Of late there has been a lot of hue and cry about the Sethusamudram Ship Channel Project owing to the proposed breaking of the Adam’s Bridge or Rama Sethu. It has assumed religious angle and polarised Hindus across the length and breadth of the country.Religion apart, let us analyze whether it makes sense to construct the channel which the proponents of the project say will save nearly 400 nautical miles between ports of West and East coasts of India. The Sethusamudram Ship Channel Project is estimated to cost Rs. 2500 Crores.The present proposal entails dredging of a channel of 300 metres width over a length of 48 nautical miles (19 miles at Adam’s Bridge area and 29 nautical miles at Palk Strait) to a depth of 12 metres. The total length of the channel will be 90 nautical miles, i.e. 42 nautical miles of the channel will not require any dredging. The channel is proposed to cater to two-way passage of vessels of upto 215 metres length, 33 metres width having a draft of 10 metres.The traffic projected (in terms of number of vessels) as per Detailed Project Report( available on the official website of Sethusamudram Corporation Limited) is tabulated below:
| YEAR | PESSIMISTIC | MODERATE | OPTIMISTIC |
| 2008 | 2858 | 3055 | 3249 |
| 2010 | 3140 | 3417 | 3683 |
| 2015 | 3900 | 4432 | 4895 |
| 2020 | 4784 | 5621 | 6343 |
| 2025 | 5883 | 7141 | 8234 |
Projected savings in distances and steaming time is shown below:
| FROM | TO | DISTANCE BY EXISTING ROUTE | DISTANCE VIA SETHU CHANNEL | SAVINGS IN NAUTICAL MILES | SAVINGS IN STEAMING TIME AT 12 KNOTS |
| CAPE COMORIN | CHENNAI | 755 | 402 | 353 | 1 DAY 05 HOURS |
| CAPE COMORIN | VIZAG | 1014 | 719 | 295 | 1 DAY 01 HOURS |
| CAPE COMORIN | KOLKATA | 1357 | 1098 | 259 | 0 DAY 22 HOURS |
Savings shown above are impressive but they only tell half the story.Mariners are aware of a phenomenon called “SQUAT”. When a ship moves through the water, it pushes the water ahead of it. This results in the formation of the bow wave at the fore part of the ship as result of which a low pressure is created just behind this wave. This is results in the bow being “sucked down” and thereby increasing the draft of the vessel. Squat is directly proportional to the vessel’s length, draft and speed. It also depends on the available depth of water and under keel clearance (UKC). Underkeel clearance is the vertical distance between the ship’s keel and the seabed. There is pronounced squatting when the UKC is less, i.e. in shallow waters and in case timely reduction in the vessel’s speed is not made may result in the grounding of the vessel. Just to give an indication of squat, a vessel of about 200 metres steaming at 12 knots at 10 metres draft in waters of depth of about 15 metres may have a squat of nearly 1 metre. As a thumb rule for a ship to safely navigate through shallow waters should have at least 20% of its draft as UKC. In such a case vessel of such a size will need nearly 13 metres depth of water. But since the channel is to be dredged to 12 metres only, such a vessel should reduce speed to reduce squat to 8 knots approximately.Since the channel has many tricky bends and is exposed to vagaries of nature, an experienced mariner need to be employed to guide vessels’ transit. Ships’ Captains are not well acquainted with local conditions. Hence a pilot needs to be employed for each vessel when it transits the channel. Hence in addition to the delay due to forced reduction of speed, time will be consumed in reducing speed to facilitate boarding and disembarkation of pilots which may take at least one hour each time.Taking all the above factors into consideration, actual savings in time at various speeds is recalculated and tabulated below:
| FROM | TO | TIME SAVED AT VARIOUS SPEEDS IN HOURS | ||||
| 12 KNOTS | 14 KNOTS | 16 KNOTS | 18 KNOTS | 20 KNOTS | ||
| CAPE COMORIN | CHENNAI | 24 | 19 | 15 | 12 | 9 |
| CAPE COMORIN | VIZAG | 19 | 15 | 11 | 8 | 6 |
| CAPE COMORIN | KOLKATA | 16 | 12 | 9 | 6 | 4 |
Savings for container vessels which steam at more than 20 knots at sea is negligible and they are not expected to use the Sethu Channel. Only small old feeder container vessels on the coastal run may use the channel.In the case of Bulk Cargo Traffic, no owner or charterer is willing to lose money by way of dead freight by loading vessel upto 10 metres only. A 215 metre long vessel of 33 metres beam for which the channel is designed has load draft of at least 12 metres and the shipowner by loading the ship upto 10 metres will lose freight for at least 10000 Tonnes of cargo which may be in excess of US$100,000.In other words, the traffic projection through the Sethusamudram Ship Channel is too good to be true. In the proposal a new word has been coined to indicate ships of maximum size that can transit the channel which is “SETHUMAX” similar to “SUEZMAX” and “PANAMAX” which indicate maximum size of ships which can transit Suez and Panama Canals respectively. It is too farfetched to say that a shipowner would order a shipyard to build a ship especially designed for Sethusamudram Channel Passage when one considers quantum of savings shown.Taking all the above into consideration one may wonder, where is the revenue going to come from? If the authorities charge pilotage fees which are prohibitive a shipowner would avoid using the channel. Tariffs should be based on market dynamics rather than cost-plus approach which is the general trend among Governmental Authorities.Only small coastal vessels of about 100 metres long and having a draft of around 6 metres carrying around 5000 to 10000 Tonnes of cargo may consider using this channel. In that case dredging the channel to 12 metres is not required.To make the project viable, following alternatives may be considered:1. Dredge to 8 metres initially. Decision to dredge deeper should considered only after having analyzed the traffic for a couple of years.
2. Change the channel alignment through Pamban Pass. As presently there is already a depth of 2 metres unlike Adam’s Bridge. In fact presently ships upto 2.50 metres are using the Pamban Pass. Quantity of dredging will further reduce if Pamban Pass Alignment is used.
It is urged that powers that be have their feet firmly on the ground and not get overambitious and too optimistic. After all it is public money. Let us use it, not waste it.
