Cottrell pioneers new 7-Car soft tie trailer Cottrell is excited to introduce the first 10 car cylinder soft tie unit on a line haul, sleeper tractor. This equipment maintains the prestige, flexibility and durability of the classic, high rail Cottrell equipment. We have incorporated years of expertise into a single design that capitalizes on the future of the automobile industry. This creativity is portrayed in new types of material and strategically designed wheel pockets throughout the unit. The featured unit and existing options reflect a full of fuel weight of 42,880 pounds.