In-depth | RESEARCH VESSELS FEATURE THEME Birth of a Princess
Te research vessel Princess Royal, completed in September 2011, was specifically designed to match speed and stability in open, rough waters. Te University of Newcastle’s MAST department takes a retrospective look at the significantly detailed gestation process
of the University of Newcastle (UNEW), UK, had reached the end of her service life. Te University took the decision that the locally built and operated vessel, which had originally been commissioned in 1973, would be replaced by another in-house design, also to be built locally on the River Tyne, albeit with a number of innovative changes to suit the current requirements of the University, as well as the conditions of the region, when fulfilling tasks related to trawling, plankton sampling and bottom dredging, deep water sampling and sea floor coring. The newly formed School of Marine
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Science and Technology (MAST), which was created by a merger between the University’s Department of Marine Technology and Department of Marine Science in 2003, resolved to undertake this replacement project, fully involving a number of final year and PhD students, and led by Professor Mehmet Atlar. Te result was to be the 18m loa Princess Royal,
TECHNICAL PARTICULARS Princess Royal
Length, oa ........................................................18m Breadth, oa .....................................................7.3m Design draught ..............................................1.6m Displacement (light) ..........................36.9tonnes Operating speed ......................................15knots Maximum speed ......................................20knots Engines............2 x Cummins QSM11-610 diesel, 443kW each
Gearboxes ......2 x Quickshift; G/B ration: 1.75:1 Deck equipment ...........1 x hydraulic A-frame, 3tonnes, with 3.5m clearance 2 x trawl winches, 2tonnes each 1 x knuckle boom crane, 6.5tonnes/m
Classification
.......................................MCA Cat 2 22
n Summer2009, Bernicia, a 16.2m loa research vessel utilised by the Department of Marine Technology
which was completed at the Alnmaritec yard in September 2011.
Deep-vee concept It was decided to build the replacement vessel as a deep-vee hulled catamaran, with MAST keen to transfer the advantages that it had noted deep-vee hullforms granting to fast ferries and naval craſt, especially when it comes to seakeeping and the speeds that can be safely achieved in significant wave heights. The deep-vee catamaran concept
(monikered UNEW-DVC) features symmetric demi-hulls, with large deadrise angles that are constant after midship, and a bow section based around Serter’s anti-slamming bow feature. Tis latter feature is an atypical bow profile, which starts with a slight droop below the keel around the mid-ship and increases gradually towards the bow, thus meaning that the fore body remains in continuous contact with the water, reducing the probability of emergence of the vessel’s forefoot, in turn leading to a reduced risk of slamming. Te first vessels to fully realise MAST’s
UNEW-DVC concept were a fleet of four 14m harbour patrol vessels, including Lambeth, which were designed and model-tested by MAST for the Port of London Authority (PLA) for the 2012 London Olympics. Te anti-slamming bow feature was modified in these vessels by avoiding the droop beyond the keel level. Another modification for the PLA craſt
was made to the aſter-body of each vessel, with the introduction of a relatively steep angle of prammed aſter-body with milder V-shape cross-sections to accommodate her conventional propellers and stern gear with a 7degs shaſt inclination. Since the launch of Lambeth and her sister PLA vessels, the quartet has managed to achieve maximum speeds of 21.5knots and has been proven to display extreme fuel efficiency and excellent seakeeping, these vessels being able to operate at sea state 5 as well as being low wash.
Following the successful incorporation
of this design into the LPA boats, MAST commenced a publicity and fund-raising campaign to apply the same measures to Bernicia’s replacement research vessel. In early 2009, the UNEW executive board approved two-thirds of the replacement vessel cost, with MAST tasked with raising the outstanding amount through fund-raising, encapsulating a total project cost of GBP£1.4 million (US$2.1 million). A group of MEng students worked
on a 22m design, incorporating Serter’s anti-bow slamming specs, with a top speed rating of 25knots and a service speed of 15knots, initially deemed achievable via a pair of waterjets and a transom-mounted retractable azimuthing thruster, positioned between the demi-hulls at the wet deck level. Te thruster was intended to assist with slow-speed operations and emergency situations.
Propeller selection In Summer 2009, this prototype cat underwent a parametric design study, to determine the initial size and hullform required by the replacement research vessel to fulfil its tasks. A new limit of 18m loa was set on the vessel, and four hullforms were proposed. Two of these hullforms were selected from the original UNEW-DVC deep-vee considerations, while the other two were based on the LPA boats, albeit without the modified anti-slamming bow feature. Each pair had a waterjet and a propeller-driven alternative. The preliminary analysis, using a
potential based CFD code, showed that the propeller-driven alternatives needed less effective power to achieve the same speed, as well as displaying reduced wave-making compared to the waterjet-driven models. In this comparative analysis, hull separation was fixed at 0.25Lwl while the displacements of the hullforms varied between a minimum of 29tonnes for the PLA-based propeller-
Ship & Boat International May/June 2013
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