Kolkata Dock System is situated on the left bank of the river Hooghly in position Latitude of 22°32'53" North and Longitude of 88°18'5" East. Haldia Dock Complex is situated on the right bank of River Hugli in position Latitude of 22°02' North and Longitude 88°06'East.
The conservancy limit of Kolkata Port stretches from the outfall of the Feeder Canal at Jangipur (about 300 Km. upstream of Kolkata) to Latitude 20°45'North at Sandheads. It also includes shores of the river Hooghly which are within 45.7 metres from the highest high water levels on either side of the bank.
Kolkata Port has two approaches from the sea, one through Eastern Channel (Eastern Channel Light Vessel position Latitude 21°03'.03.12" North and Longitude 88°11'30” East) and the other through Western Channel (Western Channel Light Vessel position Latitude 21°05'03.09" North and Longitude 87°50'215.95" East). Currently Eastern Channel is being used for navigation for Kolkata Bound Vessels whereas Western Channel is used for Navigation by Haldia bound vessels. Whereas, the Pilotage distance to Kolkata is 223 Kms, comprising 148 kms. of river and 75 kms of sea pilotage, the pilotage distance to Haldia is 115 Kms comprising 30 kms. of river and 85 kms of sea pilotage.
All vessels approaching Sandheads in the vicinity of Eastern Channel light vessel are required to contact Pilot Station situated on Sagar Island identified as “Sandheads Pilot” and “VTMS Control” on Channel 16 & 68 and should not proceed North of Latitude 21°00' North without being advised to do so. For their journey from Sandheads to Pilot Boarding point at Sagar and Auckland, all ships are provided remote pilotage through VTMS guidance. Pilotage upstream of Latitude of 21°39'02.93" North is compulsory for all the vessels of 200 GRT and more.
The Port maintains a pilot Vessel/Station at Sagar Roads. The River Pilot embarks on inward bound vessels at Middleton Point and proceeds up the river. On arrival at Kolkata (Garden Reach), the River Pilot is relieved by a Harbour Pilot who takes the vessel inside the lock at KPD or NSD or the river mooring as required. From the lock, the vessel is guided to the nominated berth by a Dock Pilot. For the outward passage the process is reversed. At Haldia, the pilot bringing the vessel from Upper Auckland hands over the vessel inside the lock to the Dock Pilot but all vessels bound for oil jetties are taken alongside by the same Pilot. Since the Pilotage distance is long as compared to Sea Ports, at least 1 Pilot Cabin is required to be kept ready for the use by the Pilot on board and I additional may be required for the Pilot on passage.
Being a riverine port with numerous sand bars (shoals), advantage is taken of the rise of tide so as to obtain the maximum draft for shipping. Variation in draft occurs between spring and neap tides and forecast of draft for inward and outward ships are published by the Harbour Master (River) about four/six weeks in advance. Because of the sharp bends in the river, the length of the vessel that can be accommodated at KDS is restricted to172 metres at Kolkata and 189 metres at Budge Budge.
Maximum dimension of vessel acceptable at N. S. Dock is 565 ft. LOA and 82 ft. Beam (172mtrs. x 25mtrs.) so far on regular basis. Maximum dimension of vessel calling at Kidderpore Docks is 515 ft x 70 ft (157 mtrs x 21.3 mtrs.). Maximum dimension of vessels calling at Baj Baj is LOA 620 ft and 86 ft Beam (189 mts x 26.2 mts). Present dimension of vessels accepted at Haldia Dock are restricted to LOA 240 mtrs Beam 32.26 mtrs. For Oil jetties the largest vessels that are accepted at present are LOA 250 mtrs, Beam 44 mtrs.
Tidal bores in the river have been a constraint to shipping for the port. In spring tide, the tidal waves make an onrush with height which makes it difficult for a ship to remain in the river. The ships are then given shelter in the docks.