Electronic Control System Tugboat Turns on a Dime
A tugboat commissioned by a Japanese operator is the first to be fitted with a fully electronic control system uniquely installed on the rotor casing foundation of its Voith Schneider Propellor propulsion unit. An arrangement that not only saves space, but also simplifies maintenance and increases reliability.
The new Voith Water Tractor (VWT) ‘Shinano’, designed for harbour assistance and escort duties, was constructed by Niigata Shipbuilding based in Niigata, Japan, for owner Dr. Nakamura, who operates his fleet of tugs in the port city of Iwaki.
Voith Water Tractor ‘Shinano’: Photo credit Voith Turbo
Voith Electronic Control System
This first installation of a fully electronic control system in a VWT, now integrated into the propulsion system, offers actuation and control of the propulsion systems, remote diagnostics via the Internet and communication through an embedded CAN networks. (The CAN bus – Controller Area Network – is designed to allow micro-controllers and devices to communicate with each other within the tugboat without any need for a host computer).
The entire control system was developed in-house by Voith, whilst ergonomic design of bridge control devices, joystick, steering wheel and propulsion control lever were developed in cooperation with experts in the field at Stuttgart University.
To monitor the propulsion units, the new electronic control system records all data as well as faults. Monitoring may be done from the bridge as well as from the machine or propeller room.
VSP Control System: Image courtesy of Voith Turbo
Power and Propulsion
Integration of components of the cooling, the pump systems (mechanically driven main pump as well as electrically driven standby pump) and the lube-oil and control oil reservoirs into the propulsion rotor casing area saves space and is intended to increase reliability, possibly save fuel consumption, as well as allow easy access for maintenance work.
The VWT ‘Shinano’ is equipped with two size 32 R5 ECS/265-2 Voith Schneider Propellors with a diesel engine input power of 2,600 kW each.
Voith Turbo Fin
In addition to the new CAN bus automatic control system the tugboat has a Voith Turbo Fin to increase indirect tow-rope pull to delivers two important advantages: increased bollard pull and greater safety in towing operations especially in restricted waterways. It is actually a deep underwater skeg or fin fitted in the forepart of the tug whose position is controlled by pitch levers and the steering wheel. The fin is designed to take the largest share of the steering forces involved in towing.
Voith Turbo Fin: Photo courtesy of Voith Turbo
At the fin’s leading edge is a rotating tube that significantly improves the flow of water on the low pressure side, allowing higher operating angles without separation of the flow. Compared to the steering force of their conventional VWT’s Voith say that this system offers an improvement of up to 25% on the steering forces generated by the actual rudder of the ship being towed.