Ardagh Glass will be inviting the public to tour inside its Salem plant to see how glass bottles are made, to mark the 150th anniversary of the facility.

As well as being a century-and-a-half old, the plant is the oldest continuously operating glass manufacturing plant in the US.

Throughout history is has been owned by the following companies: Hall, Pancoast and Craven (1863-1881); Craven Brothers (1881-1895); Salem Glass Works (1895-1934); Anchor Cap and Closure Corp. (1934-1938); Anchor Hocking Glass (1938-1983) and Anchor Glass (1983- 2012). Ardagh Group purchased the plant in August 2012.

An average of 1,500 bottles a minute are made in the plant, with an annual production rate of 720,000 million bottles of all types produced in Salem, including containers for many popular beverages such as Dr. Pepper, as well as wine bottles, beer bottles, pickle bottles, canning jars and a variety of other glass containers.

With nearly 300 full-time employees, Ardagh is Salem City’s largest private employer, and when Ardagh purchased the plant there was no change in the workforce or management.

At the open house visitors will learn about the history of the plant and the glass-making process. On the tour, guests will see the entire bottle-making process, from the molten glass being formed into bottles through the inspection and packaging process.