 606.2.4 Maintenance and Repair */ updated per email from DB(CM)

2024-08-28T14:50:02Z

606.2.4 Maintenance and Repair: updated per email from DB(CM)

← Older revision		Revision as of 09:50, 28 August 2024
Line 112:		Line 112:
	'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.		'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.

	'''Splices.''' ~~Repair~~ splices for low-tension systems will be no closer than 400 feet ~~and no more than 4 splices~~ per cable within a 2000 foot run. When a repair to a low-tension cable ~~requires~~ splices closer than 400 feet ~~or more than 4 splices per cable within a 2000 foot run~~, ~~use~~ a ~~longer section~~ of cable to ~~reduce the number of~~ splices ~~within the 2000 foot run. The replacement of the full 2000 foot cable length is another option~~.		'''Splices.''' Cable repair splices for low-tension systems will be no closer than 400 feet per cable within a 2000-foot run. When a repair to a low-tension cable would require splices closer than 400 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 400’.

	~~Repair~~ splices for high-tension systems will be no closer than 200 feet per cable within a 1000 foot run. When a repair to a high-tension cable ~~requires~~ splices closer than 200 feet, ~~use~~ a ~~longer section~~ to ~~reduce the number of~~ splices ~~from turnbuckle to turnbuckle~~.		Cable repair splices for high-tension systems will be no closer than 200 feet per cable within a 1000-foot run. When a repair to a high-tension cable would require splices closer than 200 feet, repair with a sufficient length of cable necessary to ensure splices are separated by no less than 200’.

	==606.2.5 Maintenance Planning Guidelines for Guard Cable==		==606.2.5 Maintenance Planning Guidelines for Guard Cable==

Hoskir at 20:01, 22 July 2024

2024-07-22T20:01:02Z

← Older revision		Revision as of 15:01, 22 July 2024
Line 1:		Line 1:
	{\|style="~~padding~~: ~~0.3em~~; margin-left:~~10px~~; ~~border~~:~~2px solid #a9a9a9~~; ~~text~~-~~align~~:~~center~~; ~~font~~-~~size~~: ~~95%~~; background:#~~f5f5f5" width="250px"~~ align~~="right~~"		<div style="float: right; margin-top: 5px; margin-left: 30px; margin-bottom: 30px;">__TOC__</div>
	\|-
	\|'''Videos'''		<div style="float: right; margin-top: 5px; margin-left: 5px; width:300px; background-color: #f8f9fa; padding: 0.3em; border: 1px solid #a2a9b1; text-align:left;">
	\|-		'''<u><center>Videos</center></u>'''
	\|[{{SERVER}}/documents/606.2_Cable_Rail_Test.mpg Successful guard cable test]		* [{{SERVER}}/documents/606.2_Cable_Rail_Test.mpg Successful guard cable test]
	\|-		* [[media:606.1 Guard cable.wmv\|Guard Cable in Action]]
	\|[[media:606.1 Guard cable.wmv\|Guard Cable in Action]]		* [http://www.youtube.com/modotvideo#p/u/1/IZTtBN7CHxY MoDOT's You Tube Guard Cable video]
	\|-		</div>
	\|[http://www.youtube.com/modotvideo#p/u/1/IZTtBN7CHxY MoDOT's You Tube Guard Cable video]
	\|}

	==606.2.1 Guard Cable Types==		==606.2.1 Guard Cable Types==
Line 17:		Line 15:

	[[image:606.2 Guard Cable.JPG\|right\|400px\|thumb\|<center>'''Low-tension Guard Cable'''</center>]]		[[image:606.2 Guard Cable.JPG\|right\|400px\|thumb\|<center>'''Low-tension Guard Cable'''</center>]]
	~~{\|style="padding: 0.3em; margin-right:7px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#ffddcc" width="210px" align="left"~~
	\|-
	~~\|'''Median Guard Cable'''~~
	\|-
	~~\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/ss07006.pdf Summary, 2006]~~
	\|-
	~~\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or10016.pdf Report, 2010]~~
	\|-
	~~\|'''See also:''' [https://www.modot.org/research-publications Research Publications]~~
	\|}

	'''606.2.1.2 High-Tension.''' High-tension guard cable consists of three or four pre-stressed cables supported by weak posts. All high-tension guard cable shall meet NCHRP 350 or MASH 2016 TL-3 requirements and be on MoDOT’s approved products list [https://www.modot.org/end-terminals-crash-cushions-and-barrier-systems End Terminals, Crash Cushions and Barrier Systems]. All high-tension guard cable shall be installed per manufacturer’s requirements.		'''606.2.1.2 High-Tension.''' High-tension guard cable consists of three or four pre-stressed cables supported by weak posts. All high-tension guard cable shall meet NCHRP 350 or MASH 2016 TL-3 requirements and be on MoDOT’s approved products list [https://www.modot.org/end-terminals-crash-cushions-and-barrier-systems End Terminals, Crash Cushions and Barrier Systems]. All high-tension guard cable shall be installed per manufacturer’s requirements.

