Tenby and Saundersfoot’s Role in the ‘D’ Day landings took place eleven months before, where Tenby and Saundersfoot hosted a ‘top secret’ military exercise called Exercise Jantzen. (The 6th of June 1944 was designated ‘D’ Day, the day when the allied forces landed on mainland Europe to commence the liberation of the occupied countries.)

Jantzen was part of the extensive preparation and planning for Overlord. It took place in Carmarthen Bay between the 22nd of July and the 5th of August 1943. It was the first exercise undertaken to practice landing on an enemy beach and unloading supplies. 

The War department filmed the exercise and produced a short film classified as ‘top secret’ that outlined the objective of the exercise and evaluated its success or failure. Fortunately, the film (transferred to DVD) survives, and Tenby Museum & Art Gallery has a copy in its archives.

During the exercise, security in the area was strictly implemented. Entry into the designated area that included Tenby and Saundersfoot was denied to all non-residents unless they had a special pass. Tenby was placed under a curfew, and the carrying of cameras, telescopes or binoculars was forbidden. All civilians had to carry their identity cards at all times. The curfew from dusk to dawn was in operation from the 12th of July to the 9th of August. Mail, telegraph and telephone lines were subject to censorship during this period.

Port Talbot, Swansea and Tenby represented departure points from friendly territory. Several photographs taken at the time appeared after the war showing the Landing Barges (vehicle) in Tenby harbour being loaded with troops and equipment. The enemy territory was represented by the beaches from Pendine to Saundersfoot. The weather during the exercise ranged from calm to gale force eight.

The evaluation of the exercise concluded that the exercise failed to fulfil its objectives. Equipment failures were common, with one barge leaking significant amounts of petrol on Saundersfoot beach. The Alligators used to unload the beached vessels all eventually failed, and perhaps most significantly, the number of stores unloaded fell well short of the target set.

The exercise was, however, a very useful learning curve. Lessons were learned about the loading of supply ships, and the need for beach tracking was clearly demonstrated. Similar exercises were carried out on the south coast, and ten months later, on the 6th of June 1944, the ‘D’ Day landings took place.

You can learn more about Tenby and Saundersfoot’s Role in the ‘D’ Day landings by watch a four-reel edited film below from the Imperial War Museum with commentary and animated maps describing Exercise Jantzen, a large-scale amphibious exercise on the Pembrokeshire coast in July 1943, aimed to practice the supply organisation for a corps landing and discuss the lessons of the exercise.

From an original Visit Tenby post by Neil Westerman