Abstract: A settling basin of a wastewater treatment system, the settling basin comprises a collector chain for driving a plurality of flights through the settling basin, the collector chain including chain links comprising a plurality of side bars including a plurality of inner pairs of side bars and a plurality of outer pairs of side bars, and connecting pins configured to join the plurality of side bars, each connecting pin including a first end and a second end on an opposite end of the connecting pin from the first end, and flanged rollers disposed on the connecting pins between the first ends and second ends.

Abstract: A cargo carrying vehicle has a towing unit and a storage unit defining a cargo space. The towing unit is operable to: a) advance the storage unit; and b) generate electrical power for operating at least one component on the vehicle. An input is provided for external power to be supplied to at least one of: a) charge; and b) operate the at least one component. A safety system has first and second states. With the safety system in the first state, with no external power supplied to the external power input, the towing unit can be operated to advance the storage unit. With the safety system in the second state, with external power supplied to the eternal power input, the towing unit cannot be operated to advance the storage unit.

Abstract: A cargo carrying vehicle has a towing unit and a storage unit defining a cargo space. The towing unit is operable to: a) advance the storage unit; and b) generate electrical power for operating at least one component on the vehicle. An input is provided for external power to be supplied to at least one of: a) charge; and b) operate the at least one component. A safety system has first and second states. With the safety system in the first state, with no external power supplied to the external power input, the towing unit can be operated to advance the storage unit. With the safety system in the second state, with external power supplied to the eternal power input, the towing unit cannot be operated to advance the storage unit.