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# Safety Eligibility Letter B-141F

**Hardware Type:**

**Code:**

**Date:**

10/01/2010

**Testing Criteria:**

**Manufacturer:**

**Device Description:**

**View PDF:**

b141f.pdf (477.86 KB)

## Safety Eligibility Letter B-141F

**Download Version**PDF

U.S. Department of Transportation**Federal Highway Administration**

1200 New Jersey Ave. S.E.Washington, D.C. 20590

October 1, 2010

In Reply Refer To: HSSD/B-141F

Mr. Brian Smith            	Trinity Highway Products, LLC                P.O. Box 568887                Dallas, TX  75356-8887

Dear Mr. Smith:

This letter is in response to your request for the Federal Highway Administration (FHWA) acceptance of modifications to your CASS cable barrier safety system for use on the National Highway System (NHS).
> Name of  system:Trinity's Cable Safety System (CASS S3 4:1)Type of system:Four cable median and roadside barrier systemTest Level:NCHRP Report 350: Test Level 3 on 1:4 slopes or flatter Test Level 4 on 1:6 slopes or flatterTesting conducted by:Texas Transportation InstituteDate of request:March 5, 2010

You requested that we find this system acceptable for use on the NHS under the provisions ofNational Cooperative Highway Research Program (NCHRP) Report 350 "Recommended"

**Requirements**            Roadside safety systems should meet the guidelines contained in the NCHRP Report 350.The FHWA memorandum "Identifying Acceptable Highway Safety Features" of July 25, 1997,provides further guidance on crash testing requirements of longitudinal barriers.

**Description**The CASS S3 4:1 is a tensioned, four-cable barrier system that was tested with standard (non-prestretched) cables. The top two cables are positioned within a wave-shaped slot in theweb of S75 x 8 (S3 x 5.7 in English units) structural I-beam posts. The bottom two cables are supported on flanges of the I-beam post by an 8-mm (5/16-inch) hook bolt with the open end down, with the lowest cable located on the median-side flange and the next lowest cable locatedon the traffic-side flange.

The proprietary S75 × 8 (S3 × 5.7) posts were installed in steel tube sleeves set in 305-mm  (12-inch) diameter x 762-mm (30-inch) deep concrete footings. The cables within the  wave-shaped slot are separated by a plastic spacer. A stainless steel strap is mounted on the outside of the post above the top cable.

  The 3/4-inch diameter standard (non-pre-stretched) cables were set at heights of 450mm,  755mm, 960 and 1070mm (17.75, 29.75, 37.875, and 42.125 inches) above the ground surface,  measured to the center of each cable. Tension of the cables was set at 24.9 kN (5,600 pounds  force) for the tests.

  The 104.7-m (343-foot, 6-inch) test installations were anchored by Texas Transportation Institute  (TTI) Breakaway Cable Anchor Terminals which were accepted by the FHWA on  August 29, 2002.

