| LEVEL
CROSSING PROTECTION EQUIPMENT
The level crossing equipment
is designed to meet the requirements of safety and reliability
from railway signalling standards.
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Design
features
Power supply with back-up battery bank and charger operating
from 220 V AC.
Relay control elements are either of railway specification
safety type relays or of good quality industrial type relays,
depending on specific requirements.
The barrier operating machines are electro hydraulic operated
and are housed in a weatherproof metal enclosure with lockable
access doors; operational voltage to customer's requirements.
The barriers are of round or square profile aluminium, available
in lengths up to 8 m.
Audible alarms are either bells or sirens with a 500 m range.
Warning flashlights or road signals are fitted with incandescent
lamps and red lenses.
The road signals are equipped with Saint Andrew crosses appropriate
to the specific crossing requirements.
Train detection by track circuits or by a combination of one-level
crossing track circuit and rail treadle at both left and right
extremities.
The system operation is available in pure auto, semi-automatic,
or manual mode depending on customer requirements.
Half-arm barrier
The barrier-operating machines are designed and manufactured
in South Africa to comply with strict fail-safe level crossing
protection requirements.
These machines are electro-hydraulic operated and are housed
in a foundation mounted weatherproof metal enclosure with
lockable access doors.
The barrier arms are factory-set to operate from horizontal
to vertical in nine seconds. This time period may be varied
through a simple adjustment, which can be carried out on site.
The following features are part of
this machine:
'Raised' and 'Lowered' detection via two cam-operated limit
switches. One limit switch is set to detect the raised position
between 83~ and 900 from the horizontal, while the other switch
is set to detect the lowered position between 00 and 70 from
horizontal.
The beam drops away to horizontal by gravity. A manually operated
mechanical lockout facility is provided to hold the arm in
the vertical position.
An adjustable spring stop is provided for damping the barrier
arm and to ensure that the barrier arm is not elevated beyond
the maximum angle of 9Q0 from the horizontal. It also serves
to initially assist the gravitational bias when the boom is
lowered.
o Barrier booms are of round or square profile aluminium and
are available in lengths of 5,5 m, with a built-in shear point
to protect the operating mechanism in case any excessive force
is exerted against the boom.
o Standard motors supplied with the mechanism are available
in all the standard motor voltages, both AC and DC.
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