Saving space and reducing weight are two of the biggest challenges for engineers working in the marine industry. Every cubic foot or kilogramme saved results in reduced fuel consumption or improved payload.
So, when one powertrain manufacturer designed a remote PTO solution which would allow pumps to run from the main engine - thus eliminating the need for a secondary engine - there was immediate interest. At the heart of the new design was a clutch from Warner Electric.
In the offshore, marine and oil and gas sectors most workboats and dredging vessels require large hydraulic pumps for their operations, as well as fire pumps for emergency situations. These pumps often require between 300 and 500hp to operate, meaning that they are often run from secondary engines. Not only is this an inefficient solution, there is also an inherent delay as the engine comes up to speed which could be catastrophic in an emergency situation.
The pumps have to be run in this way because of an inherent shortcoming in remote Power Take-Off (PTO) systems for diesel engines. This shortcoming was identified by a marine and industrial powertrain manufacturer who noted that most transmissions have one or more PTO locations, but these only allow for a fraction of the transmission’s capacity to be transferred and often offer a limited footprint for ancillary equipment. If a more efficient solution could be designed then, for many applications, the pumps could be run from the primary engine – a far more efficient solution.
The assembly is designed to be driven from the front of the crankshaft, enabling it to run general purpose hydraulic pump drives, fire pump drives and other secondary drives from the primary motor. Part of the design required a remote operated clutch with proven reliability in the harsh marine environment. The manufacturers approached Warner Electric, part of Altra Industrial Motion, for a solution. The SFC-1525 stationary field clutch was selected due its size and design, remote electrical activation and reputation for reliability offshore.
A spokesman for the manufacturer commented: “Finding a remote clutch that met our performance requirements and also fitted to the necessary footprint was key to the project. Warner Electric was one of the few manufacturers that was able to deliver on all of our requirements, and when we started looking at reliability records and service support it was obvious that they represented the best value for money.
“The remote PTO has proven to be extremely popular, especially as many boats are currently undergoing upgrades to more fuel efficient engines and our system allows them to continue to operate secondary drives from these.
“Because the PTO is driven from the crankshaft it is driven in a left hand rotation; this isn’t a problem for most pumping applications as all hydraulic pumps and most fire pumps are available in this configuration. For other applications which require right hand rotation, an integral parallel shaft gearbox is available – this is possible thanks to the small footprint of the Warner Electric SFC-1525 stationary field clutch.”
The remote PTO has now been commissioned on many different vessels operating around the world. The clutch can be engaged in about a second, giving the crew almost instant access to the secondary systems driven by the PTO.