# THEORETICAL DRAFT

 The draft which would be available at the base of a stack if there were no friction or acceleration losses from the stack.

## Related Terms

### BENDING MOMENT

Is the result of vertical forces acting on a ship as a result of local differences between weight and buoyancy. The total of these forces should be zero, otherwise, change of draft will occur. Note: The maximum allowed bending moment of a vessel is restricted by the class bureau to certain limits, which are different under port and sea conditions.

### PACHUCA TANK

Air-agitated, solidliquid mixing vessel in which the air is injected into the bottom of a center draft tube; air and solids rise through the tube, with solids exiting the top of the tube and falling through the bulk of the liquid.

### CAPACITY PLAN

A plan outlining the spaces available for fuel, cargo, ballast, fresh water, etc, with guides on weight and volume for spaces at various drafts and displacements

### LIGHTERING

The process of transferring cargo from one vesel to another to reduce the draft of the first vessel. Done to allow a vessel to enter a port with limited depth or to help free a grounded vessel.

### PLIMSOLL LINE

A special marking, positioned amidships, that indicates the draft of the vessel and the legal limit to which the vessel may be loaded for specific water types and temperatures.

### CARGO TRANSSHIPMENT AREA

An area generally outside port limits that is specifically designated as suitable for the transshipment of oil or other materials from large ships to smaller ones. As the purpose of transshipment is usually to reduce the draft of the larger vessel to allow her to proceed to port, the operation is often known as lightening and the area may be called lightening area or cargo transfer area

### CONTROLLING DEPTH

1. The least depth in the approach or channel to an area, such as a port or anchorage, governing the maximum draft of vessels that can enter. 2. The least depth within the limits of a channel; it restricts the safe use of the channel to drafts of less than that depth. The centerline controlling depth of a channel applies only to the channel centerline; lesser depths may exist in the remainder of the channel. The mid-channel controlling depth of a channel is the controlling depth of only the middle half of the channel.

### DANGER SOUNDING

A minimum sounding chosen for a vessel of specific draft in a given area to indicate the limit of safe navigation

### DEEP WATER ROUTE

A route for deep draft vessels within defined limits which has been accurately surveyed for clearance of sea bottom and submerged obstacles as indicated on the chart.

### DANGER LINE

1. A line drawn on a chart to indicate the limits of safe navigation for a vessel of specific draft

### Related questions

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