A Look Into History: Denver Sirens, The beginning of an era. A detailed historical profile.
Posted: Mon Jan 09, 2023 8:17 pm
Over the last 12 years I have been apart of this group, I have seen the question asked time and time again.
"What was the first electric siren?"
Many people have tried to answer this question with unsubstantiated claims, and erroneous information that, historically speaking, does not collaborate with company history or time lines.
Well folks, after hours upon hours of research, we have an answer.
Our story begins around 1900 , in Denver, Colorado. In the alarm industry, steam and compressed air is King. Factories, Trains, Fire departments, Schools, and cities all across the nation use air horns and steam whistles to do their alerting, be it fire, curfew, mine blasting, end of shift, you name it--hoots and Honks could be heard all hours of the day.
Now, as you can imagine, all of this honking and hooting can get pretty confusing, especially in busy communities with sprawling industry. Fire departments, looking to upgrade from the fire bell that was rather ineffective and easily confused with church bells, began testing out various horns and whistles. Realizing the confusion that would be had by yet another whistle or horn honking about, something different was needed.
English inventor William A Box Immigrated to Denver, Colorado in 1896, and together in 1902, with Frank Dillon would form the *Dillon-Box Machine Shop in Denver. By 1910, Box would dissolve interest with Dillon and go on to form the William A Box Ironworks Company. William A Box Ironworks would occupy existing factory buildings at 33rd and Blake Streets until 1933, 2 years after it's founder passed away.
*Oddly enough, Dillon-Box Iron Works appears on most Denver Siren Tags until about 1920, when the tag was finally changed to WM. A. Box Iron Works
William A Box Ironworks facility at 33rd and Blake St, Denver Colorado
Box, already famous for the invention of the Leadville Hoist, saw opportunity to improve on a small hand cranked siren known as the "Boxco Siren" he had previously designed for fire wagons and police.. Development of the siren began in 1905, with several contraptions being tried, tested, and marked as failures. One of the problems Box faced early on was lack of availability of motors able to achieve rpm necessary to produce sufficient sound. In order to overcome this issue, a 12 port head was affixed to a gear reduction transmission that was then affixed to a motor mounted parallel to the gear box, and thus the first generation Type-A was born. This siren was tested between 1910 and 1914 around Denver, and though it initially worked well, was deemed unreliable and maintenance intensive. It is my estimate approximately 4 of these sirens were put into regular service, with none surviving.
An early electric Boxco Siren
First generation Type A siren erroneously used in all Type A depictions
Meanwhile, one of the common complaints of the type A was it's low sound output. It was evident to Box early on that something louder was going to be needed for more populous areas, and by 1914 the "B Series" was born. This consisted of the 2hp single faced 20 port OR optional 20/20 port double-faced, direct-coupled Type-B, the 3HP 20/20 port single-headed Duplex, and the massive 5hp, 6' long 21" wide 20/20/20/20 port double-headed Quadruplex. Mr box filed US Patent # 1278582A May 19, 1915, and the patent was officially granted Sep 18, 1918. This siren was marketed as a Fire, Curfew, Riot, Mining, and Factory alarm for emergency mass notification.
Add showing both Quadruplex and Duplex sirens
Around the tail end of 1914, noting the reliability issues of the first generation type A siren, and the widening availability of more powerful, higher rpm motors, further developments at refining and expanding the sirens, *the first generation Type-A would be trashed and a new variant, having the head directly coupled to the motor, would become available. One surviving example is affixed to a water tower in Canova, South Dakota, and another completely intact unit in Kanorado, Kansas.
It was around this time the Hendrie and Bolthoff Mfg and Supply Company, a well known mine and fire equipment supply company in Denver, Colorado, Eastern agents Woodhouse Manufacturing of New York, New York, and Western agents Northwest Fire Apparatus Co of Spokane, Washington, would begin sales and distribution of the sirens until 1931 **Silver Engineering Company would take over sales of remaining sirens and provided support for a number of years with the dissolution of William A. Box Ironworks in 1933
*For whatever reason, the first generation Type-A was used in all advertising material
**Very little information is available about the Silver Engineering Company, other than they took over facilities at 33'rd and Blake St between 1932 and 1933, and sold parts for a Quadruplex siren to the city of Swift Current Saskatchewan around 1933, their 1919 siren is displayed at the Swift Current Fire Museum
The Duplex and Quadruplex were a near immediate success, and by 1920 over 300 were in service in 43 states and 3 countries. Around 1918, to meet demands, keep production costs down and reduce weight in a now saturated and competitive market, the large rotors of the B series lost 15 veins per side, maintaining the 20/20 port count, but now, instead of each port having it's own vein, 4 ports shared one vein, reducing the count to 5. It is unclear how this affected sound output, if at all, though 20 vein units seem to have a cleaner, crisper note. Another option to reduce cost was the availability to purchase the larger sirens with no motor. An appropriate motor would then be added by the customer. Common motors used were Century Electric, Westinghouse Electric, and later on Howell Electric. During this time, other variations of the sirens were developed, Including a 150vDC direct coupled Type-B and full size Duplex intended for motor ships, and a suspended siren intended for use in factories as well as motor ships and anywhere else a compact siren may be needed. Coding methods, though also experimented with were unsuccessful, with one such "braking method" being depicted in a later add.
