Similarly, the determination described in (b) will rely on a good faith statement by the owner that the vessel is intended to hold only a registry endorsement. It should be noted, however, that if we learn that a vessel owner subsequently receives a coastwise or other registration that would allow the vessel to operate between two U.S. ports, we may review the validity of the exemption. This would also have a bearing on future requests for an exemption.
Category 1 and 2 engines that are exempt under this provision must be labeled to indicate that they have been certified only to the MARPOL Annex VI NOx Curve limits and that they are for use solely on vessels that meet the above criteria.
H. National Security Exemption
With regard to the national security exemption, we are applying an approach similar to that in our existing land-based nonroad and gasoline marine programs (40 CFR 89.908 and 40 CFR 91.1008). Under this exemption, only marine engines used in vessels that exhibit substantial features ordinarily associated with military combat, such as armor, permanently affixed weaponry, specialized electronic warfare systems, unique stealth performance requirements, and/or unique combat maneuverability requirements and which will be owned and/or used by an agency of the federal government with the responsibility for national defense, will be exempt from the regulations in this subpart for reasons of national security. No request for an exemption is necessary for these engines.
There may be situations in which an exemption from the emission controls is necessary for other vessels used for national security. Manufacturers may in these cases request a special national security exemption. A manufacturer will need to justify this request and get an agency of the federal government charged with responsibility for national defense to endorse it. We understand that the Navy, and all other branches of the government, will do their best to comply with the emission standards finalized in this final rule.
I. Competition Exemption
We are addressing competition engines, also referred to as racing engines, in two ways. First, engines produced by the manufacturer specifically for competition are exempt from the requirements of the rule. The Clean Air Act does not consider these to be nonroad engines, so none of the requirements of 40 CFR 94 apply, except for a requirement to label the engines. Manufacturers need only get our approval to sell engines under this exemption. Second, someone can modify a certified engine for competition purposes. Normally we would prohibit making such changes to certified engines under the anti-tampering provisions. The final rule, however, exempts these engines from the anti-tampering provisions for engines that are used "solely for competition."
Engines or vessels used for amateur or occasional competition do not meet the competition exemption criteria. Our review of a request from a manufacturer should prevent abuse of this provision for engines that are originally produced for competition. There is, however, no approval step for someone who modifies engines for competition, so we will more clearly spell out criteria indicating whether the engine will be used solely for competition. Specifically, owners meeting all the following criteria will qualify for the competition exemption:
―The engine and vessel are designed and built to be used solely for competition. For example, we would not expect engines used solely for competition to have a lifetime until rebuild greater than about 10 hours.
―The vessel is registered with a nationally recognized organization that sanctions professional competitive events.
In addition, once an engine is modified for competition, the engine is no longer certified to the requirements of 40 CFR 94 and must therefore not be used in an application where we would require a certified engine.
J. Other Exemptions
We are extending other nonroad exemptions to marine diesel engines. These include the testing exemption, the manufacturer-owned exemption, the display exemption, and the export exemption. Remember that these exemptions are not necessarily automatic, and that the engine or vessel manufacturer, or ultimate engine owner, may need to apply for them. As part of the approval, we may require labels on exempted engines.
III. Engine Categories
The engines that are the subject of this action are very diverse in terms of physical size, engine technology, control hardware, and costs associated with reducing emissions. These differences make it difficult to design one set of emission requirements for all marine diesel engines. For example, numerical emission limits that may be reasonable and feasible for a 37 kW engine used on an 5.5-meter (18-foot) boat may not be reasonable or feasible for a 1,500 kW engine installed on a tug or a 20,000 kW engine installed on an ocean-going container ship. Similarly, numerical emission limits appropriate for very large engines may be not be appropriately stringent for smaller engines, requiring little or no emission reduction.
Consequently, it is necessary to divide marine diesel engines into categories for the purposes of applying emission limits and duty cycles. We are adopting the categorization scheme summarized in Table 1. This relies predominantly on per-cylinder displacement to distinguish between categories of engines. This has the advantage that per-cylinder displacement is an engine characteristic that is not easily changed and is constant for a given engine model or series of engine models.