LauraPX
Train Attendant
It's from the Amtrak Service Standards Manual, which is updated every couple of months and is available in PDF format on this page: Amtrak Freedom of Information Act (FOIA), under the "Other Materials" heading.
The Sleeping Accommodations diagrams are on the last 2 pages.
Note: The Family Bedroom diagram is completely wrong, but I think the dimensions are correct.
Thank you for the link, I have saved it with my other Amtrak links.
Interesting that they have the info on the berth sizes so well hidden. Perhaps they thought it would be bad PR and scare away business, but I think openness is a better policy so passengers know what to expect. Boarding the train and then being very unhappy about the size of the berth is likely to produce more angry "Never again!" reactions and negative reviews on the Internet and with friends and relatives.
The Amtrak website has a page for each compartment type that lists the dimensions only for the room; I think it would be better to revert to the old policy of listing the berth dimensions on those pages as well. The TrainWeb web site has a copy of the old Amtrak page at Amtrak Sleeping Cars (with the inaccurate info about the size of the lower adult berth in the family bedroom).
And you are quite right about the family bedroom diagram being completely wrong -- they used the diagram for the Viewliner accessible bedroom! The TrainWeb page I mentioned above has an accurate diagram for the family bedroom.