DEEP TANK

The vertical stem plate connecting the bottom to deck of a square- stemmed barge.

Net Tonnage - the replacement, since 1994, for 'Net Register Tonnage.' Theoretically the cargo capacity of the ship. Sometimes used to charge fees or taxes on a vessel. The formula is(0.2+0.02 log10(Vc)) Vc (4d/3D)2, for passenger ships the following formula is added: 1.25 (GT+10000)/10000 (N1+(N2/10)), where Vc is the volume of cargo holds, D is the distance between ship's bottom and the uppermost deck, d is the draught, N1 is the number of cabin passengers, and N2 is the number of deck passengers.) 'Ton' is gured as a 100 cubic foot ton. An approximate conversion ratio is 1NT

The introduction of compressed air near the bottom of a tank or other container in order to agitate the liquid therein.

Flexible composition to isolate the bottom of a fitting from its deck foundation in order to seal from moisture or corrosion.

The system of valves and cargo lines in the bottom piping network of a tank vessel that connects one section of cargo tanks to another section.

When chemical carriers load high value and very pure products, they will commence loading until about one foot of cargo is in the bottom of the tank, then stop. They will take a sample this cargo, known as the foot sample up the facility's lab for analysis to see if during the loading of this one foot of cargo there was any contamination. If not, they will resume loading the tank until completion. If contamination is present in the foot sample they will try to determine the source, while they pump the now off spec cargo to the shore, and start over again, It is hoped that the amount loaded during the foot of cargo is enough to clean the contamination from the tank and piping. This is done to prevent the entire tank being loaded and then contaminated thereby requiring the full cargo to be reprocessed.

A pipe leading to the bottom of an oil or water tank, for guiding a sounding tape or jointed rod when measuring the depth of liquid in the tank.
Sounding pipes in the engine room are normally fitted with deadweight cocks and screw caps. Caps and cocks should be closed at all times, except when sounding tanks.

Tanks at the bottom or sides of a ship which are filled with seawater for ballasting purpose.

1. The bottom of the ship touching the bottom, but not grounding.
2. Stopping at a dock or pier for a very short time without tying up, to let off or take on crew or goods.
3. Practice of aircraft on aircraft carriers touching the carrier deck and taking off again without dropping hooks.

An opening in the side of a tank usually at ground level and covered by a plate to provide access for removal of sediments from the bottom of the tank.