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Canada-US Relations - Maritime Security - Submarines  –  May 2003 Taking the Plunge: Should Canada Use Fuel Cell Technology to make the Victoria-class Submarines more Stealthy? Excerpted from a paper given at Colloquium 2000,  University of Calgary Karen Winzoski, PhD candidate, Political Science Dept, UBC [Editor's Note: A press release, dated 7 April 2003, announced that HDW (Howaldtswerke-Deutsche Werft AG), a shipbuilder in Kiel, Germany, had begun sea trials of a new submarine powered by a hydogen fuel cell plant. In this paper from 2000,  Ms. Winzoski questioned whether a similar technology would be a cost-effective solution for the ex-Royal Navy submarines recently acquired by Canada.] On 6 April 1998, Canadian Defence Minister Art Eggleton announced that Canada had agreed to participate in a lease-to-buy program with the Royal Navy for the acquisition of Britain's four Upholder-class diesel-electric submarines (SSKs). At the same time that the details of this decision became known, Canada's Maritime Command announced that it planned to install an Air Independent Propulsion (AIP) system in the four newly named Victoria-class submarines. [The purpose of AIP is to render submarines more stealthy — ie, more difficult to detect with current submarine-sensing technology — Ed.] DND contracts with Ballard Power Systems of Vancouver, British Columbia Between 1994 and 1998, Maritime Command invested $4.8 million Cdn in Ballard Power Systems of Vancouver for the production of a 50kW XDM (Exploratory Development Model) fuel cell powerplant. Pleased with the performance of the model, in 1999,  the Department of National Defence (DND) planned to invest a further $75 million in Ballard for the production of a 250 kW ADM (Advanced Development Model). A submarine powered by this propulsion system would be able to patrol completely submerged for thirty days at 4kts. If DND is satisfied with the capabilities of the ADM,  it may decide to purchase several of the fuel cell systems from Ballard to install in all of the Victorias. Although it is not possible to accurately guess how much Ballard would eventually charge for these systems, it is reasonable to assume they would cost hundreds of millions of dollars. Two questions need to be explored in greater depth: 1. What are the strengths and weaknesses of the various modern     AIP technologies? 2. Is the Ballard hydrogen fuel cell powerplant the best choice for     the Victoria-class submarines? A Review of AIP technologies Presented here is a brief discussion about how each AIP technology works. Also described, in selected cases, are the navies which currently use (or are considering the use of) each technology. Many of these technologies are upgrades which require a 'plug-in' section. The submarine hull must be cut in two, the new section added, and the parts re-welded. 1. Autonomous Marine Power Source (AMPS) A regular diesel-electric submarine can be fitted with a plug-in section containing a nuclear-based AMPS. This SSn was developed by the Canadian ECS group of companies during the 1970s. The plant used a low-energy Slowpoke nuclear reactor to continuously recharge the SSn's batteries during submerged operations. Canada briefly considered this technology during the early 1980s. However, the SSn idea was rejected, largely due to its lack of potential and price. Currently, no navies are considering SSn technology. 2. Improved Batteries An Upholder-class submarine's lead-acid batteries weigh approximately 200 tonnes, and occupy approximately 10% of the submarine's volume. In spite of this immense weight and volume, there is a pay-off — these batteries offer enough power to sustain up to 80 hours of submerged operation. This level of performance is possible because lead-acid batteries have a very low specific energy — 30Wh per kilogram. Only the Russian Navy has converted submarine batteries from lead-acid to nickel-cadmium. It is not clear why. Nickel-cadmium batteries offer only slightly better performance than lead-acid and cost considerably more. Largely due to this dramatically increased cost, most of the world's navies, including Canada's, have ruled out switching their submarines to these new batteries. 3. Nuclear Power (SSN) Besides being politically unacceptable to the Canadian public, nuclear power has a number of other drawbacks: a. Costly maintenance facilities are required, and each facility is expensive to operate throughout its life-cycle. b. Disposal of spent uranium fuel rods presents an environmental hazard. c. Lead-based shields, separating the reactor from crew compartments, make the boats much larger, heavier, and less manoeuvrable than conventional submarines. SSNs are thus unsuited to future operations (littoral or under-ice) envisioned by the Canadian Navy. d. The noisy coolant pumps must run nearly constantly to avoid precipitating a meltdown in the reactor core. e. There are no Canadian developers of maritime nuclear reactors. Canada would thus be dependent on a country with SSN technology. There would always be the possibility that this source country could refuse to sell Canada marine reactor technology, as the United States did during the 1980s. In sum, perhaps it is for the best that the Canadian Navy was unsuccessful in its earlier bid to acquire nuclear-powered submarines. 