Specialisation yields optimum fire-fighting performance

Manufacturers of external systems say that fire-fighting equipment continues to be elaborated, with a single company increasingly responsible for every aspect of a plant, from the drive to the monitor and its controls; they also highlight other applications of the technology, at sea and ashore

External fire-fighting systems may be potential life-saving assets but, being rarely used in anger, can be regarded as ‘awkward’ items of equipment to accommodate on a relatively small vessel such as a PSV, an anchor handling tug or a harbour tug. This being the case, note manufacturers, naval architects and designers want equipment to be as compact and lightweight as possible.

At the same time, shipyards want external fire-fighting equipment to be inexpensive to procure and easy to install. For their part, owners want it to be economic, reliable and easy to operate, preferably with minimal maintenance requirements.

At Fire Fighting Systems AS in Norway, company spokesperson Truls F Aannestad noted that in his view the most obvious trend in the market is that more and more system components are of dedicated design, intended for fire-fighting alone, and are developed by a few leading manufacturers who can deliver complete packages, rather than just individual items of equipment, such as pumps or monitors. “Norwegian design and know-how plus Scandinavian quality dominates what is a global but niche market,” he claimed.

“Some 10 years ago it was still common to use pumps designed for other marine duties but which were also suitable for fire-fighting but in recent years this situation has been turned around,” Mr Aanestad told OSJ. “More recently, leading players have developed dedicated pumps that also meet all of the requirements of naval architects, designers, yards and owners with respect to size, weight and cost reduction.”

As he and other manufacturers also noted, the performance and overall quality of fire pumps has also increased dramatically, primarily as a result of this specialisation. “Common to nearly all of these new pumps is the prevailing ‘end suction’ design,” Mr Aanestad explained. “Only the very biggest pumps to meet FiFi 2 class duty standards are still of the traditional double suction type, although this may also change in the future.”

Due to the need to meet space requirements, it has become more and more common to use a close-coupled combination of pump and driver. Today, the most frequently used driver for these pumps is a step-up gearbox with built-in clutch attached to the front end of a main engine by a PTO. “It may also be only a clutch, integrated with a flexible coupling, if engine revolutions can match those required by the pump,” he told OSJ.

“This complete train – pump, gearbox and/or clutch, plus flexible coupling – can be delivered in several different combinations,” he explained, noting that more advanced and improved solutions have recently been brought to the market and in his view there is yet more to come.

Mr Aanestad also comments that the increasing trend to construct OSVs with diesel-electric propulsion layouts has opened the way for more systems with electrically driven fire pumps. To date, this option has tended to be a more costly one, he noted, but it has advantages in as much as it provides more freedom to locate the pumps wherever there is vacant space.

“We expect to see more of this as ships become more complex and the cost of fire-fighting equipment becomes more of a minor issue compared to the total cost of more advanced ships,” he noted. Some vessels are still being designed with a dedicated diesel engine to drive the fire pump, but as a solution this has the potential drawback that a dedicated pump takes up more space and adds to overall costs.

Water cannons – or monitors as they are usually known – have also advanced, and today the modern monitor is usually electrically operated and manufactured from high grade sea water-resistant materials. Such units are more efficient, and as a result do not need such a high inlet pressure, due to reduced internal losses, so that throw requirements can be achieved with less reaction force and reduced power consumption.

Systems for remote control of monitors, valves and clutches and gearboxes have developed in the direction of ‘one man’ operation. “Modern electronics and electrical components have made them far more advanced, more reliable and cheaper,” says Mr Aanestad, noting that portable touch-screen systems, which can provide all system functionality in a single, easy to use, handy panel that can be stowed away when not in use, have begun to be introduced. He believes, wireless systems have not become standard due to questions regarding potential interference with the wireless connection and the need for extremely high levels of reliability and safety.

Developments such as those outlined above and the need for ever-greater in-depth understanding of every aspect of a fire-fighting system mean that more and more often the manufacturer is assuming responsibility for overall package design and engineering, including pump capacity and head and monitor inlet pressure. In this way, a manufacturer can safely guarantee the performance of a layout, and it is much simpler for all parties involved to have a single vendor responsible for it all.

Gearboxes to drive fire-fighting pumps remain in demand, notes Jon Hansen, sales and marketing manager at Kumera in Norway. Last year, he told OSJ, Kumera delivered no less than 800 gearboxes to power fire pumps and/or deck machinery hydraulic pumps for tugs and vessels engaged in offshore service work. As a result of this high level of demand, Kumera has invested in a new 700m2 gearbox assembly facility, including a new test station which will provide additional employment at the company’s Sandefjord factory.

Mr Hansen highlighted the ongoing need for the development of new products to reduce manufacturing costs and to meet demand for more compact and versatile designs. Kumera specialises in front-end mechanical transmissions and notes that most of its business comes from well known markets where OSVs and tugs are to be found under construction – Norway, Turkey, the Netherlands, Spain and Italy when it comes to Europe, and other major builders for these types of vessels in the US, China, Singapore, Indonesia and India.

Prominent in the current production schedule at Kumera is the 6FGICC-335 gearbox, which accepts a direct-mounted fire pump, which is available with either a vertical or horizontal offset shaft. Two hydraulic pumps can be fitted to this model of gearbox, which are individually controlled from the wheelhouse or other remote station via electro-hydraulic valves operating the built-in Norgear type hydraulic clutch units from the company.

“Especially in tugs for LNG terminals we see naval architects and owners requiring back-up pumps for their deck machinery, mainly mechanically-driven through a Norgear unit on the front end of the main engines or an auxiliary engine,” Mr Hansen told OSJ. Also in demand is the type 4FGC-1200 gearbox, which gives a clutched drive to the fire pump and a continuous drive to a ship’s service alternator. The 1,200mm shaft centres permit the units thus driven by the gearbox to be positioned adjacent to each other, reducing the space required overall.

Mr Hansen agreed that increasingly OSVs are being built with diesel-electric propulsion, and that this being the case, last year Kumera released a free-standing hydraulic clutch unit – type NKHUI with a direct, flange-mounted fire pump – to the market. “This unit makes for a short installation, with all hydraulic components stacked on the clutch housing and the possibility to engage at full speed, avoiding any drop in the electrical power supply,” he explained. “This is also a popular product for owners who want to achieve FiFi 1 class using a single pump configuration.” OSJ