Kochi Port’s plan to carry out a nautical depth study aimed at reducing the recurring dredging expenses has received the Shipping Ministry’s approval.
The Ministry has approved a grant of ₹10 crore for studies on siltation and optimal ameliorative measures in which it will bear 50 per cent and the balance by the port.
It is for the first time that an Indian major port is going ahead with a nautical depth dredging, a concept which was in use in most of the Riverine ports in Europe like Netherlands, Belgium, Germany etc.
A senior port official said that the new study would help the port to implement this new concept here to reduce the depth to be dredged as well as cutting down maintenance dredging cost to about 30 per cent.
According to him, Kochi port has a muddy bottom unlike most other Indian ports that have hard bottom. The Indian National Hydrographic Organisation had prescribed 10 per cent under keel clearance for dredging, which was increasing the quantity to be dredged as well as dredging expenditure.
However, most of the European ports with muddy bottoms are carrying out shipping operations with under keel clearance based on a study to fix the navigable density of fluid mud. It helped reducing dredging quantities and expenditure.
As per the existing standards, Kochi Port has to dredge 10 per cent more than the draft of the ship to ensure proper clearance without hitting the bottom. In Riverine ports like Kochi, the channel bottom is made up of either loose clay or sand. Therefore, dredging was required only five per cent more than the draft of the ship.
The water injection method was used in Riverine ports require for dredging wherein water is pumped at high pressure to the bottom of the channel. The clay and sand at the bottom get stirred up in the process enabling vessels to sail through the suspended particles without getting stuck.
If the port is successful in curtailing the dredging expenses, the official pointed out that it would be a big achievement and beneficial in the long run. The high and recurring dredging expense is having a dent on port’s revenue forcing the management to doll out ₹170 crore last year, especially with the commissioning of the Vallarpadam container terminal.