Abs Consulting

Houston, TX, United States

Abs Consulting

Houston, TX, United States
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Wang G.,Abs Consulting | Hu K.,Jiangnan Shipyard Group Co.
PRADS 2016 - Proceedings of the 13th International Symposium on PRActical Design of Ships and Other Floating Structures | Year: 2016

Efficiency and regulatory compliance have been driving the maritime industry over the past few years. More and more people have come to realize the pressing need for evaluating performance of ship design, generating actionable insights, and ultimately, improving design and guiding future operation that are safer, greener and more efficient. The KPI-driven performance assessment scheme emerges as a viable choice for evaluating performance and providing actionable information. Having such a scheme is even more important in a world where economic uncertainty and volatility (e.g., economic growth rates, commodity prices, regulations, climate & weather pattern, etc.) are rising. This paper addresses opportunities and challenges when establishing and adopting a KPI-driven performance assessment scheme. Discussions are given to framework, main steps of establishing an assessment scheme, and some crucial aspects of data. The trendy "Big Data" offers a large body of technological solutions that can potentially improve the efficiency of the centuries-old maritime industry. This paper also intends to touch upon the feasibility of adopting Big Data solutions to assist performance assessment. Two industrial projects are used as examples to illustrate how a KPI-driven performance assessment scheme can be established, and what implications it brings to improvement of trading ship designs.

Das B.,American Bureau of Shipping | Weinberg M.,Abs Consulting
Safety Science | Year: 2012

Presence of congestion and confinement in offshore modules due to limited availability of space make Vapor Cloud Explosions (VCEs) a significant contributor to risk. There are several methods available for quantifying the blast overpressure generated over distances and time. The approaches range from one-dimensional analysis using correlation models to 3-D analysis using Computational Fluid Dynamics (CFDs). The correlation models are easy to use and well-suited for assessing a number of credible VCE scenarios. However, the overpressure results predicted by correlation models depend on a good estimate of flammable mass. This paper proposes a method to improve the estimation of flammable mass. The UKOOA Ignition model developed by the Energy Institute London is used to estimate the flammable mass; and is modified to account for the effect of mitigation measures on release rate. A directional probability for wind is also added to the model. The proposed model takes into consideration the platform geometry and offshore conditions for each scenario, release location and direction, and wind direction. An offshore production platform with three deck levels is presented as an example case. The flammable mass is also computed using CFD and the results are compared to that of the proposed and the conventional methods. The results show that the flammable masses for selected scenarios are better estimated by the proposed method, being much lower than estimated by the conventional method, though larger than the CFD results. This paper presents an interim result of a project undertaken to improve QRA studies for VCE events. © 2012 Elsevier Ltd.

Krupa P.,Abs Consulting | Myers J.,Abs Consulting
Proceedings - Annual Reliability and Maintainability Symposium | Year: 2017

Clients often associate Root Cause Analysis (RCA) with troubleshooting equipment failures. But it encompasses more than simple troubleshooting or identifying component failure causal factors. RCA investigators systematically drill deep into an organization's standards, policies and administrative controls to determine how those elements failed to prevent or eliminate causal factors associated with an incident. Accordingly, repairing these deficiencies prevents not only further occurrences of the trigger incident but any potential incident that shared the same root causes. Failing to address these so-called root causes, conversely, increases the potential that other related incidents would occur. Tracking investigation findings is crucial in assessing the value of these investments. ABS Consulting (A subsidiary of American Bureau of Shipping) utilizes root cause mapping in order to categorize investigation findings and to facilitate assessing the impact of client remedial actions. The map provides consistent naming and enumeration of root causes across different investigations. This aspect of an investigation allows ABS to evaluate the type of root causes a client experiences and to curate effective client recommendations. Over time, these records can be used to assess whether the client has addressed the root causes. Identifying and resolving major root causes as determined in RCA investigations prevents recurrence of the trigger incident as well as potential related incidents. Conversely, as demonstrated in this paper, failure to address the major root causes allows the trigger incident to recur as well as other incidents that share the same causal factors. The client failed to address identified major root causes. The records demonstrated that even though the failure modes were different, the same root causes were identified indicating that the client did not address organization standards, policies and administrative controls that would eliminate these performance gaps. This review used a table of the client's investigation findings that were comprised of approximately 70 investigations spanning eight years. To simplify this example, only a narrow segment of investigations regarding marine diesel engines were included. The failure modes for these incidents were different but the investigations revealed virtually identical root causes. The investigators uncovered numerous front line personnel performance gaps regarding operation of marine diesel engines. In all of these investigations the recommendations included reviewing training requirements, qualifications for each position and training program effectiveness. The review determined that the client had failed to address the root causes identified in each of the investigations. The finding that personnel continued to make operational errors over the span of several years indicated that the client had failed to address the major root causes. © 2017 IEEE.

