Although basic principles of operation remain the same, locks along the Erie Canal have changed over the years. The canal's first locks, products of careful stonework by masons, measured 15 feet wide and 90 feet long. The concrete lock that you see today, completed when the canal was modernized in the early 20th century, is nearly 45 feet wide and 300 feet long. Electric motors, not human muscles, are used today to open and close huge metal gates that weigh over 20 tons. The area immediately around the locks has changed as well. The homes of lock tenders and their families, sheds, barns, and the popular canal stores that existed near the locks, have been replaced with power houses, lock operator control stands, and the blue & yellow electrical cabinets.