ACA Hurricane 130

**Type of siren** | Rotating Supercharged Electromechanical

The **Hurricane 130** is a supercharged rotational outdoor warning siren designed by James E. Biersach, unveiled in 1968 alongside a large and diverse lineup of sirens from Alerting Communicators of America. Starting out with a square horn and an internal design that bottlenecked the siren's performance, the Hurricane went through many changes in design, sound, and overall functionality, despite being in production for only just over 10 years.

Hurricanes are extremely rare, as all but one have been replaced by newer sirens. As of today, only one ACA Hurricane 130 MKII remains in service, in Milwaukee, WI, with the rest abandoned in place or in private collections. A single example of a Hurricane 130 MKI is in private possession after its removal from Centralia, IL. There is speculation that one other MKI was discovered at a junkyard in Brainerd, MN, but was scrapped by the owner after people continued asking for it. The source of this claim relies solely on a Google Maps aerial image and information of a Hurricane MKI that was installed in neighboring Baxter, MN being sent to said scrapyard after its removal in 2006.

## Hurricane 130

The Hurricane 130 was heavily inspired by the Thunderbolt, which had been seeing great success, and ACA wanted a siren which could compete with its performance. Like all of ACA's other sirens such as the Allertor, Cyclone, Screamer and Banshee, the Hurricane made use of all-fibreglass casting, which was brand new and prevented the siren from corroding from the elements.

The Hurricane 130 originally released with a square fibreglass horn with two throats leading to each rotor, a small, cylindrical rotator using a gear reduction drive, and the siren's standpipe was mounted directly on top of its horizontal roots blower. Like the Thunderbolt it competed with, the Hurricane utilized a roots blower driven by a 25HP AC motor, which supercharges the siren by forcing a large volume of air up the standpipe and into the rotors. Unlike the Thunderbolt's blower, the Hurricane's blower was direct-drive. Without the blower, the Hurricane becomes extremely quiet. The blower itself outputted 450cfm at 10psi. The controls for the siren were mounted to the side of the blower box, which also had cooling vents. Originally, the siren was only available in 10/12 port dual tone. The MKI Hurricane uses a 2 horsepower motor with a fully custom frame enclosing the entire unit, making maintenance difficult. 36 of these units were produced.

Around 1970, the siren would be redesigned. The rotator was enlarged, now using a separate chain-driven rotator, with its own separate 1/4HP motor rotating the unit at 3RPM. This rotated along with the siren. This was more reliable and easier to maintain, with an access door on the side for easier maintenance. In addition, 8/10 port dual tone became the standard, with 10/12, along with 8/12, 8/8, 10/10 and 12/12 port options being offered as well, although none of these units are known to have existed. In addition, a prototype version capable of a "yelp" signal was demonstrated, and eventually sold to an ACA/Klaxon dealer in South Africa. This was the only known coded unit ever produced. The rotator could also be specially ordered with a mechanism that allowed the horn to oscillate within a specific range, similar to a Whelen WPS-3000 or 4000, instead of rotating 360 degrees. This likely used a similar oscillating mechanism to the oscillating variant of the Alertronic AL-6000R.

## Hurricane 130 MKII

In 1973, the siren underwent a massive overhaul, called the "Hurricane 130 MKII" by ACA. The square horn was replaced with a much larger round, exponential horn ending in two throats, which performed significantly better and was easier to produce. In addition, the rotator would be redesigned again, now being completely stationary, and now in a teardrop shape. The rotator used a 1/4HP AC motor, and rotated the horn at 2.5RPM. The blower would also be significantly redesigned, now being vertically mounted to the side of the siren's pole. The direct-drive blower was replaced by a belt driven blower, driven by a 30HP AC motor, and the controls were separated from the blower, now being housed in their own separate cabinet. The blower's output was identical to the MKI, at 450cfm at 10psi. The MKII Hurricane used a much simpler chopper assembly, with a basic dual rotor/stator setup mounted on the ends of an off-the-shelf 1HP motor, making rotor swaps, bearing swaps, and general maintenance much easier. These changes significantly improved the siren's performance and reliability, allowing it to reach its full 130 dB at 100ft decibel rating. This would ultimately be the design the siren would use until its discontinuation.

The Hurricane could come in two, three or even 5-signal models, utilizing slide-valve solenoids to cut off the output from one or both of the choppers. This would allow the siren to create hi-lo, pulse, or even alternating wail signals depending on what the customer desired. The exact appearance and design of these coded Hurricanes are unknown, as none are known to have been documented and none survive today. The solenoids are made by Trombetta Corp situated in Menomonee Falls. It is likely placed in between the two throats completely hidden without a external box for the solenoids unlike the Thunderbolt 1003s.

The corporation continued production of the Hurricane until 1980, when it was replaced in ACA's lineup with the significantly more powerful 50HP ACA Penetrator-50, which proved to be both louder, and more reliable without the need for a blower. These sirens often suffered from reliability issues often due to poor maintenance, due to their complexity. This often led to their replacement.