Great Lakes Towing Co. builds tugs for a new century of service
The Great Lakes Towing Co. is making steady progress with its fleet replacement plan.
Illinois departed this spring from Great Lakes Shipyard in Cleveland for Detroit, roughly 120 miles to the west. It is the sixth of 10 tugboats in the Cleveland class. The seventh tugboat, Indiana, is under construction and scheduled for delivery later this year.
The 64-by-23-foot Illinois shares the same conventional powertrain as the five-year-old Cleveland rather than the diesel-electric platform installed on sister tugs Michigan, Pennsylvania and Wisconsin, or the variation of that hybrid system installed on Ohio.
Joe Starck, president of the towing company, said the three hybrid tugs have performed exactly as expected. They’re reducing fuel consumption, generating less emissions and reducing wear on the 1,000-hp MTU main engines, which saves on operating costs.
“But we’re still getting to know the systems, and that is more the reason why we did not proceed with that system on vessels six and seven,” he said during an April interview at the company’s Cleveland headquarters. “We wanted to take a step back and get some data on the performance, which we expect to have later this year. That should give us an accurate read on the cost-to-benefit. It’s a very expensive system, and we want to make sure it makes complete financial sense.”
The Great Lakes Towing fleet consists of about 40 tugboats spread across 13 ports from Duluth, Minn., to Buffalo, N.Y. Most of the tugs are more than a century old, driven by a single medium-speed diesel engine. The six Cleveland-class tugs will have replaced 13 older tugs.
Construction is slated to wrap up on the Cleveland class in the next two to three years, at which point the company will still have about 20 of its historic “G” tugs from its legacy fleet still in service. Starck is aiming for a zero-emission solution for the next tugboat series that will replace most or all of those remaining older tugs.
“After Hull No. 10 (in the Cleveland class) of the Damen 1907 ICE design is completed, we’re looking really closely at all-electric,” he said. “Our application is great for all-electric tugboats because so much time is spent at the dock.”
When this project will begin is an open question. Planning is already underway, and Great Lakes is pursuing funding options — including grants from the Environmental Protection Agency (EPA) — to hasten the retirement of its less-efficient older fleet. Funding from the Ohio EPA helped offset costs on the hybrid tugs in the Cleveland class, and money from EPA Region 5 assisted with Illinois and Indiana. The EPA funding was provided through Diesel Emissions Reduction Act (DERA) grant programs.
“The EPA would like to see those antique boats go away,” Starck said. “They are all powered by World War II-era surplus engines.”
Great Lakes Towing announced the Cleveland class in 2016. The timing coincided with the onset of Subchapter M inspection rules for towing vessels. The company’s entire fleet is on pace to receive Coast Guard certificates of inspection (COIs) before the July deadline. That required millions of dollars of reinvestment in addition to the capital investment in the new tugboats.
The six new tugs now in service have been assigned to Cleveland, Toledo/Detroit and Chicago/Burns Harbor, Ind., which are among the busiest ports on the Great Lakes. That will likely remain the case with all 10 tugs in the series, Starck said.
Illinois, like its five predecessors, is built to the Damen Stan 1907 ICE platform rated to IMO Ice Class C. The vessels are nimble, responsive and designed for operating in tight quarters and narrow waterways like the Cuyahoga River in Cleveland.
“She’s fantastic for what we are doing here in the Great Lakes,” Capt. Scott Baker said of the tug Cleveland in 2019. “You can trust her to get where she needs to be and do what she needs to do.”
Towing work on the Great Lakes is different than along the coasts. Great Lakes Towing tugs assist massive U.S.- and Canada-flagged freighters that primarily carry bulk cargoes. They also serve the 250 or so oceangoing ships that call on the region each year, including a container service linking Cleveland and Rotterdam. The tugs also perform occasional ATB and barge assists.
Despite their size, the Cleveland–class tugs are powerful enough to assist all comers on the Great Lakes. The propulsion package on Illinois consists of the MTU mains driving three-blade, 71-inch Kaplan-style props in nozzles through straight steel shafts. Bollard pull is 30 tons.
The diesel-electric hybrid package on Michigan, Pennsylvania and Wisconsin uses the FlexaDrive system developed by Logan Clutch with custom-designed Twin Disc double-clutch reduction gears. Canal Marine provided the hybrid power system and performed the electrical integration.
The FlexaDrive allows the tugs to operate without the main engines. Electrical power from one 99-kW generator powers 75-hp motors installed on each gearset. Those motors turn the gears, which drive the shaft and propellers.
The three tugs outfitted with this system can reach 5 knots using just the electric motors. The FlexaDrive system can also operate in tandem with the main engines, adding about 10 percent more power.
“The best attribute of our system for the Great Lakes tugs is no batteries,” said Andrew Logan, the president and CEO of Logan Clutch, which is based in Cleveland.
“The Great Lakes operating profile provides optimum utilization of a hybrid system,” he continued. “Transiting from job to job with limited use of the main engines for propulsive power offers huge environmental and operational savings to the crew, owners and the environmental stakeholders — the community in which the tugs operate.”
Although Great Lakes Towing is still gathering data on the hybrid system, the early returns are promising. Fuel burn and emissions are reduced by between 30 and 40 percent. The projected payoff period for the system is seven years, Starck said.
Indiana, which was roughly 60 percent complete as of late April, will have the same conventional powertrain as Illinois. Starck said it is not clear whether the final three boats in the series will have hybrid propulsion. However, they will be powered by Cummins diesel engines rather than MTUs.
The Cummins QSK38-M1 mains meet EPA Tier 3 emissions rules. Great Lakes Towing laid keels for all 10 Cleveland-class boats in 2016, before the deadline for EPA Tier 4 took effect. The need to install Tier 4 engines for any subsequent newbuilds is a factor in the company’s decision to explore electric propulsion.
The split-level interior on Illinois is nearly identical to its sister tugs in the series. Upon entering the tug from the aft deck, crew can walk up into the wheelhouse or down below into a crew galley and lounge area. Moving aft, Illinois has a head with a shower. Although used primarily as a day boat, there are two double bunks in the bow.
Like its predecessors, Illinois is not equipped with a winch. Great Lakes Towing tugs do most of their tows with a soft line connected to an H-bitt forward or aft of the deckhouse. The tugs also have a 15-hp electric DMT Marine Equipment capstan aft of the house. Schuyler Cos. fendering protects the bow, while tires provide cushioning on the sides.
The exhaust is discharged from piping at the transom rather than through traditional stacks, which allows for an unobstructed 360-degree view from the wheelhouse. Operators rely on Furuno electronics for navigation and Icom VHF radios for communication while underway.
With more than half of the Cleveland-class tugs now in service, Starck said the vessels are checking all the right boxes. They have reduced maintenance by replacing some of the oldest and most challenging tugs in the fleet. And the two engines on Illinois still use less fuel than the single 1,200-hp GM/Cleveland Diesel 278A mains installed on most of the company’s older tugs.
“These (new) vessels are safer and more reliable, with minimal downtime,” Starck said. “At the end of the day, that is exactly what we wanted from this newbuild program.”