HÖRMANN HLS
| HÖRMANN HLS | |
| |
| Company | HÖRMANN Warnsysteme |
|---|---|
| Produced | 1966-1985 |
| Type | Omnidirectional Pneumatic Electromechanical |
| Sound output | 120 dB @ 100 ft (HLS F71) |
| Frequency | 50 Hz |
| Succeeded by | HÖRMANN ECL |
The HÖRMANN HLS (Hochleistungssirene, and in English High Performance Siren) is a series of large pneumatic electromechanical siren that was produced by HÖRMANN Warnsysteme during the mid to late Cold War. Designed to be far more powerful than a standard electromechanical siren, these sirens are some of the largest siren units ever built.
While they are rare today, they certainly left their mark on everybody who has heard them. They would be produced until 1985, when they would be replaced by the electronic ECL and later ECN series of sirens.
History and design
In the mid-to-late 1960s, in accordance with the West German government, HÖRMANN, alongside Pintsch Bamag and Rickmers Werft, would start developing a pneumatic siren intended to warn the public of air raids and nuclear attacks from the Eastern Bloc. After it was realized that a large number of civil defense systems in Germany did not have adequate warning in case of enemy attack, the government sought to introduce a siren which would be able to be heard from an extremely long distance to get the attention of citizens throughout the country. Pintsch Bamag was the leader in siren development for this project, having created their Anlage 1 and Anlage 2 pneumatic sirens. However, when Pintsch Bamag faced insolvency in 1966, the role was given to HÖRMANN. HÖRMANN used Bamag's sirens as a basis, developing and releasing their HLS F71 in late 1966. The siren used an air compressor that feeds through a pipe leading through the chopper, and thus supercharges the siren while also driving the rotor.
This siren saw much success, with several units being installed globally. The HLS F71 would be discontinued in late 1974 and was soon followed up with the HLS X73 series in early 1975, which used the same general design while improving on its predecessor. The series was more compact compared to the HLS F71, while also being more efficient. The siren's core was also slightly altered, with the disk rotor being replaced by a vaneless cylindrical rotor. The HLS X73 series would be sold until 1981, when it was replaced by the HLS 381. The HLS 381 would go on to be sold until 1985, when it phased out of HÖRMANN's lineup.
HLS F71 (1966-1973)
The HLS F71, originally the HLS 167, was the first siren to be introduced of this lineup, debuting in late 1966. Many of these would be installed across West Germany and had a decibel rating of 120 dB at 100 ft. Units built between 1967 and 1971 would have the year they were built included in the name. For instance, an HLS F71 produced in 1967 would become an HLS 167. This practice ceased in late 1971 when the siren's name became the HLS F71.[1] The F71 is effectively direct successor to the Pintsch Bamag Anlage 2, which was discontinued upon the company's insolvency in 1966.
The HLS F71 is similar to the sirens that were produced by Pintsch Bamag and Rickmers Werft, being cylindrical in shape with 4 holes on each side, with these essentially being horns for sound to pass through. The siren also has what looks to be a platform with railings on top of it. The siren uses a slotted disc as the rotor instead of a standard cylindrical rotor, similar to other high-performance sirens such as the Chrysler. While this disc was efficient, it required a large amount of space, necessitating the large head of the siren. HÖRMANN ditched the cylindrical tube surrounding the pipe and instead used a triangular steel lattice tower, which saved on costs significantly. The pipe is attached to one side of the tower for stability. The rest of the siren was identical to its predecessor.
The siren's air tank is placed upright underneath the tower, and is typically left exposed unlike its predecessor. The tank was enlarged to hold 6000 litres of compressed air, and is attached to a heavy duty Klein Schanzlin & Becker (later JP Sauer & Sohn WP25L-301) air compressor, driven by a Farymann G20 diesel engine. The F71 could be optionally built with a small building underneath the siren, which would house its controls, compressor and air tank. If there was a lack of adequate room, air would be stored in four 1500 litre underground tanks.
The HLS F71 was sold to many countries during its production, most notably Israel, who maintained a system of HLS F71s until they were replaced with ATI HPSS-32s. The HLS F71 would be discontinued in 1973, when it was replaced with the HLS 381. Today, most HLS F71s have either been put out of service or removed, and very few active units remain.
HLS X73 (1973-1981)
The HLS X73 series was introduced in 1973 as a successor to the HLS F71, and was more compact, possibly louder, and easier to install. These ranged from the HLS 273 to HLS 673, with each being a variant of the HLS 273. The HLS 273 replaced the large head with a much smaller one with four large square horns. The much more compact design provided more mounting opportunities and took up less space, while also being louder due to more efficient airflow. This was achieved by replacing the slotted disc rotor with a much smaller cylindrical rotor.
Due to the significantly smaller weight and size of the X73's head, the steel lattice tower was replaced by a thin cylindrical mast which surrounded the main pipe for standard installations. For structural strength, the mast is wider at the bottom with three distinct sections. The lattice tower was kept as an optional add-on for those who ordered it. The air tank (or tanks) was moved underground by default to save space. The X73 uses the same JP Sauer & Sohn WP25L-301 air compressor as later F71 units, driven by the same Farymann G20 diesel engine.
Variants
The HLS 273 was also available with a compressor powered by an electric motor, with the variant being named the HLS 373. HÖRMANN also offered the siren head and controls by themselves, intended for areas that had their own compressed air supply. Units sold without the compressor or air tank are named HLS 473s. The HLS 573 was essentially a heavier duty HLS 273, utilizing several 200 bar bottles of compressed air, as opposed to the HLS 273's 16.5 bar compressed air tank. This made the unit much more compact and was generally easier to install. Finally, the HLS 673 is essentially an HLS 573 that lacks a compressor. This results in the siren's air bottles having to be replaced or filled externally.[2]
The HLS X73 series would be discontinued in 1981, when they were replaced with the HLS 381.
HLS 381 (1981-1985)
The HLS 381 was introduced in 1981 as a successor to the HLS X73 series. There are very few differences between them and the HLS 381, with the only known ones being the size of the intake tube and the mast. The tapered tube was replaced by an improved octagonal mast produced by Pfliederer, with a standard height of 29.5m (96.78 ft). The lattice tower was finally discontinued as well. The Farymann G20 diesel engine was replaced by a Hatz KG E108 U-183b 15 kW diesel engine, and the positions of the engine and compressor were swapped. The welded intake tube was replaced by an aluminum casted intake tube.
The HLS 381 presumably also had several other variants, although no documentation confirming this is known to exist. The HLS 381 would be sold until 1985, when they were phased out of HÖRMANN's lineup, with the electronic ECL series taking its place. Due to the siren's short production run, relatively few units are known to exist today.[2]