| Better Bridges
How to inspect a movable bridge safely
Ensuring safety during a movable
bridge inspection is a complex effort. A movable bridge inspector is
subject to the hazards common to fixed highway bridges as well as those
unique to movable bridges.
by Bert Crouthamel, Rick Newcomb, Graciela Patino,
and Mark VanDeRee
The hazards that can arise during the inspection,
operation, or maintenance of a movable bridge should be understood and
controlled before any activity involving the bridge is planned or
conducted.
 Accidents
can be prevented if inspection engineers provide bridge operators and
maintenance people with complete schedules that include the location of
the inspection staff and give enough advance notice to schedule
maintenance activities without a conflict with inspection activities.
Bridge personnel will need this information in case a
bridge operation is required or an emergency situation develops. In
addition, inspection, operations, and maintenance personnel should attend
safety meetings held prior to the start of an inspection to review proper
safety procedures during bridge inspections and bridge-specific safety
practices as well as any unusual features or hazards of the individual
bridge. Contingency plans in the event of an emergency should also be
developed.
Each inspection day should begin with an informal but
informative tail-gate meeting to coordinate the day’s activities with
all personnel present on the bridge. The inspection engineers are
responsible for carrying all safety equipment needed to perform the
inspection, including safety glasses, hard hat, ear protection, safety
vest, harnesses, and lanyards.
What to check
Objects and debris. Prior to an inspection, the bridge
should be cleared of all objects and debris, such as large bolt heads,
welding rods, lumber scraps, and tools that can accumulate on the
structure. These objects are potential tripping or falling hazards. They
can also become projectiles and may cause damage to open machinery.
This clearing is particularly important for bascule
bridges that have not been operated for a long period of time or that have
had recent structural work. Often, hard objects literally rain from the
leaf during the first opening of the bridge.
Walking surfaces. In addition to clearing objects,
walking surfaces should be clean. Lubrication and hydraulic oil, vital for
maintaining the service life of moving parts, can cause slipping hazards
on walking surfaces and ladders.
Biological hazards. Caution must also be exercised
regarding biological and personal safety hazards. Snakes, rats, birds, and
insects can pose immediate health hazards. The U.S. Public Health Service
has identified histoplasmosis, a difficult to cure and often fatal fungal
infection, as an occupational health hazard for bridge inspectors. This
fungus attacks the lungs and endocrine system. It is found growing most
often in decaying pigeon feces. Inspections should be halted in locations
where the inspector must come in contact with or breathe byproducts of
animal waste until the areas are cleaned.
Human waste and homeless residents are also encountered
on occasion. The bridge owner should be notified immediately and the
inspectors should leave the area upon discovering someone living on the
bridge.
Supplemental lighting. Some bridge inspections and
testing require that the bridge be closed for long periods to prevent
potential hazards to roadway or waterway traffic should there be a
malfunction. In these cases, owners may require that inspection (and
testing) be done late at night to minimize public inconvenience.
Inspection of a bridge in poorly lit areas worsens hazards that can
potentially cause tripping or falling. When night inspections are
required, time should be taken to install any supplemental lighting that
may be required and to conduct a pre-inspection walk-down.
Lockout devices. Inspectors must closely observe, touch,
or disassemble mechanical equipment (such as gears, shafts, bearings,
motors, and locks) during routine inspection. These actions could present
an immediate hazard if the equipment is inadvertently activated during
such work, so lockout devices should be used at the point of power
disconnect to prevent bridge operation. The team leader or authorized crew
member should be responsible for setting the lock and determining that
each crew member is in a safe location before removing these devices. In
addition, the main control panel should be deactivated and the bridge
operators warned when inspectors are working on electrical power systems.
Reporting safety problems
As the inspection proceeds, any deficiencies that
compromise safety should be reported to the owner immediately because
formal reports often take weeks to prepare. If an incident occurs from the
time when the inspector makes a critical observation to when the report is
submitted, the inspection firm may be liable.
The importance of timely reporting may extend beyond one’s
area of direct responsibility. While the scope of the inspections is
generally divided into structural, mechanical, and electrical elements,
inspectors should not have tunnel vision if they notice something outside
of their scope. If there are other qualified inspectors for the elements
in question on the bridge, they should be alerted. If no other inspectors
are available, the owner should be notified in an informal but written
memo. In fact, the formal inspection report should not contain
out-of-scope observations — owners do not usually appreciate such
observations being included.
Health and safety plan
Bridge owners should be encouraged to develop health and
safety plans because they can enhance the safety of bridge personnel and
the general public. A bridge that is kept safe for operations and
maintenance personnel is also safer for inspectors as well.
Movable bridge health and safety plans can be prepared
as a supplement to any general operations and maintenance plans that
owners have in place. Some owners prefer to develop such a plan for each
bridge, while others choose to develop a general document to cover all of
their movable bridges.
 Movable
bridge safety is a complex subject. It is rare to find one source that has
the necessary combination of information and experience to either predict
all possible hazards or to develop corrective measures for each bridge.
The group developing bridge-specific health and safety plans should
include representatives who are experienced in the bridge design and the
inspection and maintenance practices of the owner, and others who have
backgrounds in safety programs.
Health and safety plans should not be static documents
but, rather, should evolve as new information and challenges emerge. The
plan should be reexamined and may need to be amended in response to any
safety related incidents.
Movable Bridge Planning
The plan for a movable bridge should cover 11 areas:
1. Statements of general health and safety policies.
2. Administrative responsibilities for implementing the
safety plan, including identification and accountability of personnel
responsible for accident prevention and safety aspects of the movable
bridge environment.
3. Employee responsibilities for adherence to the health
and safety plan.
4. Means for controlling and checking procedures used
for inspection and maintenance activities of in-house personnel and
outside entities.
5. Maintenance procedures to keep the bridge in a safe
condition.
6. Procedures for maintaining safe access to various
areas of the bridge.
7. Procedures for safety training of new personnel
involved in inspection,operation, and maintenance.
8. Protective equipment requirements for personnel
involved in inspection, operation, and maintenance.
9. Provisions for periodic unscheduled inspections of
the bridge site to determine compliance with the plan.
10. Responsibilities and procedures for reporting
accidents and unsafe or hazardous conditions.
11. Contingency plans for the event of a bridge shutdown
caused by hazardous structural, mechanical, electrical, or operating
conditions.
Bert Crouthamel is senior electrical engineer, Rick
Newcomb is lead electrical engineer, Graciela Patino is an electrical
engineer, and Mark VanDeRee is a supervising electrical engineer, all
with Parsons Brinckerhoff.
Reprinted from Better Roads Magazine
November 2001 |
