By United Marine International LLC, USA
From Port Technology International, Eighth Edition, Published by ICG Publishing, Ltd.

Abstract

Trash and debris often finds its way down-stream into ports, harbours and attractive tourist areas. This article looks at the UMI TRASHCAT™ trash skimmer that is able to remove the unsightly debris, and outlines some of the locations where it is in use.

As we approach the millennium, ports and harbours around the world are gradually taking on a new look. The economies of many of the old working harbours and their surrounding neighborhoods are being converted from heavy industrial/commercial areas to revitalized, multipurpose waterfronts. Changes in business patterns, lifestyles and recreation have forced governing bodies to rethink land usage, and what better way than to bring people to the waterfront? Rundown buildings and dock areas are now finding themselves being replaced by hotels and condominiums, boutiques and restaurants, "strolling pavilion areas" along the waterfront, tall ships and submarines, science centers and aquariums, marinas and condominiums, luxury boats, paddle boats and water taxis. These are all geared toward providing revenues for vendors and the cities, while at the same time providing citizens and visitors with an enjoyable and relaxing experience.

Skimming for debris in tourist areas of Baltimore's famous Inner Harbor, Baltimore, Maryland, USA
(photo enlargement)

With progress and major investment comes a new facelift. The cleanup and upgrade includes the gutting and restoration of old buildings, new building construction, landscaping, pile driving, new roadways, parking lots, a variety of restaurants and snack shops, souvenir shops, convention centers, entertainment ... and most important in all successful waterfront projects ... CLEAN WATER.

It is common knowledge and a known fact that "all waters flow to the sea". With most harbours and seaports strategically established with easy access to the sea, it is no wonder that trash and debris finds its way downstream to the very places that we are now trying to upgrade. The problem which most large cities face today is that the infrastructure, containing the "plumbing" of virtually all public works facilities, is permanently in place. Huge storm water and combined sewer pipelines are buried beneath existing roads and highways, buildings, bridges, railroad tracks, sidewalks and utilities. In many areas of the world, and not only in developing countries, inadequate garbage collection services result in huge amounts of household trash and yard debris conveniently finding its way into nearby streams, apparently the only or easiest method of disposal. And this does not even address the arrival of dead animals, trees and other products of nature's watershed runoff resulting from rains or flooding, which in many areas is channeled to the sea via "flood control" canals ... more debris for the Harbour. Heavy contributions of commercial and industrial man-made debris are everyday activities that end up in the water ... and again, the downstream recipients are our ports and harbours.

Birth of the TRASHCAT™

The birth of the current UMI TRASHCAT™ trash skimmer occurred in the early 1980s when New York City's Department of Sanitation (NYCDOS) found itself with an environmental problem at their Fresh Kills landfill complex in Staten Island, NY. Operating the world's largest (approximately 3200 acres) landfill 24 hours per day, 365 days per year, and receiving upwards of 20,000 tons of the City's solid waste daily by refuse barge, some of the material unavoidably ended up in the water during unloading operations. This not only created an unsavory condition for New York City, but wind and tidal conditions caused some of the water-borne refuse to float over to the New Jersey shoreline. Under pressure from both local and federal authorities, NYCDOS awarded a $1.75 million contract to design and construct five (5) trash skimmers, these being the first of the "conveyorized" skimmer vessels today recognized world-wide as the TRASHCAT™.

TRASHCAT™ Systems

Today's TRASHCAT™ consists of a catamaran type, twin-hull vessel on which are mounted hydraulically powered and controlled open mesh conveyor systems to move materials. Using a diesel engine to power hydraulic pumps, all functions are hydraulically driven and remotely controlled by one operator. Twin, over-the-rear hydraulically powered propellers, each independent, variable speed and reversible, are used to propel and steer the vessel. These propellers can be remotely raised and lowered to clear debris without the need to take the vessel out of the water. A front mounted continuous conveyor can be lowered into the water and is capable of skimming floating debris off the surface to depths of up to 2-1/2 feet below the surface. Equipped with vertical, conveyorized skimming "wings" mounted on each side of the main pickup conveyor, UMI TRASHCATS™ are capable of skimming 16 feet wide.

Debris coming up the main pickup conveyor dumps into the vessel's storage area which, with its sidewalls, can retain and store up to 12,000 pounds or 700 cubic feet of material. Long logs and items of up to 48 inches in diameter are not a problem. Mounted in the solid bed of the storage area is a continuous, one-piece open mesh conveyor that runs the full length of the skimmer. Driven by hydraulic motors, the conveyor which can be indexed rearward by the operator as the storage area loads and fills up, thus making room for additional debris as it comes up the main conveyor and onboard the vessel.

Once fully loaded, the vessel heads back to shore, where the operator offloads the material onto land based, height adjustable, transfer Shore Conveyors that conveys it into dumpsters or dump trucks for off-site disposal. In addition to the Shore Conveyors, UMI offers matched Tilt-Deck Trailers to haul the vessels over the roads and to launch or retrieve them. Portable gasoline/hydraulic Power Packs are available to supply hydraulic power to the Shore Conveyors in remote or inaccessible areas. The TRASHCATS™ come in three sizes, each with different skimming widths and storage capacities. All Systems are mobile.

Spreading the Word

Shortly after New York's success with the TRASHCAT™, the City of Baltimore, Maryland, sought out the new skimmer vessels for use in removing floating trash and debris from their world class Inner Harbour. In 1987, Baltimore acquired its first of six TRASHCATS™ to remove thousands of tons of floating debris that empty directly into the beautiful Inner Harbour from 28+ stormwater outfalls that are fed by a network of hundreds of interconnecting storm sewer openings in the surrounding Baltimore area. This year, Baltimore ordered two additional UMI TRASHCATS™.

