VESSEL REVIEW | Thomas X. Grasso – Maintenance and dredging support tug for New York Power Authority

The Power Authority of the State of New York (NYPA) has taken delivery of the first unit in a new series of steel inland tugs.

The 64.5-foot (19.7-metre) Thomas X. Grasso is being operated by NYPA subsidiary New York State Canal Corporation (NYCC). Design work was undertaken by naval architecture firm the Bristol Harbor Group while construction took place at Blount Boats in Warren, Rhode Island.

“In 2017, jurisdiction of the NYCC was transferred from the New York State Thruway Authority to the NYPA,” Bill Jordan, Senior Naval Architect at the Bristol Harbor Group, told Baird Maritime. “Also at that time, the US Code of Federal Regulations Subchapter M was enacted for towing vessels, requiring US Coast Guard inspections and invoking certain design and construction features.”

He added that some of the existing vessels in the NYCC fleet had dated back to the late 1920s. Many are single-screw vessels, and several were converted to diesel power from steam in the early 1970s.

“The existing fleet is diverse. Most vessels were acquired from other commercial services over the years, not purpose-built for their duties on the canals, and many needed extensive or prohibitive repairs and/or refit to comply with the new regulations. In several instances, the best option was to decommission existing vessels and replace them with a new, compliant design.”

NYCC required a design that could serve multiple purposes to suit the needs of the eight regional sections of the New York State Canal System using a single, uniform design.

Compact platform with reinforced hull for icebreaking

“There are four organisational units (based in Waterford, Utica, Lyons, and Albion) serving those eight sections, responsible for 524 miles (843 kilometres) of canal and navigable waterways including some 57 locks, 300 bridges, and associated infrastructure. The tug's operational duties are varied from section to section, and season to season.

"The design is intended to perform multiple functions well, without significantly compromising the ability to perform other tasks that may take priority in a different section or during a different season."

Jordan added that the tug is configured to meet several sometimes conflicting requirements – shallow draught, low freeboard, low air draught (to enable passage underneath bridges), excellent visibility, high manoeuvrability including when downstreaming or backing off of dams, the ability to push, tow, and tow alongside – as well as capable of breaking ice in areas where ice dams have caused flooding and damage to infrastructure.

The vessel also needed to be capable of navigating through narrow waters, as the canal system was only 140 feet (43 metres) wide in some areas.

“Also, it needed to provide crew comfort with some amenities including a well-heated and conditioned interior with a shower, a small galley, and the capability to accommodate a limited crew (i.e., two or three people) overnight if necessary.”

Jordan said that as such, the vessel is a tug in the conventional sense, rigged with a tow bitt aft and clear poop deck for the towline. She is also equipped with quarter bitts for pushing alongside and push knees and barge winches forward for pushing inland dredging equipment with, in many instances, very low freeboard.

Finally, the hull is heavily reinforced and plated with ABS grade D steel shell plating (providing high toughness at low temperatures), an ice knife forward, ice knives/horns on the rudderstocks, heavy shafting and propellers, and a specialty coating for service in seasonal ice, thus allowing for year-round operation.

Although able to operate with a limited crew, a maximum of eight personnel can be accommodated in the heated and air-conditioned liveaboard spaces.

“The vessel will operate throughout the New York State Canal System,” Jordan told Baird Maritime. “The primary duty system-wide is to support dredging and maintenance operations, pushing or towing dredgers, derricks, deck barges, hopper scows, quarters vessels, and other support equipment for dredging as well as maintenance and repair of infrastructure.”

The tug will also be employed to deploy, retrieve, and service buoys and other navigation aids, support new construction and maintenance and repair work on canal infrastructure including locks, dams, bridges, bulkheads, and other facilities. She will also aid in pollution response and cleanup as well as performing debris collection throughout the canal network.

In certain areas of the canal system, the vessel will support icebreaking operations.

