In-depth | GREEN SHIP TECHNOLOGY Hybrid hopes for Scotland and Ireland
CalMac is planning to operate what has been deemed to be the world’s first seagoing ro-ro passenger hybrid ferry, due for completion in 2013.
A
n innovative new generation of small
ferries powering arrangements
featuring hybrid is
planned for Scottish west coast services. The envisaged design will employ an electric propulsion system in which diesel generators are complemented and augmented by banks of batteries, affording a high degree of operating flexibility and a reduced environmental footprint. Te new class of ro-ro equipped vessel
is required for the modernisation of a number of the shorter Hebridean and Firth of Clyde routes encompassed by the Caledonian MacBrayne(CalMac) network. The ferries will be of double-ended
type, affording a drive-through ro-ro configuration for 23 cars or two heavy goods vehicles, plus provision for 150 passengers. Scheduling needs call for a service speed of 9knots. It is anticipated that the first vessel will be ready for operation during the early part of 2013.
The Small Ferries Project Te engineering concept design for what is claimed will be the world’s first seagoing ro-ro passenger hybrid ferry, equipped with a combined battery/diesel-electric installation, has been developed by Caledonian Maritime Assets(CMAL), the owner of the CalMac fleet and harbour facilities. Model tank tests have been conducted at Hamburgische Schiffbau-
versuchsanstalt’s facilities in Hamburg. CMAL is inviting tenders for two such vessels, with a view to awarding the shipbuilding contract in October this year. Te pioneering nature of the proposed
type reflects not only a drive for improved life-cycle operating
economics and
enhanced environmental performance, but also a desire to put Scotland at the forefront in this field of maritime technology. Publicly-owned CMAL has fed results
from an EU-funded research endeavour, known as the Small Ferries Project, into its plans for new ships. The company has been partnered in the project by government departments from Northern Ireland and the Republic of Ireland. Te aim is to establish a common set of design parameters addressing future fleet needs for small ferries to serve remote communities off the Scottish and Irish coastlines. At least eight routes in Scotland and Ireland have been examined under the study, which has set a basis for reducing overhead costs and improving operational efficiencies. Although the final design and outfit will
be drawn up by the shipbuilding contractor and turnkey suppliers in accordance with the owner’s specifications, the vessel type as proposed by CalMac is of 43.5m length overall, 12.2m breadth and 140dwt. Each will be powered by small diesel generator sets, feeding energy to a 400V switchboard supplying power to electric propulsion
A side elevation impression of CalMac’s proposed new ro-ro passenger hybrid ferry.
motors driving the propellers. In addition, lithium ion battery banks will be capable of powering the propulsion motors through DC (direct current) links. Te technical rationale for the hybrid
system and the overall economic and environmental benefits it promises, relative to a conventional diesel mechanical installation, lies in the varied operating profile and also the typically very low proportion of available power actually used for propulsion over each 24-hour cycle on the routes studied. Te solution will allow ferries to run in diesel generator/ diesel generator plus battery/battery-only modes, allowing power delivery to be matched to precise, overall energy needs at any point, whether sailing, manoeuvring or alongside.
Battery power Te installation comprises four 253kVA main gensets, a ‘split’ main switchboard covering all ships’ services as well as propulsion, two 350kWh battery banks linked direct to the electric propulsion motor drives, two 395kW propulsion motors and two propellers, each absorbing a maximum 375kW. Machinery is distributed between forward
and aſt engine rooms, in accordance with the use of a propeller at each end of the double- ended ferry. Each propeller will be offset, positioned on the port side in relation to the direction of travel. Separate banks of batteries will also be located in forward and aſt rooms. The batteries will supply a minimum
of 20% of the energy consumed on board, reducing carbon dioxide(CO2
) and other
emissions, and will be charged overnight from the national grid when the vessel is lying alongside. It is considered that the new generation of ferries could easily be modified to take advantage of future developments in battery and fuel cell technology, and thereby reduce the reliance on the diesel gensets. Te Scottish Government has set targets
on cutting climate change emissions, and is looking towards technological initiatives to secure up to half of the reduction in the nation’s carbon footprint sought by 2020. SBI
22 Ship & Boat International July/August 2011
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64