<p class="chapo wysiwyg-labeur1">The installation of breakwaters in front of the beaches made it possible to protect the landing operations prior to the construction of artificial harbours.</p><h2 class="titleBold"><em>Mulberries</em> and <em>Gooseberries</em></h2><p>Beginning on D-Day, the Allies started building two artificial harbours (<a href="/node/6642" data-entity-type="node" data-entity-uuid="0167a718-b755-44ce-a64b-c66885e5cb6f" data-entity-substitution="canonical"><em>Mulberries</em></a>), so that they could land troops and equipment before traditional ports were recaptured from the Germans. But the weather was not favourable and <em>Mulberry </em>B (for <em>British</em>) was not operational until 18 June 1944, while <em>Mulberry </em>A (for <em>American</em>) had to be abandoned after the storm of 19–21 June. The remains of these two artificial harbours were the subject of a <a href="/node/6652" data-entity-type="node" data-entity-uuid="fa9002e2-1b59-4b11-b57a-f8de1804870b" data-entity-substitution="canonical">geophysical survey</a>, using a <a href="/node/6659" data-entity-type="node" data-entity-uuid="d8fa3b9e-a330-4ff9-aaa7-fba20c2a0f8a" data-entity-substitution="canonical">multibeam echo sounder</a>. The <em>Mulberry A</em> remains, located in the Saint-Laurent-sur-Mer sector, were studied during the <a href="https://www.history.navy.mil/">NNHC </a>campaigns in 2000–2002 and those of <em>Mulberry</em> B, around Arromanches, by <a href="https://www.gov.uk/government/organisations/uk-hydrographic-office">UKHO </a>in 2011.</p><p>Because neither of these two artificial harbours were operational on D-Day, the Allies rapidly installed five breakwaters in order to protect operations in the five landing sectors. Code-named <a href="/node/6630" data-entity-type="node" data-entity-uuid="86bb650e-3880-4234-b7e1-326f6424977e" data-entity-substitution="canonical"><em>Gooseberries</em></a>, they consisted of rows of old vessels that were deliberately sunken as blockships, to protect smaller vessels from the swell. The <em>Mulberries</em> A and B were then set up around <em>Gooseberries</em> no. 2 (Omaha) and no. 3 (Gold). The height of the largest caissons in these <em>Mulberries </em>allowed them to accommodate deep-draft vessels at high tide. The Americans landed 10,000 tonnes daily, on average, in the shelter of the <em>Gooseberries</em>, compared with 6,000 tonnes in <em>Mulberry </em>B.</p><h2 class="titleBold">Studied <em>Gooseberries</em></h2><p>While <em>Gooseberry</em> no. 4, in front of Juno, has not really been studied, breakwater no. 1 (in front of Utah) and no. 5 (in front of Sword) were the subjects of geophysical surveys by the <a href="https://www.culture.gouv.fr/Thematiques/Archeologie/Acteurs-formations/…;, in 2017 and 2019 respectively.</p><p>At Sword, surveys precisely located of the hull bottoms of the <em>Empire Tamar</em>, the <em>Courbet</em>, the <em>Becheville </em>and the <em>Dover Hill</em>, wrecks that were extensively scrapped, and have been documented by Caen Plongée. The <a href="/node/6623" data-entity-type="node" data-entity-uuid="e1fd134f-2f42-40ce-8680-145d1df12c4c" data-entity-substitution="canonical">acoustic data</a> confirms that, at best, only some debris remains of the five other <a href="/node/6612" data-entity-type="node" data-entity-uuid="fe65cd10-a9f8-4f90-9882-98a05a23dac2" data-entity-substitution="canonical">blockships </a>that made up the eastern portion of this breakwater. This difference is due to the evolution of <a href="/node/6626" data-entity-type="node" data-entity-uuid="6e07509b-8796-47d6-a0e1-cbdfc7131adc" data-entity-substitution="canonical">salvage </a>methods; in the western part of the breakwater, only sheet metal protruding from the substrate was cut with a blowtorch, at the surface or by divers, whereas the wrecks situated to the East, such as the <em>Sumatra</em>, were destroyed by explosive, and the remains were removed using a claw crane that could dig into the mud.</p><p><em>Gooseberry</em> no. 1, off Utah Beach, consisted of nine metal-hulled blockships and two <a href="/node/6627" data-entity-type="node" data-entity-uuid="9249ba4f-b844-4ee5-97ff-d53c02258b38" data-entity-substitution="canonical">ferrocement </a>freighters, the <em>Vitruvius </em>and the <em>David O’Saylor</em>. Due to their composition, these two wrecks were not salvaged and remain well preserved.</p>