Navigation suite optimised for canal operations

The tug’s twin main engines are Caterpillar C9.3s each rated 375 hp (280 kW) at 1,800 rpm mated to Twin Disc MXG5114SC gearboxes and conventional shafts. The shafting is Aquamet 22HS turning Michigan Wheel four-blade ice-strengthened stainless steel propellers, with Thordon SXL self-lubricating bearings for propulsion shafts and all rudder stocks. The tug’s power is provided by two Caterpillar C2.2 generators each rated 25 kW at 1,800 rpm.

“The vessels are equipped with dual flanking rudders ahead of each propeller, for improved manoeuvrability with a tow or when backing off the various dams and locks,” said Jordan.

The onboard electronics include navigation equipment supplied by Simrad with dual NSS EVO 3 touchscreen multi-function displays.

The other equipment includes Icom VHF radios, a Standard Horizon loudhailer, a Kahlenberg electric horn, Carlisle-Finch Xenon searchlights with beam focus, an LED “wall of light” option and remote joystick control, a Vingtor Stentofon general alarm system, a Zenitel sound-powered phone system, a Maretron tank gauging display and sensors, a JBOX navigation panel, Paneltronics DC panels, and a Ritchie compass.

“Due to the route and operating restrictions on the fleet, the tug is not required to carry radar, despite the otherwise extensive suite of equipment provided.”

Emissions-reducing features

The deck equipment consists of Nabrico 10-ton manual barge winches and single roller chocks for pushing, a Nick Jackson aluminium main davit with electric hoist, and a Columbia stainless steel portable davit. The laminated fenders were meanwhile supplied by Schuyler.

“The vessel is equipped with three different socket locations so the portable davit can be utilised to assist with man overboard recovery, debris collection or anchor deployment and retrieval, as well as equipment replacement in the engine room by shifting from one location to another,” said Jordan.

Thomas X. Grasso and her sisters are each equipped with a three-phase inlet to receive shore power. In addition, they each have a dedicated “heat-only” shore power inlet capable of supplying just the onboard boiler and hydronic heating system, for freeze protection in cases where the vessel must dock or moor at a worksite where normal ship’s shore power connections are not available. The heat-only circuit can be supplied using a standard extension cord and 120-volt receptacle.

The second tug in the series will be equipped with a secondary shore power inlet configured to receive 240V single-phase power and convert it to three-phase to energise the switchboard. This vessel will thus have flexibility to accommodate the varied shore-side supply that may be encountered throughout the canal network, as well as highly flexible options for which loads may be energised onboard when generators are switched off.

The tug’s tank capacities are 4,100 gallons (16,000 litres), 350 gallons (1,300 litres) and 350 gallons for fuel, freshwater and gray water, respectively.

Maximising available space for greater comfort

“The biggest overreaching challenge in designing the tug was probably accommodating as many features and multi-purpose capabilities as possible in a compact package, while keeping equipment layout and crew access as ergonomic as possible,” Jordan told Baird Maritime.

“For instance, the full headroom pilothouse is located directly above a full headroom crew space, which is located directly above fresh and black water tanks, above a double bottom to the shell, all within a nine-foot (three-metre) depth of hull and approximately a 15.5-foot (4.72-metre) air draught.”

Similar to the fresh and black water tanks, all fuel tanks are independent of the shell, with accessible double bottom spaces below, providing protection from collision. In addition, the arrangements provide excellent all-around visibility from the pilothouse, while still complying with the draught and air draught limitations.

“We learned to try to receive operator input as early in the process as possible,” Jordan explained when asked how the design challenges were overcome.

“Clear communication is the key to determining the most elegant solution to operational issues or design problems. Rarely is there a perfect solution that doesn’t interfere with other competing design constraints, but determining the best possible solution requires as much operator input and expertise as it does our design capabilities.

“On this project, we are also able to rely heavily on the cumulative experience at the shipyard for construction-level design and installation details that are simple, effective, and user-friendly.”

Thomas X. Grasso was built in compliance with US Coast Guard Subchapter M requirements covering towing vessels.