Safety Eligibility Letter CC-121
1200 New Jersey Ave. S.E.
Washington, D.C. 20590
July 30, 2012
In Reply Refer To: HSST/HSST/CC-112A
Mr. Barry D. Stephens, P.E.
Sr. Vice President Engineering
Energy Absorption Systems, Inc.
3617 Cincinnati Avenue
Rocklin, CA 95678
Dear Mr. Stephens:
This letter is in response to your request for the Federal Highway Administration (FHWA) to review a roadside safety system for eligibility for reimbursement under the Federal-aid highway program.
Name of system: | 3-bay QuadGuard® M10 (QG M10) Narrow & Wide |
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Type of system: | Redirective Crash Cushion |
Test Level: | AASHTO Manual for Assessing Safety Hardware (MASH) Test Level 2 (TL-2) |
Testing conducted by: | E-Tech Testing Services, Inc. |
Task Force 13 Designator: |
SCI30: QG M10 Narrow |
Date of request: | March 3, 2011 |
Date of completed package: |
June 15, 2012 |
Decision
The following device is eligible, with details provided in the form which is attached as an integral part of this letter:
- TL-2 3-bay QuadGuard® M10 (QG M10) Narrow & Wide
Based on a review of crash test results submitted by the manufacturer certifying the device described herein meets the crash test and evaluation criteria of the American Association of State Highway and Transportation Officials' Manual for Assessing Safety Hardware (MASH), the device is eligible for reimbursement under the Federal-aid highway program. Eligibility for reimbursement under the Federal-aid highway program does not establish approval or endorsement by the FHWA for any particular purpose or use.
The FHWA, the Department of Transportation, and the United States Government do not endorse products or services and the issuance of a reimbursement eligibility letter is not an endorsement of any product or service.
Requirements
To be found eligible for Federal-aid funding, roadside safety devices should meet the crash test and evaluation criteria contained in the American Association of State Highway and Transportation Officials' Manual for Assessing Safety Hardware (MASH).
Description
The QG M10 Narrow and QG M10 Wide TL-2 systems are redirective, non-gating 3-bay crash cushions. The nose cartridge is not counted as a separate bay. The MASH design has been revised from the National Cooperative Highway Research Program (NCHRP) Report 350 design to include:
- reinforced lower front bracket
- new upper front bracket
- new cartridge types
The QG M10 3-bay system has an overall length of 13 feet (3.96 meters) and can be configured with backup widths of 24 inches [610 millimeters), 30 inches (762 millimeters), and 36 inches (914 millimeters) for QG M10 Narrow systems, and 69 inches (1753 millimeters) and 90 inches (2285 millimeters) for QG M10 Wide systems. The overall height is 32 inches (817 millimeters). The system consists of energy absorbing cartridges surrounded by a framework of steel Quad-Beam™ guardrail panels that telescope rearward during head-on impacts. The system has a backup structure that will resist movement during head-on impacts and a center monorail that will resist lateral movement during side impacts when anchored to an asphalt or concrete base as per manufacturer specifications.
Components from the TL-3 version of the QG II unit that are used on the new TL-2 3-bay QG M10 unit are:
- QG foundation-anchored center Monorail
- QG Fender Panels
- QG Diaphragms
- QG Backup
- MP-3®™ Concrete Anchors
- 14ga steel wrap-around sheet metal Nose
- 2 inch [50 mm] Lower Nose Cartridge Bracket
- 10ga steel rail guide Shims
Components that were modified or added to the TL-2 QG M10 to achieve the required performance include:
- QG Type M-I cartridges (3 required)
- QG Type M-II cartridges (1 required)
- A hold down bracket was added to the nose cartridge to contain the cartridge and maximize its energy absorption.
- The bottom nose cartridge bracket attached to the diaphragm was reinforced to help restrain the cartridge to maximize its energy absorption.
Design details of the 3-bay QG M10 systems, both narrow and wide are included as an enclosure to this correspondence.
