Concrete structures are prestressed when predetermined compressive stresses are applied to them to counter expected future tensile stresses as a result of field loads. In Prestressed Concrete Lined Cylinder Pipe (L-301), prestressing is achieved by helically wrapping, under measured tension and at uniform spacing, a high tensile strength wire around the concrete-lined steel cylinder. This wire wrap places the steel cylinder and concrete core in compression, developing the pipe’s ability to withstand specified hydrostatic pressures and external loads with a safety factor comparable to other waterworks piping materials. Concrete’s high compressive strength and steel’s high tensile strength are combined to form an elastic structure. This feature allows the pipe to perform even when design working loads are exceeded.