Maritime Propulsion

 

There is no doubt that geopolitical conflicts and the impact they have on the price of oil affects energy technology. Alternative fuels or means of supplying power; whether that means solar, fuel cell or wind, rise in popularity when crude prices exceed ~ $80 per barrel and then fail to maintain that interest when the market falls below $50 a barrel. Historically, the problem has not been the price of oil, but the price of the alternative infrastructure. Few will argue against the need to reduce our use of our natural resources and begin a long-term conservation process. That plan needs to follow emissions reductions, develop cleaner means of providing energy and reduce our dependency on oil. We have seen the shift occur in the automotive industry and honestly, it has been painless. Gasoline now lives alongside hybrid batteries and natural gas. We may even see Hydrogen enter mainstream automotive technology in the very near future. If they can live together in the car and truck market, then why not marine transportation?

 

Can we tell you that the price point is X? No. Why? Because the decision to burn natural gas and make that propulsion change reaches beyond fuel price economics. The company making the change has to believe in a long-term environmental compliance plan. In our experience, most of the customers we discuss the change with have a client base that demand that environmental compliance as part of their mission statement. Can we say that low sulfur diesel fuel at $1,000 a metric ton made LNG look very attractive? Yes, we can. That said; many operators discontinued the gas discussions when low sulfur diesel and gas oil dropped below $500 a metric ton. Make no mistake there are other companies that continued with their commitment to make the switch to natural gas regardless of price. I would like to think it is because they are working towards leaving a cleaner planet for our children and reaching beyond current economics. The lack of interest at this point is the fact that many of the operators received an education on LNG and cryogenics which in turn opened their eyes on how complicated the use of LNG as fuel can be. It is not for everyone, nor does it fit every propulsion application. 

Technology innovation moves at speeds that make it difficult for us to keep up with the latest and greatest products. Because of that speed, we see owners being forced into more new construction and fleet replacement to keep up with their competitors. Unmanned vessels, alternative propulsion systems and any form of new innovation will require data analysis. We see that low hanging fruit every day. When Big Data demands real time emissions monitoring at the funnel and the direction an owner will have to take to report that data and to whom, that is when alternative fuels and more efficient engines will grow.

 

This is not a simple question to answer as the gas engine type and the load application affects the actual gas combustion process. Many technical papers will tell you gas engines will not need after treatment to meet Tier 4 requirements. Otto Gas engines with their homogeneous combustion generally have low NOx emissions and high efficiency and can comply with IMO Tier III without exhaust after-treatment. That said; an Otto Gas Engine requires a certain gas fuel stability to protect against self-ignition or “knocking.” The methane number affects the knocking and the combustion must be carefully developed in order to keep un-burnt gas (“methane slip”) to a minimum. Spark-ignited and diesel-ignited gas engines show some differences especially when dealing with part load during maneuvering or in a generator application. LNG propulsion of ships is currently seen as one of the most promising ways of complying with future IMO Tier III NOx emission limits already being implemented within the ECAs of Northern Europe. 

 

The gas engine applications have been dual fuel engines and with that engine type comes a different analysis of after treatment as liquid diesel fuel is injected with the gas. The dual gas engines have diffusion burning which ensure good capability of burning gases with low knocking stability or low methane number and at the same time producing low methane slip emissions. This engine type requires a high-pressure gas injection system and exhaust after treatment is needed to comply with IMO Tier III NOx emission limits. Although not part of the IMO emission limits, there is an increasing focus on Smoke and Particulate Matter emissions along the coasts and in our harbors. LNG propulsion is seen as capable of complying with new PM regulations, if and when they come into play. One of the most disturbing reports we came across in our development of gas propulsion with Coastal Connect was the fact that Particulate Matter emissions were being measured in infant deaths in and around our U.S ports. A combination of ship emissions and the truck congested associated with the port areas were the reason the medical industry took on the investigation. It is worth the 20 percent price premium and in the future, that may be considered priceless when it comes to our health and environmental protection.

 

With Tier 4 of the US Environmental Protection Agency (EPA) Clean Air Act now in force for diesel engines built after January 1, 2016, GE’s eight-year investment in Exhaust Gas Recirculation or EGR technology is now delivering major benefits for the company in the U.S. build market. EGR reduces the NOx component at the combustion source and a closer look at the technology with GE will show how it selects certain cylinders when accomplishing this reduction. NOx emissions are inherently high in two-stroke propulsion engine sizes and slow rotational speeds – more time for NOx to form around the burning fuel spray and less heat transfer to surroundings. The GE engine is a high-speed engine at 900 and 1,000 rpm, which helps to reduce the NOx formation. Low speed two stroke engines cannot make that claim. This GE development was announced in 2015 and AMTECH selected the technology for an ATB construction project we were handling up in Sturgeon Bay at Bay Shipbuilding. We had certain power requirements we were looking for and the 250MDC engines were available in 12- and 16-cylinder V configurations that met those power requirements while meeting emissions regulations. We tried to develop a competitive process with other engine selections for our customer but found that the GE engine was ultimately our only choice available without a total redesign of the tugboat. An eight-cylinder in-line model is on the product line and we understand a six-cylinder in-line is already planned for future development. Yes: workboats can benefit. GE’s latest engine meets both EPA Tier 4 and IMO Tier III emissions standards without the need for exhaust after-treatment by Selective Catalytic Reduction (SCR). NOx emissions have been reduced by 70 percent compared to EPA Tier 4 and IMO III emissions limits. We like the fact that SCR and the operating costs associated with that type of after treatment compliance is not required.

