BEST practice for the inspection and maintenance of marine terminals is driven by external and internal requirements, including federal and state regulatory requirements, customer requirements, and corporate standards.
In the wake of the disaster last year at the BP offshore drilling platform in the Gulf of Mexico, storage terminal marine facilities are certain to face even more government scrutiny, according to John Chapman, vice-president and project director of Ocean and Coastal Consultants (OCC) Inc.
“What has happened in the Gulf is probably going to result in knee-jerk reactions, including possibly some tightening of existing regulations,” he said. “It's clear that the MOTEMS (Marine Oil Terminal Engineering and Maintenance Standards) in California are going to make their way to other states. There are several other states that have strict requirements. The bottom line is, it's still the operators who are dedicated to asset management who will be most effective at reducing risk and controlling unforeseen costs.”
Along with Stephen Famularo, OCC's chief project manager, Chapman presented “Marine Terminal Inspection and Maintenance Best Practices” at ILTA's 20th annual International Operating Conference that took place in Houston, Texas in 2010.
Chapman said that a marine terminal is a facility that can be mobile or fixed, and is located inshore of the three-mile limit, not including LNG or offshore platforms.
External drivers for owners and operators to adopt a best practice can include federal and state regulatory compliance, customer-contract conditions, site-specific conditions, and consultant advice. Internal drivers primarily are limited to company-established risk management and tolerance policies.
He said the primary federal statutes are 33 CFR 154.310, a US Coast Guard operations manual required by the facility operator; and the Occupational Safety and Health Administration (OSHA), which is primarily focused on personal safety issues, with some requirements for lifting equipment certification.
“Neither addresses structural integrity nor gets into the detail we feel is necessary,” Chapman said.
He said regulatory compliance can vary from state to state, especially the differing regulations for booming vessels in New York and New Jersey. State regulatory compliance rarely focuses on marine structures evaluation, with the exception of MOTEMs.
MOTEMs were established by the California State Lands Commission in 2004 and are explicitly tailored to waterfront structures, with a focus on marine oil terminals. The requirements address environmental risks posed by heavy loading (vessel impacts) or seismic conditions. They're being considered for adoption by other regions.
“It's safe to say that, as California goes, the rest of the country will follow,” he said.
In terms of internal drivers, there are a number of company culture questions:
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What is the value placed on maintenance and inspection of marine structures?
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What level of risk reduction is necessary beyond what is required by federal and state regulations?
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What is the cost/benefit of delaying inspection and rehabilitation when considering and prioritizing risk?
“The ultimate goal of most responsible terminal operators is to prevent catastrophic failure, for reasons of human safety, the environment, and business impacts,” he said.
Berthing arrangements
He said the typical berthing arrangement is to have a main-access pier and piping to the ship manifold; bow and stern mooring anchor points; and breasting and spring line anchor points.
Mooring dolphin structures (monopole, onshore, piles and concrete cap) are the primary means of securing a vessel after berthing.
“A significant load capacity is based on vessel displacement and environmental conditions — wind, current, and wave,” he said. “The failure of a single mooring point can lead to significant operational constraints, such as the use of standby tugs.”
Breasting dolphin structures are the primary point of impact for vessels.
“The design is driven by vessel displacement, approach velocity and angle, and the arrangement relative to the vessel,” he said. “Mooring structures often carry spring line loads and are important for vessel-moored force distribution.”
He said hose towers are more commonly used and supported by gravity- or pile-supported foundations. The hose tower design provides flexibility of product types and vessel sizes, compared to loading arms, which typically are found in higher throughput terminals.
Approach piers may carry vehicular loads in addition to supporting product lines and utilities to the head of the pier. He said the loading system used will influence approach-pier requirements.
Famularo said structures in the marine environment are subject to conditions and situations not encountered upland.
“All parts of the structure are outdoors and subject to the environment — oxygen and moisture,” he said. “Marine structures interact with large and moving objects on a regular basis — barges, tugs, vessels. Along the coast, seawater has a dramatic effect on the service life of marine structure materials. Deterioration is often hidden from view.”
Because of both rapid and hidden deterioration, marine structures are inspected regularly, he said. The Navy and Coast Guard inspect all of their facilities on a three- to five-year cycle, performing maintenance repairs as needed.
