<P> A turntable ladder (TL) is perhaps the best - known form of special purpose aerial apparatus, and is used to gain access to fires occurring at height using a large telescopic ladder, where conventional ladders carried on conventional appliances might not reach . The name is derived from the fact that the large ladder is mounted on a turntable on the back of a truck chassis, allowing it to pivot around a stable base . To increase its length, the ladder is telescopic . Modern telescopic ladders are either hydraulic or pneumatic . These mechanical features allow the use of ladders which are longer, sturdier, and more stable . They may also have pre-attached hoses or other equipment . </P> <P> A ladder can also be mounted behind the cab . This is sometimes called "mid-ship" and the arrangement allows a lower travel height for the truck, and also can be more stable in certain conditions . </P> <P> The key functions of a turntable ladder are: </P> <Ol> <Li> Allowing access or egress of firefighters and fire victims at height </Li> <Li> Providing a high - level water point for firefighting (elevated master stream) </Li> <Li> Providing a platform from which tasks such as ventilation or overhaul can be executed </Li> </Ol>

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