I eventually gave up on the 9 hour upload but, with a little help from Adrian, tracked the problem down to my use of sftp. Having switched to ftp the speed shot up five-hundred fold from 200KB/s to 10MB/s bringing the upload time down to just over 10 minutes! Over the IBM intranet I think I can cope with the lack of security for that much an increase in speed.
how do you change the sftp to ftp
I tend to use Filezilla, in which case you explicitly chose the “servertype” when setting up a connection.