Shaping the future

The latest generation of tube bending machines are being used to create complex parts for the UK’s Astute submarine programme

Developers of software-controlled all-electric tube bending systems claim the technology has passed another landmark after being used to aid part production on one of the UK’s biggest ever naval projects.

Since first appearing on the market 15 years ago, all-electric tube bending has made steady inroads into major industries thanks to what are claimed to be key advantages over conventional hydraulic equipment.

These are said to include increased flexibility, dramatically reduced energy consumption – claimed to be up to 90 per cent less – and lower scrap material levels.

All-electric bending specialist Unison said that the use of one of its machines on the Astute submarine programme at the Barrow Shipyard in Cumbria marks a major endorsement for the technique.

Unison said the all-electric machine is BAE Systems Submarine Solutions‘ first piece of bending equipment to include both right and left-handed bending capabilities. The feature provides significant benefits in terms of scale and production efficiency, allowing the company to rapidly fabricate a complex tubular part shape without the need to construct smaller pieces. In addition to increasing speed, the process eliminates expensive X-ray and crack-detection testing, which would otherwise be required to validate the strength of welded joints, added Unison.

The Astute programme, which will provide the Royal Navy with a new generation of nuclear-powered attack submarines, is one of the most complex engineering projects ever undertaken in the UK, with each vessel containing more than one million individual components and a demanding production schedule that can be thrown off course by the failure to produce any single part correctly.

Alan Pickering, Unison’s managing director, said: ‘Naval shipbuilding is possibly the most demanding application there is for tube bending machinery. A constant stream of application-specific parts are required, and typically need to be produced just-in-time as work progresses along the vessel. The software-centric nature of all-electric tube bending machines, with their attributes of fast, accurate set-up and ultra-precise bending, provides versatile automation to support this dynamic work environment.’

The 20mm machine uses a servomotor-based movement axes to achieve accurate position control. Programs are input into the design database and transferred to the motor to provide precision cutting and bending. As no manual intervention or adjustments are required, the system can be set up for operation in about 15 minutes — around half the time needed for the more power-hungry hydraulic bending machines, claimed Unison.

The environmental credentials of all-electric bending are often flagged up by its proponents as a key reason to use it as an alternative to hydraulics.

The fact that the design does not include continuously running hydraulic pumps means that a significant electrical current is only drawn upon in the action of making a bend. The system also minimises scrap metal, which is often produced in excess by hydraulic bending equipment. The all-electric machines are also claimed to be quieter and produce less hard-to-dispose-of waste products.

Unison, which is based in Scarborough, said that the ability to provide sophisticated monitoring and support to reduce production downtime was another factor in its favour.

Over the past few years Unison, which claims to have pioneered all-electric bending, has reported an increase in demand for its machines, largely driven by global increases in the cost of both tubing materials and energy. It said these cost factors were helping propel the technology out of niche areas such as those involving exotic materials and into use on major engineering projects such as the Astute submarine programme.

In addition to ship builders, Unison has supplied tube bending machines to manufacturers in the aerospace industry. The machines are used to produce airframes on engines in both fixed-wing aircraft and helicopters. They are also employed in aircraft repair facilities where parts are reverse engineered and re-created. Airbus has used Unison all-electric tube bending machines on components such as tubular hydraulic fluid lines. These carry fluid in the wings of the A380, A340 and A320 aircraft. Boeing has also used all-electric bending on some of its helicopter projects in the US.