Philly yard delivers LNG-ready US tankers
Prudent engineering evident in Crowley Maritime Corp’s new MT50-class vessels is intended to
future-proof investment in ‘Jones Act’ tanker trades, writes Davix`d Tinsley.
Jacksonville-based Crowley Maritime Corp has put down a fresh marker for US-flag Jones Act
shipping by commissioning the first two vessels in a new generation of product tankers designed and
prepared for possible future operation on LNG fuel.
Use of clean-burning LNG as fuel is an attractive option, in a US context, for ensuring compliance
with IMO Emission Control Area (ECA) criteria. To date, only the North American ECA, within which
the tankers will operate, and the US Caribbean Sea ECA, have been designated for control of SOx,
NOx and particulate matter.
Crowley’s debut MT50-class vessel, the 50,000dwt Ohio, was phased into the home trade after
handover during October. Second-of-class Texas followed in December, and will typically be
employed in the traffic from the US Gulf coast to ports to Florida, mainly Port Everglades and Tampa,
and occasionally Jacksonville. Shipbuilding contractor Philly Shipyard, the former Aker Philadelphia
Shipyard, has third and fourth Crowley newbuilds in hand for delivery this year.
The MT50 type is based on a design from Hyundai Mipo Dockyard (HMD), among the world’s top
echelon of constructors of product carrier tonnage, albeit as part of a much wider portfolio.
HMD and the US yard had previously collaborated in the construction of 14 product tankers of the
MT46 Veteran class, produced at Philadelphia for US owners between 2007 and 2013. In fact, the
last two ships in that earlier programme were commissioned into the Crowley fleet as the 45,800dwt
sisters Pennsylvania and Florida, both recently sold to Kinder Morgan.
Cargo flexibility
The latest design embodied in the Ohio and Texas marries cargo carrying flexibility, for crude oil and
IMO Type 2 chemicals as well as refined products, with a raft of fuel saving features. The MT50
tankers are broadly similar to the earlier 14, aside from extra steelweight to meet new regulations,
various production-led design changes, and the provisions for LNG fuel. From a shipping perspective,
there is a pronounced advance in that they are over 20% more fuel efficient.
The cargo section offers a total loading capacity of 337,000 barrels, or about 54,000m3, and is
divided by a centreline bulkhead to create six pairs of cargo tanks. Each of the 12 tank
compartments is fitted with a Framo SD200 vertical, centrifugal cargo pump powered by a hydraulic
motor. The stainless steel pumps are individually rated at 600m3 per hour, and the system as a
whole has a maximum discharge or loading rate of 3,600m3/h. The renowned Norwegian make is
now an Alfa Laval brand.
The deck gear comprises a 10t hose handling crane at the midships manifold, two Aker Pusnes (now
MacGregor Pusnes) combined anchor windlass/mooring winches and six double-drum mooring
winches.
The MAN ME-series electronically-controlled, two-stroke main engine was built under licence in
South Korea by Hyundai Heavy Industries (HHI). The six-cylinder, S50ME-B9 diesel provides direct
drive to a four-bladed, fixed-pitch propeller of 6.6m diameter, also
sourced from HHI.
While the engine model’s nominal maximum continuous rating (MCR) is 10,680kW at 117rpm, the
specified rating for each of the tankers is 8,200kW at 99rpm. With the machinery operating at a
normal continuous rating of 6,175kW at 90.1rpm, ship service speed is about 14.5 knots at the
design laden draught.
Energy saving duct
An important energy saving feature is the Mewis Duct, positioned immediately forward of the
propeller, and which has the effect of maximising flow and increasing thrust in relation to power.
The device was developed for full-form ships to provide either fuel savings at a given speed or,
alternatively, to allow the vessel to proceed faster at a given power level. It consists of two fixed
elements, whereby the duct straightens and accelerates the wake into the propeller, with the
integral fin system engendering a pre-swirl to the ship wake, boosting thrust by reducing losses in
the propeller slipstream.
The three diesel generator aggregates employ MaK 6M20C engines, yielding 830kW apiece at
900rpm. The voltages for the main consumers are 440V and 220V, 60Hz.
The four-ship series has been assigned to ABS class and is the first to adopt the society’s LNG-Ready
approval for potential operation on LNG fuel in the future.
