The 1920s and 1930s were years of economic austerity. Many of Northern Ireland's traditional industries, notably linen and shipbuilding, were in recession. This contributed to the already high level of unemployment. Serious rioting broke out in 1932 in Belfast in protest at the inadequate nature and level of relief for the unemployed and the threat of rioting was ever present. In response to the growth of motorised transport the RUC Traffic Branch was formed on 1 January 1930. In 1936 the police depot at Enniskillen was formally opened and an £800,000 scheme to create a network of 196 police barracks throughout Northern Ireland by rationalizing or repairing the 224 premises inherited from the RIC was under way. In May 1937 a new white glass lamp with the RUC crest went up for the first time to replace the RIC crest still on many stations. About the same time the Criminal Investigation Department (CID) in Belfast was significantly expanded, with a detective head constable being appointed to head the CID force in each of the five Belfast police districts. There was sporadic Irish Republican Army activity in the 1930s.