Ship Design and Construction, Volume II

| AP | Aft perpendicular | |
| ASD | Azimuthing stern drive | |
| ATB | Articulated tug-barge system | |
| B | Breadth or beam, molded | |
| BHP | Brake horsepower | |
| BP | Bollard pull | |
| BS | Breaking strength | |
| C b | Block coefficient | |
| Class | Classification Society(ies) | |
| D | Depth, molded | |
| DNV | Det Norske Veritas | |
| F b | Escort braking force | |
| F s | Escort steering force | |
| Fi-Fi | Fire-fighting | |
| FP | Forward perpendicular | |
| GM | Vertical distance from VCG to metacenter | |
| IMO | International Maritime Organization | |
| ITB | Integrated tug-barge system | |
| KW | Kilowatts of power | |
| LCG | Longitudinal center of gravity | |
| LOA | Length, overall | |
| LWL | Length, waterline | |
| N c | Cubic number (=LxBxD/100) | |
| OPA '90 | Oil Pollution Act of 1990 | |
| T | Draft | |
| USCG | United States Coast Guard | |
| VCG | Vertical center of gravity | |
| VSP | Voith Schiffstechnik Cycloidal Propeller |
Perhaps more than any other vessel type, the ubiquitous tugboat has a personality which evokes a worldwide following, including fan-clubs who photograph it, draw it, model it, and trace its movements and registry changes. The tug has had numerous children's books written about it, and recently a highly successful children's TV program Timothy Tugboat, based on the aspirations of a humble little harbor tug. Perhaps it is the character of the tug, the unsung worker of ports and harbors worldwide, every one slightly different yet ever so familiar that stirs this attraction. Whatever the cause of the interest, the harbor tug continues...