Open Box Beam is suitable for use at the road
edge or in the center reservation of motorways
or high speed roads.
It is also preferred to other forms of safety
fencing for use on embankments,for protection
of bridge abutments and in other hazardous
situations such as elevated roads,tunnels,dock
sides and industrial loading bays.
The strength of the barrier
lies in the section of the rails, which are
normally supplied in 4.8M and 2.4M lengths.
These are connected together by fishplates
which match the profile of the rail and sit
inside bridging adjoining beams.
There is no limitation on the length of run
which can be installed but both the approach
and departure ends should be anchored at ground
level to strong SHS posts or to full height
anchor frames.
Also because of the rigid nature of Open Box
Beam some allowance must be made for the effects
of changes in ambient temperature, therefore
a special expansion assembly must be fitted
every 100M.
The most
convenient method of installation is on driven
posts which are,as the name suggests,driven
into the ground at 2.4 M centers by means
of a special hydraulic driving rig.
Driven posts are the quickest method but whether
or not they can be used depends upon the ground
conditions. They must be subjected to trial
pull tests.
If standard posts fail then extra long ones
can be used.
Concreted in posts take longer
to initially install, but have one major advantage
over driven posts.
They can be used with sockets cast into the concrete
footings (into which the posts slide once the
concrete has set). This makes future replacement
after accident damage faster and easier, saving
time and money.
Black plastic covers can
be used to cover the socket openings to prevent
the ingress of water and dirt. The covers have
a tightly fitting aperture to match the z-shaped
profile of the posts.
Heavier duty Z-section posts are used for mounting
open box beam in double row format where a particular
hazard exists from vehicles with a higher center
of gravity.
SAFETY FIRST
from Hill and Smith Tel:
+44 (0) 1902 499400
Highway
Barrier 
Crash
Cushions 
