By Dialogo March 04, 2011 Good workâ€¦ During a firefight, the last thing a machine gunner wants to do is stop fighting to change barrels, but that’s how it has always been done with standard, single steel-barrel machine guns. The reason for the barrel change is that at high temperatures barrels lose “strength properties,” according to engineers working on a promising alternative. One of the engineers is Vinny Leto, systems project engineer, of the Armament Research, Development and Engineering Center, or ARDEC, Weapons System Technology Directorate. During a test firing of a proof-of-concept barrel in December, Leto witnessed a measure of success with the High Performance Alloys for Weapons Applications Project. During testing, the first rifled, cobalt-alloy machine gun barrel ever produced using the “flow forming” process consistently reached high temperatures without degraded performance. The proof-of-concept barrel was made of an alloy that contains more than 50 percent of the metal cobalt. Cobalt alloys are erosion- and corrosion-resistant metals that are designed to retain high strength during long-term exposure to high temperatures. Cobalt alloys are frequently used in the aerospace industry, such as the hot-gas section of turbine engines, explained Leto. Cobalt alloys are also used as short liners for machine gun barrels. “If you look at steel in a machine gun environment, it gets very hot at a high rate of fire,” said Leto. “The benefit of the cobalt alloy is that it is designed to operate in high-temperature, high-stress environments. It has the added benefits of corrosion and erosion resistance.” While cobalt alloy barrel liners have been produced for years, it is very difficult with existing machining techniques to impart rifling. “The material, for all of its phenomenal properties, is very difficult to manufacture and machine,” said Leto. Different from machining, flow-forming is an advanced process used to manufacture precise cylindrical components. The process consists of high-pressure rollers exerting pressure on the exterior of a cylinder, pressing material against a rod-called a mandrel-on the interior of the cylinder. For this project, the flow-forming process was modified to produce the rifling in the barrel bore. More testing and data gathering will be required before engineers know if flow forming manufacturing can be achieved with the alloy. Success, however, would provide war fighters with three potential benefits: lightening their load, increasing barrel service life, and giving them a barrel that could operate at higher temperatures compared to a steel barrel, Leto said. Soldiers and Marines typically carry spare barrels into battle so that they have a cool barrel to exchange if they engage the enemy in a firefight, explained Leto. Having that strength at higher temperatures means that barrels may not need to be changed during a firefight, eliminating the need for the extra barrel and maintaining a steady stream of firepower. Engineering team members met all of their proof-of-concept test objectives when they fired more than 24,000 rounds and achieved an 1,100 degrees barrel temperature. Leto said the alloy barrel was fired from the ARDEC-designed Advanced Remote/Robotic Armament System. Steel begins to lose strength at approximately 1,000 degrees, Leto noted, and the test yielded data needed to assess and design the next round of improvements. The team is planning to produce another prototype that will be fired from a fielded infantry weapon later this year. Previously, the engineers had produced a half-length barrel as an initial demonstration of the flow-forming process before moving on to manufacturing full-length barrels. The Office of Naval Research assigned the engineers as principal investigators into the flow forming manufacturing technology. They are leveraging ARDEC’s expertise with metallurgy and small arms design and analysis. Prototype testing will be conducted here at the Armament Technology Facility, which is ARDEC’s small arms design and evaluation facility. Previously, the engineers had worked with the Office of Naval Research in development of lightweight 60mm and 81mm mortar tubes made with a nickel-based alloy. The team is also working with the Joint Services Small Arms Program, which is also based at Picatinny Arsenal. The JSSAP office oversees the day-to-day implementation of the plan by the joint services regarding the development and investment in small-arms technologies.
DesignPro hydrokinetic technology (Image: DesignPro Renewables) Irish company DesignPro Renewables has opened an opportunity for an experienced researcher to get involved in a renewable energy project related to hydrokinetic power under the SFI Industry Fellowship Programme.DesignPro Renewables is developing and commercializing small-scale hydrokinetic turbines as part of our EU-funded Horizon 2020 SME Instrument project, having just installed a 25kW turbine variant for trials at French river test site for hydrokinetic technology SEENEOH.According to the company, the potential research project as part of the fellowship could relate to remote identification of high potential resource areas, analysis of the interaction of the turbines and their environment, or mooring design and stress modelling.For full-time fellowships, researchers can spend up to 12 months working on the project. There is also an option for part-time fellowships, according to DesignPro Renewables, which added the research project will begin in April 2019.Aside from the 25kW variant under tests in France, the company is currently in the design phase for the larger 60kW machine, which will be built at the DesignPro facility in Limerick in Ireland before being deployed at a selected test site location.
Those who did not sing properly did not deserve to represent the country, said Yoshiro Mori, a former prime minister with a history of gaffes.He was speaking to 300 athletes at a send-off ahead of the August Olympic Games to be held in Rio de Janeiro.Reports say attendees had just sung Kimigayo, Japan’s national anthem.”When you go up to the podium, please do not be mumbling but sing the national anthem,” Mr Mori told those gathered on Sunday.”Athletes who cannot sing the anthem should not be considered to be Japan’s representatives,” the Asahi newspaper reports him as saying.Mori, who served as prime minister from 2000 to 2001, is well known for his off-the-cuff remarks.In February 2014, he claimed that English was the “enemy’s language”, when asked why he spoke Japanese instead of English while addressing an international audience.He also came under fire after he criticised Japanese figure skater Mao Asada’s performance at the Sochi Olympics.The Tokyo 2020 Olympic and Paralympic Games has also met with controversy – its first choice of logo was thrown out when the designer was accused of plagiarism and the design for the main Olympic stadium had to be scrapped because of spiralling construction costs.