BOOM GUARD Russian patent published in 1997 - IPC

FIELD: construction of hydraulic structures, in particular, hydraulic structures of moored ships or other floating objects used for their protection against extreme influence of solid ice fields. SUBSTANCE: boom guard uses booms located across the ice width on the water surface, the booms are made of two members engageable along an inclined stage through a spacer, which is broken at the instant when the load exerted by ice attains the value at which the device should "respond"; after that the boom members start displacing on the inclined stage relative to each other. The spacer area may be varied before installation of the boom guard or in service. The coefficient of friction over the surfaces of contact of the boom members and spacer may be varied. The slopes of the surfaces of contact of the boom members and spacer may be varied. Besides, the boom members may be made pliable so as to reduce the influence on the structure (object) at ice loads not exceeding the "respond" level of the device. The provide ice break from a vertical shear with a subsequent thrust of blocks of ice, the boom guard ensures protection against solid ice fields thicker than 0.8 to 1.0 m. The device provides for an accurate determination and control of ice load at which the device "responds" (ice is broken). The response range may be controlled by varying the slope or area of the spacer, and by its replacement with another one with an another compression strength. EFFECT: enhanced reliability. 5 cl, 1 dwg