Operation Anvil (Mau Mau Uprising) the reserves. The "Grey" grade was made up of prisoners believed to be passive Mau Mau sympatherisers though for whom strong evidence suggesting their true loyalties was lacking. The last category, "Black", was reserved for detainees identified by the hooded informers or the Special Branch of the Kenya Police as potentially violent insurgents or terrorists. A few may have been prosecuted by the government, but most were funneled through the "Pipeline", a system of work camps, decreasing in brutality until an individual was "re-educated" and deemed safe to release on a native reserve. Operation Anvil (Mau Mau Uprising) Operation Anvil
Mau Mau Uprising ordered all Mau Mau suspects to be screened. Of the scores of screening camps which sprang up, only fifteen were officially sanctioned by the colonial government. Larger detention camps were divided into compounds. The screening centres were staffed by settlers who had been appointed temporary district-officers by Baring. Thomas Askwith, the official tasked with designing the British 'detention and rehabilitation' programme during the summer and autumn of 1953, termed his system the "Pipeline". The British did not initially conceive of rehabilitating Mau Mau suspects through brute force and other ill-treatment—Askwith's final plan, submitted to Baring in October 1953, was intended