The concept of bouldering circuits comes from the world famous sandstone bouldering area Fontainebleau just South of Paris, France.The first painted circuit (small colored arrows and numbers are painted onto the rock to signify each bloc) was created in 1947 by Fred Bernick in the Cuvier Rempart area, followed by routes at Les Gorges d'Apremont painted by Pierre Mercier in 1952. The standardization of route color by difficulty (Yellow = PD, Orange = AD, Blue = D, Red = TD, Black = ED, White = ED+) dates back to the 1980s. At the time, people would climb in Fontainebleau primarily to train for mountain climbing. Thus, the 1936 French expedition to Karakoram included several Bleausards (Bleau climbers). Bleausards Robert Paragot, Lucien Bérardini and René Ferlet made the first ascent of the South Face of the Aconcagua in 1954.
An indoor circuit is a set of blocs of the same color holds within a certain grade range. In the UK, most people would agree that The Climbing Works (Sheffield) was the first major indoor climbing centre to introduce circuits within their route setting programme when they opened in 2006. Nowadays, bouldering circuits are widely used in many climbing centres throughout the UK.
Circuits, by creating a ‘tour’ of boulder problems that flow around the climbing centre, are an excellent training tool for our customers. Colour coded blocs are an obvious and visual course to follow in a session or when warming up and easier to identify than searching for specific grades using a small tag (that may have fallen off).
Like with the original Fontainebleau idea, climbers here use the circuits themselves as a tick-list or goal for that climbing session or set. Not assigning a specific number grade allows climbers to try problems they would not usually try because they feel it's outside their ability level or they are put off by the number associated with the bloc ("I would never try a V6..."). An individual circuit at the Castle now comprises of 40+ blocs and offers a perfect goal for a single session. A full Castle Yellow circuit (V4-V6) would be serious bit of climbing and may even come close to matching some of the legendary Fontainebleau red circuits like Roche aux Sabots.
Setting circuits isn't about making life easier for the setters because don’t have to grade every specific bloc- it's about creating bands of grades we feel suit the groups of ability levels within our customer base to guarantee something for everyone.
Some walls think it's such a great idea that they only set circuits! However, as in Fontainebleau (our favourite bouldering venue) The Castle also has ‘off-piste’ blocs that are not colour coded and have individual grades. This gives the setters a bit of freedom to use holds differently and to give each area a distinctive flavour. However, as with all grading, these are only a guide for climbing within The Castle and are not meant to be taken as historical, benchmark or landmark grading. We aim for consistency and quality and I think we mostly get it right. However, as with Font grading, sometimes easy problems can seem very hard if they're not your style or if the conditions aren't right!
Many centres that use circuits tend to re-set an entire circuit at a time. We don't becuase we feel that this limits how much you can change the layout of each area using volumes. Instead, we change each of our 8 areas as complete overhauls and re-set all the blocs, including the circuits, within those areas. We feel this keeps areas always looking fresh and different.
To learn more about climbing in Fontainebleau this UKC article linked covers a lot of the details. And remember... Font can be reached in less that a day travelling from the Castle!