How an ATB could solve the US Navy’s fuel transport and storage problems

While acknowledging that T-AO oilers are vital links to replenishing the Navy’s warships while underway, Mr McCoy made the point that their price tag excessive.

In November, the Navy awarded a US$1.7Bn contract to San Diego shipbuilder General Dynamics NASSCO to construct two John Lewis-class fleet replenishment oilers. These tankers will primarily be used to refuel Navy warships at sea as part of carrier strike groups. The 50,000-tonne-displacement tankers have a helicopter flight deck for vertical replenishment, multiple port and starboard refuelling stations, double hulls and can carry dry stores, diesel and jet fuel and provisions.

“US$850M apiece [is] a hard number to justify as a taxpayer,” said Mr McCoy. “My argument is that the Navy should build oilers, but hopefully at a better price.”

Why ATB?

He sees the NavalLinks SupplyLink ATB as part of the solution. An ATB unit consists of a tug that fits into a notch in the stern of a barge, where it is connected using an articulated coupling system. An ATB unit offers numerous commercial advantages over towed barges, including increased efficiency, speed, fuel savings, and enhanced crew comfort and operation in a wide range of sea conditions. The detachable tug – the most expensive asset of the ATB unit – and its crew are kept working, dropping off one barge and picking up another, avoiding idle time in port while loading and unloading operations are conducted.

For the last four decades, a core part of Intercon’s business has been designing, engineering, and manufacturing different models of the Intercon Coupler for tugs ranging from 400 long tons (LT) to 4,200 LT displacement. The largest tug, towing and marine cargo transportation companies in the US operate ATB units with INTERCON Coupler Systems. Among the biggest ATB units are those built for Crowley and OSG (now part of Saltchuk) with capacities of more than 300,000 bbl. The vessels are also capable of operating in significant wave heights of 7 m.

“It makes sense from a fuel transport and fuel storage perspective”

While well known in the maritime business for its coupler systems and winch machinery, Intercon makes about 70% of its revenue from US Navy-related subcontract manufacturing, said Mr McCoy. “We have produced the main reduction gear housings for Arleigh Burke-class destroyers, Ford-class aircraft carriers, and the last two Nimitz-class carriers. We produce two of the three major housing components of the main propulsion motors for the new Columbia-class submarines. So, Navy work is important work for us. They just don’t happen to be our own products. We build them for someone else.”

NavalLinks’ ATB concept

Mr McCoy explained NavalLinks’ vessel concept “pulls together a number of existing systems: the ATB coupler and computer vision systems” that provide situational awareness at sea, in combination, along with a reimagined ATB unit with a large clear deck design. The computer vision systems would eliminate the need for an elevated wheelhouse on the ocean tug and the clear deck design was necessary “to support the Navy’s need for either container storage or flight deck space to accommodate vertical take-offs or landing aircraft.”

Mr McCoy shared some of the highlights of the NavalLinks’ SupplyLink ATB concept. “We have a central manifold for taking on and offloading the fuel product. This particular barge design has three segregations, though we are only expecting to carry two different fuel types at any given point in time: jet fuel; and diesel. All piping between the segregations is handled under the main deck. The main deck is reinforced to be able to support vertical take-off and landing aircraft.

“The Navy absolutely needs fuel, and they need fuel in quantities that are hard to fathom sometimes. But the Navy needs a lot of other materiel support as well. This vessel is designed to carry 200,000 barrels, as well as 120 TEUs of containers in a single stack. Now at a lower capacity, we can carry up to 330 TEUs of containers in triple stack,” explained Mr McCoy.

The vessel concept also incorporates defensive measures, with anchoring points to support anti-drone modules from Danish company SH Defence.

Mr McCoy pointed out that over the last four decades there has been ample capability, knowledge, and capacity to design, build and operate ATB units in the US. “You have operators that are experienced and yards that are experienced in building barges this size,” he said.

Estimates suggest the NavalLinks’ SupplyLink ATB ocean-going vessel concept – with the ability to deliver more materiel than a John Lewis-class T-AO oiler – could be built at a cost of US$110M.

“You could build 30 NavalLinks barges for the price of four T-AO oilers,” said Mr McCoy. The barges would be able to be used as floating fuel storage and distributed across the Pacific to support the Navy fleet.

Mr McCoy believes Navy T-ATS salvage tugs under construction at Bollinger and Austal could be retrofitted with coupler systems to act as detachable power units to use in connection with the tanker barges: “It makes sense from a fuel transport and fuel storage perspective. It presents the Navy with options. They would own an asset that stores and moves the fuel, and provides a standard interface and standard design.”

Designed for salvage and rescue operations in support of the Navy, T-ATS tugs could be retrofit with coupler systems for operation as part of ATB units for about US$15M to US$20M each, according to Mr McCoy.

“You have yards that are experienced with building barges of this size, and a system that’s been classed for 25-plus years for unrestricted ocean service. It’s a no brainer. But that doesn’t mean it is going to happen,” concluded Mr McCoy.