 Complete the following phrase:  Colin Chapman developed the 56 as a potential F1 contender, part of his plan to have a single design to compete at both the Indy 500 and in Formula 1, but it was too heavy and never competitive. The car was designated as the 56B and Emerson Fittipaldi tried it in the 1971 Race of Champions and International Trophy non-Championship meetings. At Brands Hatch, during wet practice, the 56 was far and away the fastest car on the track, but the race was held in dry weather and the car was lost in midfield. At the Silverstone-based International Trophy, the car only lasted three laps of the first heat before suspension failure forced Fittipaldis retirement. Dave Walker ran the car in the 