This training technique, also referred to as 'goblet' / 'gobelet' training is the most common and probably also the oldest technique for training grapevines on walls. It is predominantly used outside wine-growing regions and is inferior to the strict cordon forms, because fans often become messy and unmanageable (earning them the descriptors wild-, irregular-, and free form). Nevertheless, to provide a complete picture of vine training techniques, we present it here.
A fan/goblet vine can be more or less branched and varied, and can be encouraged into an extensive stem framework- in order to frame windows, for example. You'll want to limit the number of arms and branchings, however, to ensure a space of 0.5 to 1.0 metres between them at the outer edge of the vine. For optimal results (i.e a good yield), we prune differently depending on the level of the vine: we spur (short) prune the lower area, rod (medium-long) prune the middle zone, and cane (long) prune the upper canopy. This can be a bit tricky for beginners, and unfortunately, the situation can quickly become messy and confusing if the trunk frame and arms are not clearly separated -- usually a result of insufficient pruning knowledge or experience.