Findings
Full-scale physical crash testing was conducted according to the MASH. The following tables list all required crash tests per MASH for Test Level 2 Systems:
Narrow Systems 24 inches (610 millimeters), 30 inches
(762 millimeters), and 36 inches (914 millimeters)
Illustration | Test # | Completed | Notes |
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2-30 | NO | Test 2-32 was passed with a 3-Bay 2286 mm [90 inches] Wide System. This test was completed as worst case for the 1100C and thus Test 2-30 can be waived for the Narrow Systems. |
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2-31 | YES | 3-Bay 610 mm [24 inches] Narrow System was tested. - Impact speed = 70.6 km/h - Ridedown = -15.1 g's - Longitudinal ΔV = 9.0 m/s Passed all ORV's. In addition and as per AASHTO MASH Section G, an analysis was subsequently conducted on Test 2-31 data. The analysis results has determined MASH Test 2-38 (i.e., 1500A mid-sized vehicle) is required.
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2-32 | NO |
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2-33 | NO |
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2-34 | NO |
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2-35 | NO |
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2-36 | NO |
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2-37 | NO |
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2-38 | YES | 3-Bay 610 mm [24 inches] Narrow System was tested. - Impact speed = 68.3 km/h - Ridedown = -15.9 g's - Longitudinal ΔV = 8.6 m/s Passed all ORV's for Test 2-38 |
Wide Systems 69 inches (1753 millimeters)
and 90 inches (2285 millimeters)
Illustration | Test # | Completed | Notes |
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2-30 | NO |
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2-31 | NO |
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2-32 | YES | 3-Bay 2286 mm (90 inches) Wide System was tested. - Impact speed = 70.3 km/h - Ridedown = -13.5 g's - Longitudinal ΔV = 9.9 m/s Passed all ORV's. |
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2-33 | NO |
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2-34 | NO |
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2-35 | NO |
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2-36 | NO |
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2-37 | NO |
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2-38 | NO |
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Since the shorter 3-Bay wide system has a side that is at a steeper angle (10 degrees) than that of the 6-Bay wide system (5 degrees), this 3- Bay wide system installation specification must indicate the traffic-side panels as parallel as possible to the edge of the road or travel way, but no more than 5 degrees off parallel.
One-page test summaries for each of the conducted crash tests are included as enclosures to this correspondence. In addition, NCHRP Report 350 crash test summary sheets as also included for 5-bay QG II (wide) and original QG (narrow) systems.
Manufacturer requests previous successfully conducted MASH TL-3 tests 3-34, 3-35, 3-36, and 3-37 be accepted in lieu of proposed MASH TL-2, tests 2-34, 2-35, 2-36, and 2-37 because the redirective ability of the QGM10 is not reduced due to its length due to most of anchor loading occurred in the immediate initial impact area and was not transmitted to adjacent diaphragms.
Summary and Standard Provisions
Therefore, the system described and detailed within this correspondence is eligible for reimbursement and may be installed under the range of conditions tested.
Please note the following standard provisions that apply to FHWA eligibility letters:
- This letter provides a AASHTO/ARTBA/AGC Task Force 13 designator that should be used for the purpose of the creation of a new and/or the update of existing Task Force 13 drawing for posting on the on-line ‘Guide to Standardized Highway Barrier Hardware' currently referenced in AASHTO Roadside Design Guide.
- This finding of eligibility does not cover other structural features of the systems, nor conformity with the Manual on Uniform Traffic Control Devices.
- Any changes that may influence system conformance with MASH will require a new reimbursement eligibility letter.
- Should the FHWA discover that the qualification testing was flawed, that in-service performance reveals safety problems, or that the system is significantly different from the version that was crash tested, we reserve the right to modify or revoke this letter.
- You are expected to supply potential users with sufficient information on design and installation requirements to ensure proper performance.
- You are expected to certify to potential users that the hardware furnished has the same chemistry, mechanical properties, and geometry as that submitted for review, and that it will meet the test and evaluation criteria of the MASH.
- To prevent misunderstanding by others, this letter of eligibility is designated as number CC-121 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.
- This 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 FHWA does not become involved in issues concerning patent law. Patent issues, if any, are to be resolved by the applicant.
Sincerely yours, /* Signature of Michael S. Griffith */
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Enclosures