ABS published the Guide for LNG Fuel Ready Vessels in 2014. The LNG-Ready endorsements allow
shipowners and yards the flexibility to limit initial investment outlay while planning for future
conversion to dual-fuel or gas-powered machinery. By achieving compliance with the Guide, Crowley
has the option to adapt the product tankers for LNG-fuelled propulsion at a later date, having
already been granted a conceptual review.
Rob Grune, Crowley’s senior vice president and general manager, petroleum services, said the
company was proud to be the first to receive this designation from ABS. “As our business continues
to shape itself to better meet the requirements of our customers, these vessels that stand ready and
able to operate on a cleaner, alternative fuel source are our way of anticipating future demands.”
ABS chairman Christopher J.Wiernicki stated: “This milestone builds upon our work to provide
owners with the guidance and support they need to move ahead with shipbuilding projects that
allow them the flexibility to respond to changes over the lifetime of their vessels.”
Should the company decide to take up the LNG option, the requisite installation will include three
510m3 Type C LNG fuel tanks, to be located on the weatherdeck together with a fuel gas room and
port and starboard bunker stations.
Retrofit options
The practical, usable LNG fuel gas storage in the four deck tanks will be 1,375m3, or 90% of the total
nominal capacity of 1,530m3. For operating the ship wholly on LNG, this should confer an endurance
of approximately 25 days.
To retrofit the ME main engine to ME-GI configuration will necessitate new components in the shape
of double-wall gas pipes, electronic gas injection (ELGI) valves, large-volume accumulators, and the
associated control and safety system, together with modification of the cylinder cover.
Crowley’s Seattle-domiciled naval architecture and marine engineering consultancy Jensen Maritime
was retained to provide construction management services for the series on-site at the Philadelphia
yard.
The group’s modernisation and expansion of its shipping interests also embraces two combination
container/ro-ro (con-ro) vessels destined for the traffic between Puerto Rico and the US mainland,
another sphere of Jones Act trade. The two 26,500dwt newbuilds at VT Halter Marine’s Pascagoula
yard are distinguished not only by a bespoke design but also by the nomination of LNG dual-fuel
propulsion and auxiliary machinery.
To support Crowley’s LNG needs, contracted fuel supplier Eagle LNG Partners is to establish a natural
gas liquefaction plant in Jacksonville. The state-of-the-art facility is slated to be operational by early
2017, ahead of the service entry of the two con-ros, El Coqui and Taino.
Continuity in the workload
Texas became the first vessel handed over by the US shipbuilder under its new identity as Philly
Shipyard, the name assumed at the beginning of December 2015 following the divestment of
shipping assets. Listed on the Oslo Stock Exchange, ownership of the company remains unchanged,
whereby the Aker-controlled investment firm Converto Capital Fund is the majority shareholder.
Contracts for the Crowley quartet were signed in August 2013, at a total value of approximately
US$490m. The vessels were to be part of a product tanker operating and chartering joint venture
between Crowley, the shipyard and certain affiliates, announced at the time of the order. Aker
Philadelphia, as it was then, made a strategic decision to invest US$115m in the series. However,
two years later, in September 2015, the shipyard sold its interest in the joint venture to a subsidiary
of Marathon Petroleum Corporation.
The current production run in the MT50 tanker programme extends to eight vessels, as the four
ships for Crowley are to be followed by a quartet to the account of the Kinder Morgan subsidiary
American Petroleum Tankers (APT). The APT series had originally been ordered by Philly Tankers, but
the contract was taken over by Kinder Morgan in August last year for an all-in price of US$568m.
The four LNG-ready product tankers for APT are scheduled to be delivered between November 2016
and November 2017, and will be placed in US domestic service. The keel-laying ceremony for the
lead vessel from Philadelphia took place in January.
Philly Shipyard’s current workload also encompasses the latest stage of investment by Matson
Navigation Co. The contract entails two 3,600 TEU Aloha-class containerships, booked in 2013 at a
combined value of US$418m for completion in the third and fourth quarters of 2018.
As the largest Jones Act cellular boxships to date, the 23-knot duo will be utilised for the owner’s
service linking the US West Coast with Hawaii, and will be powered by MAN dual-fuel two-stroke
machinery. The project constitutes a renewed contractual relationship, since Matson took delivery
of four container vessels of 2,500-2,600 TEU from the Philadelphia yard between 2003 and 2006.
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