The Philippine Coast Guard formally took delivery of offshore patrol vessel BRP Gabriela Silang on 18 December 2019. The ship was built by French company Ocea at its Les Sables d’Olonne shipyard on France’s Atlantic coast. At 84m, this is the largest aluminium-monohull patrol vessel in the world. Thirty years’ experience in aluminium boat- and shipbuilding combined with related R&D have given the company the expertise to undertake this ambitious project. While aluminium offers widely acknowledged benefits, some feel that it is less suitable for larger vessels because they fear structural fatigue due to torsional loads. Ocea has overcome these challenges, confidently claiming that its large aluminium vessels are as rugged and reliable as steel ones. The secret? Thicker plating. In plain terms, Ocea uses ‘over-spec’ plating that is thicker than required by regulatory guidelines. This enables the company to guarantee hull reliability over longer lifetimes.
A longliner under construction in Ocea’s aluminium hull workshop at Les Sables d’Olonne (© Mer et Marine – Vincent Groizeleau)
The Gabriela Silang at Ocea’s Les Sables d’Olonne shipyard a few days before launching in July 2019 (© Ocea)
Lower fuel consumption and CO2 emissions
Aluminium has two key advantages over steel, namely that it does not rust and is much lighter. A lighter hull also means lower fuel consumption, hence reduced CO2 emissions. “The Gabriela Silang’s fuel consumption is 42% less than that of a comparable steel-hull vessel. The fact that the Philippine Coast Guard selected Ocea following a keenly contested international competition demonstrates that our bid was competitive and that our design meets the client’s operational needs in addition to meeting the PCG’s demands regarding sustainable development,” says Fabrice Weinbach, Ocea’s head of marketing and sales. With a fuel consumption that is over 40% lower than comparable vessels, the PCG’s operating costs will be radically lower throughout the OPV’s lifetime. And lower fuel consumption goes hand in hand with lower CO2 emissions. Ocea estimates that over the vessel’s first 20 years in service it will emit at least 20,000 tonnes less CO2. When talking to potential clients with strong environmental policies, Ocea has consistently found that a vessel’s lifetime CO2 emissions are increasingly important. This is, moreover, one of the main reasons that France’s Department of Maritime Affairs awarded its latest patrol vessel contract to Ocea. To objections that aluminium production results in high levels of pollution, the shipyard responds that lower long-term CO2 emissions far outweigh the environmental impact of using aluminium, particularly as the material can be recycled up to ten times, which is far more than for steel given the amount that is lost due to corrosion.
The Gabriela Silang at sea (© Ocea)
Diesel-electric propulsion and no funnel
BRP Gabriela Silang is named after a Filipino revolutionary who died in 1763 at the age of 32 after leading the independence movement against Spain. The ship has a length of 83.6m for a beam of 15.4m and features diesel-electric propulsion. Like the 58-metre Fouladou delivered to the Senegalese Navy in 2016, the Gabriela Silang is powered by two MTU 16V4000 M73 diesels rated at 2560kW and a pair of electric motors supplied by Leroy-Somer. Whereas the PCG’s vessel is based on Ocea’s OPV 270 design, the Fouladou is based on the smaller OPV 190. The Gabriela Silang uses electric propulsion at speeds from 0 to 12 knots and direct diesel power at higher speeds. During its sea trials, the ship recorded a top speed of 22kts, or 2kts better than the PCG’s specification. The design also includes a pair of bow thrusters for improved manoeuvrability in port. Note too that, like other Ocea vessels, the design has no funnel as engine exhaust gases are passed through a water injection system then through pipework to outlets just above the waterline on the port and starboard sides of the transom.
Engine room of the Fouladou OPV delivered to the Senegalese Navy. This vessel, like the Gabriela Silang, is powered by two MTU diesels (© Mer et Marine – Vincent Groizeleau)
Closeup of one of the OPV’s two exhaust outlets on the transom (© Mer et Marine – Vincent Groizeleau)
Five weeks’ endurance
The Gabriela Silang offers five weeks’ endurance and a range of 8000nm at 12kts. The platform is stabilised by two pairs of stabiliser fins and a passive Flume® system that attenuates roll, pitch and yaw by moving a liquid between specially designed tanks.
