Liftech Blog

Last night, Liftech received an Award of Excellence from the Structural Engineers Association of Northern California (SEAONC) in recognition of our engineering work on the 1700 t floating crane, also known as the Left Coast Lifter. 

The Left Coast Lifter is a barge-mounted crane designed to erect the major components of the San Francisco-Oakland Bay Bridge self-anchored suspension span.  The crane was delivered to the Bay Area in 2009 and was quickly put to work constructing the temporary steel falsework in preparation of the tower and deck erection.  

The Left Coast Lifter is owned by the contractors for the new bridge span, American Bridge/Fluor Daniel Joint Venture (ABF), and was fabricated by Shanghai Zhenhua Heavy Industry Co., Ltd. (ZPMC) in Shanghai, China.  The 100 ft wide x 400 ft long barge was fabricated by US Barge LLC in the United States.  Liftech provided structural engineering consulting services to ABF for the crane structure, including technical specifications, design, and fabrication review assistance.  The crane structure design was a collaborative effort by ZPMC, Liftech, and ABF, with ZPMC as the design-build contractor. 

The crane is the largest crane barge on the West Coast.  The boom, the arm of the crane that lifts the loads, is 25 stories tall and can lift 1700 metric tons, equivalent to approximately one thousand automobiles or a container crane at the Port of Oakland. 

We thank the SEAONC selection committee for selecting our project.  We are grateful for the opportunity to contribute to this exciting project and enjoyed collaborating with the team of American and Chinese engineers.  The credit goes to everyone who contributed to the success of this project. 

Project Poster

Anna Dix, a Liftech engineer, represented the company at the twelfth triennial ASCE Ports 2010 conference last week.  About 600 people in the port and harbor development industry attended the conference.  Most attendees were from North America. 

Anna had her first experience as a conference speaker, presenting two Liftech papers.  “Extreme Loading of Wharf Crane Girders” is about wharf crane girders subject to extreme loads, their expected performance, and which loads should be considered in the girder design.  “Container Crane Recycling: Upgrade and Relocation” discusses reasons for reusing cranes and considerations for upgrading and relocating existing cranes.

The two papers and presentations are now available on our website.

A damaged pier at McNear’s Beach Park in Marin, California, was repaired by replacing portions with new structure.  The new structure was designed to meet current seismic design criteria.  This required a high performance pile-to-pile cap connection.   The high performance connection was designed using a fiber reinforced bearing pad, isolating the sides of the embedded pile, and unbonding the dowels for 24 inches of length. 

The high performance pile-to-pile cap connection used for this project added little additional cost to the project and significantly improved the seismic performance of the pile connection and the entire structure.  Testing by the University of Washington has shown that these connections perform significantly better during seismic loading than a classical pile connection.  We expect little damage at the pile connection during the design earthquake load.

Read Erik Soderberg’s paper on high performance pile connections.

High Performance Pile Connection

Anna Dix will present at the PORTS 2010 Conference in Jacksonville, Florida, next week.

The presentation on “Contain Crane Recycling: Upgrades and Relocation” will be presented on April 28, 2010, from 10:30 to 12 during the Port Infrastructure: Novel Approaches session.

The presentation on “Extreme Loading of Wharf Crane Girders” will be presented on April 27, 2010, between 3:15 and 4:45 during the Port Infrastructure: Automation and New Technology session.

Pacific Steel Casting Company (Pacific Steel) graciously opened its doors yesterday for Liftech engineers to tour their Berkeley steel foundry.  The tour was guided by some highly experienced Pacific Steel employees, including the president, Joe Emmerichs, and a knowledgeable technical sales representative, Dave Standafer.

The tour began at the technology center, where we learned how computers help determine the optimum mold arrangement to reduce shrinkage voids and residual stresses for the various casting geometries.  The technology office looked like a regular engineering office with computers and ergonomically arranged work stations, but one thing was very different–every minute or so the ground shook several times as the operators at the forge next door dropped their giant hammers.

After an interesting demonstration of the software, we headed over to the hot part of the foundry, the electric arc furnace.  We were lucky enough to witness a batch being heated and then poured into a large ladle for transport to the molds.  After the appropriate quantities of materials are weighed and put into the furnace, the mix is heated by two 6 to 8-inch diameter electrodes.  The sound of the mix heating is exactly as you would expect, the sound of viscous liquid sloshing with undertones of buzzing electricity.

We also toured the area where they make the molds.  The molds are primarily made of sand and resin, and are formed from a wooden pattern.  The patterns, which are outsourced, are quite pricey at several thousand dollars per pattern.

