Computer Aided Design Of Shipping Saddle

Abstract

The pressure vessels are transported in two successive modes; from the shop floor to the harbor/jetty by road transportation and from jetty to the sea port by river or sea transportation. While transportation, the vessels are supported on vertical cradles, known as Shipping Saddles. The number of saddles required for particular vessel transportation depends upon the static/dynamic load and the load carrying capacity of the axle/barge. The size of the shipping saddle depends on the specification of the vessel to be transported and hence, so far, it is designed for every individual case. As any of the pressure vessel design standards does not provide the specific methodology to design the shipping saddle, there are certain problems and drawbacks faced by the designers which had motivated us to setup the methodology to design the shipping saddle. Hence, an attempt is made to arrive at the generalized methodology for the shipping saddle design. To validate the methodology, the shipping saddles for a particular case of vessel transportation has been designed and validated through FEM. Furthermore, the topological optimization has been performed to find the best use of material. The saddle parameters for different combinations of the design factors have been determined by using this methodology and tabulated. The main advantage of this standardized design is that the designer can directly pick the saddle parameters from the table as per the requirement. However, the designer can use the method which has been developed for the shipping saddle design. The design of shipping saddles for every individual case consumes so much time and hence uneconomical. For this purpose, the design software is developed using the Visual Basic as a programming tool. Further more, to achieve the manufacturing drawing automation of the shipping saddle, the software is linked to the Solid Edge which is used as the drafting tool for the manufacturing drawing of saddle. The software also provides complete design of the saddles with respect to the vessel specification provided by the user. The linking of the design software with the Solid Edge modifies the template manufacturing drawing of the shipping saddle prepared in Solid Edge.