Various city, state, and federal organizations may have their own guidelines. The general standard of practice is documented in the American Society of Civil Engineers (ASCE) Standard Practices Manual, which defines inspection types and frequency and guidelines for selection, standardizes terms for condition ratings, documentation, and reporting, and establishes inspector qualifications.
The different inspection types and their purposes:
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New construction: Quality assurance during construction.
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Baseline: Verify dimensions and configuration details.
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Routine: Assess general overall conditions, assign ratings, and recommend actions.
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Repair design: Document relevant attributes for repair and generate bid documents.
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Special investigation: Detailed testing or investigation to determine need for repairs.
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Repair construction: Quality assurance, troubleshooting problems, and documentation of payment quantities.
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Post-event: Rapid evaluation to determine need for further assessment or attention.
He said routine inspections should be done in intervals of six months to six years, depending on the structure. Structural concerns should be directed toward crushing of timber, local buckling of steel, and failed connections (ie, batter piles providing lateral stability).
“Assess the cause of deterioration: Are concrete cracks due to corrosion or a chemical breakdown of the concrete matrix?” Famularo said. “Measurements should be taken of existing conditions: pile diameter and steel thickness, and exposed pile length. The quantity of measurements must be statistically significant. Measurements are typically used to calculate existing capacity versus as-built.”
Report data
Famularo added that upon completion of any investigation, documentation of the findings and significance is necessary. Reports containing data only — such as steel thickness ratings — are useless without interpretation.
A typical report's contents:
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Description of structure.
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Observed conditions: element rating summaries; data statistics; overall condition ratings; and safety issues.
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Structural assessment: This is an interpretation of observed conditions in comparison to structure/facility load requirements. “While some assessments can be made using professional judgment, load capacity calculations are often a necessity,” Famularo said. “Calculations can assess the reduced capacity of elements, such as pile capacity, and operational restrictions necessary. Typical calculations should include pile capacity due to reduced section; allowable live loading for topside access; and maximum vessel line loads. Without existing design criteria for a terminal, berthing/mooring analyses should be used to evaluate safe vessel sizes and operating environmental windows.”
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Recommendations for further action: Results of the structural assessment should be used to provide recommendations.
“When do I have to do my repairs and what do I have to repair?” he said. “And the key thing is, how much? What do I have to spend now, in five years, in 10 years? Every routine inspection helps you to have a long-term plan. A lot of times, we'll find that a cost-benefit analysis — even a simple one — can reveal a lot about what the best actions are to take. We'll come across repairs that have been done, and it might be that replacement, though it might cost 25% to 50% more, is going to provide a quick return on investment in five to 10 years.”
Chapman said the hard part comes when recommendations have to be given on general maintenance items (safety painting, handrail repair, or anode replacement, for example); when and how much to repair; the opinion of probable cost for current needs and in the future; and a repair-versus-replacement evaluation.
“We have a great inspection report, and we lay it on the owner's lap, and there's usually a big thud,” he said. “It's difficult to bring news like that to the owner — that he needs to spend a significant amount of money to bring the facility up to speed. This is where the rubber meets the road and decisions are made.”
Maintenance planning includes asset management, which is the whole-life optimal management of the physical assets of an organization to maximize value.
“By managing assets, organizations can maintain safety and minimize risk, maximize operational efficiency, reduce capital and operating expenses, and extend service life.”
Life cycle asset management is a continual process of extracting maximum productivity from the asset. He said it optimizes capital and expense budgeting annually to maximize the time value of money and provides guidance regarding the cost effectiveness of alternative recommendations from the inspection program.
There are two types:
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Reactive: Fix or repair when broken or when there's imminent safety or operational risk. It features short-term planning.
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Proactive: Inspect regularly and repair or improve at the optimal time. It's part of long-term asset planning, with lead time to plan interruptions to operations.
Asset management approaches include a flat file (tabulation of assets, conditions, permit status, recommendations, cost, etc), a spreadsheet (electronic flat file), and Database Management System (DBMS).
The DBMS has data tracked in custom software — inspection reports, as-built drawings, permits, and current berth capacity — that is readily accessible by others across the organization.
“These systems are very robust,” he said. “They can be developed to be very complex or simple.”