Class 67's, the 'odd-job locos'?

Built for a traffic that no longer exists as such (Royal Mail postal and parcels), the class 67 diesels seem to have become the odd job locos on the network. Although having an engine horse power output close to the class 66's, the tractive effort (31750lb) precludes them from heavy freight hauls when compared to the 92,000lb tractive effort of the class 66's, and the locos don't get chance to use their designed top speed of 125mph. This video shows the locos on 'Thunderbird' duties and Network Rail test trains in the Retford and Doncaster areas.