<p>London Underground 1972 Bakerloo tube stock train - on the left is part of an 'uncoupling driving motor' car (UNDM) and on the right is part of a "driving motor" car (DM).
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Both of these have electric motors which help power the train but only the DM also has a driver's cab.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/47739225@N08">citytransportinfo</a>
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/citytransportinfo/50731029151/">1972Mk2-UNDM-DM-P1670395</a>