What do I buy with Rotortug®?

A Rotortug® is a tug fitted with a patented Rotortug® Propulsion configuration. You buy the right to use a custom-made Robert Allan Ltd. design fitted with this Rotortug® propulsion configuration. This is a one off fee, subject to bollard pull, length and beam of the tug as well as the number of tugs. The patent fee is linked to the registration number of the tug.


How does the co-operation with Robert Allan Ltd. exactly works?

Robert Allan ltd. is the exclusive designer of the Rotortug®. We combine over 75 years of operational experience in the towage industry with great design! You can request for a Rotortug® package offer through Robert Allan Ltd or Rotortug B.V.


Do the front thrusters not interfere with the aft thruster?

Only at maximum bollard pull the aft thruster is interfered but this is minimal. The maximum bollard pull is generally achieved by turning the forward thrusters 8 degrees outward.


How cost effective is a Rotortug® design?

As a genaral rule of thumb: you pay for (installed) power. Dividing the power over two or three drivetrains make no difference. In the range from 65 tons to 80 tons of bollard pull you can achieve a competitive advantage due to smaller sized thrusters and engines.

Comparing the Z-drive to Voith-Schneider propulsion types, the Z-drives generally has a much better bollard pull to power ratio. This can save you up to 20% in capital investments and fuel consumption for equally powerful tugboats.


What about the fuel consumption?

Average fuel consumption is equal to a tractor type tug. In general drivetrain configuration (controllable pitch – or fixed pitch propellers), hull form and not in the least human behavior are the predominant drivers of fuel consumption on your tugboats.


What about the maintenance costs?

By example maintenance costs for a 80 tons bollard pull Rotortug® are on average 10k €/year higher compared to Z-drive ASD- or tractor type tugs. This is due to the special survey costs for the third thruster after 5 years. Filters and spares for smaller engines are generally cheaper.

In return you get a level of redundancy where you can safely operate your tugboat in case of engine or thruster failure and maintenance, especially when operating remote terminals. It’s better to have one tug operating on 66% capacity, then none at all.


Is the Rotortug® difficult to steer, having only two hands and three handles to operate?

In general, it takes a week of on-the job training to educate an experience ASD Master to sail a Rotortug, a little less for a Voith or tractor Master.


Why are there  hybrid Rotortugs® and not yet a diesel electric Rotortugs®?

The optimal drivetrain setup depends on your operation sailing profile. A fully diesel-electric Rotortug® can perfectly suit your off-shore operations with a lot of idling operating hours.

The hybrid propulsion system offers an intermediate solution for harbor operations where owners generally prefer to have all the tugs power mechanically available. We are more than happy to look into diesel-electric, hybrid or diesel-direct solutions for your application.


How is the fi-fi arrangement set up?

Generally we mount the fire-fighting pump from a power take-off on the portside main engine. This way the Rotortug® retains full maneuverability and station-keeping capability. Twin engine tugboats generally require a third engine to drive the fire-fighting pump or expensive high-duty slipping clutches.


Is training part of the deal?

We offer basic- and advanced training courses by certified training masters. Training can either be on the job or in a simulator model environment. Basic training is included in the Rotortug® package.