Wolf's World Famous Airlamp Range Updated

11th March 2024

At the begining of 2024, Wolf completed a major update to its world-famous Airlamp range. Michael Morley, our recently retired Technical Director, has given us some background to the project and some history about Wolf airlamps in general.

The story of the Wolf Airturbo lamp begins almost 100 years ago in the 1930s, when the compressed air driven lights were originally used underground in mining applications. They were designed and built to be “miners pick proof", with extremely strong brass enclosures which were ideal for use in harsh environments. The new ATEX A-TL44/45C models continue the tradition of robust design, now with aluminium castings to reduce both size and weight.

The Airlamp's operating principle involves compressed air flowing through the lamp to expel any potentially hazardous atmosphere. The same compressed air is utilised to drive a turbine which is connected to a shaft, bearings and magnet. As the magnet rotates within a stator winding, electricity is generated. This electricity powers the 55 watt Airturbo or 250 watt Turbolite bulb. The same airflow serves to cool the entire lamp, creating a safe internal space for the electrical machine and bulb to operate in.

The design utilises a reverse air principle; this means that the turbine is driven after the air has purged the interior of the Airlamp, also cooling the bulb and enclosure. Therefore, if the enclosure (glass lens, seal or casting) is damaged, the airflow is lost, the lamp cools and it stops generating electricity - it's fail safe. This basic principle has been refined and improved over many decades of use.

And advert for Wolf Airturbo Lamps from the 1930s

1982 saw the introduction of the Turbolite™, and with it a number of major improvements to the Airlamp. Having collaborated closely with the University of Sheffield, Wolf enhanced the electrical machine's efficiency by incorporating multiple air nozzles to drive the tubine; this enabled a stronger rare earth magnet rotor to be driven, which in turn increased output to 250 watts.

The Airlamp range continued to evolve following the introduction of the ATEX Directive in 2003, when the new ATEX Turbolite™ was introduced. Using the first principle technical file route, a test plan was agreed to prove the lamp was safe even under fault conditions: the bulb glass envelope was broken, the lamp was filled with an explosive gas and the air supplied turned on - with the result that the compressed air purged the lamp and removed any risk of explosion before the bulb filament was hot enough to ignite it. The introduction of a new semi-sealed bearing further improved reliability and ease of maintenance.

Fast forward 20 years, and the market for Airlamps has changed: Wolf has developed a range of temporary lighting which now covers many of the applications where Airlamps were previously used and where electrical power is available. There are still a number of applications where using an Airlamp is preferable - for example, marine tank cleaning applications which have been using the airlamps for decades. There is still a need for high power lighting that can run where there is no easy access to an electrical supply, or using electrical equipment may not be preferable due to other safety concerns, for example trailing cables.

The new A-TL44/45C aluminum lamps are ATEX, IECEx and UKEX certified, with the castings now being manufactured using a high pressure die cast process. This gives the benefit of a smaller, lighter Airlamp, with no loss of strength. With decades of proven reliability, the electrical machine has been retained from the previous ATEX Turbolites™, including the same turbine, magnet, stator, and bearings. Improvements include the option of a piped exhaust for “silent” running, and options for use in dust applications.

The future for the ATEX A-TL44/45C Airlamps is bright.

Fully updated in January 2024, the ATEX A-TL44/45C is smaller, lighter and even easier to maintain than previous models

About the Author

Michael Morley was Wolf Safety's Technical Director until he retired at the end of December, 2023; he now acts as a part-time technical consultant for Wolf.

He joined the company in 1995, with initial tasks including the establishment of an R&D department and the introduction of drawings and systems controls, including separating manufacturing drawings from certification drawings. At the same time, he was a member of the BSI (British Standards Institution) Intrinsic Safety Committee, helping to drive standards of safety in the UK.

During nearly 30 years with Wolf, Michael was fundamental in helping the company prepare for numerous changes in legislation (for example the EMC Directive prior to ATEX, and then ATEX Directive itself in 2003), ensuring that Wolf products achieved the market leading performance and reliability that Wolf products are known for today whilst at the same time achieving the highest standards of safety and certification.

Product development he was responsible for included the development of the Portable Lighting range, including the primary cell torch range launched in 2003, the rechargeable torch range in 2006, the changeover from bulb to high power LED products in the early 2000s; the development of the Temporary Lighting range in the 2010s and more recently our Installed Lighting range.