Four tests were conducted with the CASS S3 4:1 system installed in a 9.1m (30 foot 0 inch) wide   depressed median with 1V: 4H side slopes, and one test with the CASS S3 4:1 system installed  on level terrain:
                      -  The NCHRP Report 350 Test 3-11 (modified) - 2270P at 102.6 km/hour (63.7 mph) witha 25.4 degree impact angle. The test article was the CASS S3 4:1 with 3.2-m (10-foot,6-inch) post spacing installed on the foreslope of a 9.1-m (30-foot, 0-inch) widedepressed median with 1V: 4H side slopes at 1.22m (4 foot, 0 inch) from the break point.  The CASS S3 4:1 on 1V:4H foreslope contained and redirected the 2270P vehicle. Thevehicle did not penetrate, under ride, or override the installation. Dynamic deflection inTest 3-11 (modified) with 3.2-m (10-foot, 6-inch) post spacing was reported by TTI to be2.16m (7.1 feet). 
                      -  The NCHRP Report 350 Test 3-10 - 820C at 102.1 km/hour (63.4 mph) with a20.8 degree impact angle. The test article was the CASS S3 4:1 with 6.1-m (20-foot,0-inch) post spacing installed on the backslope of the 9.1-m (30-foot, 0-inch) widedepressed median at 3.35m (11 feet 0 inch) from the median bottom. The test vehiclecrossed the median bottom and traveled up the backslope before impacting CASS S3 4:1.  The CASS S3 4:1 on 1V:4H backslope contained the 820C vehicle, which thensideslipped along the system until loss of contact. The vehicle did not penetrate, underride, or override the installation. Dynamic deflection in Test 3-10 (backslope) with 6.1-m(20-foot, 0-inch) post spacing was reported by TTI to be 1.34m (4.4 feet). 
                      - The NCHRP Report 350 Test 3-10 - 820C at 97.3 km/hour (60.4 mph) with a 19.5 degreeimpact angle. The test article was the CASS S3 4:1 with 3.2-m (10-foot, 6-inch) postspacing installed on the foreslope of a 99.1-m (30-foot, 0-inch) wide depressed medianwith 1V: 4H side slopes at 1.22m (4 foot, 0 inch) from the break point.  The CASS S3 4:1 on 1V:4H foreslope contained and redirected the 820C vehicle. Thevehicle did not penetrate, under ride, or override the installation. Dynamic deflection inTest 3-10 with 3.2-m (10-foot, 6-inch) post spacing was reported by TTI to be 1.04m(3.4 feet).
                      - The NCHRP Report 350 Test 3-11 (modified) - 2270P at 102.4 km/hour (63.6 mph) witha 25.4 degree impact angle. The test article was the CASS S3 4:1 with 6.4-m (21-foot,0-inch) post spacing installed on the foreslope of a 9.1-m (30-foot, 0-inch) widedepressed median with 1V: 4H side slopes at 1.22m (4 foot, 0 inch) from the break point.  The CASS S3 4:1 on 1V:4H foreslope contained and redirected the 2270P vehicle. Thevehicle did not penetrate, under ride, or override the installation. Dynamic deflection inTest 3-11 (modified) with 6.4-m (21-foot, 0-inch) post spacing was reported by TTI to be2.59m (8.5 feet).
                      - The NCHRP Report 350 Test 4-12 - 8000S at 79.9 km/hour (49.6 mph) with a 13.6degree impact angle. The test article was the CASS S3 4:1 with 3.2-m (10-foot, 6-inch)post spacing installed on level terrain.  The CASS S3 4:1 on flat ground contained and redirected the 8000S vehicle. The vehicledid not penetrate, under ride, or override the installation. Dynamic deflection inTest 4-12 with 3.2-m (10-foot, 6-inch) post spacing was reported by TTI to be 2.42m(8.0 feet).

The 4-cable barrier systems described above are acceptable for use on the designated 1V:4H orflatter slopes under NCHRP Report 350 Test Level 3 or 4 conditions as noted. The systems aredetailed in the enclosed drawings and are acceptable for use on the NHS when such use is

**Findings**The 4-cable barrier systems described above are acceptable for use on the designated 1V:4H or flatter slopes under NCHRP Report 350 Test Level 3 or 4 conditions as noted.  The systems are detailed in the enclosed drawings and are acceptable for use on the NHS when such use is acceptable to a highway agency.

Although the barrier performed well under idealized test impact conditions, the likelihood ofpassenger car underrides of any cable system may increase as the post spacing increases,particularly when the barrier is installed on non-level or slightly irregular terrain and the cablesare not restrained from lifting at each post. Consequently, some transportation agencies havelimited post spacing to approximately 6m (20 feet) for cable barriers. The dynamic deflection ofthe barrier is likely to increase when it is installed along the convex sides of horizontal curves,

Please note the following standard provisions that apply to FHWA letters of acceptance:
                      - This acceptance is limited to the crashworthiness characteristics of the systems and does not 					  cover their structural features, nor conformity with the Manual on Uniform Traffic Control 				  Devices.
                      - Any changes that may adversely influence the crashworthiness of the system will require a new 				    acceptance letter.
                      - Should the FHWA discover that the qualification testing was flawed, that in-service 					  performance reveals unacceptable safety problems, or that the system being marketed is 					  significantly different from the version that was crash tested, we reserve the right to modify or 				    revoke our acceptance.
                      - You will be expected to supply potential users with sufficient information on design and 				    installation requirements to ensure proper performance.
                      - You will be expected to certify to potential users that the hardware furnished has essentially the 					  same chemistry, mechanical properties, and geometry as that submitted for acceptance, and 				    that it will meet the crashworthiness require of the FHWA and the NCHRP Report 350.
                      - To prevent misunderstanding by others, this letter of acceptance is designated as number 					  B-141F and shall not be reproduced except in full. This letter and the test documentation upon 					  which it is based are public information. All such letters and documentation may be reviewed 				    at our office upon request.
                      - The CASS barriers are patented products and considered proprietary. If proprietary systems are 					  specified by a highway agency for use on Federal-aid projects, except exempt, non-NHS 					  projects, (a) they must be supplied through competitive bidding with equally suitable 					  unpatented items; (b) the highway agency must certify that they are essential for 					  synchronization with the existing highway facilities or that no equally suitable alternative 					  exists: or (c) they must be used for research or for a distinctive type of construction on 					  relativdy short sections of road for experimental purposes. Our regulations concerning 				    proprietary products are contained in Title 23, Code of Federal Regulations, Section 635.411.
                      - This acceptance letter shall not be construed as authorization or consent by the FHWA to use, 					  manufacture. or sell any patented system for which the applicant is not the patent holder. The 					  acceptance letter is limited to the crashworthiness characteristics of the candidate system and 					  the FHWA is neither prepared nor required to become involved in issues concerning patent 					  law. Patent issues, if any, are to be resolved by the applicant.				  
|   | Sincerely yours,

