United Marine International (UMI) Successfully Commissions a New Generation of TrashCat™ Trash Skimmer Vessels in Hong Kong and Singapore

By Louis E. Shenman, United Marine International LLC, Washington Twp, NJ, USA


Everything gradually works its way down to the sea! In this day and age, it is unfortunate that litter generated anywhere eventually ends up in our rivers and harbors, as is the situation in the harbors of Hong Kong and Singapore.

Trash skimmer vessels, and specifically the UMI TrashCat™, have proven themselves as a recognized non-invasive tool in the war against floating debris that invades virtually every river and harbor throughout the world. This article reveals the latest efforts of two (2) important Southeast Asia ports, Hong Kong and Singapore, to deal with this ongoing environmental problem .


It has been over 15 years since the TrashCat™ was first conceived and introduced for use in the removal of floating trash and debris from the waterways surrounding the world’s largest sanitary landfill, New York City’s Fresh Kills Landfill complex in Staten Island, New York, where the City’s garbage is offloaded from the NYC Department of Sanitation’s fleet of refuse barges and transferred to land filling operations.

United Marine International, with 50+ TrashCat™ units in operation worldwide, has successfully commissioned a new generation of trash skimmer vessels in two of the world’s busiest ports.Hong Kong and Singapore. The TRASHCATST employ new technology to remove a wide range of floating trash and debris from the waterway.some as large as telephone poles, or as small as floating paper cups. to improve marine safety and the environment.

Both Hong Kong and Singapore have taken the initiative to solve the problem of floating trash as a matter of public policy so that their ports can continue to serve as economic growth engines consistent with environmental concerns.

Hong Kong

Hong Kong TRASHCAT™,  Model #TC-150L, operating in Hong Kong’s harbor–this model has an on-board storage capacity of 1 ton or 150 cu. ft. (4.3 cu. meters)

The Hong Kong and Shanghai Bank, under the auspices of the Private Sector Committee on the Environment, sponsored the introduction of TrashCat™ technology to Hong Kong. Secretary of Planning, Environment and Lands, Mr. Gordon Siu, noted during a commissioning ceremony that Hong Kong’s floating trash problem adds up to almost 10,000 tons per year. The Hong Kong Marine Department estimates that over 80% of the floating refuse in the harbor comes from shore dumping.

The new skimmer boat, with its ability to pick up and discharge trash via conveyors without human contact, will increase the safety and efficiency of the clean-up effort. The TrashCat™ was personally financed by Mr. Clement Fung, Chairman of Asia Standard Co. Ltd., headquartered in Hong Kong, as a service to the community. Hongkong Salvage and Towage Co. Ltd. is operating the equipment under contract to the Hong Kong Marine Department, which has prime responsibility for the clearing of floating refuse in the Hong Kong harbor.

In addition to the TrashCat™ vessel, a compatibly sized SHORE CONVEYOR, used to offload and transfer recovered debris from the boat to on-shore dump trucks or dumpsters for ultimate off-site disposal, will eliminate the need for any human contact during pickup and transfer operations. This virtually eliminates the potential for transmitted diseases often associated with exposure to waterway contaminants.

David Eldon, Chairman of the Hong Kong & Shanghai Bank, noted during the Hong Kong commissioning ceremony that privatized floating trash pick-up has proven four to five times more efficient (measured by tons collected per day per boat) than previously run municipal operations utilizing other technologies.

Hong Kong acquired UMI’s Model TC-150L TrashCat™, the smallest of the skimmer vessels being offered by United Marine. This compact skimmer allows the 1-man operation (a 2nd operator is often utilized to assist the primary operator and for on-board safety) to maneuver in tight and restricted quarters of busy marinas, typical of many areas within the Hong Kong harbor.

Basic specifications for the Model #TC-150L are as follows:

Operating (L x W x H) 34′-1″ x 8′-11″ x 8′-3″
Shipping Weight 9,600 lbs
Twin pontoon, catamaran-type
Length/Beam 24′-6″ / 8′-6″
Draft (empty/loaded) 16″ / 21″
Pick-up Capacity:
Width 10′-0″
Depth 18″
Storage Capacity:
Weight 2,000 lbs
Volume 150 cu.ft.
Power Plant:
Diesel engine, air cooled 60 HP @ 2400 RPM
Fuel capacity 20 gallons (U.S.)
Hydraulic System:
Pump(s) – Piston type with Variable Displacement (2 units)
2 units hydraulically driven, independently bi-directional and variable speed propellers
Deployment – stern mounted and power tilt
Operator’s Cab:
Side mounted, low-profile type with knock-down capability


Singapore TRASHCATS™ Model(s) #MS8-1500B working in Singapore Port–this model has an on-board storage capacity of 1500 lbs. or 120 cu. ft. (3.4 cu. meters).

The Maritime and Port Authority (MPA) of Singapore awarded a contract to Tian San Shipping (Pte) LTD, a Singapore based marine service company, for provision of a craft and crew for the collection of garbage from vessels and the clearance of flotsam from port waterways.

Tian San Shipping (Pte) LTD, having previously commissioned various types of environmental control vessels to fulfill this contract, is now including two (2) new TRASHCATST which are deployed daily to retrieve floating trash and debris from the port waters.

