means a temporary reduction in the number of ordinary hours of work owing to vagaries of the weather, a slackness of trade, a shortage of materials, a breakdown of plant or machinery or a breakdown or threatened breakdown of structures, or any unforeseen contingencies and/or circumstances beyond the control of the employer or a temporary reduction in the number of ordinary hours of work owing to riots, unrest or acts of terrorism or disorder, which directly affect the employer’s ability to provide work.