The effects of salt water on electro- mechanical devices not only include all of the same ill effects as with electrical devices, but also the likely fouling of non-electrical mechanisms. The result is a device that has several possible failure modes, including the loss of mechanical integrity due to corrosion. In Fig. 2, the boiler over-temperature safety switch has been corroded in place. The switch cannot activate — and in turn the safety system it serves is disabled. Small devices like this can easily get overlooked in a post- disaster review of damaged infrastructure.
Galvanized conduits inundated with salt water will accumulate salt deposits and start to rust as soon as they are affected — resulting in roughened interior surfaces that make replacement of related electrical conductors difficult, if not impossible. Additionally, the nylon slip sheet found on many wires can be very susceptible to salt water at typical elevated operating temperatures. The result is a sheath that peels off, adding to the difficulty of removing the conductor. Unused conduits inundated with salt water may provide such a roughened surface that the slip sheaths and insulation sheaths of any new wires can be damaged during their installation.
With most electrical conductors, the insulation sheath can act as a pipe to channel water down the length of wire strands contained within the sheath. The extent of this channeling is based on the amount of wire under water and the hydrostatic pressure the floodwater exerts on the wire. In most cases, if the terminated end of a conductor was under water, any length of wire associated with it that was also underwater will be affected.
The salt water and salt residue on the wire can be conductive enough to expose flaws and weaknesses in the insulation sheath of the wire. Although most sheath...
Fig. 4 —This termination point, cleaned twice, continues to corrode due to salt water wicking from the associated conductor.
Fig. 5 —The terminals of a newly installed breaker corrode due to saltwater wicking from the existing conductors. The salt water wicked up from the wires terminated at the bottom of the breaker.
Fig. 6 — Salt residue engulfs a conduit bonding clamp. Corrosion will continue until the salt or clamp is consumed.