	A common installation of high-tension guard cable employs concrete footings into which metal tubes are cast, forming sockets. The socket allows a post to be replaced with relative ease during a repair operation. The damaged post can be removed from the socket and replaced with a new post. Socketed systems eliminate the requirement for specialized post driving equipment and subsurface utility location for each repair.		A common installation of high-tension guard cable employs concrete footings into which metal tubes are cast, forming sockets. The socket allows a post to be replaced with relative ease during a repair operation. The damaged post can be removed from the socket and replaced with a new post. Socketed systems eliminate the requirement for specialized post driving equipment and subsurface utility location for each repair.

			<div style="float: left; margin-top: 8px; margin-right: 15px; margin-bottom: 8px; padding: 18px; border: 1px solid black; border-radius:5px; box-shadow:5px 5px 5px #888888">
			'''<u><center>Median Guard Cable</center></u>'''
			* [https://spexternal.modot.mo.gov/sites/cm/CORDT/ss07006.pdf Summary, 2006]
			* [https://spexternal.modot.mo.gov/sites/cm/CORDT/or10016.pdf Report, 2010]
			* '''See also:''' [https://www.modot.org/research-publications Research Publications]
			</div>

	==606.2.2 Warrants==		==606.2.2 Warrants==
Line 61:		Line 56:
	==606.2.3 Design and Installation Guidelines==		==606.2.3 Design and Installation Guidelines==
	===606.2.3.1 Lateral Placement in the Median===		===606.2.3.1 Lateral Placement in the Median===
	~~:Figure notes (In Lateral Placement - All Low-Tension should be deleted)~~

	'''Dynamics of Cross-Median Incidents.''' When a vehicle leaves the roadway and enters the median, certain predictable dynamics occur. Vehicles may enter the median at a variety of speeds and angles but for the purposes of roadside safety research and testing, a 62 mph departure at a 25° angle is generally used.		'''Dynamics of Cross-Median Incidents.''' When a vehicle leaves the roadway and enters the median, certain predictable dynamics occur. Vehicles may enter the median at a variety of speeds and angles but for the purposes of roadside safety research and testing, a 62 mph departure at a 25° angle is generally used.
Line 118:		Line 112:
	'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.		'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.

	'''Splices.''' Repair splices for low-tension systems will be no closer than 400 feet and no more than 4 splices per cable within a 2000 foot run. When a repair to a low-tension cable requires splices closer than 400 feet or more than 4 splices per cable within a 2000 foot run, the full 2000 foot cable length ~~may be replaced with the engineer’s approval~~.		'''Splices.''' Repair splices for low-tension systems will be no closer than 400 feet and no more than 4 splices per cable within a 2000 foot run. When a repair to a low-tension cable requires splices closer than 400 feet or more than 4 splices per cable within a 2000 foot run, use a longer section of cable to reduce the number of splices within the 2000 foot run. The replacement of the full 2000 foot cable length is another option.

	Repair splices for high-tension systems will be no closer than 200 feet per cable within a 1000 foot run. When a repair to a high-tension cable requires splices closer than 200 feet, a longer section ~~may be replaced~~ to reduce the number of splices from turnbuckle to turnbuckle ~~with the engineer’s approval~~.		Repair splices for high-tension systems will be no closer than 200 feet per cable within a 1000 foot run. When a repair to a high-tension cable requires splices closer than 200 feet, use a longer section to reduce the number of splices from turnbuckle to turnbuckle.