4. Stirling Engines Developed in Sweden, the Stirling engine burns cryogenically stored liquid oxygen (LOX) and a special low sulphur fuel called Ligroin to produce heat which is then used to expand a working gas, presumably helium, to drive a series of pistons. The exhaust created is then cooled from approximately 800 degrees Celsius to 25 degrees Celsius and then pressurized to 20 bar before being ejected into the surrounding seawater. Many navies have considered procuring the Stirling engine for retro-fitting into existing SSKs. In 1988, the Swedish Navy installed an 8m Stirling plug-in section into the submarine, Nacken. In 1995, Sweden installed Mk2 Stirling systems in its new Gotland-class submarines. Other navies considering Stirling engines include the Royal Australian Navy (RAN), the Japanese Maritime Self-Defense Force (JMSDF), and the Taiwanese Navy. Canada also evaluated the Stirling engine in 1997, but rejected it due to the "large plant size and low overall system efficiencies." 5. Module d'Energie Sous-Marin Autonome (MESMA) The MESMA system, developed in France, is so far the only AIP system to have been offered for export and purchased by a foreign navy [Pakistan]. The MESMA system burns cryogenically stored LOX and ethanol fuel at 700 degrees Celsius and 60 bar pressure. Because the system is pressurized to 60 bar, the exhaust produced by the combustion of the ethanol and oxygen may be expelled from the submarine at any depth above 600m. MESMA is an improvement over diesel engines in several ways. First, it uses "rotating machinery rather than reciprocating machinery" which cuts down on noise produced. Furthermore, it can operate at depths up to 600m. Finally, MESMA offers a submerged endurance of three to five times greater than that delivered by a diesel-electric powerplant. The MESMA system does have many drawbacks: a. Installation of a plug-in section is required. b. Operating temperatures of 700 degrees Celsius increase the submarine's infrared signature [now detectable by space-based sensors]. c. Warm carbon dioxide-based gases are expelled and can be detected using infrared or chemical means. d. Ethanol is not typically used as a maritime fuel. MESMA-equipped navies cannot rely on allies for refuelling, are limited in interoperability, and thus their submarines' range is restricted. e. Operating pressures are very high, and may present safety concerns. f. Construction of maintenance facilities is required — the alternative is sending submarines to France for repairs. g. Submerged speed is limited to 4kts — suitable for routine patrol, but not to combat situations or high speed transit. Considering these limitations, it is unlikely that the Canadian Navy will ever procure MESMA technology from France. 6. Closed-Cycle Diesel (CCD) The simplest AIP conversion is the closed-cycle diesel. A conventional SSK's diesel-electric powerplant is a robust and reliable system having been refined for well over half a century. As the name suggests, a CCD system simply closes the cycle — oxygen for combustion is supplied from LOX rather than from the atmosphere. This simple addition of liquid oxygen in a cryogenic tank allows a CCD-equipped SSK to increase its submerged endurance by a factor of five compared with the existing technology. There are no large engineering firms currently producing CCD powerplants in Canada. However, it would probably be possible to assemble a Canadian engineering consortium to build an affordable CCD propulsion system for the Victoria-class submarines. World leaders in CCD technology, Germany's Thyssen Nordseewerke (TNSW) and RDM submarines of the Netherlands, have been working on CCD since the late 1980s. They have produced a 300kW powerplant known as SPECTRE (Submarine Power for Extended Contact Trailing and Range Enhancement). In 1988, TNSW installed the SPECTRE system in a decommissioned German Navy submarine (the former U 1) for sea trials in the Baltic. TNSW and RDM have actively marketed the SPECTRE system to the navies of Argentina, the Netherlands, Germany, and South Korea. So far, they have had no success finding a buyer. This is a shame. CCD offers submerged speeds higher than those currently available from any other AIP system. It requires minimal changes to existing technology, maintains interoperability, and does not require construction of support infrastructure. 7. Hydrogen Fuel Cells Fuel cell propulsion systems designed for submarines rely on Advanced Proton Exchange Membrane technology. All APEM fuel cells work in basically the same way. Hydrogen, either extracted from methanol or metal hydride, is fed into the fuel cell where it breaks down into electrons and protons, with the help of a platinum-based catalyst. The electrons are used to generate the electrical power for the submarine, while the protons migrate across the proton exchange membrane. On the other side of the membrane, the electrons leave the electrical circuit and re-combine with the protons and with oxygen to form pure, potable water, which is the only by-product of this reaction. Germany Many engineering firms around the world are developing APEM fuel cell technology, and many navies are considering using this new technology in submarines. The German firms