The major ports across the United States and in other parts of the world have seen their throughput drop thirty to forty percent or more. The financial woes of the shipping industry have continued over several months with a series of warnings about the extent of the downturn and how long it will last. The economic conditions are not expected to improve significantly until after 2010. Port authorities and terminal operators across the globe have substantially curtailed their capital expenditure and, in some cases, frozen it outright. However, some operators are faced with having to invest in equipment to improve terminal productivity, promote new business, or replace obsolete equipment. The price of new ship-to-shore cranes has increased significantly over the last five years due to the increase in fuel and energy prices and changing market conditions. The financial crisis has not significantly reduced the price of new cranes. Terminal operators are taking a serious look at recycling existing cranes or investing in used equipment. Upgrading and recycling existing cranes may be worth consideration financially, with the added benefit of conserving precious resources. Money for recycling cranes is also primarily spent locally thus helping the local economy, whereas new cranes are purchased from foreign suppliers.
Recycling
Recycling cranes includes refurbishing, modification, modernisation, and relocation. Refurbishment could include catching up on deferred maintenance and correcting any existing problems with the crane’s physical condition. The modifications generally involve geometry changes, which are primarily driven by the deployment of larger vessels or the requirements of a new terminal if the crane has been relocated. Modernisation generally involves capacity and speed increases, which are driven by productivity and obsolescence. Relocation could be local, where the cranes are moved between berths or terminals, or across oceans. Relocating cranes frequently involves geometrical changes to adjust to the new terminal such as changing the crane’s rail gauge, adding and relocating stowage pins and tie-downs, or both. Recycling costs vary a great deal depending upon the type of work and the new location of the equipment. The cost of moving cranes large distances is often a deterrent to crane recycling. The best way to demonstrate recycling cranes is to review what has already been done. The following examples are taken from Liftech’s crane modification projects that are either recently completed or are underway.
Three Hitachi Cranes
Matson Navigation and Horizon Lines vessels call at a terminal in Guam. The existing container cranes were too small and too slow to service the newer vessels and impractical to modernise. The Port Authority of Guam considered purchasing one or two new cranes at USD10 million each. Matson and Horizon located three retired cranes at the Port of Los Angeles, modified them for operations at Guam, and transported them to Guam. The Hitachi cranes were built in the mid-1980s and provided satisfactory service for the Port of Los Angeles until they were recently replaced by new cranes able to serve the larger container vessels. The total cost of USD18 million to purchase and modify the three Hitachi cranes and wharf at Guam was less than the cost to purchase two new cranes for USD20 million, plus the cost of modifying the wharf at the stowage areas. Although the new cranes would have larger outreach, lift height, and capacity, the modified Hitachi cranes met the users’ needs for the next 10 years. The extra crane will allow faster ship turnaround and provides redundancy. Matson and Horizon also installed new tie-down and stowage sockets for the cranes, and modified the crane rail girders in the stowage areas. The three Hitachi cranes are sister cranes to an existing crane at the same terminal and thus provide the benefit of having common parts, maintenance, training, and operations features. A significant benefit was the faster delivery of the three Hitachi cranes than the new cranes. The three cranes were transported on one barge. Significant voyage bracing was required because of the long voyage across the open ocean. Ship transport was not an option since there were no US ships available that are capable of transporting the cranes.
Drive upgrade
A terminal operator operates four dockside container cranes: two built in 1980 and two built in 1994. The operator is experiencing difficulty obtaining mechanical and electrical parts, leading to high maintenance costs and unacceptable crane downtime. Replacing the cranes with new cranes was an expensive proposition as new cranes could cost USD10 to 14 million each. The terminal operator opted to modernise the drives and controls of the existing cranes. At the time of writing this paper, bids have been issued to modernise four cranes with state-of-the-art drives, controls, and communication systems. The decision on how many cranes to upgrade will be made based on the bid price for the work. The average cost to upgrade one crane is estimated at USD1 million and the work is expected to be completed in early 2010. The two 1994 vintage cranes would be modernised at a fraction of the cost to purchase new cranes. The modernised 1980 vintage cranes would provide reliable supplements until the operator is able to replace them.
Two A-frame cranes
SSA Marine operates container terminals in many parts of the world including Panama and Mexico. Their terminal in Manzanillo, on the west coast of Mexico, needed two dockside container cranes in a few months. Their terminal in Colon, on the Atlantic side of Panama, could spare two cranes. The two cranes, supplied by Hyundai Heavy Industries in 2000, were in good operating condition and met the operating demands at Manzanillo. Liftech reviewed the structural design of the original cranes for Panama. The rail gauge at the Mexico terminal is 55 feet versus 75.8 feet at the Panama terminal. The Mexico terminal is also located in an active seismic area. The following modifications were made to operate at the Mexico terminal. Reduce the rail gauge of the two cranes. The portal beam was deepened and the landside legs were shortened and relocated from the 75.8 feet position to the 55 feet position. Since the rail gauge was reduced, the cranes needed approximately 75 tonnes of ballast at the landside for operating stability. Storm tie-downs on the cranes were added. As the legs were relocated, the elevator needed to be relocated also. The existing landside leg was used to support the elevator tracks up to the portal beam. A new column was added above the portal beam to support the elevator track. The two cranes were moved on a barge from Colon, Panama, to Manzanillo, Mexico. The barge transited through the Panama Canal. In order to clear the Americas Bridge at the Pacific side of the canal, the crane legs below the portal beams were cut off and the crane lowered to the deck. The cranes were raised upon arrival at Manzanillo, Mexico.
Too old to recycle?
At some point, recycling a crane is no longer economically practical. The owner must consider all the costs of the recycling project including the desired life of the crane. Often the question is asked: but what about the structural life of the crane? Structural failures, other than accidents, can be sorted into two groups: infant failures and aging failures. Infant failures occur during the initial operation of the crane and are due to faulty design, workmanship, or a combination of both. Infant failures are not of concern for cranes that have been operating for a few years. Aging failures occur over time and are due to slow crack growth. The application of fluctuating stresses causes small undetectable cracks to grow. If uncontrolled, these cracks grow until fatigue failure occurs. Although the phenomenon is called “fatigue,” it is only crack growth due to fluctuating stress. The steel does not get tired. The material beyond a crack is like new and is not affected by a nearby crack. If the crack and the s
mall yield region in front of the crack are removed and the weld is repaired, the life of the structure starts over. When considering recycling a crane, maintenance and reliability need to be considered. How reliable are the existing details? How often have cracks been found and repaired?
Costs
The cost of crane modernisation and relocation depends a great deal on the extent of modifications and differences in the site-specific conditions. For example to increase lift height by 20 feet costs an estimated USD900,000, to increase outreach 20 feet an additional USD 1 million and upgrade drives and controls a total of USD 1 million. The cost to dispose of a dockside crane depends on the type of crane and the price of scrap metal. In 2009, the cost of dismantling and disposing of a typical A-frame crane was about USD150,000.
Conclusion
Recycling existing cranes may be the most economical and expedient option for some terminal operators if they need larger, faster, or more modern cranes. The size and performance of existing cranes can be increased often for a fraction of the cost of new cranes, but not always. The economics and practicality of modernising the cranes depend on many factors. Each case should be looked at carefully. Recycling cranes may have the advantage of helping the local economy as much of the work is performed locally.