	==606.2.5 Maintenance Planning Guidelines for Guard Cable==		==606.2.5 Maintenance Planning Guidelines for Guard Cable==

Hoskir: updated per RR3850

2024-05-06T18:58:56Z

updated per RR3850

Show changes

Kleins1: /* 606.2.3.1 Lateral Placement in the Median */

2021-12-09T06:55:55Z

606.2.3.1 Lateral Placement in the Median

← Older revision		Revision as of 01:55, 9 December 2021
Line 82:		Line 82:
	Every guard cable incident is slightly different because of a host of site-specific factors. In general, however, the front of the vehicle must engage at least two of the three or four cables present in order to be contained by the system. Given the dynamics described above, lateral placement of the cable can be grouped into two main categories: medians wider than 30 ft. and those narrower than 30 ft.		Every guard cable incident is slightly different because of a host of site-specific factors. In general, however, the front of the vehicle must engage at least two of the three or four cables present in order to be contained by the system. Given the dynamics described above, lateral placement of the cable can be grouped into two main categories: medians wider than 30 ft. and those narrower than 30 ft.
	[[image:606.2.4.1 Placement.jpg\|600px\|right]]		[[image:606.2.4.1 Placement.jpg\|600px\|right]]
	'''Medians 30 ft. or wider.''' The guard cable should be installed no more than 4 ft. downslope of the edge of the shoulder. With wider shoulders, the downslope location could be less than 4 ft., but in any case, there shall be 8 ft. between the barrier and the edge of traveled way. There are several advantages to this location but chief among them is the performance of the system in an incident. At the 4 ft. downslope location, the errant vehicle adjacent to the barrier, while airborne, is not at a great enough altitude to override the cable during a front side encounter. From the opposing direction, or backside, the suspension of the errant vehicle will have recovered enough to allow an impact to occur under relatively normal impact conditions.		'''Medians 30 ft. or wider.''' The guard cable should be installed no more than 4 ft. downslope of the edge of the shoulder. With wider shoulders, the downslope location could be less than 4 ft., but in any case, there shall be a minimum of 8 ft. between the barrier and the edge of traveled way. There are several advantages to this location but chief among them is the performance of the system in a incident. At the 4 ft. downslope location, the errant vehicle adjacent to the barrier, while airborne, is not at a great enough altitude to override the cable during a front side encounter. From the opposing direction, or backside, the suspension of the errant vehicle will have recovered enough to allow an impact to occur under relatively normal impact conditions.

	If the 8 ft. separation cannot be obtained, the designer must work with the Central Office Design Division to assess the potential safety impacts of a decreased deflection distance. A different barrier system should be considered.		If the 8 ft. separation cannot be obtained, the designer must work with the Central Office Design Division to assess the potential safety impacts of a decreased deflection distance. A different barrier system should be considered.

	'''Medians narrower than 30 ft.''' In medians narrower than 30 ft., the guard cable should be installed within 1 ft. of the vertex of either a V or flat-bottomed ditch. As previously discussed, this location performs the most advantageously. ~~The~~ 4 ft. downslope ~~location starts to fail~~ in ~~narrower~~ medians as the suspension of the vehicle impacting from the back side (i.e. the opposite direction) is ~~the~~ most tightly compressed ~~around~~ that location. ~~Again, a fully~~ compressed suspension has ~~proven~~ to ~~be the principal reason for vehicles underriding~~ the system.
			'''Medians narrower than 30 ft.''' In medians narrower than 30 ft., the guard cable should be installed within 1 ft. of the vertex of either a V or flat-bottomed ditch. As previously discussed, this location performs the most advantageously. When placed 4 ft. downslope in narrow medians, the suspension of the vehicle impacting from the back side (i.e. the opposite direction) is most tightly compressed near that location. A compressed suspension has potenial to underride the system.

	'''Alternating Sides.''' The designer may choose to alternate the sides of the median where the barrier is placed for the purpose of reducing any shy line issues or discomfort for motorists. The change should occur at natural breaks in the barrier such as emergency crossovers or median bridge columns.		'''Alternating Sides.''' The designer may choose to alternate the sides of the median where the barrier is placed for the purpose of reducing any shy line issues or discomfort for motorists. The change should occur at natural breaks in the barrier such as emergency crossovers or median bridge columns.

Kleins1: /* 606.2.2 Warrants */

2021-12-09T06:47:49Z

606.2.2 Warrants

← Older revision		Revision as of 01:47, 9 December 2021
Line 50:		Line 50:
	Analyses of cross-median incident history and traffic volume provide valuable information in determining the likelihood of future incidents on these routes. In order to prevent future incidents, it is important to focus safety efforts on locations that will benefit the most from safety countermeasures.		Analyses of cross-median incident history and traffic volume provide valuable information in determining the likelihood of future incidents on these routes. In order to prevent future incidents, it is important to focus safety efforts on locations that will benefit the most from safety countermeasures.

