|VMS backup tapes are ANSI labelled tapes, and yes a Unix DD should be able to copy the file to disk.|
Then binary transfer the file to VMS.
On VMS the record-type probably will be wrong, and has to be corrected either by SET FILE/ATTRIBUTE=(RFM:FIX,LRL:n), where n is the backup blocksize to be determined.
There are some FIX_SAVESET programs on various freeware distributions to do the correction.
The newer VMS version (8.+) have an option /REPAIR on the backup command.
But be aware, VMS disk backup files can have a maximum block size of 32256. If the saveset on tape has been written with larger blocksize, then it is not possible to handle it as a disk saveset.
As a last resort, there is a vmsbackup available for the Unix and Windows world, which can extract files from backup savesets, although only stream and variable length record files, which can be handled on Unix, no libraries and indexed files.
Joseph Huber, http://www.huber-joseph.de