The second half of the tour was all about finishing the castings.  We learned about form removal, cleaning, visual inspection, dye penetrant and ultrasonic testing, cutting, and welding.  We also caught a glimpse of some of the finished products ready to export to clients.  The size of castings fabricated at the Berkeley foundry range in weight from a few ounces to several thousand pounds.

You can learn more about Pacific Steel at http://www.pacificsteel.com/.

Thanks for a great experience, Pacific Steel! 

Arun Bhimani, president of Liftech, made two presentations at the Terminal Operations Conference (TOC Asia) in Shanghai, China, on March 17-18.  The conference was attended by about 200 delegates from the worldwide commercial maritime community.  Mr. Bhimani’s special presentation on Chile provided an update on the damage to the Chilean port facilities from the recent M 8.8 earthquake.  The second presentation was part of a three hour workshop on equipment safety.  Mr. Bhimani briefed the audience on numerous crane accidents and failures, probable causes, repairs and resolution, and mitigation measures to minimize accidents.  The workshop was attended by terminal operators, crane designers, maintenance personnel, and others.

Arun Bhimani’s TOC Asia presentations on the earthquake in Chile and quay crane accidents are now available on our website.

Erik Soderberg, a Liftech vice president, made a presentation at the Structural Engineering Education Reunion (STEER) conference in Austin, Texas, on March 5, 2010. His presentation discussed Liftech’s structural engineering design services for a variety of colossal cranes and included some of the basic design issues associated with these cranes. 

The conference occurs every 3-5 years and is a forum for alumni, professors, and existing students to meet and share their structural engineering experiences.  The focus of this year’s event was Dr. Karl Frank’s retirement from the university faculty.  Dr. Frank was Erik’s research professor when he attended the university. 

The event was attended by about 120 alumni, students, and professors of the University of Texas structural engineering graduate program. 

Erik Soderberg’s STEER presentation on colossal cranes is also available on our website.

Following are Feroze Vazifdar’s first hand observations of the damage to the major terminals in Chile, supported by local consultants’ preliminary reports.

San Antonio

San Antonio has seven berths with six ship-to-shore gantry cranes.  Two of these cranes were damaged due to ship collisions.  Another crane was derailed, but has no significant structural damage, and was placed back on the gantry rails within a few days.  Some cranes had minor damage to the mechanical systems, including salt water damage to motors due to the tsunami.

The pile-supported concrete wharves performed well, and did not experience damage.  Minor pavement damage occurred at the interface between the wharf and backlands due to relative wharf movement.

The retained-earth section of the yard adjacent to the container wharves experienced liquefaction, causing damage to the pavement and rails.

Valparaiso

Valparaiso has nine berths with five ship-to-shore gantry cranes.  No significant crane or wharf damage was reported at the Valparaiso port.

Other Terminals

A small terminal at Puerto Panul has two rail-mounted bulk unloaders.  One bulk unloader’s grab bucket was in the ship’s hold when the ship departed after the earthquake struck, causing the unloader’s upper structure to collapse.

San Vicente has three berths.  One of the wharves experienced significant relative movement of two adjacent segments.  Also, separation and movement of the pavement occurred.   In one location, the separation was as much as 22 cm and the cavity was 2.3 m deep.  The pile-supported wharf appears to have performed relatively well, with only limited damage.

Crane Gallery

Wharf Gallery

Three new Evergreen container cranes arrived today at the Port of Oakland!

Liftech performed a brief structural performance review of these cranes related to applicable crane seismic provisions.  We also reviewed the wharf structure for the crane loads during the transfer from the ship to the wharf.

See the article from the San Francisco Chronicle for more information and images of the cranes arriving.

The drive into San Antonio took almost two hours, with stop and go traffic over several damaged bridges.  Along the way we noticed a few damaged canopies, one major landslide, and damage to a newly built casino.     

San Antonio is a very quaint town with only a few high-rise structures.  A five-story building with a lower soft story suffered significant damage, with spalled concrete columns and severe damage to infill panels.  Other than this, damage appeared light.  The only Chinese restaurant in town suffered major damage, but luckily the owner had started building a newer more modern restaurant next to it, which survived.  Loss of life in San Antonio was less than 50 people, most dying from the Tsunami that followed the earthquake.   

I was in San Antonio for five days.  During that time, the city was subjected to at least six or seven earthquakes with a shaking intensity either equal to or greater than the 1989 Loma Prieta earthquake.  Having been through the Loma Prieta earthquake, I thought I was battle hardened.  Little did I know how wrong I was.   

I am glad to be home, but there is much more work to be done. 

Airport Chaos

High-Rise Damage

Damaged Chinese Restaurant

Look for Arun Bhimani’s newly added special presentation on the Earthquake in Chile at the TOC Asia Conference.

Make sure to check out Arun’s other presentation as well.