The morning of D-Day saw American Rangers heading for Pointe du Hoc to silence the big 155mm guns believed to be installed at the top of the cliff. To assault the cliffs, bombardment from British Destroyers were to keep the German heads down along with air assault. The rangers had rocket fired grappling hooks to scale the cliff by rope and DUKWs equipped with ladders from London fire brigades. These ladders had Vickers K guns installed at their tops, to help keep the German at bay while men climbed up.
About half of the landing force made it to the cliffs, but an hour late and lost the element of surprise. The Rangers that landed were on their own, as the reinforcements were redirected towards Omaha Beach due to the delay.... Which was a good thing for Omaho Beach, as the Rangers were partially responsible for getting the stalled landing off the beach. This reduced force still made it to the top of the cliffs with few casualties and did secure the gun position. The guns weren't installed, however, but Rangers used thermite grenades to disable them anyway. Alas, the British ladders and guns couldn't be brought to bear due to the heavy surf. The real threat was the Maisy gun position a few miles inland, which the Rangers did take out 3 days later.