A Short History of the Light Bar

Today's modern light bar (or lightbar) has come a long way from its humble origins. A warning light on an emergency vehicle started life as directional, ie front and rear steady burn halogen lights. Once the technology of the time advanced, these steady burn lights were able to flash. Some of them simultaneously and some would flash alternately left and right. These were the original flashing lights because that was all they could do.

The image to the left is an early rotating beacon.

In the 1950's an American company called Whelen Engineering Co was formed by its founder George W Whelen, who were manufacturing a rotating beacon for use on aircraft as an anti-collision beacon. This design was adapted for use as a magnetic beacon by the police, fire and public safety departments. It was also used to convert hearses to ambulance service. The image to the left is of an early American beacon that used sealed beam halogen lamps as its light scorce.

It wasn't long before other companies started producing these rotating beacons and several manufacturers became established in this period of time. Some of them have evolved into the giants of the emergency warning industry. Of particular note is the Federal Signal Corporation, and is today probably the biggest warning light manufacturer in the world.

The invention of the rotating beacon was a great leap forward in vehicle warning light technology, a simple mirror revolving around a stationary light, has provided one of the most effective warning beacons ever made. The use of the single beacons soon evolved into using two or more lights, and multiple colours. In order to use more than one light, it became necessary to install a bar across the vehicle roof to provide a level surface to mount the lights onto. This was the origin of the Light Bar. These lightbars would often have additional "lollipop lights and a central siren speaker in between the two beacons. These lights would have been specifically produced in-house for the agency using them. It wasn't long before the companies manufacturing the beacons caught on to this, and they started producing their own custom light bars as off the shelf units.

The image to the right is from Whelen Engineering Co of it's Edge  9000 series lightbar.

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The 1970's saw numerous lightbar designs produced mainly in the US, it wasn't until the 1980's that light bars started to appear on police vehicles here in the UK. Also in the 80's research began into the use of strobe lights to replace the beacons in lightbars began. The strobe lightbar market has been dominated by the US Company Whelen Engineering Co, who are based in Chester Connecticut. Thier "Edge Series" lightbar has been so successful; it can be seen all over the world. In my opinion for what it's worth, the Whelen Edge is the best lightbar ever produced.

To the left you can see a strobe light bar by German manufacturer Hella. In the mid 1990's the lightbar companies started experimenting with LED technology. The only raw materials they had available at the time were simple 5mm LED's The problem with these LED's is that you need a lot of LED's to make a light bright enough to use as a warning light. It is not unusual to have multiples of 30, 50 or even 100+ LED's in a light head module. These are still produced today, and provide a useful warning light. As technology has advanced, so has the output power of the latest generation of LED light heads. Typically, lightbar manufactures now use 1 - 3 watt LED's in thier lightbar design, and a full size lightbar may have as many as 200 Generation 3 LED's  compared to 1000 Generation 1 LED's to make a similar product.

The image above right is of Code 3's MX 7000 lightbar.

The latest LED Light Bar may be extremely bright, but that brilliance comes at a cost. High power LED's generate a lot of heat and this is what will destroy an LED. There is considerable research and development that goes into today's modern lightbar design and heat dissipation is one of the biggest challenges companies face. This coupled with the relatively high cost of the LED's themselves are some of the factors which make the aquisition cost of an LED Light Bar so high. However, this has to be compared to the maintenance costs of the lightbar over it's lifetime. These are virtually nil as there are no bulbs to break, no filaments to burn out etc. It should also be noted that you can leave a full size LED Lightbar on with the vehicle engine turned off. If you consider this over several years, the savings in petrol will offset the initial cost of the light bar. As more and more vehicles have to have lightbars fitted as part of thier operational equipment these days, with the "Low Profile" aerodynamic designs available today,a further saving in fuel can be achieved over time. Above left is a Redtronic 47" LED Lightbar.