The global light rail industry is forecasted to reach $4.97 billion by 2026, growing at an annual rate of 9.8%. While Europe continues to maintain the highest market growth, the recent rise in light rail passengers across major U.S. cities has led to approvals for light rail extension projects throughout the country — expecting to drive market growth even further. Light rail vehicles produced by companies like Bombardier, Siemens, Kawasaki, Hitachi, Alstom, Ansaldo, and others are expanding across the nation due to advancements in areas like noise reduction, comfort and safety.
In cable assemblies and wire harnesses, there are hundreds and often thousands of opportunities for defects per assembly. Therefore, it is imperative that a manufacturer takes rigorous steps to mitigate the risk of incurring those defects. Multiple process controls must be deployed to ensure that a wire assembly is produced that meets or exceeds the customer’s requirements. Many of these measures are taken before the components are even built. Revision-controlled quality requirements---specified on prints and in workmanship standards---must be understood. Operators must be trained and must demonstrate this understanding. As an assembly is produced, a predetermined regimen of tests and other validations are employed, both by operators and technicians. These validations, depending on the project, can include mechanical, electrical, and environmental tests. Each of these stages in the quality assurance process ultimately ensures that the product meets or exceeds the customer specifications.
Making sure wire bundles are adequately secured or contained is an important step in creating a quality product, even after the necessary electrical or environmental protection has been applied. It is imperative that a wire assembly be secured adequately, and it is also crucial that the bundle fits well within the physical space allotted. This is where various wire bundle management techniques come into play. Wires can be held together using heat shrinkable tubing, lacing, stitching, tie wraps, metal bands, or braided coverings. The style and material used to secure the assembly helps it achieve the best performance possible.
Molding protects the connectors of a wire assembly from a variety of potential harmful influences. These include environmental factors such as water and chemical damage, as well as abrasion and other physical damage in service. Using the best material for the job also ensures the best possible adhesion for the components, yielding reliability and longevity of the end product. The choice of molding material used is directly related to the desired function and level of performance, and utilizing the best materials in the industry---such as urethanes , silicones, and epoxies---ensures the highest quality of assemblies according to client needs.
Insulation materials provide wiring harnesses with a layer of necessary protection in a variety of ways, depending on the specific requirements the product must meet. Insulation helps protect the product mechanically, electrically, or environmentally, meeting particular needs according to the product’s application. Additionally, a variety of materials used in wiring harness insulation ensure the various functions of cable harnesses are carried out in the best way possible using the best materials for the job.
Braided coverings and shieldings are an excellent way to make wiring configurations neat and uniform. Braiding gives wires more flexibility and a longer lifespan and can also offer a layer of electric protection or abrasion resistance. Although there are two different types of wire braiding widely used in the industry, machine braiding and premade (or slide-on) braiding, machine braiding offers more versatility, cost savings, and consistency, and should be something a contract manufacturing partner should be able to do in-house.
This November, Liberty Electronics will celebrate five years since producing its first in-house 3D printed part in 2013. The company added two additional 3D printers to its roster in 2016, another this month, and is looking ahead at the possibility of adding metal-capable machines in the future. The implementation of additive manufacturing has proven to be incredibly successful for the company and has continued to set Liberty apart as a versatile innovator in the industry.
Recently, the Washington Metro Area Transit Authority (WMATA) in the nation’s capital was forced to decommission nearly 75% of its new 7000-series rail cars due to crimping defects. The rail cars had crimping defects that went undetected until WMATA’s quality inspectors discovered them. The WMATA’s Quality Assurance, Internal Compliance and Oversight office (QICO), estimates that the rail cars will take over a year to be repaired. Going forward, QICO is requiring that in-process quality checks and high standards of engineering design be more explicitly outlined in WMATA’s manufacturing contracts.(1)