When an offshore installation – production platform, floating production system, or drilling rig – is on fire, or in danger of igniting, fire-fighting systems come into their own. Oil companies operating worldwide need to be fully prepared for a major offshore incident that could involve hydrocarbons, high temperatures, fire and explosions. An essential part of any preparation is to have fire-fighting (FiFi) equipment on support vessels.
There are three categories of OSV fire-fighting systems. A FiFi 1 system is the basic level with two monitors, one to two pumps and capacity of 2,400 m3/hour, a throw length of 120m, and height of 45m. An OSV with a FiFi 2 class notation has two to four monitors, two to four pumps and total pump capacity of 7,200 m3/hour. A FiFi 2 system has a minimum throw length of 150m and height of 70m. The most sophisticated products are FiFi 3 that are similar to FiFi 2, but with a total pump capacity of 9,600 m3/hour and throw length of 180m.
Shipowners that install FiFi systems can occasionally recoup their investment in fire-fighting equipment. An example of this was the chartering of vessels to provide emergency back-up during the Elgin platform gas leak in the North Sea. When gas started leaking from the Elgin platform in March 2012, operator Total evacuated the facility and hired at least six ships to provide emergency cover (OSJ May 2012).
Total chartered four anchor handlers from four different operators from the spot market and two 2007-built platform supply vessels (PSVs) from Island Offshore as fire-fighting vessels as a precautionary measure. Total said it hired 2010-built, VS 4622 Clean Design Loke Viking, with FiFi 2, from Viking Supply Ships, and 2010-built, VS 491 design Siem Aquamarine, also with FiFi 2, from Siem Offshore.
Brokers at the time said both vessels were earning £72,000 per day. Total also chartered DOF’s 2011-built AH08 design Skandi Saigon with its FiFi 2 system and Deep Sea Supply’s 1999-built KMAR 404 design Sea Bear, which only has FiFi 1. These vessels were earning day rates of £40,000 each, according to brokers. Also in attendance at the Elgin platform and nearby Rowan Viking jack-up drilling rig were UT 755 LN design PSVs Island Express and Island Empress, and the ROV support vessel Highland Fortress.
The ability of FiFi systems is important to offshore operators as fire-fighting systems need to be able to reach fires on the decks of production platforms and rigs from safe distances. The inadequacy of lower capacity systems was highlighted during the fire on the Deepwater Horizon semi-submersible in the Gulf of Mexico in 2010, when vessels had to be deployed close to the rig to fight the inferno. Other aspects to consider in a fire-fighting situation are the vessel’s stability and station keeping when the fire-fighting monitors are in operation and the vessel’s self protection abilities.
Suppliers of fire-fighting systems for OSVs have seen increasing demand for FiFi 2 systems over FiFi 1. The fire-fighting equipment should be fully integrated with the other vessel systems. According to Norway-based company Fire Fighting Systems (FFS), the power source for the FiFi on DP vessels is from the main engine, using the energy not used for manoeuvring during fire-fighting operations. The power is transferred to the pumps via a remotely operated clutch and transmission system. Alternatively, the pump could be powered by a dedicated diesel, or electric, or hydraulic driver.
For the best performance, the pumps should be installed in the engineroom and deliver water to the discharge pipe going to the monitors on top of the bridge. Water is pumped through the monitor nozzle to produce a jet that should carry the required distance. In an integrated system, the vessel’s station keeping and manoeuvring will compensate for the force of the waterjet. More sophisticated systems have a self-protection deluge system, where water is extracted from the FiFi lines and diverted to form a water spray covering the vessel.
Various types of foam can also be mixed with the water to enhance the fire-fighting characteristics of the system. Other parts of a FiFi system are the remotely operated valves with electric actuator, limit switches and manual back-up, the deck mountings and bridge controls. When designing the FiFi system, designers need to calculate the pump head pressure, water storage capacity of the vessel, pipe routeing, power consumption and the requirements of the class notation on performance and safety.
Jason Engineering also supplies FiFi equipment that is integrated with other vessel systems. It delivers ship sets that include fire monitors, fire pumps, and transmissions as well as electric/hydraulic control, all of which comply with class notations. It can also deliver telescopic masts and dispersant solutions.
On the transmissions side, Jason can supply an integrated step-up gearbox with a built-in operated hydraulic clutch for fire pump drives. These can deliver 2,000 rpm and 1,300kW of power with a maximum pump capacity of 2,100 m3/hour. It can also supply a standalone version with a pump speed of 1,800 rpm while consuming 2,600kW of power. In the portfolio, there is also a diesel engine drive, rated for 24 hours continuous operation and an energy rating up to 2,400kW, and an electric (IP 23 to IP 55) motor drive.
Jason’s standard FiFi 2 pump is a double suction, one stage axially split centrifugal pump. It can be horizontally mounted with side-side, bottom-top, side-top and bottom-side suction/discharge execution. The pump capacity range is 2,000-4,500 m3/hour at 1,000-1,800 rpm. The company’s dedicated fireboat system has a capacity range of 500-4,500 m3/hour, monitor capacity of 3,900 m3/hour and water throw length up to 240m. Jason recently re-engineered its dispersant system for X-Bow type vessels and for oil spill clean-up. The DSP-XB was developed in collaboration with Norwegian technology group Sintef. It can be used on vessels with enclosed bow sections to spray dispersants on to oil spillages and at vessel speeds of up to 18 knots.
Rival manufacturer, Fischcon, supplies FiFi pump sets with capacities ranging from 150-3,600 m3/hour with pressures of up to 20 bar. One of its main products is the Hellbeater self-contained fire-fighting system, which is mounted in a standard 10ft container. The Hellbeater 1200 can provide a waterjet of up to 1,400 m3/hour from a top-mounted Alco HR377 monitor. Inside the container is a Caterpillar 3412 Dita fire pump with a Nijhuis single stage split case pump that has a capacity of 1,200 m³/hour. There are also galvanised suction manifold and suction hoses, strainers and valves.
Fischcon’s Hellbeater 600 is a portable FiFi that sits directly on a deck, outside a container, with a Volvo Penta TAMD740 diesel engine and a Nijhuis single stage end suction pump with a capacity of 600 m³/hour. For FiFi systems on floating production, storage and offloading vessels (FPSOs) and storage vessels, water may need to be drawn from greater depths with hydraulic-driven submersible pumps that have their own diesel-driven power packs, or electric submersible pumps.OSJ
© 2023 Riviera Maritime Media Ltd.