Latest: KMRL has tweaked the EOI to be boats of steel or aluminium. Lets look at the final specs docs.
KMRL (Kochi Metro Rail Limited), after a long wait, has taken the first step in realising their planned water metro project for Kochi. They have called for tender to build thirty six number of 100 passenger boats with an option of eighteen more with the same firm. As the largest project of its kind for any city in India, no doubt that this is under a lot of scrutiny.
In all pages (in this short technical brief), KMRL talks of getting fuel efficient boats, the intention summarised in this sentence from their website, “The project intends to bring in a fleet of 78 fast, fuel efficient, air-conditioned ferries plying to …”. So there is mention of electric propulsion, model test of hull, permanent magnet propulsion, e.t.c. When all these are mentioned, the elephant in the room, is missed.
World over, when one talks of electric propulsion, whether it is in boats, automobiles or aeroplanes, the most important focus is to design the transport to be as light as possible using lighter materials. In case of boats, it is almost always FRP (fibre glass) or aluminium. Steel and wood are mostly not used for the very fact that boats made of these materials for the same functional needs are twice as heavy compared to FRP or aluminium boats.
A related glaring issue is the total disregard of the philosophy of electric (solar) boat design (the choice of steel is an outcome of that too). From a project that needs to be technology driven (if electric), it is now shipyard driven and core technology is merely a sub-contractor. They are not accepting that boat building (even steel) is a very low tech activity where as electric propulsion is high tech. But then that is digression!
So, as expected, most of the people who attended the pre-bid meeting had this question in their mind, “how on earth did KMRL come to conclusion that steel boats are better!” Some of us, raised this question. However, KMRL officials refused to answer, claiming that this was not a press meet.
They however did allude to the fact that there was lot of deliberation before coming to this decision. There surely was lot of discussion since it took more than a year to arrive at this conclusion. The blame is put on consultant for the choice of material. The interesting fact is that six months before, the same consultant was talking of FRP or aluminium boats. What transpired in this time and who educated the consultant to enable this change is worth knowing.
The experience of Kochi metro (train) should have given them the insight on the importance of pricing to get ridership (considered to be expensive ride). With SWTD coming up with modern boats and operating at extremely low price, what will entice people to shift to high priced KMRL boats is a mystery. It will be high priced because its fuel consumption will be high due to weight and drag.
People in KMRL think that evading the question and refusing to answer will eliminate the issue. This merely reinforce the perception that the said decision was made with a vested interest.. This increases the resolve in all of us to get to the bottom of the issue.
What KMRL officials does not realise is that these fifty four boats will be a monument in testimony of their decision that will be around for around twenty years as a reminder.
The following is summary from paper computing effect on TCO by changing material of hull and keeping superstructure as GRP and propulsion by diesel engine: Impact of Hull Material on TCO of Inland Passenger Ferry Boat (Draft Paper).
|Parameter for comparison||Steel hull||FRP hull||Aluminium hull|
length x breadth x depth x draft (metres)
|19 x 6.5 x 1.6 x 2||19 x 6.5 x 1.6 x 1.5||19 x 6.5 x 1.6 x 1.5|
|Boat weight (tonnes)||30||15||16|
|Engine power (kW) for 6 knots*||2 x 30 kW||2 x 19 kW||2 x 21 kW|
|Energy cost (lakh rupees)||26||17||18|
|OPEX (lakhs) annual||30||20||22|
|Total Lifecycle cost in 25 yrs
Please note that the assumption is for 6 knots speed. For higher speed the power, fuel, OPEX and CAPEX is even wider. For example, for 8 knots the power would be more than double that at 6 knots. Also other features that is common in all is not factored. Also the CAPEX is lowest in steel only if we assume diesel propulsion. If it is diesel-electric the cost of larger battery bank in steel (higher weight) will make even CAPEX higher.