	The risk of cross-median crashes can be influenced by median width and the traffic volume on both roadways (two-way AADT). Figure 606.2.2 shows various levels for implementation based on the anticipated benefits of reducing ~~severe~~ crashes compared to costs for installation, maintenance, and overall crash impact. The [http://sp/sites/ts/Pages/default.aspx Highway Safety and Traffic Division] may be contacted for additional details on how the anticipated benefits of guard cable installation were determined.		The risk of cross-median crashes can be influenced by median width and the traffic volume on both roadways (two-way AADT). Figure 606.2.2 shows various levels for implementation based on the anticipated benefits of reducing crashes compared to costs for installation, maintenance, and overall crash impact. The [http://sp/sites/ts/Pages/default.aspx Highway Safety and Traffic Division] may be contacted for additional details on how the anticipated benefits of guard cable installation were determined.
	<center>		<center>
	{\| style="margin: 1em auto 1em auto"		{\| style="margin: 1em auto 1em auto"
Line 67:		Line 67:
	It is important this data analysis is accurate and complete for all roadways. Due to at-grade intersection incidents on these routes, a simple query of cross-median incidents may include unwanted events and exclude necessary ones. Accuracy of this data is vital in decision-making.		It is important this data analysis is accurate and complete for all roadways. Due to at-grade intersection incidents on these routes, a simple query of cross-median incidents may include unwanted events and exclude necessary ones. Accuracy of this data is vital in decision-making.

	The data should be reviewed regularly to validate priorities and identify any emerging cross-median safety concerns. A regular review of divided highway traffic volume and incidents will provide information to address ~~severe~~ cross-median incidents.		The data should be reviewed regularly to validate priorities and identify any emerging cross-median safety concerns. A regular review of divided highway traffic volume and incidents will provide information to address cross-median incidents.

	'''606.2.2.2 Traffic Volume.''' Recent research has connected traffic volume growth directly to cross-median incidents. As volume increases, the probability of a motorist crossing the median and hitting an oncoming vehicle also increases. Instead of relying solely on incident history, there is an opportunity to proactively address this incident type before the incidents occur by studying traffic volume patterns and installing a system of median guard cable on routes with sharply increasing volumes. See Figure 606.2.2 for the anticipated impact traffic volume has on ~~severe~~ crash risk and anticipated value for guard cable installation.		'''606.2.2.2 Traffic Volume.''' Recent research has connected traffic volume growth directly to cross-median incidents. As volume increases, the probability of a motorist crossing the median and hitting an oncoming vehicle also increases. Instead of relying solely on incident history, there is an opportunity to proactively address this incident type before the incidents occur by studying traffic volume patterns and installing a system of median guard cable on routes with sharply increasing volumes. See Figure 606.2.2 for the anticipated impact traffic volume has on crash risk and anticipated value for guard cable installation.

	'''606.2.2.3 [[231.1 Median Width\|Median Width]].''' Recent national experience has shown that cross-median incidents can occur on highways with median widths above MoDOT's initial 60 ft. threshold. Although this width has largely proven to be effective in deterring such incidents, no route will be excluded from analysis solely on the basis of median width. Divided highways with very wide medians are expected to have a low risk of cross-median incidents. See Figure 606.2.2 for the anticipated impact median width has on ~~severe~~ crash risk and anticipated value for guard cable installation.		'''606.2.2.3 [[231.1 Median Width\|Median Width]].''' Recent national experience has shown that cross-median incidents can occur on highways with median widths above MoDOT's initial 60 ft. threshold. Although this width has largely proven to be effective in deterring such incidents, no route will be excluded from analysis solely on the basis of median width. Divided highways with very wide medians are expected to have a low risk of cross-median incidents. See Figure 606.2.2 for the anticipated impact median width has on crash risk and anticipated value for guard cable installation.

