Behold, the loudest siren ever built! Built between 1942 and 1957, Chrysler and Bell Laboratories worked together to create a siren that could outdo everything else. Boasting a deafening sound output of 138 decibels at 100 feet, a single Chrysler could fill the role of tens or even hundreds of smaller sirens. Back in WW2 and the Cold War, expense was secondary to making sure everyone could hear the warning.

Powered by a 180 horsepower Chrysler Firepower HEMI V8 (units between 1942-52 used a 140 hp IND-9 inline-8) gas engine, the Chrysler was not only powerful, but also able to run entirely independently of grid power so that they could not be silenced by attack. The engine drove a gigantic slotted disc known as a chopper at 3400 RPM, through which pressurized air was forced through its openings by a two-stage compressor. The chopping of the pressurized air at a certain frequency is what creates the noise, with the Chrysler peaking at about 460 hz. The entire siren sat on a turnable, which pointed its six large horns in all directions as it rotated at 2 RPM.

Unfortunately, such a siren is not exactly the easiest to maintain or run. Older units required someone to sit atop the siren and run it manually, until remote start and run capabilities were developed in the early 50s. The engine is fuel-hungry and requires a lot of maintenance, which made them unpopular with those who had to keep them running. As a result, all of these sirens were decommissioned by the 1980s. Many were removed, others left to rot, and some thankfully survive in preservation. By 1957 engine-driven sirens fell completely out of favour, as powerful electric sirens such as the Thunderbolt, Super Sirex, and Mobil-Directo performed very well without requiring much maintenance.