Chen N.-Z.,Abs Consulting | Wang G.,ABS | Guedes Soares C.,University of Lisbon
Engineering Fracture Mechanics | Year: 2011

A Palmgren-Miner's rule and fracture mechanics (FM) based approach coupled with Bayesian updating in order to establish inspection plans for marine structures is proposed. A FM formulation based upon the British Standard (BS) 7910 is calibrated by S-N curves and Palmgren-Miner's rule. A model is developed taking account of the uncertainties associated with S-N curves and Palmgren-Miner's rule to quantify the random growth of a flaw predicted by the calibrated FM formulation. The long-term stress range acting on a structural component is fitted to a two-parameter Weibull distribution, according to the rules of the American Bureau of Shipping (ABS). The reliability after inspection is updated by the Bayesian approach accounting for the probability of detection (POD) and inspection results. An inspection plan is then set up on the basis of the comparison between the updated reliability and a target reliability index. Typical fatigue-prone structural details from a tanker are utilized for demonstration of the capabilities of the approach proposed. © 2011 Elsevier Ltd.

Goodno B.J.,Georgia Institute of Technology | Gould N.C.,Abs Consulting | Caldwell P.,Schneider Electric | Gould P.L.,Washington University in St. Louis
Earthquake Spectra | Year: 2011

The focus of this survey was to collect data on the performance of mechanical and electrical systems at selected critical facilities in Haiti. First-hand observations confirmed that nonstructural elements that are well anchored and=or laterally restrained will perform well during a moderate seismic event. However, the investigation also revealed that many critical institutions in Haiti did not utilize state-of-the-art engineering design or construction practices when installing nonstructural equipment that turned out to be crucial to their post-earthquake operations. The survey team believes that absent or poorly implemented seismic anchorage of nonstructural elements hampered the ability to restore essential systems to operation after the event. © 2011, Earthquake Engineering Research Institute.

Fitzgerald G.A.,Abs Consulting
49th Annual Loss Prevention Symposium 2015, LPS 2015 - Topical Conference at the 2015 AIChE Spring Meeting and 11th Global Congress on Process Safety | Year: 2015

Consequence-based Facility Siting Studies (FSSs) typically requires the user assume a credible leak size to use in the evaluation of potential releases, which is often up to a 2" diameter leak. Many facilities tend to be less complex in comparison to large refineries or petrochemical plants, leading operators at the less complex facilities to ask why they should assume the same leak sizes as more complex facilities. Other facilities have unique processes with safety systems and factors they would like to quantify in a FSS. One solution would be to perform a Quantitative Risk Assessment (QRA) to capture the risks from all potential release locations and release sizes. However, many companies have not defined risk tolerance criteria and are resistant to do so for various reasons or do not want to invest in a QRA, which are more costly than a consequence-based study. A unique approach developed by ABS Consulting and first presented in 2011 is called the Maximum Design Leak (MDL) approach [1]. This approach calculates frequency-based leak sizes and then applies the leak size that exceeds a frequency criterion (events/year) in a consequence-based FSS instead of assuming a given leak size as credible. This avoids having to establish risk criteria in terms of fatalities/year and having to model a large number of scenarios yet takes advantage of many features in a QRA. This paper presents three case studies as examples of how the MDL has been applied and illustrates the advantages of calculating leak sizes specific to scenarios being evaluated for low complexity and low risk facilities.