	==606.2.3 Design and Installation Guidelines==		==606.2.3 Design and Installation Guidelines==

Kleins1: /* 606.2.3.4 Slopes */ This article is being edited based on ballot comments effective January 2022

2021-12-09T06:41:33Z

606.2.3.4 Slopes: This article is being edited based on ballot comments effective January 2022

← Older revision		Revision as of 01:41, 9 December 2021
Line 99:		Line 99:

	===606.2.3.4 Slopes===		===606.2.3.4 Slopes===
	~~'''~~1V:6H (6:1) ~~or Flatter Slopes.''' Guard cable, like most roadside hardware, is intended for use on slopes that are~~ 1V:6H (6:1) ~~or flatter~~. ~~This requirement is based on both computer modeling and full-scale crash testing and represents sound theory~~. ~~In practice, however, slopes as flat at 1V:6H are often the exception~~.		[[131.2 Proprietary Items and Public Interest Findings#131.2.1.1 Proprietary Items\|Proprietary]] high-tension systems are approved for use on slopes with gradients between 1V:6H (6:1) to 1V:4H (4:1).
			[[image:606.2.4.6.jpg\|right\|275px\|thumb\|'''<center>Anchor Assembly</center>''']]

	'''Steeper Slopes.''' All of the [[131.2 Proprietary Items and Public Interest Findings#131.2.1.1 Proprietary Items\|proprietary]] high-tension systems are now approved for use on slopes with gradients from 1V:6H (6:1) to 1V:4H (4:1). Their use, while generally more expensive, represents the most cost-effective solution for shielding steeper slopes.
	~~[[image:606.2.4.6.jpg\|right\|275px\|thumb\|'''<center>Anchor Assembly</center>''']]~~
	===606.2.3.5 Vegetative Barrier===		===606.2.3.5 Vegetative Barrier===
	[[:Category:822 Roadside Vegetation Management\|Vegetation control]] in the area between the cable and the passing lane should be addressed. Failure to provide some positive form of vegetation control will hinder the future maintenance of the system. The core team shall consult with the local maintenance personnel to arrive at a vegetative control measure that is mutually agreeable. Vegetation control may not be omitted from a project as a practical design or value engineering measure. See [[#602.4 Maintenance and Repair\|EPG 606.2.4 Maintenance and Repair]] for vegetation maintenance.		[[:Category:822 Roadside Vegetation Management\|Vegetation control]] in the area between the cable and the passing lane should be addressed. Failure to provide some positive form of vegetation control will hinder the future maintenance of the system. The core team shall consult with the local maintenance personnel to arrive at a vegetative control measure that is mutually agreeable. Vegetation control may not be omitted from a project as a practical design or value engineering measure. See [[#602.4 Maintenance and Repair\|EPG 606.2.4 Maintenance and Repair]] for vegetation maintenance.

Kleins1: /* 606.2.4 Maintenance and Repair */ This article has been updated based on ballot comments for January 2022 effective date.

2021-12-09T06:38:09Z

606.2.4 Maintenance and Repair: This article has been updated based on ballot comments for January 2022 effective date.

← Older revision		Revision as of 01:38, 9 December 2021
Line 116:		Line 116:
	'''Vegetation Maintenance.''' District maintenance shall provide vegetative control around guard cable systems. Vegetation maintenance measures should include mowing, [[:Category:821 Herbicides and Roadsides\|herbicides]], a geotextile-aggregate strip or an asphalt apron may have been constructed during initial installation.		'''Vegetation Maintenance.''' District maintenance shall provide vegetative control around guard cable systems. Vegetation maintenance measures should include mowing, [[:Category:821 Herbicides and Roadsides\|herbicides]], a geotextile-aggregate strip or an asphalt apron may have been constructed during initial installation.

	'''Cable Tension.''' If ~~prestressed~~ cables are used for high-tension systems and compensators are properly compressed for low-tension systems, the tension in the cable should properly acclimate to any weather condition.		'''Cable Tension.''' If pre-stressed cables are used for high-tension systems and compensators are properly compressed for low-tension systems, the tension in the cable should properly acclimate to any weather condition. Tension logs shall be stored in the contract specific eProjects folder. The tension log form is available at [[:Category:101_Standard_Forms\|EPG 101 Standard Forms]].

	'''Cable Height. ''' ~~Maintenance personnel should be aware~~ of cable ~~heights~~ and ~~encouraged to identify locations where~~ erosion or the ~~accumulation of silt have altered~~ the ~~relative cable height~~.		'''Cable Height. ''' The importance of cable height to properly capture and redirect errant vehicles has been demonstrated. Although cable height is relatively static in all systems, erosion and tire rutting under the barrier can sometimes cause a localized increase in height, resulting in possible underride. When ditch erosion or rutting causes the cable heights to be outside the manufacturer’s recommended maximum, corrective measures should be performed by either the on-call contractor or by in-house Maintenance forces.