Depiction showing Both 2hp Type-B models available. Note the double faced unit fixed with a DC motor for use on motorships
Depiction of a braking method for "coding"
Tag of a Quadruplex Siren a the Swift Current Fire Museum Photo Credit Flickr user OoyVing NOTE: Dillon Box Ironworks on tag, this unit was built in 1919 before the switch to the WM. A. Box tag.
Around 1925, a 5hp, 3000rpm 6/6 port center driven Duplex Siren was developed, in an attempt to remain competitive with Federal Electric and Sterling Siren Fire Alarm Co, however with William Box's passing in 1931, production of all sirens ended. Only one of these sirens (to my knowledge) was ever installed at Wheat Ridge Fire Station No.1 in Wheat Ridge Colorado. The fire department is long gone, as well as the siren.
Denver Duplex Center-Drive siren
Other interesting material:
Comprehensive map of known locations:
https://www.google.com/maps/d/edit?mid= ... sp=sharing
Sources:
Colorado School Of Mining Magazine; multiple volumes
Electrical Engineering Yearbook
A History of Mining and Mining Equipment -The Colorado Magazine
Denver Public Library
Professional Noise Making by Richard Rubincam VP of William Box Ironworks
In closing, a LOT of work went into this project. When I first joined there was very little information regarding Denver Sirens, let alone sirens of the 1910's. Understandably so, as it is quite an obscure topic. Diving into the history of such an old company has been an incredibly rewarding experience, and I invite anyone with the time and interest in not only just sirens but the early years of industrialization in general, to read from the sources listed above.
EDIT: I had originally believed Swift Current's siren was purchased from Silver Engineering in 1933 based on an insurance report. Further investigation shows Swift Current's siren was purchased in 1919 and Silver Engineering likely serviced or repaired the siren. Changes have been made above to reflect this.
"What was the first electric siren?"
Many people have tried to answer this question with unsubstantiated claims, and erroneous information that, historically speaking, does not collaborate with company history or time lines.
Well folks, after hours upon hours of research, we have an answer.
Our story begins around 1900 , in Denver, Colorado. In the alarm industry, steam and compressed air is King. Factories, Trains, Fire departments, Schools, and cities all across the nation use air horns and steam whistles to do their alerting, be it fire, curfew, mine blasting, end of shift, you name it--hoots and Honks could be heard all hours of the day.
Now, as you can imagine, all of this honking and hooting can get pretty confusing, especially in busy communities with sprawling industry. Fire departments, looking to upgrade from the fire bell that was rather ineffective and easily confused with church bells, began testing out various horns and whistles. Realizing the confusion that would be had by yet another whistle or horn honking about, something different was needed.
English inventor William A Box Immigrated to Denver, Colorado in 1896, and together in 1902, with Frank Dillon would form the *Dillon-Box Machine Shop in Denver. By 1910, Box would dissolve interest with Dillon and go on to form the William A Box Ironworks Company. William A Box Ironworks would occupy existing factory buildings at 33rd and Blake Streets until 1933, 2 years after it's founder passed away.
*Oddly enough, Dillon-Box Iron Works appears on most Denver Siren Tags until about 1920, when the tag was finally changed to WM. A. Box Iron Works
- Screenshot 2023-01-09 1.51.40 PM.png (114.81 KiB) Viewed 3917 times
Box, already famous for the invention of the Leadville Hoist, saw opportunity to improve on a small hand cranked siren known as the "Boxco Siren" he had previously designed for fire wagons and police.. Development of the siren began in 1905, with several contraptions being tried, tested, and marked as failures. One of the problems Box faced early on was lack of availability of motors able to achieve rpm necessary to produce sufficient sound. In order to overcome this issue, a 12 port head was affixed to a gear reduction transmission that was then affixed to a motor mounted parallel to the gear box, and thus the first generation Type-A was born. This siren was tested between 1910 and 1914 around Denver, and though it initially worked well, was deemed unreliable and maintenance intensive. It is my estimate approximately 4 of these sirens were put into regular service, with none surviving.
- Screenshot 2023-01-09 2.34.43 PM.png (83.26 KiB) Viewed 3917 times
- Denver19152.jpeg (110.54 KiB) Viewed 3917 times
Meanwhile, one of the common complaints of the type A was it's low sound output. It was evident to Box early on that something louder was going to be needed for more populous areas, and by 1914 the "B Series" was born. This consisted of the 2hp single faced 20 port OR optional 20/20 port double-faced, direct-coupled Type-B, the 3HP 20/20 port single-headed Duplex, and the massive 5hp, 6' long 21" wide 20/20/20/20 port double-headed Quadruplex. Mr box filed US Patent # 1278582A May 19, 1915, and the patent was officially granted Sep 18, 1918. This siren was marketed as a Fire, Curfew, Riot, Mining, and Factory alarm for emergency mass notification.
