VESSEL REVIEW | Muziris – Indian metro ferry operator goes hybrid electric with 100-pax newbuild

Indian government-owned transport company Kochi Metro Rail (KMRL) recently took delivery of a new hybrid electric catamaran ferry from Cochin Shipyard (CSL).

Named Muziris after an ancient harbour city located in what is now the Malabar Coast region of southern India, the newbuild is the first of 23 hybrid electric ferries that CSL is building for KRML. Its daily operations will entail providing commuter ferry services between the southern Indian city of Kochi and 10 nearby islands.

The service area covers a distance of 76 kilometres with stops at 38 different terminals and two boatyards. The batteries on the ferries were thus designed and built to be capable of being fully charged in as little as 10 minutes at regular intervals to provide uninterrupted service for Kochi's 100,000 residents as well as tourists.

Muziris has an aluminium hull, a length of 24 metres, a draught of 0.9 metres, and capacity for 100 passengers, 50 of which will be seated. The ferry is equipped with a Siemens electric propulsion system that draws power from a DNV-approved Echandia Marine 122kWh lithium-titanium oxide (LTO) battery pack, which, when fully charged, can enable it to sail for up to one hour. Sajan P. John, General Marine Manager of KRML, said that the company decided LTO batteries were the safest option after it conducted a comparison of various types of lithium batteries.

Alternatively,  the vessel can run on power generated by the onboard diesel generator sets as well as in hybrid mode, which utilises the generators in conjunction with the batteries.

The vessel's rather compact size and hybrid electric propulsion were the answers to a design brief that called for ferries that could easily traverse the shallow, narrow waterways of Kochi's backwaters while still maintaining a decent speed of around 10 knots. The wake generated also needed to be minimal so as not to disturb nearby fish farms. Thus, keeping the weight of the vessels as low as possible was a key concern.

The fleet of new ferries must also be able to run for up to 16 hours per day on a tight timetable. The batteries fitted on Muziris were therefore built to be extremely secure, presenting no risk of overheating or short circuiting. Safe supercharging capability was also incorporated to avoid delays. This attribute also helps minimise the risk of thermal runaway, a phenomenon wherein lithium-ion cell temperatures exceed a certain thermal threshold and cause the release of excessive heat and flammable gases, which could then combine and cause an explosion.

The introduction of Muziris and its near-identical sisters is the first stage of a larger project that will involve the use of 78 low-emission vessels, which battery supplier Echandia Marine said will comprise the largest fleet of electric ferries in the world.

Muziris was designed and built in compliance with Indian Register of Shipping rules. The ferry was handed over to KMRL in late December 2021 and is currently undergoing operational trials prior to starting regular sailings in July. It will operate under KMRL's Kochi Water Metro service.

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