BRIDGE REPAIR/REHABILITATION FEASIBILITY STUDY

accordance with the NFPA Life Safety Code. This can be accomplished with the introduction of
additional horizontal timber railing members or stainless steel cables located in between the
timber rail elements.
Functionality and Safety: The addition of horizontal timber railing members or intermediate
cable rails between the horizontal timber rails proposed under the Rehabilitation Scope would
increase the safety for pedestrians.
Load Capacity: The bridge railings are not considered to contribute to the load carrying capacity
of the bridge. As such, there is no reduction in load carrying capacity due to the condition of this
element.
Maintenance: Replacing the timber railings now would reduce maintenance in the short-term by
reducing the need to make periodic repairs to the deteriorating railing members or to reapply inplace
preservative treatments.
Visual Impacts: Replacing the timber railings in-kind would not introduce a visual impact. The
addition of horizontal railing members or intermediate cable rails between the horizontal rail
elements is not anticipated to introduce a significant visual impact.
4.2.6 Deck Joints:
NBIS Condition Rating: 4 (Poor)
Condition Description: The timber deck joints between the bascule leaf and approach spans are
currently a concern due to the tight contact between these elements that cause the bascule leaf to
periodically become stuck during bridge operation and/or to not seat properly and thus create a
discontinuity (typically as much as ½”) in the roadway and sidewalk surfaces. The magnitude of
this tight fit varies based on the ambient temperature and moisture content of the deck. It is also
possible that the substructure and timber piles are slowly shifting slightly toward the channel as
vehicles decelerate and brake while on the bridge, as often found on movable bridges, although
this cannot be confirmed.
Repair Scope: It is recommended that a wider joint opening be provided between the tip of the
bascule leaf and approach span if the timber wearing surface and structural deck are replaced.
Rehabilitation Scope: The Rehabilitation Scope would be the same as that above for the Repair
Scope (i.e. no upgrades are required to meet current design standards.)
The hinged flap in the deck that provides clearance during operation of the bascule span may
need to be modified if the location of the pivot is shifted to improve the navigation opening. The
length of the flap may need to be increased if the opening angle is increased. A larger flap will
likely be heavier and may require a longer lever arm for the operator to lift the flap.
Repair/Rehab. Feasibility Study March 10, 2011
Bridge No. C-07-001 (437) 21 Final Report