Under Pressure: From Pressurized Hulls to Pickles

By Clare Sully-Stendahl

If you’ve visited the Maritime Museum, you’re likely familiar with the Ben Franklin – the submarine located at the entrance to the museum. While we have several objects in our collection relating to the Ben Franklin and its crew, there’s one that definitely stands out as a little different.

While I was looking through the donor file of Don Kazimir, captain of the Ben Franklin on its voyage through the Gulf Stream, I came across a glossy printed advertisement for “The Amazing LID POP.” It turns out we have one in our collection – and that Don Kazimir is the inventor of this “Best Way Ever For Opening Vacuum Sealed Jars.”

The reverse side of the advertisement features a lengthy written piece by Don Kazimir, titled “The Story of the Lid Pop.” Kazimir explains how he decided to use his skills as “an experienced engineer” to create a tool to easily open vacuum sealed jars. He describes that jars are difficult to open not because of the tightness of the lid, but because “the presence of a vacuum in the jar results in atmospheric pressure pushing down on the lid making it very difficult to twist.” He calculated that “a perfect vacuum in a jar with a 3 inch lid would result in a downward force on the lid of over 100 lbs.”

 This is where Kazimir’s experience as captain of the submarine Ben Franklin comes into the kitchen. Kazimir writes in the advertisement: “I remembered the problem of opening the hatch after a dive deep in the cold Atlantic. As the air in the submarine cooled down, the pressure dropped and when we surfaced, the atmospheric air pressure was much higher than that in the submarine. To overcome this problem, the submarine designers provided a small valve to the outside so that when it was opened, the pressure inside the submarine became equalized with the outside air.”

While this is the only advertisement for a kitchen tool that I can think of that includes a diagram of pressure in a submarine hull, it is indeed the exact same forces at play – although, since Kazimir “couldn’t put a valve in a jar lid,” he experimented with puncturing the lids of sealed pickle jars to equalize the air pressure and unscrew them with no effort. The result was The Amazing LID POP, which easily punctures jar lids to break the vacuum inside.

Of course, the result is that you’re left with a hole in the top of your jar – an unfortunate consequence of the tool that (thankfully!) doesn’t exactly mirror what happens in a submarine. The advertisement begins by noting that “it seems like everything you buy today is hard to open.” You may need slightly more advanced (not to mention resealable) systems in your submarine, but Kazimir’s tool is good enough for your pasta sauce – and illustrates an interesting way that he applied his maritime experience to what he saw as an everyday issue.