MAXIMIZATION OF SHIP DRAFT IN THE ST. LAWRENCE SEAWAY: VOLUME 1, SQUAT STUDY

The maximum operational draft for the stretch of the St. Lawrence Seaway between Montreal and Iroquois Lock is currently limited to 8.0 m. With changing water levels in the Seaway and a desire to manage the allowable loading of vessels rationally, a better understanding of the factors influencing under-keel clearance (UKC) is needed, particularly the ship operational phenomenon known as squat. This study, part of a larger project to improve the Seaway's ability to handle traffic, seeks to determine squat and UKC of ships through the system and formulate a squat model. This project entails the systematic collection of accurate ship sinkage (squat) data on 33 vessel transits between two locks and four extended runs; the collection and analysis of hydrographic data, currents and ship descriptive parameters; and the development of sinkage and, therefore, UKC predictors for the subject ships. A combination of existing hydrographic data, differential global positioning system technology, and an acoustic doppler current profiler, was used to develop the squat model of key areas of the seaway. Reduction of all data gathered was performed and a unified set of ship position, ship characteristics, channel data and operational parameters was developed. A series of existing squat models was examined in relation to the synthesis data set and comparisons of actual and predicted squat measurements were made. Analysis of the data set identified inherent levels of uncertainty and a series of recommendations for the applicability of numerical predictions is presented. Squat model recommendations resulting from this study vary according to channel segment and ship type. Areas of future research are suggested.

• Record URL:
  • http://data.tc.gc.ca/archive/eng/innovation/tdc-summary-13800-13888e-728.htm
• Supplemental Notes:
  • This study co-sponsored by the St. Lawrence Seaway Management Corporation, the St. Lawrence Seaway Development Corporation, the Canadian Shipowners Association and the Shipping Federation of Canada.
• Corporate Authors:

  Transport Canada

  Transportation Development Centre, 800 Rene-Levesque Boulevard West, Suite 600
  Montreal, Quebec  Canada  H3B 2X1

  Fleet Technology Limited

  311 Legget Drive
  Kanata, Ontario K2K 1Z8,   Canada 
• Authors:
  • Stocks, D T
  • Dagget, L L
• Publication Date: 2002-6

Language

• English

Media Info

• Features: Figures; Tables;
• Pagination: 97 p.

Subject/Index Terms

• TRT Terms: Channels (Waterways); Doppler sonar; Global Positioning System; Guide clearances; Hydrodynamics; Hydrographic surveying; Keels; River currents; Ship operations; Ships
• Uncontrolled Terms: Ship draft; Sinkage; Squat
• Geographic Terms: Saint Lawrence River
• Subject Areas: Hydraulics and Hydrology; Marine Transportation; Operations and Traffic Management; Vehicles and Equipment;

Filing Info

• Accession Number: 00941168
• Record Type: Publication
• Report/Paper Numbers: TP 13888E
• Files: TRIS
• Created Date: Apr 10 2003 12:00AM