Product and Installation Manual: Sentry Barrier TL-4 ThrieBeam System
ACP
| September 2020 |
Page
4
New South Wales
Sydney
02 8708 4400
Victoria
Melbourne
02 8708 4400
Queensland
Brisbane
07 3442 6200
Western Australia
Perth
02 9772 4172
Introduction
The
Sentry Barrier TL-4 ThrieBeam System
is a roadside Thrie-beam guardrail system suitable for
containing, redirecting and shielding vehicles from roadside obstacles. The barrier has been
designed and tested to meet the evaluation criteria of MASH Test Level 4 for a longitudinal barrier.
This is the current state of the art performance criteria, exceeding the requirements of NCHRP 350
Test Level 4.
The
Sentry Barrier TL-4 ThrieBeam System
has an initial installation height of 1050 mm to the top
of the rail, providing the system with the ability to withstand numerous road surface overlays without
the need to relevel of lifting of the barrier. The
Sentry Barrier TL-4 ThrieBeam System
can be
installed with an approved energy absorbing terminal end on the approach end, however it is
recommended that an approved tangential or flared MAX-TENSION terminal end be used for optimal
performance.
The rounded edges to the
Sentry Barrier Post TL-4
and closed shape on the approach direction
provide increased protection for vulnerable road users. The compact
Sentry Barrier Post TL-4
are
easy to drive into all soil types and provide increased resistance to rotation in the soil when
impacted. Unlike other systems on the market, any damage caused to the top of the posts or to the
rail mounting points during installation will not affect the performance of the system.
The connection system between the rail and posts is formed using conventional fasteners providing
it with the greatest tolerance of any system on the market. If the connection is damaged in any way
it can be easily replaced without replacing the posts allowing for simpler installations and repairs.
The
Sentry Barrier TL-4 ThrieBeam System
is installed quickly using conventional installation tools
and equipment.
System Overview
The
Sentry Barrier TL-4 ThrieBeam System
is designed to provide acceptable structural
adequacy, minimal occupant risk and safe vehicle trajectory as required by the latest in safety
standards, AASHTO MASH 16 Test Level 4 (TL4). This standard requires the system to be
independently evaluated with full scaling testing using 1,100 kg and 2,270 kg vehicles traveling at
speeds of 100 km/hr and impacting the system at an angle of 25 degrees, as well as a 10,000 kg
truck travelling at 90 km/hr impacting the system at an angle of 15 degrees. The requirements of
MASH 16 TL4 are so stringent that the system is required to absorb more energy during the impact
than the out-dated NCHRP 350 standard Test Level 4 (TL4).
When impacted by an errant vehicle, the
Sentry Barrier TL-4 ThrieBeam System
will redirect the
vehicle along the face of the barrier system, bringing it to a controlled stop. The system has been
developed to produce no debris during an impact, with all posts designed to remain firmly located in
the soil and the connection details to remain attached to the rail. Repair of the system is completed
by removing and replacing any bent or damaged ThrieBeam and posts impacted accordingly.
