Railway Expansion Joint for Bridges over Navigable Waterways

Railway bridges over navigable waterways require expansion joints that can withstand the marine environment while preventing debris from falling into the waterway below. The environmental requirements and inspection access challenges are unique to this type of bridge. Marine environment corrosion protection for railway expansion joints over water must be enhanced compared to inland bridges. The combination of high humidity, salt spray (for coastal waterways), and the potential for flooding creates a highly aggressive environment. Hot-dip galvanizing plus a three-coat epoxy system is the minimum requirement for steel components. Debris management is critical for bridges over navigable waterways. Any debris that falls through the joint gap could damage vessels passing below or create a navigation hazard. The joint design must prevent debris from falling through, either by using a closed joint design or by providing a debris collection tray below the joint. Debris collection trays below the joint must be designed to collect and retain all debris that passes through the joint. The tray must be large enough to catch debris that is deflected by the joint structure, and must have sufficient capacity to hold the accumulated debris between cleanings. The tray must be accessible for cleaning without requiring closure of the waterway. Inspection access for bridges over navigable waterways requires coordination with the waterway authority. Inspection from below the bridge may require a boat or a suspended platform. The inspection must be scheduled to avoid interference with vessel traffic. Any maintenance work that could drop debris into the waterway must be performed with appropriate containment measures. Environmental protection during maintenance work on bridges over navigable waterways requires containment of all waste materials, including concrete debris, paint chips, and lubricants. Environmental permits may be required for maintenance work that could affect the waterway. The maintenance contractor must have a spill response plan in case of accidental release of materials into the waterway.