Mamala
Active shaft grounding system
The challenge
When a ship or submarine moves through the water, it generates an electromotive force caused by the use of materials with different electrochemical properties (e.g. zinc, bronze, steel, etc). This creates an electric current that flows through the bearings between the propeller, shaft and hull.
The propeller shaft should be grounded to the ship's hull to help prevent corrosion and spark erosion in the shaft bearings and gearbox. If shafts are not grounded, the resulting spark erosion can damage propeller shafts and engine bearings.
The propeller shaft grounding required in this situation provides very low electrical resistance to the hull, preventing erosion damage. Without this grounding, electrical current will damage the bearings on ships and submarines over time.
Our solution
When the propeller shaft of a ship or submarine rotates, it is essentially electrically insulated from the rest of the hull. This can lead to costly and time-consuming spark corrosion in the shaft bearings and gears.
The Mamala active shaft grounding system by HENSOLDT protects the bearings and gears by reducing corrosion. It reduces the voltage difference between the shaft and the hull to just a few mV.
By effectively regulating and reducing electrical currents, HENSOLDT’s active grounding systems also significantly improve ships’ electromagnetic discretion. The performance of these systems is far superior to a simple passive grounding system, making them the perfect solution for protecting the propulsion systems and contributing to the degaussing of ships and submarines.
Features and benefits
Features
- Reliable, rugged, durable system
- Available currents: 30, 35 and 60 A
- Control and monitor system status from a local HMI or remotely via an Ethernet connection
- IP55
- Natural convection cooling
- Single-phase, 230 V AC power supply
- Can be installed on new vessels and can also be retrofitted or used to replace entire existing systems (passive or active)
Benefits
- COTS product
- Adaptable: form factor, input network
- Two operating modes: passive and active (for greater efficiency)
- Automatically switches to passive mode in the event of power failure
- Suitable for harsh environments thanks to high IP65 rating
- Training programmes in the use and maintenance of the system are available, which can be delivered on board (using customer equipment) or in classrooms using dedicated HENSOLDT equipment
