Powering Above The Field


We were given the opportunity to carry out some FE work for Powerfield Ltd, part of the Rolls-Royce group specialising in power systems for the British Army and Royal Navy.
This was a job with a difference: the new range of Field Electrical Power Source (FEPS) mobile generators are required to be air-transportable and the tests involved confirming structural integrity and detailed stress calculations of the equipment on 3m and 5m slings under a Chinook helicopter at 120 knots.
The generator set and trailer, which together weigh over 3 tonnes, were suspended with constraints applied at the centre of gravity of the unit and loads along the direction of the sling arms. The loads were factored to give a 5g loadcase - a weight of 16 tonnes on the attachments. Powerfield had obviously put a great deal of thought into the design because it came through the analysis with flying colours!
Final airworthiness validation was carried out by the RAF.