Evolution of Fog Signal Technology

For thousands of years, the only way to make a sound loud enough to be heard at a distance was with gunpowder or a massive bell. A cannon was given to the first US lighthouse to warn ships in a fog, taking an incredible 4lbs of powder per shot. 

You will hear a much smaller example of this ancient technology in-person during this demonstration!

After the industrial revolution brought about steam, large whistles were used to warn ships of danger in poor weather. Far more efficient and powerful than cannons or bells, they weren't without limitations.

Learn how the sound is created and how the whistle size influences what we hear. You'll hear a real 5" diameter steam whistle blown on compressed air!

The massive Type F diaphones with their signature grunt and the 2-tone Type F2T with its famous "Beeeee-Ohhhh" sound were the most recognizable fog signals of all time. Learn what a diaphone is and how the powerful sound is generated through its slotted piston and cylinder. Why is such a little horn so powerful? Here, you'll hear a small version of these powerful horns with a horn originally made for fire use - the Type B diaphone made by Gamewell.