The UMI Model #MS8-1500A TrashCat™. skimmer vessels, recent additions in southeast Asia, have an on-board storage capacity of 1500 lbs., or 120 ft3 (3.4m3) This smaller model achieved speeds of over 7 knots fully loaded during acceptance trials. Equipped with catamaran hulls and hydraulically driven dual propulsion systems, the boat’s variable prop speeds allow for extreme maneuverability, important in recovering trash from hard-to-get corners. The remote hydraulic controllers make for easy operation by only one man, including self-loading and unloading via hydraulically powered conveyor systems. Due to the compact size of the TrashCat™, it can be easily trailered over the road from one place to another.

Basic specifications for the Model #MS8-1500A are as follows:

Operating (L x W x H) 31′-7″ x 8′-0″ x 8′-6″
Shipping Weight 8,000 lbs
Twin pontoon, catamaran-type
Length/Beam 21′-5″ / 8′-0″
Draft (empty/loaded) 16″ /’ 20″
Pick-up Capacity:
Width (Max) 8′-0″
Depth (Max) 1′-6″
Storage Capacity:
Weight 1,500 lbs
Volume 120 Cu. Ft.
Power Plant:
Diesel Engine, liquid cooled 55.3 HP @ 3300 RPM
Fuel Capacity 20 Gallons (U.S.)
Hydraulic System:
Pumps – multiple axial piston
2 Units, hydraulically driven, independently bi-directional and variable speed propellers
Deployment – Stern mounted and power tilt
Operator’s Cab:
Side mounted, low profile type with knock-down capability

The standard TrashCat™ skimmer vessels are available in two (2) other sizes:

A. Mid-size unit – Model #MS12-5000B:

Dimensions (operating) 10′ wide x 40′ long
Pick-up Capacity 12′. wide x 2′-6″ deep
Storage Capacity (on-board) 5000 lbs./400 cu. ft.

B. Large unit – Model #MS16-12000B:

Dimensions (operating) 12′ wide x 50′ long
Pick-up Capacity 16′. wide x 2′-6″ deep
Storage Capacity (on-board) 12000 lbs./700 cu. ft.

Selection of an appropriate size depends upon such typical factors as:

  • type and size of debris – lightweight household-type.cups, cans, bottles, paper, styrofoam, etc. ;
  • transporting of recovered debris is non-productive, especially over long distance (between waterway areas containing floating debris and suitable shore offloading locations)..larger vessels allow more skimming and loading before having to stop to head back to shore for offloading;
  • anticipated volume of debris to be handled in a given time period;
  • water and current conditions;
  • physical conditions within the waterways – i.e. confined canals and marina areas; open harbor areas, etc.

Standard Features

Both of these small skimmers, as well as larger TrashCat™ models, employ unique design features that enhance their performance:

  • The twin pontoon hull allow water to flow through the hull. With the main pick up conveyor operating below water and between the forward section of the pontoons, virtually all the debris that comes within the confines of the front conveyorized “”wings” is captured, directed to the main pick-up conveyor, and removed from the water.
  • The vertical conveyorized “wings” enable the TrashCat™ to remove “floatables” while the skimmer is moving forward, backing up, and/or moving backwards. This is especially helpful in the removal of light and elusive floating debris from “dead” or stagnant areas.
  • The propulsion system is comprised of twin hydraulic propellers drive units. Each can be powered up and down over the rear pontoons, allowing for easy clearing of debris from the props in the event they become fouled during operations.
  • The skimmer’s storage area is divided into two (2) sections – one (1) for storage; one (1) for storage and offloading. The entire assembly utilizes one (1) continuous conveyor, thereby eliminating debris spillage onto the vessel’s deck.
  • The entire operation of the TrashCat™ is accomplished by one operator in the side-mounted cab, using remote hydraulic controllers.


In addition to Hong Kong and Singapore, the UMI TrashCat™ skimmer boats can be found operating in many ports, harbors, rivers, hydroelectric and flood control dams, and similar waterways around the world, including: Port of Dubai, United Arab Emirates (4 units); Paris, France (2 units); South Korea (14 units); Rio de Janeiro; Japan; United States – New York City (9 units), Baltimore, Maryland (7 units); Washington, DC (2 units); Chicago, IL (2 units); Ft. Lauderdale, FL; Austin, TX, 5 major hydroelectric plants in the U.S.; and many others.

To quote Mr. Edwin Lau, Chairman of the Private Sector Committee on the Environment (PSCE): “To master Hong Kong’s environmental problems, it is not enough to be aware of them. There also needs to be a realistic expectation of surmounting them and a viable strategy for doing so.”(1)   Both Hong Kong and Singapore have adapted this approach with a fundamental policy of “sustainable development”..the introduction of new strategies and teamwork which will lead to a quality marine environment. The use of the TrashCat™ to clean up floating refuse is one forward step toward restoring their most valuable asset.their ports and harbors.

References: (1) ECO-Advantage Magazine, Kowloon, February 2000 Issue

For more information, contact:
E-mail:  [email protected]
Phone:  800-243-1406 US only, or 715-246-2888
Fax:      715-246-2573