Editorial Notes

The River Hooghly and the Port of Calcutta:

The Port of Calcutta depends on the Navigability of the River Hooghly. The River Hooghly, though it looks so large, is a difficult river to navigate, because it is not so deep as is desirable everywhere, developes unexpected shoals, has its deepest portions in discontinuous winding channels, forms strong, treacherous eddies, that often cause vessels to run aground, and has several bars that cannot be negotiated by deep draught vessels, except in certain states of tide. Only vessels of a certain speed corresponding to the draft can take advantage of the tide to pass over these bars. There is an economical limit to the speed that a vessel should have; and the economics of shipping show that the cost of transportation is increased by reduction of draught and reduced by an increase of draught, so much so, that the most economical draught for a 1000 ft. long vessel having a speed of 30 knots has been determined to be 60 ft.* Such a deep draught is not at present available at any Port in the World. But the authorities of the Port of London took this into account when determining the depth of a tunnel to be permitted below the bed of the river so as to allow for future increase of depth by dredging or other means. The designed draught of vessels has been gradually increasing throughout the world for economical reasons; and Ports all over the World are endeavouring to increase their depths to take in vessels of greater draught which bring in greater trade and increase the revenue.