U.S. Navy Ship Salvage Manual Volume 6 - Oil Spill Response

S0300-A6-MAN-060Figure 4-13. Staggered Boom Deployed Across a Channel.Boom can be laid across slow-moving streams leading to open waterways to prevent oil spilledupstream from spreading into the waterway. The boom can be permanently deployed as a preventivemeasure against spilled oil flowing uncontrolled from the source. This barrier provides a suitablecollecting point for shore-based vacuum trucks or portable skimmer systems for quickremoval of the oil. If not predeployed, then the boom can be located ready for deployment at predeterminedsites. Following a spill, personnel should be dispatched quickly to place the boom intothe most effective position. Contingency plans should identify the areas where predeployedbooms are to be located, how they should be deployed and with what equipment.Diversion of oil from a river into the open sea may lessen the impact on sensitive estuaries andshould be considered as an alternative. When oil is diverted into the open ocean by current, it maydissipate in the water column or evaporate. Diversion into open water may be desirable when theenvironmental impact is considered, especially if water depths increase rapidly offshore and prevailingcurrents will carry the oil offshore.4-3.1.8 Beach Interface Boom. Beach interface boom acts as a barrier to oil as the tides rise andrecede. Air-floated, water-ballasted boom is very effective in this application. Because the skirt iswater-ballasted, the boom sits upright on the ground when the tide recedes. During flooding, aseal between the ground and boom is provided by the weight of the water-filled skirt pressingagainst the ground. As the water rises with the incoming tide, the float barrier and water skirt risewith the water level. The vertical barrier between the oil and beach is never interrupted. Moreconventional floating boom might allow oil to get past the skirt during the time the nonsealingskirt is laying lazy and not perpendicular to and in close contact with the ground.4-21