>> There was, however, inconsistency in the manner in which they were designated: the longer 535 Class, which were 535 feet in length overall
, AND the 502 or 522 Class, 502 feet in length between perpendiculars
(LBP) and 522 feet in length overall (LOA). Why this confusing distinction in determining class length, I dunno. >> [I have added the italics
> Merchant ships were generally referred to by length between perpendiculars, and the Shipping Board types were always referred to that way. >
I agree with the "generally", but emphatically disagree with the "always". Of the two classes of early 1920s USSB vessel types, the shorter was the 502 Class, which I concede is usually how this class is designated, and for certain, that refers to the LBP of 502+ feet. The longer type was the 535 Class, which refers to the LOA, because the LBP was 518 feet. Now whereas the longer is ALWAYS the 535 Class (NEVER the 518 Class*), the shorter is sometimes designated the 522 Class, obviously to achieve some consistency in their designations, in this case in the direction of the LOA. Thus my statement that the original designations--LBP versus LOA, one class versus the other--afford a confusing distinction.
for APL confirmation of these two types and yet another prewar photo of SS President Adams
(1st)/SS President Grant
*Okay, okay, NEVER write NEVER, but at least this usually observant reader has not seen a 518 Class.