*/* Signature of David A. Nicol */*

David A. Nicol, P.E.							Director, Office of Safety Design |
|--------|---------------------------------------------------------------------------------------------------------------------|

Enclosures
| General Information           | Impact Conditions                                                               | Post-Impact Trajectory |
|-------------------------------|---------------------------------------------------------------------------------|------------------------|
|  Test Agency             | Texas Transportation Institute                                                  | Speed                  | 49.6 mi/h | Stopping Distance | 348 ft dwnstrm               46 ft twd traffic |
|  Test No.                | 400001-TCR33                                                                    | Angle                  | 13.6 degrees | Vehicle Stability |   |
|  Date                    | 2009-09-04                                                                      | Location/Orientation   | 1 ft upstream | Maximum Yaw Angle | -23 degrees |
| Test Article                  | Exit Conditions                                                                 | Post 16                | Maximum Pitch Angle | -3 degrees |
|  Type                    | Longitudinal Barrier                                                            | Speed                  | Not obtainable | Maximum Roll Angle | 1 degrees |
|  Name                    | Trinity CASS                                                                    | Angle                  | Not obtainable | Vehicle Snagging | No |
|  Installation Length     | 343.5 ft.                                                                       | Occupant Risk Values   | Vehicle Pocketing | No |
|  Material or Key Element | 4 wire ropes supported by slotted S3x5.7 support posts spaced at 10 ft-6 inches | Impact Velocity        | Test Article Deflections |
| Soil Type and Condition       | Concrete footings in crushed limestone, dry                                     | Longitudinal           | 3.6 ft/s | Dynamic | ~8 ft |
| Test Vehicle                  |                                                                            | Lateral                | 4.9 ft/s | Permanent | 0.9 ft |
|  Type/Designation        | 8000s                                                                           | Ridedown Accelerations |   |
|  Make and Model          | 1994 International NaviStar 4700                                                | Longitudinal           | -1.4 G | Working Width | 9.1 ft |
|  Curb                    | 12,400 lb                                                                       | Lateral                | -1.3 G | Vehicle Damage |   |
|  Test Inertial           | 17,710 lb                                                                       | THIV                   | 6.4 km/h | VDS | 01RFQ1 |
|  Dummy                   | No dummy                                                                        | PHD                    | 0.12 | CDC | 01RFEW1 |
|  Gross Static            | 17,710 lb                                                                       | Max. 0.050-s Average   |   | Max. Exterior Deformation | 1.5 inches |
|                          | Longitudinal                                                                    | -06.g                  | Max. Exterior Deformation | 1.5 inches |
|                          | Lateral                                                                         | -1.1G                  |   |
|                          | Vertical                                                                        | 0.4 G                  |   |

