The use of lightweight advanced composites in the aerospace and defence industries has delivered major performance improvements for operational aircraft, significantly reducing product life-cycle costs through improved fuel efficiencies and much lower maintenance, repair and overhaul bills.
According to TRB Lightweight Structures (TRBLS), these major long-term benefits have driven leading manufacturers, such as Airbus and Boeing to design and build the latest commercial aircraft, such as the A380 and B787 Dreamliner, with over 50% of their structural parts made from fibrous composites. The composite system primarily specified for commercial aircraft is a honeycomb prepreg composite laminate produced in an autoclave, which is extensively used for interior applications including: sidewalls, ceiling and floor panels, galleys, toilets and partition walls; and also for exterior applications, such as: wing sections, flaps, ailerons, antenna radomes, access panels and doors.
TRBLS says that rail is poised to make the same sorts of gains in operating efficiency, performance and lifecycle cost benefits by using advanced technology composite materials for the next generation of high performance trains, which also need to be lighter, faster, more energy efficient and cheaper to maintain. To meet these new materials needs, TRBLS explains that it has added major new composites design and manufacturing facilities, certifications and people and is now able to help train manufacturers take advantage of the significant benefits in using advanced composites solutions.
TRBLS adds that it has been helping train manufacturers and operators for many years, with a long history as an IRIS-approved, Tier 1 supplier of lightweight engineering solutions for train builders worldwide. TRBLS claims it has designed, manufactured and sometimes installed components for projects as diverse as Hitachi’s new high-speed train, the London Victoria Line, and the UK West Coast Mainline to name just a few.
TRBLS says its design and materials processing capabilities now includes alternative lightweight composites materials that comply with the latest and most stringent fire, smoke and toxicity guidelines detailed in EN 45545. These materials include phenolic SMC (sheet moulding compounds), modified epoxy glass prepreg, fire retardant foam cores, carbon/phenolic prepreg, and select thermoplastic materials. The new 4000 sq. ft clean room, built to ISO 14644 standards, along with a newly installed autoclave (3m long x 1.5m wide) heated pressure vessel were key investments to meet the exacting needs of the Aerospace and Defence market: autoclaving is an established manufacturing processing step where only the highest quality composite structures are acceptable and is used extensively for making Aerospace approved components. TRBLS has also recently gained AS9100 (BS EN 9100) aerospace accreditation, a globally recognised quality standard for the aerospace and defence industry, adding to the IRIS (International Railway Industry Standard) and ISO 9001 certifications already in place.
Some recent high-profile Rail projects have begun to take advantage of more advanced lightweight materials and are reaping the benefits. Bombardier’s new AVENTRA platform – to substitute the Electrostar – weighs only around 30-35 tons, a decrease of up to 28% compared to earlier 42 tons designs: the new platform consumes 50% less electricity than the Class 319 equivalent and is faster, enabling quicker journey times. The new Siemens Desiro City platform is a modern, lightweight and energy efficient train, which is on average 25% lighter than current UK trains in service and consumes far less energy.
TRBLS explains that it has been working in partnership with rail customers to develop lightweight solutions in a wide variety of applications. Recent composites projects they have delivered include developing a new lightweight composite antenna cover for Alstom Transport, reverse engineering a stiffer and lighter coupler hatch for the West Coast Pendolino, and providing an innovative way to repair corrosion damage to sections of the castellated steel roofs on a fleet of train carriages; using a new TRBLS composite based patching system. TRBLS is also working confidentially with key OEM’s to design and build cost-effective composite solutions to remove significant weight from key components – up to 60% in some cases.
The new train roof composite repair system developed by TRBLS engineers, the company adds, has been approved by Virgin Trains in preference to using conventional welded mild steel patch repairs, which remain susceptible to corrosion and subsequent re-repair; polymeric composites materials inherently do not corrode. It is the first composite repair work of this type to be used for rail maintenance in the UK. According to revalidation engineering criteria, the composited patched roof section provides the same structural integrity as a welded steel patch.
The TRBLS says its composite roof repair sheet material is made from a glass fibre reinforced epoxy prepreg resin, which is first laid up in the clean room and then moulded at high temperature under pressure to aircraft specification quality standards in the autoclave. Standard 1m2 x 0.765mm thick sheets are produced, which can be cut to size as needed, allowing for the train roof design profile requirements. Roof repairs are made by bonding an epoxy glass patch over the damaged section using a rail approved structural adhesive certified to BS 6853 and BS 476 fire standards
This cost effective new roof repair system is designed to offer train operators significantly reduced maintenance costs, providing long lasting corrosion free repairs, and avoiding the need to replace the entire train roof at an estimated renewal cost of circa £100,000. Rolling stock is also out of service for less time; a TRBLS composite patch can be easily and quickly applied to repair a train roof within 24 hrs.
The TRBLS management team reports it has made major strategic investments to grow its capabilities while employing continuous improvement programmes across the business to increase efficiency, reduce costs, and raise quality even higher. Over the last four years, the business has expanded by approximately 10% annually, adding around 4,000sq.ft per annum of new factory space.
Speaking about the new strategy and business expansion, Richard Holland, Managing Director of TRBLS commented, “Over the last 18 months, in addition to putting in place our new composites capabilities, we’ve implemented improvements across the business. TRB Lightweight Structures is now, probably, one of the very few UK manufacturing companies with such a long history of supply to the rail industry, able to design from concept and deliver such a broad range of latest technology lightweight materials solutions. We are ready to take on and play a leading role in delivering the future needs of the rail industry.”
Companies: TRB Lightweight Structures
Industries: Mass Transport