Hydrodynamic data on resistance, yaw moment, and lateral force for tug-barge systems were obtained with 1/25-scale models ( 7.6-ft long for barges and 4.5-ft long for a tug ). Resistance test results for barge systems are presented in non-dimensional forms and in full scale, with discussion of the effects of loading conditions, skeg configurations, number of barges, bow configurations, and head seas. Results indicate that resistance-per-ton for tested barge trains is roughly equal to that for a single barge when the space between barges is very small ( approx.= 0 )or very large ( approaching infinity ), and that it is larger ( by roughly 30 percent ) than that for a single barge when space/barge length approx.= 0.07. Equations of motion of the tug-barge system in the horizontal plane are formulated to examine directional stability. Automatic controls of rudder ( tug ) and flap ( barge ) are included. Stability analyses based on captive model-test results indicate that the barges themselves are hydrodynamically unstable, but that some of them can be made directionally stable under proper towing conditions. Towed barges are more stable at light -load conditions than at full-load conditions because of increased resistance-per-ton and relative skeg area. The directional stability is improved with skeg and drag increase. When flaps which are trailing portions of skegs are activated, the stability is significantly improved without substantial increase in resistance. ( Author )

  • Corporate Authors:

    Stevens Institute of Technology

    711 Hudson Street
    Hoboken, NJ  United States  07030
  • Authors:
    • Eda, H
  • Publication Date: 1968-4

Media Info

  • Pagination: 92 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00007134
  • Record Type: Publication
  • Source Agency: Maritime Administration
  • Report/Paper Numbers: SIT-DL-69-1303
  • Contract Numbers: MA-2701
  • Files: TRIS, USDOT
  • Created Date: Dec 22 1973 12:00AM