I was on the outskirts of Istanbul this past weekend at the epicenter of Turkey’s bustling shipbuilding industry where the naming ceremony of the world’s first LNG-powered tugboat took place.
Built by Sanmar Shipyard for Norwegian tug owner Buksér og Berging, the DNV-classed M/T Borgøy and her sister vessel M/T Bokn are the product of two years of collaborative engineering work by Buksér og Berging, Marine Design AS as well as engine manufacturer Rolls-Royce.
Following sea trials next month, the Borgøy will sail on her own bottom from Turkey to Kårstø gas terminal in Norway to begin her long term operational contract for Statoil.
- LOA: 35 meters
- Beam: 15.4 meters
- Draft: 7.5 meters
- DNV-class, 1A1, EO, Gas-fuelled, Oilrec, FiFi 1, Escort (100, 10).
- Enhanced escort capacity of 100 tons with 130 ton winch.
- Speed: 13.5 knots
- Accommodations: 6 persons
Straddling the 130 ton bow-mounted winch are the ventilation stacks for the 80 cubic meter cryogenic fuel tank, enough fuel to last up to 5 or 6 days at 10 knots of speed.
Powered by Rolls-Royce Bergen C26:33L6PG spark-ignited gas engines, these new tugs will emit nearly 30 percent less CO2 and up to 90 percent less NOx than conventionally-powered tugs. At 1,000 RPM, these engines will deliver a combined output of 3410kW to a pair of azimuthing thrusters.
“Gas is gaining in popularity as a maritime fuel,” commented Neil Gilliver, Rolls-Royce, President – Merchant. “Its environmental credentials, combined with lower costs are seeing many operators select it over traditional fuels, across a range of ship types.
“Most of the world’s tug fleets operate close to shore, where emissions regulations are most stringent. As LNG becomes more widely available, I have no doubt that many major ports will soon opt for this clean, lower cost and smoke-free fuel to power their tugs.”
Auxiliary electrical power is provided by diesel powered generators.
The propulsion package includes two of the latest Rolls-Royce US35, 3000 mm ducted azimuth thrusters with controllable pitch. Over the past few years, Rolls-Royce has supplied 50 sets of thrusters to Sanmar.
To perform vessel escort assistance off Norway, these tugs are designed with a huge foil-shaped keel running 75 percent of the length of the vessel aft from the bow. Although the tugs are rated for 65 tons of bollard pull, they can use the shape of their hull to exert upwards of a 100 tons of steering pull at 10 knots. To accomplish this, the thrusters are used to put the vessel at an angle to the forward direction of the escorted ship which is secured to the tug via a bow line. The resistance created by the tug’s foil-shaped hull then acts essentially like an external rudder to help compliment the steering of the assisted vessel.
Buksér og Berging, which just this week celebrated its 100th birthday, notes that roughly 1500 escorts are performed every year in Norway effectively reducing the risk of ship groundings by approximately 75 percent.
Sanmar Shipyard was established in 1976 and is the first privately-held tugboat builder and operator in Turkey with ownership of 18 vessels operating in 7 different ports.
The yard is extremely prolific delivering approximately one new tug every four weeks. 22 tugs are currently on order representing approximately 18 months of backlog.
Sanmar has 72 employees and has an additional 269 subcontractors at the yard on any given day.
Next door to Sanmar is an endless horizon of gantry cranes and ships in all states of repair, or disrepair.
The following is a satellite image of this area:
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