VESSEL REVIEW | North Arm Tempest – Powerful barge-handling tug designed for BC’s remote areas

North Arm Transportation, a towing and ship handling company headquartered in Vancouver, British Columbia, has taken delivery of a new tug from local shipyard ABD Boats.

Built to a design developed by naval architects A.G. McIlwain, North Arm Tempest is a near-identical sister of Renegade, an earlier tug that joined the North Arm fleet in 2012.

The newer tug has an LOA of 19.7 metres, a beam of 8.2 metres, and a draught of 4.2 metres. Its primary duties will be in support of deliveries of fuel, heavy equipment, and other types of general cargo, particularly to customers in the more isolated ports along the northern BC coast.

Interestingly, whereas nearly all barge-towing tugs that operate along the BC coast are fitted with conventional propellers that are housed in nozzles, the propulsion units on North Arm Tempest are in the form of two Veth VZ-900 Z-drives with 1,700mm propellers. This makes the tug capable of assisting with ship handling, but importantly, it is also more capable of safely manoeuvring barges in isolated up-coast ports.

Power for the two Veth drives will be supplied by a pair of Cummins KTA38-M main engines, each producing 745 kW at 1,800 rpm. The engines will drive the Z-drives through Vulkan torsional flexible couplings and composite shafts. Port and starboard drive units are housed in separate spaces accessed by a passageway aft of the engine room.

The propulsion arrangement enables North Arm Tempest to reach speeds of around six knots. There are also two auxiliary engines from John Deere.

The engines have also been fitted with optional fuel monitors. North Arm fleet supervisor Paul Kruse said that such custom features were installed partly to enable the company to comply with environmental regulations in its area of operations in BC's more remote coastal areas.

A split-drum, combination anchor and hawser winch by Burrard Iron Works is mounted forward while a single drum towing winch from Burrard is mounted on the aft deck. Both winches will operate on hydraulics off the two auxiliary engines. Towing pins were supplied by Western Machine Works while the wrap-around fendering was provided by Schuyler Companies.

The towing winch is designed to enable the tug to tow up to three barges simultaneously in a tandem arrangement. The hawser winch, meanwhile, may be used in barge connections as well as in shipdocking.

The accommodation spaces for the tug's crew of six include two one-person cabins, two double cabins, a laundry area, and a galley. All interior spaces benefit from reduced noise thanks to the installation of exhaust silencers from Harco.

The electronics suite consists of radars, GPS, AIS, and a satellite compass from Furuno, a Simrad autopilot, ICOM VHF radios, and an Iridium satellite phone. For firefighting, the tug has two dedicated pumps, a Kidde CO2 suppression system, and a Honeywell alarm.

North Arm Tempest also comes equipped with two Carlisle and Finch searchlights, Advantec windows for the wheelhouse, a man overboard davit, and exterior coatings from International Paints. The wheelhouse features aft-facing controls and secondary controls on the top flying bridge while the mast may be hydraulically lowered to allow the tug to easily sail underneath low-hanging bridges.

See more stories from this month's Tug and Salvage Week here.