Monday, 30 April 2018

The Zeebrugge and Ostend Raids: The blockships

The five blockship used during the Zeebrugge and Ostend Raids on 23rd April 1918 were all drawn from the Apollo-class of 2nd class Protected Cruisers. There were twenty-one ships in the class plus eight of the slightly modified Astrea-class, and they were built between 1889 and 1892.

Their characteristics when built were:
  • Displacement: 3,600 tons
  • Dimensions:
    • Length: 314' (96m)
    • Beam: 43' 6" (13.26m)
    • Draught: 17' 6" (5.33m)
  • Speed: 19.75 knots
  • Complement: 273 to 300 officers and men
  • Armament: 2 × 6-inch (152mm) QF Guns; 6 × 4.7-inch (120mm) QF Guns; 8 × 6-pounder QF Guns; 2 or 4 × 14-inch (360mm) Torpedo Tubes
By the time that HMS Dreadnought was launched, the protected cruisers were already becoming obsolete, and seven of the class (HMS Andromache, HMS Apollo, HMS Intrepid, HMS Iphigenia, HMS Latona, HMS Naiad, and HMS Thetis) were converted into minelayers in 1907.

Six of the class were converted into blockships for the Zeebrugge and Ostend raids. These were:
  • HMS Intrepid: Expended at Zeebrugge
  • HMS Iphigenia: Expended at Zeebrugge
  • HMS Thetis: Expended at Zeebrugge
  • HMS Brilliant: Expended at Ostend (1st raid)
  • HMS Sirius: Expended at Ostend (1st raid)
  • HMS Sappho: Intended to be used at Ostend (2nd raid), but broke down on the way and not used
HMS Intrepid

HMS Iphigenia

HMS Thetis

HMS Brilliant

HMS Sirius

HMS Sappho

To prepare them for their use as blockships, the vessels were stripped of most of their armament and many compartments were filled with concrete. The extent of the damage inflicted on the blockships during the raids can be gauged by the following photograph:


  1. Very interesting. Not an action I knew much about until you started this series of posts.

    1. Lee Hadley,

      You are not alone in not knowing much about these raids. At least two fictional film accounts and numerous books have been written about the St Nazaire Raid during Workd War 2, but these raids - which were much larger and equally audacious - have not received anything like the same attention. Perhaps we need the British equivalent of Peter Jackson to produce and direct a film about the raids to make them famous.

      All the best,


    2. Totally agreed .. and out to see was the whole of the Grand Fleet is over the horizon in support .. but crazily it was also a surface (batleship mentality) answer to what was an undersea problem. How the Admiralty tried to thwart the U-Boat menace in WWI was fascinating. Jellicoe wrote a post war book ( which defending in statistics why it took the Admiralty so long to introduce the Convoy system! Don't get me wrong I am a Jellicoe fan .. but he did not understand the submarine mode of operation .. unlike WATU (see Connections UK 2017) in WWII. Hopw this did not sound like a rant ;)

    3. Geordie an Exiled FoG,

      The raids were proposed because Admiral Bacon's Channel Barrage - which was intended to literally catch the U-Boats in its nets - wasn't thought to be working as they were still getting through. As it was, blocking the canals to Bruges proved ineffective, and alternative methods of defeating the threat had to be pursued.

      The Admiralty's reluctance to employ convoys was both a reflection of the 'big ship' mentality of its members and a lack of effective anti-submarine weapons. Once the latter became available, defending the convoys became more feasible.

      It is interestingy to note that Max Horton was a submariner by training, and therefore had a better understanding of the submarine's strengths and weaknesses. This is possibly why - under his leadership - the Western Approaches Command was able to develop effective anti-submarine systems, tactics, and weapons as the war progressed.

      All the best,


    4. Geordie an Exiled FoG,

      Some years ago I met a frigate captain who'd done the Royal Navy's Perisher course. I understandt that such moves from poacher to gamekeeper are not unusual.

      All the best,



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