**Figure 15. Summary of results for*NCHRP Report 350*test 4-12 on the Trinity CASS on level ground.**
| General Information           | Impact Conditions                                  | Post-Impact Trajectory |
|-------------------------------|----------------------------------------------------|------------------------|
|  Test Agency             | Texas Transportation Institute                     | Speed                  | 60.4 mi/h | Stopping Distance | 214 ft dwnstrm               30 ft twd traffic |
|  Test No.                | 400001TCR35                                        | Angle                  | 19.5 degrees | Vehicle Stability |
|  Date                    | 2009-10-08                                         | Location/Orientation   | Midspan btw posts 15&16 | Maximum Yaw Angle | 32 degrees |
| Test Article                  | Exit Conditions                                    |                   | Maximum Pitch Angle | 9 degrees |
|  Type                    | Cable Barrier                                      | Speed                  | Not obtainable | Maximum Roll Angle | 14 degrees |
|  Name                    | Trinity CASS                                       | Angle                  | -3.6 degrees | Vehicle Snagging | No |
|  Installation Length     | 343.5 ft.                                          | Occupant Risk Values   |   | Vehicle Pocketing | No |
|  Material or Key Element | CASS with S3x5.7 posts installed on 4H:1V forslope | Impact Velocity        | Test Article Deflections |   |
| Soil Type and Condition       | Concrete footings in Standard Soil, Damp           | Longitudinal           | 12.8 ft/s | Dynamic | 3.4 ft |
| Test Vehicle                  |                                               | Lateral                | 12.8  ft/s | Permanent | 0.1 ft |
|  Type/Designation        | 820C                                               | Ridedown Accelerations |   | Working Width | 4.2 ft |
|  Make and Model          | 1995Suzuki Swift                                   | Longitudinal           | -5.3G | Vehicle Damage |   |
|  Curb                    | 1881 lb                                            | Lateral                | 6.3 G | VDS | 11LFQ3 |
|  Test Inertial           | 1850 lb                                            | THIV                   | 18.2 km/h | CDC | 11FDEW3 |
|  Dummy                   | 167                                                | PHD                    | 7.5 G | Max. Exterior Deformation | 10.6 inches |
|  Gross Static            | 2017 lb                                            | Max. 0.050-s Average   |   | Max.Occupant Compartment Deformation | 0.6 inches |
|                          | Longitudinal                                       | -2.9 G                 |   |   |
|                          | Lateral                                            | 4.3 G                  |   |
|                          | Vertical                                           | 3.7 G                  |   |

**Figure 16. Summary of results for NCHRP Report 350 test 3-10 on the Trinity CASS with S3x5.7 posts installed on a 4H:IV forslope.**
| General Information           | Impact Conditions                                                | Post-Impact Trajectory |
|-------------------------------|------------------------------------------------------------------|------------------------|
|  Test Agency             | Texas Transportation Institute                                   | Speed                  | 63.7 mi/h | Stopping Distance | 425 ft dwnstrm               83 ft twd traffic |
|  Test No.                | 40000-1TCR32                                                     | Angle                  | 25.4 degrees | Vehicle Stability |
|  Date                    | 2009-08-12                                                       | Location/Orientation   | At post 16 | Maximum Yaw Angle | 39 degrees |
| Test Article                  | Exit Conditions                                                  |                   | Maximum Pitch Angle | -6 degrees |
|  Type                    | Longitudinal Barrier                                             | Speed                  | Out of view | Maximum Roll Angle | 28 degrees |
|  Name                    | CASS on 4H:1V Slope                                              | Angle                  | Not obtainable | Vehicle Snagging | No |
|  Installation Length     | 343.5 ft.                                                        | Occupant Risk Values   |   | Vehicle Pocketing | Yes |
|  Material or Key Element | CASS with S3x5.7 posts spaced at 10ft-6 inches on 4V:H1 forslope | Impact Velocity        |   | Test Article Deflections |   |
| Soil Type and Condition       | Cruch Limestone, Dry                                             | Longitudinal           | 8.2 ft/s | Dynamic | 7.1 ft |
| Test Vehicle                  |                                                             | Lateral                | 13.4  ft/s | Permanent | 0.5 ft |
|  Type/Designation        | 2270P                                                            | Ridedown Accelerations |   | Working Width | 8.2 ft |
|  Make and Model          | 2003 Dodge 1500 Quad                                             | Longitudinal           | -3.5G | Vehicle Damage |   |
|  Curb                    | 4871                                                             | Lateral                | 4.3 G | VDS | 11LFQ1 |
|  Test Inertial           | 5007                                                             | THIV                   | 15.9 km/h | CDC | 11LFEW2 |
|  Dummy                   | No Dummy                                                         | PHD                    | 5.0 G | Max. Exterior Deformation | 10.6 inches |
|  Gross Static            | 5007                                                             | Max. 0.050-s Average   |   | Max.Occupant Compartment Deformation | 0 |
|                          | Longitudinal                                                     | -2.0 G                 |   |   |
|                          | Lateral                                                          | 3.5 G                  |   |
|                          | Vertical                                                         | -2.9 G                 |   |

