March 12, 2004 

 

Refer to: HSA-10/B123 

Mr. David A. Hubbell 

Managing Manager 

Composite Structural Design, LLC 

P.O. Box 600 

Saranac Lake, New York 12983 

Dear Mr. Hubbell: 

In a July 2003 letter to Mr. Richard Powers of my staff, you requested acceptance of an all-steel 

barrier for use on the National Highway System (NHS) as a test level 5 (TL-5) or a TL-6 traffic 

barrier/bridge rail and have recently submitted additional information that he requested relating 

to the design of this barrier. 

The proprietary barrier, called the Sistema, consists of a 1000-mm tall metal safety shape with a 

pipe rail mounted on top, bringing its total effective height to 1550 mm. The barrier is made 

from 4-mm thick steel plate in 6-m long segments with closed-section steel diaphragms on the 

field side. The steel plate is fabricated from A709 Grade 36 steel. The diaphragms are spaced 

on 1.5-m centers and bolted to the bridge deck with four M20 diameter class 8.8 steel studs. The 

safety-shape portion of the Sistema barrier falls between the dimensions for the U.S. New Jersey 

and F-shape concrete barriers with the lower-to-upper slope breakpoint 270 mm above the 

pavement. There is no vertical reveal on the Sistema barrier and the actual slope angles of 

53.5 degrees and 82.2 degrees closely approximate the 55-degree and 84-degree angles on both 

the N.J. and F-shapes. 

The upper rail is made from A572 Grade 50 steel pipe that is 139.7-mm in diameter with a wall 

thickness of 12.5 mm. It is supported by 139.7-mm diameter pipes with a wall thickness of 

8 mm mounted to the top of the metal safety shape on 3-m centers. These support posts have 

tubular sleeves welded to their tops through which the pipe rail passes, and a steel base plate 

with gussets for a four-bolt attachment to the top of the barrier. Individual barrier sections are 

connected through a combination of bolted plates on top of the barrier and steel pins that pass 

through three steel pipe “loops” welded to the backside of each segment and through mated steel 

loops in a separate steel hinge plate. Enclosures 1 and 2 show front and back views of the 

Sistema barrier with the hinge plate attached. 

 
2

Since the Sistema barrier was developed in Europe and tested there, none of the tests you 

submitted for Federal Highway Administration (FHWA) review exactly matched the tests 

recommended in National Cooperative Highway Research Program (NCHRP) Report 350. For 

the small car test, you sent data from test no. SIS/BSI-01-172, conducted at the L.I.E.R. facility 

in France. Although the car was heavier than the current Report 350 820C vehicle, the NCHRP 

Report 350 update, currently underway, will likely increase the weight of the small car to 

replicate the ever-changing vehicle fleet. Previous tests of safety shape designs with the 820C 

test vehicle have been satisfactory. Thus, I am willing to accept the heavier weight of the tested 

Peugeot. In all other aspects, test no. SIS/BSI-01-172 is identical to the NCHRP Report 350 test 

3-10. In your test, a Peugeot 205 XT weighing 922 kg was directed into the Sistema barrier at 

101.5 km/h and at a 20-degree impact angle. All the NCHRP Report 350 evaluation criteria 

were satisfied. Occupant impact velocity and ridedown accelerations were 6.5 m/s and 11.8 g’s, 

respectively. The car was redirected upright. 

For the tractor-trailer test, you sent data from test no. SIS/BSI-03/176, also conducted at L.I.E.R. 

In this test, a 29,850-kg articulated truck impacted the Sistema barrier at 68.5 km/h and at an 

angle of 20 degrees. Although the vehicle weight and impact speed were below the comparable 

Report 350 test 5-12 guidelines, the increased impact angle resulted in a calculated Impact 

Severity (IS) of 632.5 kJ, significantly more than the Report 350 value of 596.2 kJ. This test 

also met Report 350 evaluation criteria as the truck was contained and redirected upright. The 

barrier deflected 750 mm. In subsequent correspondence with Mr. Powers, you provided 

additional information on the test vehicle parameters and they were seen to be in substantial 

compliance with Report 350 specifications for the 36000-kg tractor-trailer. Also included in the 

material you originally submitted was a test report (test no. X61.01.A10) prepared at the German 

TUV test laboratory that documented a successful test of a 37,680-kg tractor-trailer impacting 

the Sistema barrier at 65.7 km/h and a 20-degree impact angle. In this test, the barrier deflected 

990 mm. In both tests, the deflection was the result of bolt shear failure in the area of impact and 

did not result in any significant damage to the simulated bridge deck. 

Based on reported results of these tests and on the shape of the barrier, I am willing to consider 

the Sistema barrier conditionally acceptable for use on the NHS as a TL-5 barrier without a 

pickup truck test and without a 9000-kg single unit truck test, since the safety shape has been 

tested successfully with these two vehicles in numerous tests, and the Sistema barrier has 

demonstrated adequate strength to contain the larger tractor trailer in tests SIS/BSI-03/176 and 

X61.01.A10. A successful test with a 36,000 kg tractor-tanker truck would be needed to certify 

the Sistema as a TL-6 barrier. 

Because it is a steel product, the Sistema barrier is subject to Section 635.410 (Buy America) of 

Title 23, U.S. Code, and cannot be permanently incorporated into any federally funded project 

unless it is made in the U.S. from U.S. steel. However, its use as a temporary barrier during 

construction is permissible. The Sistema barrier is also proprietary so its use must also be in 

accordance with the provisions of Title 23, U.S. Code, Section 635.411. 
3

Because it is currently made in Europe and drawings in standard U.S. dimensions and 

nomenclature are not currently available, you will be expected to certify to any users that the 

barrier provided for installation is identical to that which was tested, particularly in regard to 

material specifications and anchorage details. An in-service evaluation should be made for the 

first U.S. installations to establish cost and performance data, and to verify acceptable crash 

performance. My staff will review the evaluation report and consider upgrading the Sistema 

acceptance to fully acceptable at that time. 

Please be aware also that this acceptance letter shall not be reproduced in part nor construed as 

authorization or consent by the FHWA to use, manufacture, or sell any patented device for which 

the requestor does not hold the appropriate patent or patents. Our acceptance is based only on 

the crashworthiness characteristics of the candidate device, 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, 

 

 /Original Signed By/ 

 

 John R. Baxter, P.E. 

 Director, Office of Safety Design 

 Office of Safety 

2 Enclosures 
e-mail: dhubbell@adelphia.net

Fax: (518) 891 4322

Phone: (518) 891 1669

New York, USA 12983

P.O.Box 600 Saranac Lake

COMPOSITE STRUCTURAL DESIGN L.L.C.

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e-mail: dhubbell@adelphia.net

Fax: (518) 891 4322

Phone: (518) 891 1669

New York, USA 12983

P.O.Box 600 Saranac Lake

COMPOSITE STRUCTURAL DESIGN L.L.C.

DRAWING :

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CHECKED BY :

DRAWN BY :

DATE :

DATE :

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COUNTY :

SUB CONTRACTOR

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