5 - 1 Chapter 5 DEMOLITIONS This chapter introduces Rangers to the characteristics of explosives (low and high, Table 5-1), to initiation systems, modernized demolition initiator (MDI) components, detonation systems, safety considerations, expedient explosives, breaching charges, and timber cutting charges (FM 5-250). • Low explosives have a detonating velocity up to 1,300 feet per second, which produces a pushing or shoving effect. • High explosives have a detonating velocity of 3,280 to 27,888 feet per second, which produces a shattering effect.