Sydney, Australia--One of the most grueling races in the 2000 Olympic Games in Sydney is already underway. It's the race to develop an electric transit system to ferry athletes and spectators the nearly 30 km from the Olympic Village to the competition sites.

Though the Games themselves won't start until September 15, 2000, this particular race could be a squeaker. Clyde Engineering, reportedly Australia's largest supplier of locomotives, began design work on the so-called 4GT (Fourth-Generation Train) in October 1998. That start date, which had been delayed by the public bidding process, leaves little room for error if the trains are to run on time, Clyde engineers say. But, run on time they must: The Olympic Committee has declared that the 2000 Games be green. No cars allowed. Clyde officials are hoping that 3D solid modeling software will help them get the project on track. Engineers are using the Helix 98 solid modeling system from CSC/MICROCADAM Inc. (Los Angeles).

Initial plans call for Clyde to design and build about 20 double-decker trains, though that number could increase to 30 later. One-hundred percent electric, "the trains will consist of sets of four-coupled vehicles," says Reginold Gragham, Clyde's project manager. Two of the sets will have drive motors and two lead/end unit trailers, he says. "The trains run backward on the return trips to avoid reversing, switching, or roundtable times," Clyde reports.

Ruggedness and easy maintenance are among the design challenges, says Robert Cantwell, executive head of engineering at Clyde. The double-deck design stretches the limit of stiffness for light trains (42 tons for the cars vs 55 tons for similar ones in the U.S. and Canada). In previous train designs, Clyde used MSC/PATRAN and MSC/NASTRAN for finite element analysis.

Double-curved interior stairways on the trains also present a design problem, says Clyde Draftsman Phil Egans. The stairwell panels will incorporate LED readouts and hidden security cameras. "Engineers are backing up from the artistic rendering to more basic shapes to help pattern makers modify the design to accommodate the camera mounts," he says.

Engineers will use Helix's hybrid solid modeling package for all design, engineering, analysis, detailing, and documentation. In addition to solid geometry, they'll use wire frame, surface and integrated 2D tools. "We may recycle much of the design, and one of Helix's strengths is its ability to pull previous 2D designs quickly into 3D models," he adds.

The Clyde team will streamline the lead/trailing cars with Helix surfaces, using control splines to create the surfaced model defining the body. They'll use those shapes to generate patterns that drop off automatically in the associative 2D cross sections for manufacturing. Using the software's kinematics capabilities, engineers will analyze the interaction of the wheels, torsion suspension, and anti-roll bars with the coach bodies.

The move to 3D solid modeling required Clyde to engage in extensive training for those of its engineers who were using 2D design and drafting. The company actually re-wrote its design manual to help engineers take advantage of 3D capabilities.

Just like the Olympics themselves, the design project is an international undertaking. Alsthom in France is supplying traction units, sending its designs to Clyde engineers through IGES. Knorr in Germany supplies the train's airbrakes, which it designs in Medusa (Parametric Technology Corp., Waltham, MA). The company passes the designs to Clyde through IGES and STEPfile formats.

While the Clyde team is running at full speed, some team members question whether they'll finish the race in time for the start of the Games. But even if they miss the start, they say, they will still have an electric train for the new millennium.

The 4GT at a Glance