ExpressMarine3D to ShipConstructor

Shipyards and Design Agents that employee both Naval Architects and Marine Engineers have always used some rapid modeling naval architect software in effort to get a quick 3D model of a ship hull structure as an initial design. However, typically these early-stage 3D design models are not easily transferable into a detailed 3D production model that can be utilized to manufacture detailed structural components of a ship.

This project found a way to pass a rich early phase structure-model to a detail-engineering production tool without losing properties and metadata from an early-stage design tool (ExpressMarine3D) into a detail production design models tool (ShipConstructor and its Marine Information Model - MIM, which is built on top of AutoCAD, and also utilizes Navisworks).

In a shipbuilding detail design environment, dedicated tools focus on handling the level of accuracy, versatility and model completeness necessary to produce high quality production support information.   Prior to the shipbuilding detailed engineering, tools for early and basic design must be adapted to handle the rapid changes that are characteristic of the early design phase.  

The goal, through calculation of parameters critical to the design, is to ensure that the ship's hull design is feasible.  Flexibility and modelling speed are the dominant requirements as the ship design progresses through iterations.  In early structural models for weight and center of gravity calculations, you may find as much as 90% of the main structural components defined.  This early-stage design model fulfills the requirements of investigation and rapid analysis but the transition to detailed production design models doesn’t carry over the same data without manual intervention.

The objective was to avoid redoing work in the ship's detail design phase that had been carried out already in the early design phase.   Further, the objective was to get a “kick-start” of the detailed 3D ship structural model by utilizing a modelling tool designed for quick creation of the main object as a starting point for the detailed model.   Time and money are saved on completing the detailed 3D ship structural model and thus allowing the production to start earlier.

In summary, the objective was twofold: avoid re-work during the detail design phase based on information from the early design phase models and accelerate detail production design model creation.

The ExpressMarine Integration project focused on integrating early-phase structural models, with their associated metadata and information, to a detail-engineering production model without losing the properties or metadata.

Early-stage design is often rapid and conceptual in nature while architects and designers consider general ship design principles.  In some cases, a preferred approach is to allow free-form modeling and “what-if” scenarios as conditions are rapidly changed.  There is often a desire to utilize parametric modeling techniques (parameters of parts of a design are dependent on the conditions from other areas, e.g.: stiffener spacing is a function of overall beam of a deck or stiffener size/type is dependent on the thickness of the deck being attached to).

The benefit of early-stage design tools is the ability to quickly and easily manipulate the model to support the design spiral and alternate options. Once the early-stage design has matured to a certain point the work then needs to transition to a detailed production-design tool.  Prior to this project the state-of-the-art was to then re-create all of the work from the early-stage design in the detail design software manually.  There was not an easy means of translating data from an early-stage design system to a detail design tool until now.

This was accomplished by considering the early design software ExpressMarine3D (running on Rhinoceros 3D) and the detailed production design software ShipConstructor (running on AutoCAD, also utilizing Navisworks and Inventor).  Through integration work and under guidance from industry partners, the project team was able to successfully export/import early-phase design structural components from ExpressMarine3D to ShipConstructor.

Given a large-scale chemical tanker design example, early phase rapid modeling and export compared to scratch-built detailed design models could realize a significant cost savings ratio.  For the example scenario, the following time estimates were derived:

• ShipConstructor / AutoCAD 3D Modeling Times (Detailed Design): 250 man hours
• Planar group & Unit creation: 25 man hours
• Hull module Work: 50 man hours
• Structural Modeling: 175 man hours

Verses

• ExpressMarine3D: ~10 man hours

The project team tracked these metrics through collaboration with National Shipbuilding Research Program project team member shipyards to quantify the savings possible through a full implementation of the project results.

Prior to this integration development, the means for transferring this early-stage design data was an entirely manual process of re-creation of parts in ShipConstructor / AutoCAD based on the Rhino/ExpressMarine3D model. There were no real “shortcuts” to the required work in order to arrive at a detailed production model.  

The results of the integration efforts yielded a savings of 25:1 in migrating an early-stage conceptual design model into a ShipConstructor/AutoCAD production detail model and represents a substantial cost saving for this crucial design process. The results of this project are immediately available to be leveraged by any shipyard or design agent seeking substantial time savings moving conceptual, early-stage designs (ExpressMarine3D into a production design environment (ShipConstructor / AutoCAD).