- Electricalarmsignalpt101-09 1.29.31 PM.png (140.23 KiB) Viewed 3917 times
- Electricalalarmssignalpt2.png (252.16 KiB) Viewed 3917 times
- Denvermodels2.png (66.8 KiB) Viewed 3917 times
Around the tail end of 1914, noting the reliability issues of the first generation type A siren, and the widening availability of more powerful, higher rpm motors, further developments at refining and expanding the sirens, *the first generation Type-A would be trashed and a new variant, having the head directly coupled to the motor, would become available. One surviving example is affixed to a water tower in Canova, South Dakota, and another completely intact unit in Kanorado, Kansas.
It was around this time the Hendrie and Bolthoff Mfg and Supply Company, a well known mine and fire equipment supply company in Denver, Colorado, Eastern agents Woodhouse Manufacturing of New York, New York, and Western agents Northwest Fire Apparatus Co of Spokane, Washington, would begin sales and distribution of the sirens until 1931 **Silver Engineering Company would take over sales of remaining sirens and provided support for a number of years with the dissolution of William A. Box Ironworks in 1933
*For whatever reason, the first generation Type-A was used in all advertising material
**Very little information is available about the Silver Engineering Company, other than they took over facilities at 33'rd and Blake St between 1932 and 1933, and sold parts for a Quadruplex siren to the city of Swift Current Saskatchewan around 1933, their 1919 siren is displayed at the Swift Current Fire Museum
The Duplex and Quadruplex were a near immediate success, and by 1920 over 300 were in service in 43 states and 3 countries. Around 1918, to meet demands, keep production costs down and reduce weight in a now saturated and competitive market, the large rotors of the B series lost 15 veins per side, maintaining the 20/20 port count, but now, instead of each port having it's own vein, 4 ports shared one vein, reducing the count to 5. It is unclear how this affected sound output, if at all, though 20 vein units seem to have a cleaner, crisper note. Another option to reduce cost was the availability to purchase the larger sirens with no motor. An appropriate motor would then be added by the customer. Common motors used were Century Electric, Westinghouse Electric, and later on Howell Electric. During this time, other variations of the sirens were developed, Including a 150vDC direct coupled Type-B and full size Duplex intended for motor ships, and a suspended siren intended for use in factories as well as motor ships and anywhere else a compact siren may be needed. Coding methods, though also experimented with were unsuccessful, with one such "braking method" being depicted in a later add.
- Denvermodels.jpeg (199.5 KiB) Viewed 3917 times
- Denvermodels3.png (83.13 KiB) Viewed 3917 times
- singlehead1915.jpeg (78.75 KiB) Viewed 3917 times
- 319207187_2381096555378680_5685571742869222610_n.jpg (50.19 KiB) Viewed 3917 times
- Screenshot 2023-01-09 2.32.58 PM.png (78.31 KiB) Viewed 3917 times
- Swift Current Denver 6.jpg (36.4 KiB) Viewed 3917 times
Around 1925, a 5hp, 3000rpm 6/6 port center driven Duplex Siren was developed, in an attempt to remain competitive with Federal Electric and Sterling Siren Fire Alarm Co, however with William Box's passing in 1931, production of all sirens ended. Only one of these sirens (to my knowledge) was ever installed at Wheat Ridge Fire Station No.1 in Wheat Ridge Colorado. The fire department is long gone, as well as the siren.
- DenverCenterDrive.png (306.21 KiB) Viewed 3917 times
Other interesting material:
- Convincing the skeptic 1920.jpeg (457.13 KiB) Viewed 3917 times
- TheDenverSirenWay.jpg (112.19 KiB) Viewed 3917 times
https://www.google.com/maps/d/edit?mid= ... sp=sharing
Sources:
Colorado School Of Mining Magazine; multiple volumes
Electrical Engineering Yearbook
A History of Mining and Mining Equipment -The Colorado Magazine
Denver Public Library
Professional Noise Making by Richard Rubincam VP of William Box Ironworks
In closing, a LOT of work went into this project. When I first joined there was very little information regarding Denver Sirens, let alone sirens of the 1910's. Understandably so, as it is quite an obscure topic. Diving into the history of such an old company has been an incredibly rewarding experience, and I invite anyone with the time and interest in not only just sirens but the early years of industrialization in general, to read from the sources listed above.
EDIT: I had originally believed Swift Current's siren was purchased from Silver Engineering in 1933 based on an insurance report. Further investigation shows Swift Current's siren was purchased in 1919 and Silver Engineering likely serviced or repaired the siren. Changes have been made above to reflect this.
