Editor’s Choice

OZ LIFTING EXPANDS STAINLESS STEEL RANGE

OZ Lifting Products LLC has added to its ever-growing stainless steel range with a 0.5ton capacity manual chain hoist and trolley.

The Winona, Minnesota-based manufacturer already has 1-ton and 2-ton versions of both products, in addition to beam clamps in the same capacities, all of which are made from stainless steel.

The manual hoist is the centerpiece of the stainless-steel range. Like other products in the line, the 0.5ton version is designed for lifting and pulling. The hoist is lightweight and minimal effort is required to lift loads, but it is durable enough for some of the most demanding marketplaces. The trolley, meanwhile, fits most common I-, S- and W-beams; end users have different types of beams depending on the construction requirements of the building or structure where the lifting equipment will be installed and employed.

Steve Napieralski, president at OZ Lifting, said: “We’ve had increasing demand for lower capacity products, so I’m pleased to offer 0.5-ton versions of both the manual chain hoist and trolley. As always, we will continue to listen to our dealers and end users, and I wouldn’t be surprised if 0.25-ton, 3-ton and even 5-ton versions are put to market in the future.” The 3-ton and 5-ton capacity stainless steel hoist and trolley are already available as a special order. is used in corrosive environments, including wastewater treatment plants, saltwater, or wash-down applications.

Napieralski pointed out other key features of both products. Minimum headroom for the chain hoist is 14.8 in. with a head weight of only 16 lbs., offering 1.5 lbs. per ft. of lift. Standard heights of lift are 10 ft., 15 ft., 20 ft., and 30 ft., although custom lengths are available upon request. Regardless, all products are rigged in the USA. The trolley, meanwhile, weighs 19 lbs. and fits on a 2.6 in. flange width.

The products require a similar maintenance program as their steel counterparts, Napieralski explained. He also stressed the importance of adhering to maintenance and inspection programs, especially if the equipment is being operated in a highly corrosive environment. OZ Lifting outlines these requirements in an owner’s manual, included with every shipment, along with test certification. As the documentation states, the product meets a range of standards, including the American Society of Mechanical Engineers (ASME).

Both the 0.5-ton capacity manual chain hoist and trolley are in stock and ready to ship.

For more information on OZ Lifting Products visit www.OZLiftingProducts.com

There is no specific application for this kind of manual hoist and trolley, beyond the fact that stainless steel

A revolutionary seismic isolation system—provided by Casper, Phillips & Associates Inc. (CPA)—has been installed on two quayside container cranes for the first time this year.

The crane base anti-seismic isolation system (BASIS) is built on nonlinear time history analysis (NLTHA) and can protect the crane main structure from damage even in contingency level earthquakes. BASIS has been successfully installed and commissioned on two cranes that are in a major seismic zone in Turkey. The cranes, installed at Asyaport, have a 100 ft. (30.48m) gantry span, 223 ft. (68m) outreach, 66 ft. (20m) backreach, and 152 ft. (46.3m) lifting height above the gantry rail.

CPA, which has been utilizing NLTHA for research and engineering projects since 1991, offers a wide variety of heavy-duty industrial services, including procurement, specification, design, manufacturing review, modification, and accident investigation.

BASIS is installed between the sill beam and main equalizer beam, about 13 ft. (4m) to 16 ft. (5m) from ground level depending on the crane’s size. It includes two friction damper assemblies, two energy restoring device assemblies, a guiding device, and two friction damper locking devices.

Mike Zhang, the head mechanical engineer at CPA, said: “The initial container crane isolation system that we developed included dampers in both gantry travel and trolley travel directions. [NLTHA] analysis revealed that the base shear in the gantry travel direction varied within only 5% between a crane with a seismic isolation system and a crane without it. However, in the trolley travel direction, the base shear is significantly reduced by incorporating our seismic isolation system. Therefore, to reduce costs while maintaining a high level of effectiveness, our final seismic isolation system is designed to operate only in the trolley travel direction.”

Zhang, who has co-authored a white paper on the BASIS concept with Jeffery Hubbell, the head structural engineer at CPA, explained that ports located in seismic zones and crane manufacturers are both taking note of the system. Typically, he said, the ports specify the seismic requirements, while the crane manufacturers propose the isolation system. The port then makes the final decision on the proposed purchase.

Aerospace proving ground

This type of friction damper was used extensively at the Boeing commercial airplane factory in Everett, Washington, about 20 years ago. The same type of dampers were tested on a ship-toshore (STS) crane in 2020.

STS cranes have historically been designed for 0.2 g’s static horizontal acceleration in major seismic areas. This is adequate for lighter Panamax or Post-Panamax container cranes with a gantry rail gauge less than 80 feet (24m). However, for Super PostPanamax size or larger cranes with 100 ft. (30m) or wider gantry rail gauge, the crane may be seriously damaged or even collapse in a major earthquake event. These cranes can be subjected to more than 0.6 g’s lateral acceleration in the trolley direction even during a moderate earthquake. the restoring device is based on a Conductix-Wampfler buffer, while the mounting base and system assembly are provided by the crane manufacturers. BASIS, which received a Chinese patent in 2018, can thusly be installed on new cranes or as part of a seismic upgrade of existing cranes. To verify the effectiveness of the system for different sizes of quayside cranes, CPA teamed up with Dalian Huarui Heavy Industry Group Co. Ltd. (DHHI) engineers.

Zhang added: “There are alternative crane seismic systems on the market, but BASIS outperforms them. The friction damper does not slip under normal operations, so the structure maintains the same dynamic and static stiffness as a crane without the seismic device. During a hurricane, when the tie-downs are engaged, the seismic system can be locked to prevent the dampers from slipping. We have also developed a special stowage pin assembly that can accommodate the crane movement during an earthquake, even during a microburst or storm wind when there are no tiedowns engaged. Also, the same profile damper can be set at a different sliding force to accommodate various cranes and seismic zones.”