There can be no doubt that ISTD, anchored throughout the war at Manchester College, produced a range of intelligence outputs that were strategically vital to British and Allied operations. The contribution to the D-Day landings naturally stand out, but it is in the detail of smaller operations that the remarkable nature of the work involved is brought to the fore. One such was a raid on German ships anchored at the French port of Bordeaux, made famous in the film The Cockleshell Heroes. The attack was to be conducted by canoeists, who would enter the Gironde estuary, find their way to the mouth of the Garonne River, canoe up it, and attach limpet mines to their targets. This entailed paddling eighty miles. The task of ISTD was to provide as much detailed information as possible to help the brave souls who had volunteered to undertake this daredevil, and potentially suicidal, enterprise. ISTD staff at Manchester furnished information on tides and currents and pinpointed safe hiding places where the men could lay up during daylight hours. To do this, more than 2000 ground and aerial photos of the region were studied and over 600 silhouettes composed to enable the canoeists to identify their position while moving under cover of darkness, working out heights of landmarks and natural features, and even providing information on the distinct smells of the region, emanating, for example, from a brewery and a chemical factory.
The second example comes from Heidi Brønner, one of the Norwegians working in Section B. Her job was to produce marked maps and detailed images of targets to be attacked, constructing mosaics made from glued together photos in order to do so. ‘A target at Skien river is to be attacked by Mosquito planes from low altitude’, she wrote of one such operation. Only the day before, British photo reconnaissance aircraft had flown over the area, and now, as a result, Heidi had before her two heaps of photos, rushed to Manchester when aircraft landed at their Oxfordshire base following sorties over Norway. Heidi then put the photos under a stereoscope, a device that allowed the viewer to see a 3-D image and that was essential if accurate intelligence on heights, depths, and features was to be generated.
Now I look down through the lenses for the first time. For a few seconds my eye muscles are opposing, then the terrain jumps up towards me in three dimensions, so suddenly that I jump. There is snow on the ground, all mixed up colours and tints have gone away. And there is sunshine. Trees and houses pop up so alive that you want to touch them with your finger, and by the shadows on the snow you may study the vertical forms as if you were standing there yourself. One of important things we find is a cable which is stretched over the river between two tall masts, and on the mosaic this is marked by white ink and a warning text added [for the benefit of the pilots who would deliver the attack at low altitude].
