Magazine serving the bus and rail transit & motorcoach operations since 1904
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Partnering with purpose AECOM partners with our clients to offer fresh, innovative and state-of-the-art transit solutions. Our vision is to create more livable neighborhoods and thriving business communities. Visit us at booth no. 1537. www.aecom.com Photo credit: Metropolitan Transportation Authority / Patrick Cashin. 86 < m ETRO m AGAZINE SEPTEMBER/OCTOBER 2014 metro-magazine.com areas to identify unexpected high tem- perature zones is a good "best practice." Needless to say, fre prevention is an ongoing process; and, even when dealt with vigilantly there is always some re- sidual risk of an event as seen in Figure 2. Most would see this as unfortunate accident and we can sometimes believe that determining the origin and cause resolves the problem. Such incidents The engine compartment, which is one of the more well-known fre risks, poses several challenges that efect the detection and suppression of fres. Ven- tilation, through fans and openings in the engine compartment, can produce high levels of airflow. This facilitates necessar y cooling of the engine and compartment, but can also increase the intensity and spread of flames, which can have an enormous impact on fire detection times and suppression sys- tem efectiveness. The varying designs, geometry and clutter represent risks that must be an- alyzed. Te frst step in this process, and perhaps the most important one, is to conduct a thorough fire risk analysis, which should include a Failure Mode Efects Analysis (FMEA) during the de- sign phase. Te FMEA will identify the highest risks with regard to occurrence a n d s e ve r i t y a n d w hat m e t h o d s a re used to detect them. Tis will help en- sure maintenance practices and train- ing address the risks identifed. Te frst few months of operation and operation in all seasonal conditions are also critical. High temperatures created in the engine compartment can cause premature failure of components and potentially increase surface tempera- tures, which could ignite flammable fuids more readily than expected. Te use of temperature strips in high risk BUS FIRES Fig.2: Bus fres are a common issue worldwide.