Siemens and HDW (Howaldtswerke-Deutsche Werft AG) have developed an APEM fuel cell powerplant that they hope will be fitted into new German submarines. [Update: The German Navy has begun sea trials on U 32, a Type 212 SSK (see press release). The Type 212s are hybrids  –  fitted with both an APEM and a diesel for surface cruising  –  Ed.] To hold fuel, these German submarines use one large tank containing liquid oxygen and several small, reinforced tanks containing metal hydride fuel kept outside the pressure hull. HDW's 300kW fuel cell powerplant will allow Type 212 submarines to travel submerged for approximately 14 days. While operating, these powerplants are virtually soundless, producing no exhaust except for pure water, which may be consumed by the crew. Russia The Kristall-27E system developed by Russia's Rubin Central Marine Design Bureau works in a rather similar way. Rubin designed the Kristall system for use in Russia's new Amur-class SSKs, or for retro-fitting Russian Kilo-class submarines. However, the Russian Navy is reluctant to procure Kristall fuel cell technology due to the "large overheads associated with shore-based infrastructure." Russia is also reluctant to export the technology without further testing. Canada The fuel cell system developed by Ballard works similarly to the German and Russian fuel cells except that it does not obtain the necessary hydrogen from metal hydride tanks, but from a single tank containing methanol (CH3OH). There are several reasons methanol fuel is preferable as a hydrogen source. Methanol is an inexpensive renewable resource, and it can hold 40 percent more hydrogen atoms than can a similar volume of metal hydride. However, extracting hydrogen from methanol requires a piece of equipment called a 'reformer'. This extra step in the process reduces overall system efficiency. Using methanol fuel also creates carbon dioxide exhaust. Ballard intends to dispose of this carbon dioxide by dissolving it in seawater.  The details are not yet clear  –  we need to know more about the process that Ballard intends to employ for this purpose. There is a distinct possibility that this disposal will either reduce system efficiency (by requiring a noisy compressor) or limit the diving depth of the submarine.  Carbon dioxide exhaust also works against the goal of stealth, because it can be detected by chemical means. Ballard Benefits Ballard's fuel cell technology has many benefits. It is widely regarded as having the greatest potential for development of any AIP technology. Operating at about 80 degrees Celsius, it has a low heat signature, and even with a reformer it is quieter than a diesel generator. It produces no sulfur-based exhaust, and is more efficient than most other systems. Perhaps most importantly, BC-based Ballard  –  the world leader in fuel cell development  –  is a Canadian company. The Downside For all their benefits, Ballard fuel cells are not perfect. Aside from the operational problems arising from the use of methanol fuel mentioned above, fuel cell technology is well-known for being the most expensive AIP technology. Furthermore, the technology is still quite new. It will be at least a decade before any Ballard-made products are installed in Canadian submarines. Even then it is doubtful whether they will be able to offer performance better than a CCD system. Methanol fuel is not currently used as a maritime fuel by any other navy, nor is it being considered as a potential fuel by other navies looking into AIP. For these reasons, our submarines would not be able to refuel in allied ports. Cryogenic facilities for LOX, and tanks modified to store methanol, would have to be constructed on both Canadian coasts, along with other types of shore-based maintenance facilities. Interoperability with our allies, especially the United States, would be limited. Our submarines would not be able to participate in blockades or other joint operations far from Canadian ports without being accompanied by a Canadian AOR (replenishment ship) modified to carry LOX and methanol. Methanol may be inexpensive, but, as a naval fuel, it cannot compete with the ready availability, or the lower price, of diesel. Summary If Canada were to invest in Ballard fuel cells as its preferred AIP technology, it would require extensive shore-based maintenance and fuel storage facilities, and it would reduce its interoperability with allied navies. Furthermore, Ballard fuel cell technology: • would cost more than any other AIP • would not be ready for use for another decade • may render our subs unable to dive to our desired depth of 500m • may not run silently  –  other technologies are capable of silent running. Taking all this into account, we need to reconsider [any] decision to invest in Ballard fuel cell propulsion for Canada's Victoria-class submarines. Follow-up to R&D on Victoria-class Submarine Propulsion Systems Ballard fuel cells [had] two features that appealed to DND: long-term 'growth' potential and a Canadian developer.  DND  [had]  hoped that this new Ballard powerplant would provide enough energy to replace the Victoria-class' conventional diesel generators. However,  some time after the 1999 test model was delivered,  the research relationship between BC's Ballard Power Systems and DND was discontinued.