Diesel Engines and their Usage in the Marine Vessels

The inventor of diesel engine is Rudolf Diesel. Although, he invented the engine, but to keep it functioning on board vessels, marine engineers work hard. The uses of diesel engines are many and they vary from ships to ships. Diesel engines are also technically known as compression ignition in the shipping industry.

fast ferries are for sale

To operate and maintain a diesel engine, it is required to understand how it works. Diesel engines basically work on simple principle and prove to be reliable if maintained properly.

Ways to classify diesel engines

  • Speed – Classifications are made on slow/ medium and high speed
  • Usage – Locomotive engines, automotive engines, marine engines
  • Operation – 2-stroke engine, 4-stroke engine, double acting, single acting
  • Cylinder Arrangements – vertical, horizontal, vee, radial

It can be observed from the classification that marine engines are used in ships, boats, submarines and so on. In the marine industry, both 2 and 4 stroke engines are used. The low speed two-stroke engines are generally used for the key propulsion or for turning the propeller of the ships. The 4-stroke high speed diesel engines are used for providing auxiliary power.

2-Stroke and 4-Stroke Engines

Let’s get an overview on the 2 stroke engine first. There are a variety of 2-stroke engines. The popular example is uniflow type where air is introduced inside the cylinder through the ports and the valve used for exhaust.

The working cycle of 2-stroke engine:

  • Exhaust and Inlet
  • Compression and Power

Parts of a 2-stroke diesel engine are:inside of ferries

  • Inlet ports
  • Piston ring locating pin
  • Exhaust ports or exhaust valves
  • Scavenge blower

Now, let us understand the basics of a 4 stroke engine. The operating cycle of a 4-stroke diesel engine is:

  • Induction – The exhaust valve gets closed, the inlet valve gets opened. The first downward pressure of the piston pulls fresh air into the cylinder.
  • Compression – The inlet and exhaust valves, both are closed. On the 1st upward pressure of the piston, the air is compressed by heating the air. The fuel is instilled just prior to the piston arrive at Top Dead Centre (TDC).
  • Power – The exhaust valves and inlet; both remain closed. The piston is forced downward when the fuel ignites in the cylinder
  • Exhaust – The exhaust valve is open and the inlet valve is closed. The piston reaches the cylinder pushing out the exhaust gases out of the cylinder.

Each engine has a particular valve opening and closing time based on the operating requirements of the engine. The timing for valve opening and closing also depends on whether it is naturally aspirated or turbocharged. In 4 stroke cycle, there is 1 power stroke for each 2 revolutions of the crankshaft. To turn the propeller, the power stroke is used.

Marine Engine Components

Diesel engines include many components and systems. All these parts serve specific functions. These components and systems range from small nuts to comprehensive cooling or fuel systems. Some of the basic engine components are Cylinder head, Block, Inlet valve/s, Fuel lift pump, Camshaft, Flywheel, Turbo charger, Crankshaft, Air cleaner, Cylinder liners, Lubricating oil pump, Alternator and more.

All marine vessels such as fast ferries, cruises, RoRo vessels, etc. are equipped with diesel engines. A good number of fast ferries are for sale in Norway. Rely on a professional ship broker to purchase.

An Overview on How Cruise Ship has Evolved since its Invention

The cruise vessels that are available in the market today are direct successors of the original ocean liners, also popular as transatlantic passenger vessels. Most of the ocean liners of 1920s, 30s and 40s are surviving in other forms. For example, the Queen Elizabeth II has turned into a floating resort in Dubai. Another older ship – cruise shipthe original Queen Mary is now serving as a hotel or tourist attraction in Long Beach, the Rotterdam will soon become a museum in the Netherlands. Cunard’s Queen Mary II is likely to be the last contemporary ocean liner for transatlantic passenger service.
There are still a couple of older ocean liners serving all around the globe like cruise ships. But their numbers are decreasing.

Key differences between today’s vessels and old liners

  • Necessity for speed

One key difference between the ships in the recent years and the old liners is the necessity for speed. In the initial days, ocean liners were only afforded by rich and powerful people, who had an urgency to reach their destination quickly. Today’s cruise ships are indeed faster than most of the old ships, but at the time of engineering, the focus is solely not on the high speed. Now days, people are opting for cruise vessels to enjoy the relaxing ambiance and the prime objective is vacationing. Therefore, longer, slower and more leisurely trips are mostly preferred.

  • Mix of accommodations & facilities

The range of accommodations on modern cruise vessels comprise – a cabin; ‘Presidential suites’ aimed to be used by the President, although hardly any President will ever stay in those suites in recent times. Similarly, the Queen’s Grill on British-Flagged ships was the place where the Queen would actually had her dinner if she was in the sea. At present, “High Tea” on some of the cruise ships are also the successor of “The Gilded Age”.

The years 1880s to 1930s were the golden days of grand dining, when ladies in gowns and gentlemen in white tie and tails in dinner jackets circled round the dinner table to participate in grand dining. The formal nights on today’s cruises are influenced from the genteel practices of the old-gold era. There was ballroom, libraries and lounges. Over the decades, the modes of entertainment evolved with Broadway-style shows, numerous bars, rock climbing walls, game zones, water slides, nightclubs, small golf courses and more.

  • The role of Classification Society – now and then

A Classification Society is a non-governmental body that looks after the technical aspects; sets rules; ensures that design and details of every vessel meet these rules,Cruise Vesselinspect vessels at the time of construction and at frequent intervals to make sure that these vessels continue to abide by the technical rules and standards.
In the year 1760, the Register Society, the first classification society was formed to publish ships’ registrations annually. This publication was intended to classify the status of the hull and equipment of the ship. At the initial stages, the condition of every vessel was classified annually.

At present, there are several classification societies that every classification society employs surveyors for ship inspection, material engineers, mechanical engineers, electrical engineers, etc. They are authorized to examine oil rigs, ships, submarines and other marine structures. If everything meets the rules, they issue certificates on behalf of the state’s flag under which the ships are registered.

The old cruise vessels are now refurbished and used for multiple purposes. Therefore, one can get old cruise vessels for sale at reasonable prices by contacting a reliable ship broker.