Due to a failure of a Caterpillar Hydraulic Governor on the Tug Vessel “Te Matua”, operated by South Port NZ, Emee NZ Ltd of Mossburn, was consulted to check out the possibility of an improved, reliable, readily available, cost-wise and serviceable system.

Having deliberated and sourcing suitable and reliable hardware involved to substitute the original system, it was found that the movement of the Caterpillar 3606 Engines Fuel Injection Pumps mechanisms demanded a high torque to move such from idle to full throttle.

The requirement was also to have a system that originally was air control to the Bridge, superseded by simple “Rotational Dial” and have simple 4–20mA wiring connection. Other air control levers and parts subject to age failure were removed.

Recommendation and Solution

It was decided to use a combination of a GAC ACB 2001 12Ft Lb Actuator and an AXIOMATIC AX100310 Unidirectional Digital Control for each engine to supersede the original equipment.

The combination of both these products together with suitable developed programed firmware and a mechanically driven encoder has now made reliable use of this vessel.

This equipment was fitted to both Engines and to date has more than proved their worth in speed control which incidentally this vessel is used extensively for moving large ships within the Island Harbour complex and narrow channel entrance.

Installation

Installation of the Emee System is very simple, with a Manufactured Actuator Bracket fitted to each engine with linkage, also an enclosure for the required wiring and having the Axiomatic Controllers externally mounted for access.

The Axiomatic units are totally encapsulated protecting the internal hardware from the sea environment. This is a major plus to eliminate corrosion and damage. A further feature is an emergency “override key switch” which in the event of Bridge Control failure will put the engine RPM to working speed.

Used only in this emergency state. The EMEE System is simple and maintenance free.

Other Aspects

The vessel’s propulsion incorporates 2 x 1000 HP Caterpillar 3606 Marine Diesel Engines which are the prime movers for 2 Voith Schneider Units. The EMEE system has other aspects of inbuilt engine control including “PID” and “CAN” which are essential for precise engine tuning and monitoring. Smoke Limiting etc. The GAC Actuator has rotational movement and bearings on each end of the output shaft.

For engines requiring greater torque for moving the fuel pump rack another Actuator could be attached in parallel using the same above Axiomatic Controller. This Controller is capable of driving two above Actuators together.

Emee NZ Ltd would like to thank those Engineers of Both Axiomatic Technologies, GAC (Governors America Corporation) and especially the team from South Port Bluff NZ for their patience and undivided assistance in helping to achieve the goal of developing this unique control system