SHIP-RAISING PONTOON Russian patent published in 1998 - IPC

FIELD: ship-raising technology; designing of ship-raising pontoons. SUBSTANCE: pontoon has hull divided into watertight ballast compartments, hawse holes for ship-raising slings, chute-type sling shortening device, ballast compartment blow and vent valves, lower access with drives, appendages and air box. According to invention, pontoon hull consists of upper and lower portions. Upper portion is made in form of one or several vertical columns profiled in form of vertical prisms and/or cylinders at height h_I, equal to (1,1-1,2)•h_w, where h_w is rated height of waves at 3-percent factor. Base or bases of upper portion is rigidly secured to lower portion made in form of submersible volume of oblong scow-type body forming passive-active damper. Volume of this damper is equal to V₂ = (1,80...2,20)•V_Im³, where V_I is submerged total volume of upper portion of pontoon, cu.m equal to 0,5•h_I•V_I, where S_I is total area of horizontal sections of upper portion. Height of passive-active damper is equal to h₂ = (0,10...0,15)•h_I,, cu.m. Sum of natural mass and hoisting capacity of pontoon m_h and m_nat is equal to ρ(V₁+V₂), t, where ρ - is density of water, cu.m. Air box may be located in upper portion of columns. Fender may be secured at level of horizontal section of maximum area over perimeter of submerged passive active damper. EFFECT: extended functional capabilities of pontoon at enhanced reliability in swell up to Beaufort Scale Nos 5-6. 2 dwg