Optimal crew comfort
Even at low speeds, these systems stabilise the platform to ensure crew comfort and facilitate deck operations, including the launching and recovery of RHIBs and the organic helicopter. Despite the fact that some consider stabilisation a secondary issue in the case of naval and maritime security vessels, Ocea has viewed it as high priority for several years. “Talking to our clients, we’ve noted that many find it increasingly difficult to recruit crews for longer missions because today’s sailors are not prepared to put up with the levels of discomfort that earlier generations considered normal. Accordingly, we have worked hard to improve comfort and appeal so crews find longer missions more enticing. The good news is that the feedback has been excellent,” says Fabrice Weinbach, adding “given that these considerations have a direct impact on crew recruitment and retention, this is by no means a secondary issue. For Ocea, crew comfort and working conditions are top priorities.”
Officers’ twin cabin (© Ocea)
The compartment architecture is one of the design’s distinguishing features. The Gabriela Silang is spacious with living and workspaces designed and finished to higher standards than those offered by other French naval shipbuilders. When we visited the ship, we were asked not to take photos of the interior, which explains why our report contains Ocea images that, while presenting the living quarters in the very best light, do indeed match what we saw. The interiors are, in a word, outstanding. A journalist specialising in naval defence who accompanied us was particularly impressed. This being his first time aboard an Ocea vessel, he was amazed by the standard of the workmanship compared to what he sees at other naval yards. And we can only agree.
Officers’ mess (© Ocea)
Chief engineer’s cabin (© Ocea)
The Gabriela Silang is designed for a minimum complement of 40, but has cabins and quarters for up to 66. Officers, petty officers and ratings are berthed in separate areas, the last two categories in cabins sleeping six to eight according to rank. Officers are berthed in twin or individual cabins with direct access to shared toilets and washrooms. All quarters are spacious with well-designed storage spaces and amenities, including, for each bunk, side pockets, a powerpoint and space for books, a mobile phone, a tablet and the like. The air conditioning can be adjusted separately in each space and each officer’s cabin features a desk and business-class seats. The messes are also well-appointed with high-quality fittings and details. Examples include timber-look flooring, plinth lighting and various space-saving features. “We consult professional outfitters to design our interiors, furnishings and fittings as well as our colour schemes and lighting,” says Fabrice Weinbach. “This enables us to offer interiors that are functional and pleasant at little or no extra cost.” The Gabriela Silang also features a presidential suite for VIP passengers.
Ops room (© Ocea)
The ops centre is located at the very centre of the superstructure. It includes a meeting area, large screens on a partition and several workstations. The comms room is immediately adjacent. Space has been left for additional workstations should the OPV be fitted with one or more remotely controlled guns and/or more advanced electronic systems. The Gabriela Silang is equipped with Kelvin Hughes navigation and surveillance radars and a Lyncea mission system developed by French company Nexeya. The ship is built to commercial shipbuilding standards. The order was placed by the Philippines Department of Transportation for the PCG and was delivered without any weapons. Note, however, that the OPV 270 design can be tailored to naval specifications and equipped with a 40-mm or larger main gun, manual or remotely controlled machine guns and an anti-air missile system such as MBDA’s Simbad RC, or even a lightweight anti-ship missile system.
Mast with two Kelvin Hughes radars (© Mer et Marine – Vincent Groizeleau)
Bridge ops area (© Ocea)
The spacious bridge sits atop the superstructure and offers an unobstructed panoramic (360°) view. The PCG asked for a bridge divided into two areas; a forward portion for navigation and platform management and an aft portion for operations. The two areas are separated by large windows and glass doors. The bridge is surrounded by outside deck areas offering excellent viewing. Despite the midship location the forward view from the bridge extends to the bow. Three flights of covered stairs on the port and starboard sides give outdoor access to the flight and main decks.
Bridge navigation area (© Ocea)
Bridge (© Mer et Marine – Vincent Groizeleau)
Bridge deck (© Mer et Marine – Vincent Groizeleau)
Water cannons on bridge deck above flight deck (© Mer et Marine – Vincent Groizeleau)
Hangar (© MER ET MARINE - VINCENT GROIZELEAU)
Flight deck and hangar
The deck area aft of the bridge is equipped with two water cannons. These are provided primarily for firefighting should a fire occur on the flight deck further aft and one deck below. The flight deck can accommodate a helicopter weighing up to 9t and the hangar a type weighing up to 5t. The hangar is equipped for low-echelon maintenance and repairs and is well insulated. The flight ops workstation is located behind a large window on the port side of the hangar door and overlooking the flight deck.
