diameter of no less than 200 mm 8 inches. A bollard system shall consist
of a minimum of 3 bollards spaced no more than 915 mm 36 inches from
centerline to centerline of bollards across a 3.0 m 10 foot roadway.
Bollards in the lowered position shall be capable of supporting a 71 kN
16,000 pound wheel load each. Design for this load shall be in accordance
with AASHTO HB-17. Retractable bollards shall withstand a [_____] kg pound
vehicle at impact speed of [_____] km/hour mph with maximum bollard
deflection or vehicle penetration of [_____] m feet.
2.2.1
Powered Retractable Bollards
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NOTE: Based on peak hourly volumes, fill in number
of cycles per hour that the barrier will be required
to function (maximum 300 complete up/down cycles per
hour).
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The retractable bollard shall be capable of [_____] complete up/down cycles
per hour. Bollards shall be capable of being raised or lowered within a 3
to 15-second range during normal use and within 2.5 seconds for emergency
operations.
2.2.1.1
Failure Modes of Operation
The system shall be
designed to prevent lowering of the barrier in the
event of hydraulic,
electrical, or mechanical failure. A manual pump, or
other system, shall
be included for operation of hydraulic and/or
mechanical barriers
without power.
2.2.1.2
Unless otherwise indicated, electric motors shall have [drip-proof]
[totally enclosed] enclosures. For multiple barriers being operated from a
hydraulic power unit it is highly recommended that the electric motor be
3-phase.
2.2.1.3
System
The system shall be designed to maintain the barriers in the raised
position, without inspection, for period of time of up to 1 week. If a
hydraulic system is used, it shall be equipped with pressure relief valves
to prevent overpressure.
2.2.1.4
Hydraulic Power Unit
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NOTE: Retain and edit or delete paragraph based on
type of operator chosen.
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The hydraulic power unit shall contain synthetic biodegradable hydraulic
fluid which maintains its viscosity operating range, even at constant
heaviest use rate, for an ambient temperature range of [minus 7 to plus 66
degrees C 20 to 150 degrees F] [[_____] to [_____]]. A hydraulic fluid
heater shall be provided so that the viscosity remains within its operating
range, if ambient temperatures below minus 7 degrees C 20 degrees F are
expcted. Buried hydraulic lines for the connection of the hydraulic power
unit to the barrier shall be flexible or carbon steel pipe, or a
SECTION 02840
Page 13
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