Ferry Slip Apron Crane

Can anyone direct me to a good source of photos and/or plans for the crane on a railroad ferry slip that raises and lowers the apron? Specifically after the pulley arrangement, etc.

Thanks in advance.

This site has a lot of info about railroad ferry slips:

http://members.trainweb.com/bedt/indloco/developmenttransferbridge.html#Development

There also might be some useful photos in the pages about the railroads

http://members.trainweb.com/bedt/

Wow!! Thank you!! Everything I was looking for and more!! [bow]