The Gabriela Silang will carry an Airbus type H145 helicopter ordered by the PCG in 2018 and delivered in November 2019. A type H135 on hire from a commercial company was used for the OPV’s sea trials.
The Gabriela Silang and a H135 helicopter during sea trials (© Vincent Guilbault)
The Gabriela Silang and a H135 helicopter during sea trials (© Vincent Guilbault)
Two 9-metre RHIBs
While the helicopter is the ship’s primary asset for operations at sea, its two RHIBs will also undertake a range of jobs. The rigid hulls, by Sillinger, are 9.2m in length, use waterjet propulsion and have a top speed in excess of 35kts. They are modular in that they are fitted with rails so the crew can easily install or remove shock-mitigation seats and equipment. The normal configuration is ten seats; six forward and four aft of the control console. The boats are stowed in bays on either side of the superstructure and are launched and recovered, with the crew aboard, by a telescopic arm and hook system. Crew members have access to lockers in the bays and space to don apparel and gear. Note too that while the OPV was delivered without weapons, it includes a small arms armoury.
RHIB in port bay (© Mer et Marine – Vincent Groizeleau)
RHIB in side bay (© Mer et Marine – Vincent Groizeleau)
Multipurpose main deck
The aft portion of the main deck below the flight deck is a modular multipurpose area. Most of it is open to the sky. In addition to a lockup, a morgue and various storage spaces, the open-air portion includes room for two 20-foot containers, typically for cargo or mission-specific equipment. The winch and towline are sized to tow vessels up to the size of the OPV itself.
Towline and winch on main aft deck (© Mer et Marine – Vincent Groizeleau)
The boarding stations on either side of the main deck are fitted with gates and close to the waterline to facilitate boarding operations, whether for crew or survivors rescued at sea. The Gabriela Silang is designed specifically for rescue missions with a survivors’ room equipped with 35 reclining seats allowing survivors to rest or sleep in relative comfort and a large display to relay information and screen videos. Other amenities include adjoining toilets, washrooms, showers and a sick bay equipped for emergency operations. The modular survivors’ room can also be used for other purposes as the seats are mounted on rails so they can be readily rearranged or removed.
Survivors’ room (© Ocea)
The OPV 270 design offers ample provision for underwater operations, including a spacious divers’ area complete with storage spaces for diving gear and a decompression chamber. The Gabriela Silang is thus equipped to undertake a range of missions throughout the vast Philippines archipelago, including those calling for divers. The PCG’s general missions range from combatting trafficking and illicit activities at sea to policing fisheries, assisting vessels and populations in the event of natural disasters, and search and rescue operations.
Divers’ area with decompression chamber (© Ocea)
Transit to the Philippines
The Gabriela Silang was launched at Les Sables d’Olonne on 17 July 2019. By October the ship was in Saint-Nazaire for sea trials and final preparation. The vessel was formally handed over to the Philippine Coast Guard on 18 December before setting off a few days later on the 45-day voyage to the Philippines accompanied by merchant navy officers, training personnel and six Ocea employees.
Handover ceremony (© Mer et Marine – Vincent Groizeleau)
(© Mer et Marine)
The framework contract awarded to Ocea by the PCG in 2014 came into force in 2017. In addition to the Gabriela Silang, it called for the delivery of four 24-metre FPB 72 patrol boats. These were produced in France by Ocea and delivered last year. The contract also included an option on a second OPV 270 which has now been confirmed. Ocea expects a firm order to be placed later this year.
One of the FPB 72 patrol boats delivered to the Philippines Coast Guard in 2018 (© Mer et Marine)
In the meantime, the company is finalising plans to set up a facility in Manilla, initially to carry out maintenance on Ocea-built assets under guarantee over the next five years. The facility will include a regional sales office focusing on maritime security and passenger vessels.
by Vincent Groizeleau. French version (À bord de l’OPV Gabriela Silang) published online on 20 December 2019. Translated and adapted by Steve Dyson.
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