sentences:  The racing W194 300 SL was built around a mere 140-150 pound welded aluminum tube spaceframe chassis to offset the relatively underpowered M194 engine.Designed by Daimler-Benz's chief developing engineer, Rudolf Uhlenhaut, the metal skeleton saved weight while still providing a high level of strength.Since it enveloped the passenger compartment traditional doors were impossible, giving birth to the model's distinctive gull-wing arrangement.