The problem is the \r\n at the end of the first string. If you want to use "Fract/Exp String to Number" directly, you would need to strip these out and add at leat one \s instead before concatenating.
Easier would be to use "Scan strings for tokens" first as in the attached code fragment image. The default delimiters here are \s,\t,\r,\n and empty tokens are skipped.
(Of course you could also get only the seven numbers of the original string, convert the time separately, and append it to the DBL array after the loop.)