Seeking Acid Vat Information

Over a period of several years, the Hercules Historical Society has been contacted by persons in possession of an item that they refer to as an acid vat.  These persons have claimed that the item had been used in the Hercules Powder Plant many years ago.  When the plant no longer needed these items, due to the change in their manufacturing of products, they were allowed to be removed from the plant property.  The two vats that came to our attention were on the private residential property of those who acquired them under this condition and the photographs that I am providing are of them in that location.  They appear to be made of ceramic material and are very heavy.

Our organization has a vast collection of photographs of the plant, many of which were taken in the late 1800s and early 1900s when the facility was experiencing a great deal of construction changes due to the need to increase production of various products they were making for the World War I effort.  One such photograph shows some acid vats outside a building at the plant.

Acid Vats lined up in road

Acid Vats lined up in road on left side of image

From what little information we have been given by those in possession of the acid vats, when they were used, several were lined up inside a building, probably like one of the ones in the old photograph above, were upright above floor level, and attached to some kind of conduit that fed the ingredients into the top and another conduit at the bottom that carried the final mixture to another location in the plant.

We are relying upon Randy Grandin to convey to us any information you can provide to our organization about these acid vats (or whatever their technical name might have been). Feel free to send any information regarding the vessels to


Society members Dean Brightman and Steve Lawton reflect upon Hercules’ industrial and suburban past through articles and photographs:


  • John A. Cadigan John Cadigan, 74, of Fairfield, passed away Sunday, April 23, 2017 in a Great Falls Hospital. A private family service will be held. Cremation is in the care of O’Connor Funeral Home.
  • Historic Hercules Building Destroyed by Fire An unoccupied historic building was engulfed in flames and quickly destroyed by fire today. The fire was reported at 1:00 PM. Firefighters from the Rodeo-Hercules Fire District, with aid from other agencies, controlled and extinguished the fire.
  • Virgil (Pat) Patton May 30, 1928 ~ Jul. 16, 2014 Pat passed peacefully in his sleep after a year of declining health. He was a friend to all who knew him and he will be deeply missed. His greatest love was his family and his joy was spending time with his grandchildren.



About the Hercules Historical Society:

In July 1982, HHS (formerly known as the Hercules Area Restoration and Preservation Committee, Inc.) was formed by former City council-members Lynn Fissell (formerly Judnich) and John Cadigan.  Incorporated in the State of California on September 19, 1985,  the Franchise Tax Board issued tax-exempt status under Section 23701d Revenue and Taxation Code on September 12, 1986.  The Internal Revenue Service issued tax-exempt status as a 501(c)(3) organization on December 19, 1986.

HHS is a non-profit, tax-exempt corporation.  Its officers and members represent a cross-section of many community groups and professions.  Its main focus is the restoration and preservation of historical aspects of the City of Hercules.

Membership Information

  • Annual dues $10.00 per person
  • Membership period is from July 1 through June 30 each year.  Membership is open to everyone.
  • Click HERE for a membership form

Meeting Information

  • General meetings are held on the second Wednesday of each month
  • Annual meeting of the membership is held on the second Wednesday of October
  • Agenda is e-mailed prior to all meetings
  • All meetings are held at 111 Civic Drive, near Hercules City Hall, with parking in the lot that is directly adjacent to the HHS trailer.
  • Meetings start at 7:30 pm
  • Public is welcome to attend

Current Officers

  • President:   Darrel “Jay” Tucker
  • Secretary:    Lynn Fissell
  • Treasurer:   Bob Polacchi