Barrett A.M.,Abs Consulting | Adams P.J.,Carnegie Mellon University
Risk Analysis | Year: 2011

We develop and apply an integrated modeling system to estimate fatalities from intentional release of 17 tons of chlorine from a tank truck in a generic urban area. A public response model specifies locations and actions of the populace. A chemical source term model predicts initial characteristics of the chlorine vapor and aerosol cloud. An atmospheric dispersion model predicts cloud spreading and movement. A building air exchange model simulates movement of chlorine from outdoors into buildings at each location. A dose-response model translates chlorine exposures into predicted fatalities. Important parameters outside defender control include wind speed, atmospheric stability class, amount of chlorine released, and dose-response model parameters. Without fast and effective defense response, with 2.5 m/sec wind and stability class F, we estimate approximately 4,000 (half within ~10 minutes) to 30,000 fatalities (half within ~20 minutes), depending on dose-response model. Although we assume 7% of the population was outdoors, they represent 60-90% of fatalities. Changing weather conditions result in approximately 50-90% lower total fatalities. Measures such as sheltering in place, evacuation, and use of security barriers and cryogenic storage can reduce fatalities, sometimes by 50% or more, depending on response speed and other factors. © 2011 Society for Risk Analysis.

Bardetsky A.,Abs Consulting
Collision and Grounding of Ships and Offshore Structures - Proceedings of the 6th International Conference on Collision and Grounding of Ships and Offshore Structures, ICCGS 2013 | Year: 2013

It is of primary importance in the aftermath of an accident to be able to assess the possibility of progressive structural failure of the damaged ship. The progressive structural failure caused by cracks emanating from the damaged area leads to a gradual reduction of the ship's residual strength, eventually leading up to the point of total hull girder collapse. This paper presents a procedure for predicting the crack propagation under sea wave loading using the fracture mechanics approach, the spectral fatigue approach and an equivalent stress intensity factor (SIF) range concept. The SIF is obtained from the finite element model of a damaged ship subjected to sea wave dynamic loading. The validity of the SIF obtained from the finite element modeling is confirmed by the independent weight function method widely used in fracture mechanics. The procedure for estimation of the crack propagation is proposed and implemented for a typical modern 170,000DWT bulk carrier in full load condition. The results of this research work can be used to support informed decision-making on the transit voyage from the accident location to the repair facility. © 2013 Taylor & Francis Group.

Kim S.,Abs Consulting
International Journal of Naval Architecture and Ocean Engineering | Year: 2011

Seakeeping analysis has progressed from the linear frequency-domain 2D strip method to the nonlinear time-domain 3D panel method. Nevertheless, the violent free surface flows such as slamming and green water on deck are beyond the scope of traditional panel methods based on potential theory. Recently, Computational Fluid Dynamics (CFD) has become an attractive numerical tool that can effectively deal with the violent free surface flows. ABS, as a classification society, is putting forth a significant amount of effort to implement the CFD technology to the advanced strength assessment of modern commercial ships and high-speed naval craft. The main objective of this study is to validate the CFD technology as a seakeeping tool for ship design considering fully nonlinear three-dimensional slamming and green water on deck. The structural loads on a large container carrier were successfully calculated from the CFD analysis and validated with segmented model test measurements. © SNAK, 2011.

Chavez J.W.,Abs Consulting
Bulletin of the International Institute of Seismology and Earthquake Engineering | Year: 2012

This paper presents an overview of the current (2011) seismic codes in Central and South America. The main aspects of the various seismic provisions of the local model building codes used in the region are presented, and briefly discussed. The issues presented include code development, site characterization, building classification, design response spectra, seismic forces and reduction factor, design considerations, construction practice and code enforcement.

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