 

The practice will definitely continue simply because it is good design. Working efficiently means meeting regulations and filling a customer’s needs and/or price range. That’s what design is all about. There is a reason why the Tiered regulations were formatted in that matter and by limiting the size of an engine to fall into line with the requirements is efficient engineering. Is this application for everyone? No. That said; it is way to comply and should be utilized. Whether or not the regulations continue to allow this to occur is probably best answered in the “Big Data” question. Once real time monitoring takes effect, new regulations will be formulated based upon that data dump and you may see changes occur.

 

Amtech was one of the first engineering firms to deliver a Hybrid Research vessel in the United States with Derecktor Shipyard, BAE Hybrid and Corvus Energy. A second research vessel is under construction and we have also commenced design work for Harbor Harvest to deliver a short sea catamaran that will be used to move farm products between Connecticut and New York along Marine Highway 295 and down the Hudson River along Marine Highway 87. We are big believers in the technology. Many of our future power technologies such as fuel cell, solar and wind generation require suitable energy storage. The power sources can be both intermittent and at the same time capable of providing power at times when it is not needed. Large battery storage is the key to making those power sources competitive and efficient. We see new lithium technologies and battery chemical compositions filling that requirement. Scana line ferries have taken Hybrid propulsion to new levels by providing system exceeding 2 megawatts. From a Military aspect, the propulsion is silent and provides excellent stealth capability. The power response is much quicker than conventional combustion engines and you are not limited by the amount of fuel you carry on board if the charging system is designed correctly. Hybrid is our choice for future coastal propulsion designs.

 

We are currently building six new 25,000 deadweight chemical carriers with International Paint’s new cargo liner 9001. These vessels are being chartered to carry methanol and ethanol. Make no mistake: the movement of methanol is difficult and with that said; the amount of methanol now being traded as greatly increased. This will help with building a bunkering infrastructure for this fuel. The original “diesel” engine burned alcohol. A change to Methanol is not a stretch. It is a liquid and can be treated similar to normal petroleum carriage in a vessel’s fuel tanks. We have attended two vessels currently being built in Hyundai Mipo Dockyard that have installed MAN B&W dual fuel methanol two stroke engines. The methanol use is limited by an on deck fuel tank as under deck storage regulations are still under discussion. The fuel use has been restricted to periods within the ECAs. You will see continued development as the bunkering infrastructure becomes available. 

 

Noise will be the next battle for owners and operators and war has already been declared. Under the revised SOLAS Regulation II-1/3-12, the IMO “Noise Level Code” has come into force as of July 1, 2014. This follows the adoption of the Code in Resolution MSC.337(91) on November 30, 2012. Vessels with keels laid after January 1, 2015 must comply. The intention is to provide safer and healthy work places for crew. Specifically the code was developed to assist in clear communication and the recognizing of alarms while protecting seafarers hearing. Noise on board vessels, as well as ambient noise when in port, can have a significant impact on the quality of rest for seafarers. Whether seafarers get enough rest, specifically “sound” sleep is essential to avoiding fatigue related issues and ensuring a safe working environment. A Hybrid propulsion solution obviously exceeds the requirements. This was one reason the “Spirit of the Sound” was designed hybrid as the vessel’s Op Tempo included teaching sessions on deck and within the accommodations. Other engine manufacturers are also looking to increase their insulation capability and encapsulating their prime movers. The noise issue goes well beyond SOLAS requirements. Many refineries are being forced to limit their operating periods at night due to noise pollution complaints from surrounding neighbors. We have recently delivered three Medium Range Product tankers and six chemical tankers using a Marflex electric deepwell cargo pump system to reduce the noise during cargo operations. Our sister company, Southern Electric Pumping Systems, currently represents the Marflex Variable Frequency Drive pumps in the United States. Several noise reduction surveys have been completed on deck, in the crew’s quarters and underwater by Marlfex with very positive results. There are discussions taking place to limit underwater noise from operating systems and propeller cavitation to protect sea life and right whales.

 

 

(As published in the July 2016 edition of Marine News)