Turbine engine exhaust duct system and methods for noise dampening and attenuation

A mobile fracking system comprising:

• a trailer including a rear end, a front end, a bottom end, and a top end defining therebetween an interior space;
• a gas turbine at least partially housed inside the trailer in the interior space;
• and
• an exhaust attenuation assembly configured to receive exhaust gas from the gas turbine, the exhaust attenuation assembly attached to a portion of the trailer and including:
• a lower elongated plenum having a proximal end and a distal end, the lower elongated plenum extending a first distance between the proximal end and the distal end, an inlet adjacent the proximal end configured to receive the exhaust gas from the gas turbine, and
• an upper noise attenuation system movably connected relative to the distal end of the lower elongated plenum, the upper noise attenuation system being selectively movable between a stowed position, in which an outlet end of the upper noise attenuation system is positioned proximate to the distal end of the lower elongated plenum, and an operative position, in which the upper noise attenuation system defines an upper elongated plenum in fluid communication with the distal end of the lower elongated plenum and in which the outlet end of the upper elongated plenum is spaced away from the distal end of the lower elongated plenum at a second distance that is greater than the first distance, the upper noise attenuation system including an outward extending conduit configured for complementary receipt in relation to the lower elongated plenum and extending from an inlet end to the outlet end, a rod having a first end connected to a surface of the conduit at the outlet end, a guide attached to the lower elongated plenum at the distal end configured for operative slideable receipt of the rod between the guide and an outer surface of the lower elongated plenum, and a second end of the rod connected to one or more,
• (a) sheaves, or
• (b) pulleys
• configured for movement of the conduit between the stowed position and the operative position.