Inland Waterways


 Two container ships pass in San Francisco Bay



Waterways Requirements :-

The transport of containers on inland waterways vessels imposes few, if any , spacial requirements on the waterways network beyond those that apply to the transport of bulk or non-utilized general cargo . Thus the investment requirements mentioned in this context refer rather to minimum standards ensuring permanent navigability for certain size and types of vessel , regardless to the cargo carried .

Thus use of natural waterways for transport requires first the removal of obstacles which in developing countries consist mainly of seasonal variations in the water courses . Winding roots with sharp curves , instability of river beds , draught restrictions and natural rapids and waterfalls .

Apart from general conditions of navigability the minimum requirements to be fulfilled to accommodate vessels normally plying in container trades concern the minimum depth of waterways , the minimum width of waterways , the minimum vertical clearance of bridges . The minimum width of turning areas and the minimum equipment with navigational aids .

Minimum Depth of Waterways :-

Minimum depth normally constitutes the crucial variable on uncanalized  rivers . Depth must be sufficient to allow vessels of normal size to operate at economic speed and to allow larger vessels to proceeds although at reduced speed . The complex relationship between the speed of vessel and depth requirements has to be taken into consideration .

Minimum Width of Waterways :- 

For double lane traffic , the value of should be larger then 5 , the width of canal at bottom being at least 2.8 to 3.5 times the breadth of largest vessel expected .
The minimum radii of bend area are a function of the length of the vessel . For Single lane traffic radii should be at least equal to R= 6L  ; for double lane traffic R=10L  ; the minimum distance between bends should be not less then 2L ; for bend turning in the same direction and 3L for those turning in the opposite direction .
 Width requirements  in bends are larger then those normally required in lane straight section . An approximation of the increase in width (W) of single lane waterways is given by the formulae

          W   =   L/4R   for single lane traffic 
          W   =   L/2R   for double lane traffic 

Vertical clearance for bridges should be at least 0.5 m above the height of the highest vessel expected to pass under the bridge .

Minimum Width of Turning Area :-

widths requirements for turning basins differ according to the possibility of having the vessel's bow moored to the bank of waterways . Where this is the case , basin should have a width of at least 1.2L ; otherwise 1.5L to 2L is required

Minimum requirements for equipment with navigational aids can not be generally established but depend on local conditions .

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