Fatigue cracks were found in the portal beams of Noell cranes at Pier 400, Los Angeles. Cracking had occurred most frequently at the end of an internal stiffener where the portal beam tapered, and at seafastening lugs that remain on the cranes at the portal-to-leg connections. Other cracking had occurred in the main equalizer brackets.
APMT operates ten Noell machinery-on-trolley cranes at their Pier 400 terminal in Los Angeles. The original trolley structure was torsionally rigid. Some of the diagonal members cracked due to warping caused when one wheel is out-of-plane to the other three. Liftech provided design modifications to reduce the stresses in the members due to warping.
Two Paceco cranes operated by San Antonio Terminal Internacional at their San Antonio Terminal in Chile suffered damage when the cranes were struck by departing ships in the aftermath of the February 2010 magnitude 8.8 earthquake. One crane suffered significant damage to the boom and the portal frame. The other crane suffered significant damage to the boom and the trolley.
Felixstowe Dock and Railway Company purchased one rail mounted gantry (RMG) crane from ZPMC. Liftech reviewed the structural design, structural fabrication, and seafastening design and installation.
A tornado damaged six Hyundai monogirder cranes and toppled another. Liftech assessed the damage to the untoppled cranes and assisted with engineering for the repairs. Hyundai Crane 9 suffered severe damage when it collided with Crane 10. The boom detached from the right lower hinge pin, the upper hinge broke off, the forestay apex connection plate bent, and the boom rotated more than 45 degrees.
Equalizer beam fatigue cracking has occurred in many rubber tire gantry cranes at various locations. The fatigue cracking is caused by a combination of factors including high fatigue stresses, undersirable design details, and poor workmanship. Liftech has been involved in several RTG equalizer beam repairs.
As container cranes become bigger and faster, new types of fatigue problems emerge. Fatigue cracking of pin plates in equalizer beams has occurred in many cranes, made by different manufacturers, at various locations. Liftech has been involved in numerous equalizer beam repairs. We have investigated the cause of the fatigue cracking, performed structural analyses, provided modification concepts, assessed the effectiveness of the modifications, and helped develop new equalizer beam designs.
APL Limited purchased 12 Noell machinery-on-trolley cranes in the mid-1990s for their Port of Los Angeles Pier 300 terminal. The cranes were rated for 50 LT and have a 50’ backreach. The backreach for all cranes was extended 28’ for storing hatch covers. The original girder was sufficiently long to accommodate the additional 28’ backreach.
Massachusetts Port Authority (Massport) purchased two Kocks low profile cranes from the Port of Oakland for capacity expansion of their Conley Terminal. The Oakland post-Panamax Kocks cranes were a near-perfect match for the Conley Terminal. Low profile cranes, also known as shuttle boom cranes, are used where overall height is restricted because of aircraft clearance requirements.
Port of Houston purchased three dockside container cranes from ZPMC for Bayport Terminal. Liftech provided the technical specifications, reviewed the structural and mechanical designs, and provided fabrication support for the new cranes. We also reviewed the manufacturer’s structural maintenance program. Prior to the purchase of the cranes, Liftech provided a study to estimate the crane wheel load and tie-down forces.