GWR 4575 class steam loco 5521 tails a "Steam on the Met" railtour at Amersham, celebrating the London Underground's 150 anniversary. Class 20 loco 20189 leads the convoy, with Met loco 12 "Sarah Siddons" just in front of 5521.
<a href="//commons.wikimedia.org/wiki/User:Mattbuck" title="User:Mattbuck"><i>mattbuck</i></a> <small>(<a href="//commons.wikimedia.org/wiki/Category:Images_taken_by_mattbuck" title="Category:Images taken by mattbuck">category</a>)</small>
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<span class="int-own-work" lang="en">Own work</span> by <a href="//commons.wikimedia.org/wiki/User:Mattbuck" title="User:Mattbuck"><i>mattbuck</i></a>.