With the hurricane season approaching, the members of the Eagle Team remain concerned about the imminent dangers posed by the combination of oil water and hurricanes. The Gulf region has long suffered the brush of hurricanes, many of which have caused great devastation. This type around, the presence of oil in the water creates yet more reasons for the cleanup effort to happen more quickly.
One promising idea was proposed by one of our members, Rande Kessler, CEO of Advanced Coastal Technologies.
Mr. Kessler is working with BP’s High Interest Technology on a similar project and offers the following:
ProTecTube
The ProTecTube is very large (100 feet by 25 feet wide by 6 feet high at the rear "cell") and when sand-slurry filled, in shallow water, will not be moved by heavy storm activity, so that was the focus. (When a ProTecTube is completely sand-filled it weighs about 600 tons). The BP team decided on a site that requires about 600 - 700 linear feet, and will be in about 3 feet of water, just off shore. The ProTecTube has a 6-foot rear-cell crest height and we are evaluating options to have as much of that as freeboard as possible, while using the forward cells of the unit as anchors, facing seaward. Each ProTecTube will be laced to the next one. Those forward cells will be sand-filled and sit on the bottom while the rear cell of the wedge shaped ProTecTube will have part of it out of the water. Either that rear cell will be water-filled, air-filled or sand-filled, depending on our determination for best estimated effect.
Therefore, the oil "washing in" will have to climb over the 2 or 3 feet of highly durable geotextile to get to the other side. So the plan is to have this as an anchored, shallow-water barrier to absorb and dissipate wave action and remain in place during storm activity, unlike the small, floating containment barriers that will be torn and moved, and allow oil passage.
The ProTecTube is actually designed (and installed) as an on-shore (as landward as possible) dune-core structure. The purpose is to permanently contain tons of sand that could be easily washed away if not encased, and to provide a "firewall" of protection for a landward property if a storm rips in and erodes the beach. Instead of using a seawall, the property owner has a dune-type vertical protection that won't reflect wave energy and allow beach scour and flattening. If a storm wipes all the surface sand from the ProTecTube, then the property owner simply re-covers it with about 1/3 the amount of sand that would have been needed to replace the entire dune. In many cases, the after-storm effect actually re-accretes sand on the sloped surface as the currents move. ProTecTubes are normally covered with 3 feet or more of sand, and the newly created dune re-vegetated. Just think of the renourishment savings with miles of permanently contained beach sand! The initial investment for ProTecTubes would be paid for in sand savings (a disappearing resource) over the years. But, sorry for the sales pitch!
(We want property owners to see the viability of being pro-active and installing tubes inside their dunes to be ready for the "next" big storm. We have a 600-foot permitted project along New Smyrna Beach, Florida, slated for installation this fall.)
This new ProTecTube application with BP is to provide a very durable, very heavy, temporary barrier - this time "in the water." The tentative plan is to air-fill each ProTecTube at an access beach point (which can be done in 45 minutes with a couple leaf-blowers!), then tow each one out into the water and into place and temporarily anchor it. Then we'll water-fill the entire (most of) unit and sink it in place. Since water-in-water will not be too stable, even though a portion will be above the surface, the next step is to sand-fill (slurry) the leading edge cells of the "wedge" to anchor the unit. The sand can be dredged from that spot, and will be right back again and naturally re-distributed once the geotextile is cut and removed, after the danger has passed.