**Figure 11. Summary of results for *NCHRP Report 350*test 3-11 on  CASS with S3x5.7 posts on  4H:IV forslope.**
| General Information           | Impact Conditions                               | Post-Impact Trajectory |
|-------------------------------|-------------------------------------------------|------------------------|
|  Test Agency             | Texas Transportation Institute                  | Speed                  | 63.6 mi/h | Stopping Distance | 73.5 ft dwnstrm      Within cables |
|  Test No.                | 400001-TCR32                                    | Angle                  | 25.4 degrees | Vehicle Stability |
|  Date                    | 2009-11-08                                      | Location/Orientation   | At post 13 | Maximum Yaw Angle | 32 degrees |
| Test Article                  | Exit Conditions                                 |                   | Maximum Pitch Angle | -12 degrees |
|  Type                    | Wire Rope Barrier                               | Speed                  | Out of view | Maximum Roll Angle | -57 degrees |
|  Name                    | CASS with S3x5.7 posts/4H:1V foreslope          | Angle                  | Out of view | Vehicle Snagging | No |
|  Installation Length     | 343.5 ft.                                       | Occupant Risk Values   |   | Vehicle Pocketing | No |
|  Material or Key Element | CASS with S3x5.7 posts installed 4V:1V forslope | Impact Velocity        |   | Test Article Deflections |   |
| Soil Type and Condition       | Standard Soil, Dry                              | Longitudinal           | 8.8 ft/s | Dynamic | 8.5 ft |
| Test Vehicle                  |                                            | Lateral                | 12.5  ft/s | Permanent | 3.0 ft |
|  Type/Designation        | 2270P                                           | Ridedown Accelerations |   | Working Width | 9.8 ft |
|  Make and Model          | 2004 Dodge Ram1500 Quad-Cab                     | Longitudinal           | -4.1G | Vehicle Damage |   |
|  Curb                    | 4772 lb                                         | Lateral                | 5.9 G | VDS | 11LFQ2 |
|  Test Inertial           | 5026 lb                                         | THIV                   | 15.2 km/h | CDC | 11DEW2 |
|  Dummy                   | No Dummy                                        | PHD                    | 6.1 G | Max. Exterior Deformation | 7.5 inches |
|  Gross Static            | 5026 lb                                         | Max. 0.050-s Average   |   | Max.Occupant Compartment Deformation | 0 |
|                          | Longitudinal                                    | -2.0 G                 |   |   |
|                          | Lateral                                         | 3.6 G                  |   |
|                          | Vertical                                        | -1.8 G                 |   |

**Figure 16. Summary of results for*NCHRP Report 350* test 3-11 on the  CASS with S3x5.7 posts installed on  4H:IV forslope.**
| General Information           | Impact Conditions                           | Post-Impact Trajectory |
|-------------------------------|---------------------------------------------|------------------------|
|  Test Agency             | Texas Transportation Institute              | Speed entering ditch   | 63.4 mi/h | Stopping Distance | 35 ft dwnstr      11 ft field side |
|  Test No.                | 40000-1TCR34                                | Angle entering ditch   | 20.8 degrees | Vehicle Stability |
|  Date                    | 2009-10-12                                  | Speed at wire rope     | 60.8 mi/h | Maximum Yaw Angle | -172 degrees |
| Angle at wire rope            | 24.0 degrees                                |
| Location/Orientation          | Mispan 13-14                                |
| Test Article                  | Exit Conditions                             |                   | Maximum Pitch Angle | 26 degrees |
|  Type                    | Median Barrier                              | Speed                  | Out of view | Maximum Roll Angle | -34 degrees |
|  Name                    | Trinity CASS                                | Angle                  | Out of view | Vehicle Snagging | Yes |
|  Installation Length     | 342 ft.                                     | Occupant Risk Values   |   | Vehicle Pocketing | No |
|  Material or Key Element | S3x5.7 posts installed on a 4H:1V backslope | Impact Velocity        |   | Test Article Deflections |   |
| Soil Type and Condition       | Concrete footings in standard soil, damp    | Longitudinal           | 18.7 ft/s | Dynamic | 4.4 ft |
| Test Vehicle                  |                                        | Lateral                | 2.3  ft/s | Permanent | 1.9 ft |
|  Type/Designation        | 820C                                        | Ridedown Accelerations |   | Working Width | 5.2 ft |
|  Make and Model          | 1997 Geo Metro                              | Longitudinal           | -8.9 G | Vehicle Damage |   |
|  Curb                    | 1797 lb                                     | Lateral                | -8.6 G | VDS | 11LFQ4 |
|  Test Inertial           | 1861 lb                                     | THIV                   | 19.2 km/h | CDC | 11FLEW3 |
|  Dummy                   | 165 lb                                      | PHD                    | 11.9 G | Max. Exterior Deformation | 9.8 inches |
|  Gross Static            | 2026 lb                                     | Max. 0.050-s Average   |   | Max.Occupant Compartment Deformation | 1.2 inches |
|                          | Longitudinal                                | -7.8G                  |   |   |
|                          | Lateral                                     | -4.4 G                 |   |
|                          | Vertical                                    | -5.4 G                 |   |

**Figure 15. Summary of results for *NCHRP Report 350* test 3-10on the Trinity CASS with S3x5.7 posts installed on a 4H:IV backslope.**