Thanks Maggie, and belated thanks to you and Simon for sending me the photos of U9 in Dover, the one of her on the beach which we are discussing is reproduced below.
For the benefit of others, this was the most notoriously successful U-boat of WW1. Under the command of Otto Weddigen, she sank three obsolete armoured cruisers of the "Live Bait" squadron in the Broad Fourteens in the space of one hour: HMS Aboukir, Cressy and Hogue. She later sank another cruiser, HMS Hawke, and assorted merchantmen. U-9 is shown on Dover beach in 1919 with the Promenade Pier in the background. She was being towed from Harwich to Morecambe Bay for scrapping but went aground for a month enroute and was towed into Dover in sinking condition for repairs. She sank in the harbour and was raised and beached in front of Waterloo Mansions, eventually being repaired in the Camber. Those evil torpedo tubes in the photo accounted for the deaths of 1459 men of the Live Bait squadron alone.
High res image at:
http://shipsintheportofdover.fotopic.net/p53328414.html
Here is "Dover Beach" by Matthew Arnold, taken from the superb little booklet "Kingdom's Key" compiled by Christine Waterman when she was curator of Dover Museum.
High res image at:
http://shipsintheportofdover.fotopic.net/p64057327.html