Lake Michigan, Wisconsin
Listed on the US & WI Registers of Historic Places
Kewaunee Pierhead Lighthouse

Evolution of Fog Signal Technology
A Unique Demonstration of Old-Time Sound Signals

Presented by Jake Heffernan,
Historian for the Kewaunee Pierhead Lighthouse
Jake has been a "history nerd" since he was a kid, interested in Great Lakes cargo ships and the carferries that carried the railroad across Lake Michigan. After becoming involved with the Kewaunee Lighthouse in 2018, Jake began researching the lighthouse's history. A large part of that history was the bellowing diaphone fog horn, in use in Kewaunee until 1981. Diving down what he calls a "rabbit hole of fog signals," Jake befriended the owner of one of these 500 lb grunting horns and has made several trips to visit him to understand the horn's workings. After purchasing a smaller "Type B" diaphone (weighing only 40lbs) and a 5" diameter steam whistle, Jake created a mobile air supply in order to be able to bring these lost sounds to people interested in hearing them.
Jake serves as the chairman of the Kewaunee Lighthouse's City Preservation Committee and the Vice-President of the Friends of the Kewaunee Pierhead Lighthouse. Proceeds from these presentations benefit the ongoing restoration of the Kewaunee Lighthouse.
Learn About & Hear the Sounds that Helped Sailors Navigate
The job of "lightkeeper" makes us think of someone tending the lamps, filling oil, trimming wicks, polishing brass and glass lenses. Yes, their primary job throughout time was to keep the light shining.
But what happened when fog or poor weather renders the light invisible to ships?
Cannons
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!
Steam Whistles
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!
Sirens
The big advantage to using a siren vs a whistle lies in the different ports which each emit sound. While a whistle only generates sound from one orifice (opening), a siren has many. As a siren spins, each port of the siren provides its own "voice." Those individual voices build the power (but not necessarily the volume) of the final sound. In lighthouse use, the siren was attached to a long resonator to help form the final sound wave before its sent over the water.
The Diaphone
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. 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. Why is such a little horn so powerful? You'll learn why!
Diaphragm Horns
Using a metal disc that beats against the "throat" of the horn, diaphragm horns are very commonly used today in many applications. Modern boat/yacht horns use diaphragms which can be vibrated by either electricity or compressed air.
In lighthouse use, diaphragm horns commonly replaced the diaphones in favor of their ease of maintenance.

Book this Presentation for Your Organization
Using trailer mounted air compressors and tanks, Jake is able to bring these sounds to you, wherever you are!
If you would like Jake to give a presentation or just want to hear these signals for yourself, he'd love to show them off!
Do you have a steam whistle of your own you want to hear? Jake has a total of 280 gallons of air reserves and a 1.5" diameter manifold to connect up to 3 whistles to.
Email us and Jake will work with you to schedule a date and time to see and hear these cool sound signals for yourself or your group.
A small portion of the proceeds of these presentations help Jake continue to travel and maintain this equipment. The remainder goes to fund the ongoing restoration of the Kewaunee Pierhead Lighthouse.