The AVT-phx series of brake elements are steel coils that unravel when a force is applied. The gauge, width and number of coils can be specified in order to control the amount of energy absorbed and the total displacement. With no moving parts, these are some of the safest and most reliable brakes in the industry. In some cases, it may be desired to limit the activation of brake elements in order to reduce maintenance of following minor events. Both the 1000 and 3000 kJ hybrid systems have been tested with brake locks that prevent the expansion of the brake elements until a per-determined load is applied.