OCTOBER 7, 2013 — Less than 11 months after the original design contract was placed,four shallow draft, double hull, combination bulk oil and deck cargo barges are now in service delivering bulk fuel oil and deck cargoes for Canada's ITB North Ltd.
In September 2012, ITB North Ltd., a division of ITB Marine Group Ltd., contracted with Robert Allan Ltd. naval architects of Vancouver, B.C., Canada to design a new class of shallow draft, double hull, combination bulk oil and deck cargo barges for operation on the Mackenzie River, Great Slave Lake, and the Beaufort Sea in the Canadian Arctic.
An extremely tight design and build schedule was required in order to get the barges delivered to the Canadian Arctic in time for the 2013 summer operating season. The compressed design schedule involved a close collaboration between owner and designer in the development of this unique class of vessel required to operate on the Mackenzie River with its challenging 1.5 m river draft, short three month operating season, and many ports of call that are little more than a river bank.
ITB Marine Group’s knowledge and years of experience in bulk oil transport coupled with Robert Allan Ltd.’s extensive experience in shallow draft barge designs, resulted in an innovative and economical design to serve communities and industry in Canada’s northland.
Steel cutting commenced at Jiangsu Yangzijiang Shipbuilding Company in China just three months after the award of the design contract.
In all, four barges have been built to this design and have been named the ITB Deh Cho 1, ITB Deh Cho 2, ITB Deh Cho 3, and ITB Deh Cho 4.
The barges were constructed under the construction management and supervision of Seabridge Marine Contractors. The first two were transported on the deck of two 7,100 dwt deck barges towed by the Pacific Hickory in a three week tandem trans-Pacific tow and floated off in Vancouver where final outfitting took place.
They were later towed to their home port in Tuktoytuk in another three week tandem tow by Island Tug’s 3000 bhp ice class tug, Island Tugger (Ex. Canmar Tugger). The second two barges were towed direct from the shipyard in China to Nome Alaska by the Pacific Hickory and then onward to Tuktoyaktuk by the Island Tugger.
The design has many innovative features including:
- Portable ramps able to be deployed off the bow, stern, or midships P&S
- 15 t/sq.m deck load rating
- Spuds for locating the barges on the river during cargo loading/offloading operations
- Designed for both coastal towing and for pushing on the river using push knees and barge winches
- Certified for both high and low flash cargo products
- Portable cargo pump sets that can be removed and stored inside during the winter months.
- Extensive use of high strength steel to reduce deck and shell plate thicknesses reducing barge weight while not compromising plating strength
- Spill prevention and response features include:
- 300 mm high coaming surrounding all cargo tank openings and fittings
- Common cargo vent system
- Closed loading capability
- Dedicated spill tank
- High level and high-high level indication
- Cargo tank sight glasses
- Remote emergency pump shut-down
- On deck spill response container housing equipment including 1,000 feet of inshore containment boom and an Aquaguard Triton 60 skimmer.
- All towing and pushing fittings were checked using finite element analysis (FEA) to ensure required strength for the intended operations. The portable shore ramps and deck structure were also analyzed using FEA.
Particulars of the Deh Cho barges are as follows:
Length overall: 70.00 m
Beam, molded: 18.90 m
Depth, least molded: 3.40 m
River draft: 1.525 m
Loadline draft: 2.514 m
Total Deadweight at River Draft: 1,055 Tonnes
Total Deadweight at Load Line Draft: 2,410 Tonnes
Maximum Cargo oil (95% full) 2,037 m³
Arctic Diesel Capacity at River Draft 1,270 m³
Spill Tank: 19 m³
20 foot Container capacity: 78 Containers
The barges were designed and constructed to Lloyd’s Register Class requirements with the notation: +100AN Oil Barge.