Engineering news
Engineers have spoken of the challenges involved in designing and building the fourth Type 45 destroyer, HMS Dragon, which has been officially handed over to the Royal Navy at Portsmouth.
First steel was cut on Dragon in 2005 and BAE Systems' Surface Ships business has been responsible for the subsequent build of the vessel, the fourth of six due to be delivered to the navy. The ship was launched at BAE's Govan, Glasgow yard in 2008 before undergoing an extensive programme of sea trials. The vessel set off to be handed over to the MoD from Glasgow for Portsmouth on 27 August, arriving on the 31 August.
The Type 45 destroyers are intended to provide the “backbone” of UK naval air defences over the next 30 years. Each destroyer is capable of engaging a large number of targets simultaneously through its Sea Viper and Aster missile systems, which use a radar system known as Sampson to locate and track incoming aircraft and missiles. The aim is to defend aircraft carriers – such as the Queen Elizabeth class carriers currently being built by the Aircraft Carrier Alliance consortium – groups of ships, and amphibious landing forces.
Jim Hill, a systems engineer at BAE Surface Ships, has been working on the Sampson radar system for ten years, including the initial design of processing chips. The system has been tested on land at an installation in Cowes on the Isle of Wight and other facilities. The Sampson system acts as the main sensor for the Sea Viper command and control weapons system, helping to locate targets. “Sampson works as the 'eyes' for the whole Sea Viper system,” said Hill. “We've done land-based tests, but also taken it out on a sea-based platform.” The radar has been subsequently integrated on to the destroyers.
“There's been quite a few challenges during the development of the system,” Hill added, “not only in terms of the low level electronics but also the carbon fibre casing of the radar and the huge bearing it sits on, to all the cabinets.
“In terms of digital design, there are always problems with circuit boards and manufacture of circuit boards – them being affected by noise, for example, and bugs in the system. When something's been developed for ten years there's so much complexity involved it's difficult at times to drill back down to find those things.
“The paint that was used early on on the Sampson antennas turned a chalky colour – not so good for a 30 year lifecycle. And there are always going to be mechanical issues with a six tonne piece of equipment sitting on a mast. We had to attach a lot of metal to carbon fibre which presented a few interesting challenges in terms of material compatibility.”
The radar system has remained more or less same in terms of physical hardware on each destroyer, but there has been an “evolution in terms of the software and functionality used within it”, Hill said.
David McRae, senior marine engineer on the project, was responsible with his team for the Dragon's propulsion systems and machinery. He said: “We've been on this project for two and a half years and have taken it from a static box to being a vessel that can travel at 30 knots. I was very proud to see the ship propelled through the English Channel and down to Portsmouth having successfully completed all the acceptance trials.”
McRae and his team will now be responsible for the sea trials of ship number five, Defender. Static work is also being undertaken on ship six, Duncan, at BAE's Glasgow facility. “Defender is almost ready to go to sea,” McRae said.
Dougie Stewart, Type 45 project manager at BAE, said the time taken to carry out sea trials had halved since the beginning of the programme as lessons from building the first ships were absorbed.
“The first thing we will do now is get our heads together and thrash out the lessons we have learnt from Dragon. We are getting toward the optimum now – but with Defender there will be things we can do to make it better.”
McRae said: “If you look around the old traditional shipyards there's some important work going on – just look at the Queen Elizabeth class aircraft carriers.
“We're very proud of what we do up on the Clyde. The Type 45 is a very complex piece of kit and we have have a lot of people putting in a huge amount of effort. It's a quantum leap forward in terms of a Royal Navy warship and we're proud to be involved in that.”