	~~'''Median Condition. ''' The median condition, with respect~~ to ~~rutting, loss~~ of ~~vegetation and incident debris, should be remedied by Maintenance forces following each incident~~.		Maintenance personnel should be aware of minimum and maximum cable heights and encouraged to identify locations where erosion or the accumulation of silt have altered the relative cable height.

	'''Guard Cable Repair.''' Incident repairs ~~are~~ performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.		'''Median Condition. ''' The median condition with respect to rutting, loss of vegetation and incident debris should be remedied by Maintenance forces following each incident.

			'''Guard Cable Repair.''' Incident repairs shall be performed by the on-call contractor. See [[147.3 Job Order Contracting (JOC)#147.3.10 Guardrail and Guard Cable Repair\|EPG 147.3.10 Guardrail and Guard Cable Repair]] for additional Job Order Contracting requirements for guard cable repairs.

	==606.2.5 Maintenance Planning Guidelines for Guard Cable==		==606.2.5 Maintenance Planning Guidelines for Guard Cable==

Kleins1: /* 606.2.1 Guard Cable Types */

2021-12-09T06:23:54Z

606.2.1 Guard Cable Types

← Older revision		Revision as of 01:23, 9 December 2021
Line 36:		Line 36:
	During installation, the cables are placed on the posts and then tightened to the manufacturer’s recommended tension. Due to this tightening, the cable installations can be of indefinite length. The runs are typically only limited by the presence of median openings.		During installation, the cables are placed on the posts and then tightened to the manufacturer’s recommended tension. Due to this tightening, the cable installations can be of indefinite length. The runs are typically only limited by the presence of median openings.

	Typically, when a vehicle impacts the high-tension system the cable, like low-tension guard cable, it will laterally deflect. The inherent tension within the system also allows the cable to remain at the proper height, even after an impact removes several posts. The high-tension system is not designed to continue to function in that condition, therefore repairs ~~shall~~ be made as soon as practical.		Typically, when a vehicle impacts the high-tension system the cable, like low-tension guard cable, it will laterally deflect. The inherent tension within the system also allows the cable to remain at the proper height, even after an impact removes several posts. The high-tension system is not designed to continue to function in that condition, therefore repairs should be made as soon as practical.

	As of 2007, all high-tension guard cable systems are proprietary, that is, marketed under exclusive rights of a specific manufacturer. Five systems are currently marketed in the United States.		As of 2007, all high-tension guard cable systems are proprietary, that is, marketed under exclusive rights of a specific manufacturer. Five systems are currently marketed in the United States.

Kleins1: /* 606.2.1 Guard Cable Types */

2021-12-09T06:22:41Z

606.2.1 Guard Cable Types

← Older revision		Revision as of 01:22, 9 December 2021
Line 28:		Line 28:
	\|}		\|}

	Given the low tension of the system, individual installations, or “runs”, of cable are limited to 2000 ft. with an anchor assembly at each end. When a vehicle strikes low-tension cable, the system can become disabled and ~~shall~~ be repaired as soon as practical.		Given the low tension of the system, individual installations, or “runs”, of cable are limited to 2000 ft. with an anchor assembly at each end. When a vehicle strikes low-tension cable, the system can become disabled and should be repaired as soon as practical.

	Low-tension systems have proven their value by reducing cross-median incidents. However, the installation of new low-tension cable systems should be limited to small-scale installations.		Low-tension systems have proven their value by reducing cross-median incidents. However, the installation of new low-tension cable systems should be limited to small-scale installations.
Line 44:		Line 44:
	A common installation of high-tension guard cable employs concrete footings into which metal tubes are cast, forming sockets. The socket allows a post to be replaced with relative ease during a repair operation. The damaged post can be removed from the socket and replaced with a new post. Socketed systems eliminate the requirement for specialized post driving equipment and subsurface utility location for each repair.		A common installation of high-tension guard cable employs concrete footings into which metal tubes are cast, forming sockets. The socket allows a post to be replaced with relative ease during a repair operation. The damaged post can be removed from the socket and replaced with a new post. Socketed systems eliminate the requirement for specialized post driving equipment and subsurface utility location for each repair.

	High-tension systems can be used on a variety of median inslopes, often eliminating the need for costly slope corrections and drainage modifications.		High-tension systems can be used on a variety of median inslopes, often eliminating the need for costly slope corrections and drainage modifications.

	==606.2.2 Warrants==		==606.2.2 Warrants==