APT-P sound proofing requirements issue 2 (IM-NOY-049)

IMNOY.40 outlined the basic philosophy underlying the acoustic treatment of APT-P trailer cars with particular regard to the application of structural damping compounds. Vehicle Design Note No.49 summarised the design proposals in October 1973. The relevant drawing is OAPD-P-0546, the latest version being Issue 9. This memorandum reviews the...