The Common Denominator

Virtually everywhere that runoff occurs, floating trash and debris of all sizes and shapes can be found - harbours and bays, ports, marinas, rivers, hydroelectric plants and flood control dams, lakes and reservoirs, backbay waterways and lagoons ... all generating wood and logs, trees and root "balls", garbage, medical waste, plastic, combined sewer overflows, automotive tires, dead animals (and bodies), refrigerators, bottles, styrofoam, oil slicks and absorbents, mats and bogs of aquatic vegetation.

UMI's TRASHCAT™, with its ability to bring all sizes and shapes on board, has proven to be a logistical asset. By approaching the debris aggressively from the "water side" and not waiting for the debris to funnel down or spread to a land based capture site where it might impact normal operations, the TRASHCAT™, using its conveyorized wing design, can pick up floating material while moving forward, standing still, or backing up.

There are now over 50 TRASHCATS™ in operation today throughout the world, many being multiple purchases and/or repeat orders. Among the cities using the TRASHCATS™ to handle floating debris are:

New York City - the NYC Department of Environmental Protection (NYC DEP) purchased four skimmers in addition to the original NYCDOS vessels purchased in the early l980s. These boats are used throughout the city in the bays, harbours, rivers and canals, mainly removing debris generated by stormwater runoff and combined sewer overflows.

City of Chicago - the Chicago Parks Department purchased two combination trash skimmer/weed harvester machines for removal of both debris and aquatic weeds from their marinas in Lake Michigan's waterfront parks, and the Chicago Sanitary District acquired a trash skimmer for use in inner city navigable channels, rivers and canals.

Washington, D.C. - the District of Columbia Water and Sewer Authority currently owns two UMI TRASHCATS™ and this year rented a demonstration unit to supplement their cleaning activities on both the Potomac and Anacostia Rivers.

Paris, France - the City of Paris owns and operates two UMI trash skimmers, utilizing them on the Seine River and in adjoining canals that run throughout Paris.

Dubai, U.A.E. - the Dubai Port Authority operates two large vessels. One is a trash skimmer to remove floating debris, and the other a custom Crane Barge for special material handling. The Dubai Municipality uses two trash skimmers in their municipal "creek", a navigable water body that runs through the center of the city.

Rio de Janeiro, Brazil - the UMI trash skimmer owned and operated by COMLURB, the city's Department of Sanitation, is used to pick up and remove floating debris in the highly populated and developed backwater areas of Rio before they enter the open waters of Guanabara Bay or the Atlantic Ocean.

South Korea - there are currently fourteen UMI TRASHCATS™ operating in South Korea, primarily in small municipal harbours, bays and reservoirs. One "COMBO" Oil/Debris Skimmer, a "Rapid Retrofit" unit capable of operating as a trash skimmer and being quickly converted to an oil skimmer, is operating in a harbour area.

UMI TRASHCATS™ have also found their way into several U.S. and international hydroelectric and flood control dams, among which are:

Tennessee Valley Authority (TVA) - this trash skimmer, which has interchangeable main pickup conveyor heads (one for weed harvesting; the other for trash and debris), is primarily used in the removal of large floating debris accumulating at the face of TVA's Wilson Dam, and alternately in TVA's large lake impoundments to harvest and remove nuisance aquatic vegetation.

American Electric Power (AEP) - AEP purchased their trash skimmer for use at their Appalachian Power Company hydroelectric dam on Smith Mountain Lake, Roanoke, Virginia. With over 20,000 surface acres and 500+ miles of highly developed year-round homes and recreational waterfront property, this lake is highly impacted by watershed wooded debris generated after rainstorms.

Duke Power Company - has 27 reservoirs, ten of which have serious trash problems. By taking advantage of the mobility of UMI's trash skimmer systems, Duke is able to prioritize the use of their TRASHCAT™ by trailering it from site to site, as needed.

Safe Harbour Water Power Corporation and Susquehanna Electric both operate TRASHCAT™ skimmers to remove heavy floating debris at their hydroelectric dams in the Pennsylvania - Maryland areas on the Susquehanna River.

Mitsubishi Heavy Industries, Tokyo, Japan purchased UMI's TRASHCAT™ for The Government of Japan to remove a wide range of floating wooded refuse (trees, branches, root balls, vegetative matter, etc.) that accumulates at the face of the 1500 foot wide Onga-Gawa Flood Control Dam in Kyushu, Japan as the result of high impact flooding brought on by the annual monsoon rains. The dam prevents the massive debris from impacting the fishing villages (nets, docks, vessels, etc.) located below the dam in coastal, saltwater areas.

Efficiency and Cost Savings

The TRASHCAT™ equipment has several advantages:

• Mobility and transportability make this technology useful and available to multiple locations;
• On-board storage capacity allows the skimmer to pick up, store and offload a wide variety of sizes and shapes, thus providing great flexibility in its usage;
• A two man crew is normally all that is required. With remote hydraulic controllers, the TRASHCAT™ removes floating trash and debris efficiently and at low operations and maintenance cost. Capital costs are less than alternative approaches;
• A "good neighbor" image is portrayed by using this environmentally safe technology. The TRASHCAT™ is non-invasive, can be put into operation immediately after launching, and the results can be seen immediately.

Today, with over 50 TRASHCATS™ in operation throughout the world, United Marine International is recognized as the world's leading producers of marine trash skimmers.

For more information, contact:
E-mail:  info@lwtpithog.com
Phone:  800-243-1406 US only, or 715-246-2888
Fax:      715-246-2573

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