ABT TRAC DC bow and stern thrusters

ABT TRAC is an American company better known for hydraulic thrusters and stabilizers on trawlers and yachts. Its DC thrusters are the electric entry point to that world, and they're built like it. ABT TRAC's own description is blunt: no undersized propeller shafts, no light-duty motors, no compromises compared with its hydraulic and AC units. That's marketing, but the spec sheet backs up the heavy-duty part.

Three tunnel sizes, two voltages

The DC range is small and focused. Figures below are from ABT TRAC's current DC spec sheet.

Each model uses twin counter-rotating propellers. ABT TRAC lists thruster and motor weights separately, with bronze or aluminium options for the thruster body; the 12-inch 24V motor alone is listed at 159 lb.

A quick translation for anyone used to European sizing: an 8-inch tunnel is about 203 mm, 10-inch about 254 mm, 12-inch about 305 mm. So even the smallest ABT TRAC DC unit sits in a tunnel bigger than the 185 mm units that dominate 30 to 45 ft boats.

Sizing by windage, not length

ABT TRAC doesn't publish a simple boat-length range for these. Instead, each model has a chart plotting vessel windage (side profile area in square feet) against wind speed, with performance bands labeled premium, average and marginal. It's a more honest way to size a thruster. A 50 ft trawler with a tall flybridge catches far more wind than a 50 ft sedan, and length alone hides that.

To use it, you need a windage figure. We estimate it from profile drawings or measurements of the boat above the waterline. Our sizing calculator gives a starting point, but for an ABT TRAC we'd work from the charts.

Run time and the cooling fan

ABT TRAC says its DC motors are larger and heavier-duty than typical, extending run times to three minutes or more. It also offers an optional cooling fan that forces air over the motor windings between thrusting periods. ABT TRAC's explanation is the right one: DC motors build heat with use, and that heat plus the insulation rating decides how long the thruster can run. Cooling between bursts gives you more bursts.

For a trawler that spends time holding position in a current, or a boat docking single-handed in a crosswind, that matters more than a few extra pounds of thrust.

Controls

The spec sheet shows a low-profile control panel with a spring-to-center or friction-lock lever, a power-on light and an audible alarm, in single or dual (bow and stern) configurations. ABT TRAC describes these panels as proportional controls. If variable speed on the DC unit is important to you, confirm the exact control package with ABT TRAC when ordering. Larger ABT TRAC systems can also tie into TRAC Link, the company's CAN bus control network for thrusters, stabilizers and hydraulic loads.

Install: it's an electrical project

The spec sheet lists battery minimums, and they're not small:

• 8-inch: two Group 31 batteries
• 10-inch and 12-inch 24V: two 8-D batteries
• 12-inch 48V: four 8-D batteries

Combine that with 355 to 590 amps and cable up to 250 MCM, and the thruster becomes the smallest part of the job. We place the battery bank as close to the thruster as the boat allows, keep runs short and direct, and size fusing and the disconnect to match. Battery choice is covered in AGM thruster batteries and lithium thruster batteries. Tunnel work follows the usual principles on our bow thruster installation page, with heavier tunnel walls for the larger sizes.

Bow and stern pairs

ABT TRAC sells the control panel in single or dual configurations, so a bow and stern pair can run from one panel. On a trawler with a long keel and big windage aft, a stern thruster often does as much for docking as a bigger bow unit. The catch with DC is that you now have two high-current loads at opposite ends of the boat, each wanting its own battery bank or a very heavy cable run. If you're planning both, work out battery placement for the pair before choosing sizes. Our stern thruster installation page covers the tunnel side.

Where it doesn't fit

• Small boats. There's no 12V model and no tunnel under 8 inches. A 32 ft sailboat is not the customer.
• Light-weight priorities. These are heavy units by design.
• Owners wanting a broad dealer network. Support runs through the factory in Arlington, Washington and its service network. Check who covers your cruising area before you commit.

Against the alternatives

The real choice for an ABT TRAC DC buyer is often not another DC brand but ABT TRAC's own hydraulic thrusters. If the boat has, or will have, hydraulic stabilizers, a hydraulic thruster off the same system usually makes more sense. See electric vs hydraulic thrusters. Among DC options, larger Sleipner SE and Max Power CT units cover similar thrust with wider dealer networks; ABT TRAC's pitch is heavier-duty construction and run time.

Verdict

A tough DC thruster for trawlers and bigger yachts, with the run time and build to match. It makes the most sense on 24V boats with room for a proper battery bank, and especially on boats already running other ABT TRAC equipment. If that's your boat, send us the profile drawings and we'll work out windage and battery placement before anything gets ordered.

Questions people ask