Progressive collapse analysis of inland waterway cargo vessel

Abstract

Global structural response of ship hulls is generally assessed using elastic limit criterion defined by technical standards. However, scenarios in which the ship is experiencing extreme and once in lifetime loads are investigated in recent years. Such studies analyse events with potentially catastrophic outcomes, i.e., loss of the complete ship and environmental disaster. Excessive bending moments can be experienced by the hull girder due to ship's failed escape from dangerous storms, grounding, collisions, allisions, unpredicted loads, etc. Therefore, ultimate strength or hull capacity to withstand extreme loadings is emerging as one of the most significant requirements for ship hull girder strength evaluation. Technical standards for large sea-going bulk carriers and oil tankers already have ultimate strength assessment incorporated within their regulations. Ultimate strength of other cargo ships is also addressed in the rules of the classification societies. However, there are no corresponding legislative procedures for inland waterway vessels (IWV) at all. Moreover, according to authors’ knowledge, no complete studies on ultimate strength of IWV are presented in the literature so far. Therefore, the aim of this paper is to transfer the practice of ultimate strength calculations from sea-going ships to IWV and to provide the benchmark calculation. Ultimate strength is calculated here using progressive collapse analysis (PCA) on a case study of typical inland waterway self-propelled tanker vessel operating on one of the most important waterway transport corridors in the EU (Danube and Rhine). Results showed that assessment procedure used in maritime practice can be applicable to IWV. PCA method displayed the collapse sequences of the cross section, mostly governed by the buckling of segments along the vertical axis. Results based on examined vessel showed that such ultimate bending moment differs 3-20% to one calculated according to the more traditional Paik – Mansour method.