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Tailor-made machinery aims to provide precise control and trouble-free operation

July 26, 2017

Location: Staten Island, New York

Challenge: How to manage barge tilting and optimize duty cycles during loading and unloading operations at a busy container handling facility  

Solution: Specialist machines with trim, list and skew control, and custom-built cranes that can handle heavier loads

Located on Staten Island near the Goethals Bridge, one of three that link New York and New Jersey, GCT New York is a full-service container and cargo handling facility. The terminal – formerly known as New York Container Terminal or NYCT – is fitted with on-dock rail service and has one of the highest volume cargo capacities in the New York Harbor.

In 2015, GCT New York began handling containerized waste for the state of New York. After containers from the New York City Department of Sanitation arrive at the dock on barges, cranes discharge the loaded waste containers from the vessel onto bomb carts for transport to GCT New York’s railyard. In the railyard, cranes twin pick the loaded containers – or, in other words, lift them two at a time – from these specialized shuttles and place them onto railcars. These full containers are then sent via train to a facility to be converted to energy.

A dual challenge

The excessive tilting of barges during loading and unloading operations was a concern at GCT New York. This happens because the center of gravity shifts when waste containers – whether full or empty – are loaded or offloaded, affecting the stability of the vessel. These barges are specially built to handle 48 20-foot containers; each barge utilizes cell guides for two-high stacking of a maximum of 48 containers. These containers, in turn, differ from normal containers in that the doors are at the top, and they are 12 feet in height with a width of 8 feet and 6 inches.

A second challenge had to with duty cycles. Every other lift was empty, raising the issue of efficiency. Since each container is loaded to a weight of 24 LT – one LT (long ton) is 1,016 kg – the combined continuous duty cycle load would be 48 LT when discharging the barge. This load cycle is much higher than a standard container crane operation.

Customized machines to the rescue

Two Konecranes Rail Mounted Gantry (RMG) cranes and two Rubber Tired Gantry (RTG) cranes addressed these matters. “These cranes were designed to handle 60 LT loads. Normally these types of cranes handle 40 LT loads,” says Mikko Mäkitalo, Project Manager, Port Cranes, Konecranes.

The company also assembled specialist machinery to enable RMG cranes to compensate for barge tilting. Mäkitalo adds that it was the first time that Konecranes used STS spreaders in RMG and RTG cranes, specified with a 50 LT capacity with the highest classifications.

“Since the barge is only 130 feet long and 40 feet wide, we were very concerned with the trimming and listing of the vessel during loading and unloading operations. Our specification, therefore, required precise control of the trim and list of the spreader bar,” explains Douglas Jimenez, Director Cranes, GCT New York. He adds that because the barge was moored to the wharf without the use of constant tension winches, skew control of the spreader bar was also necessary.

Since the barge is only 130 feet long and 40 feet wide, we were very concerned with the trimming and listing of the vessel during loading and unloading operations. Our specification, therefore, required precise control of the trim and list of the spreader bar.

Trim, list and skew control

The operational plan for these cranes required that GCT New York would be able to twin lift the containers. “Our specification called for trim, list and skew control for the barge RMG. This was due to the size of the barge. Each container could weigh as much as 24 LT; therefore, each lift could be as much as 48 LT when discharging the barge, which would affect the trim and list of the vessel,” continues Jimenez.

GCT New York’s engineering team wanted to see to it that all machines were capable of operating trouble-free given these rigorous demands. “When we went out for pricing, we gave preference to vendors that could single source both barge RMGs and RTGs. We did this to get as much continuity with system design, control and utilization of spares as possible. Konecranes closely met our specifications while also providing the best pricing,” concludes Jimenez.