Philly yard delivers LNG-ready US tankers

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


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


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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