[Western SMT]

Found this and although I moved house that year I must have had my head in the sand as I've never heard of it before.

In 1979 approximately 50,000 truck drivers went on strike for a period of six weeks in an effort to secure a substantial wage increase. Although only 12% of all truck drivers participated in this industrial action, many were engaged in 'secondary picketing', disrupting freight flows to and from premises other than those directly operated by their employers. Much of the secondary picketing was targeted on the food distribution system. Over the first two weeks of the strike this type of picketing severely constrained food movements at the upper levels of the supply chain, forcing consumers to rely heavily on the stocks of food held at or near the points of sale. In the late 1970s, inventory levels were substantially higher than today offering a greater cushion against transport disruptions.

Can anybody remember this