Monday, May 27, 2024

MSC Cruise Ship's Streamlined Front End

I was at Malta's Grand Harbour recently (May, 2024) and noticed a large cruise ship with an unusually-streamlined "G-shape" front end.

That ship was MSC line's World Europa that entered service in December, 2022.  It's large, length = 333.3 m (1,093 ft 6 in), beam = 47 m (154 ft 2 in), passenger capacity of 6,762 passengers and 2,138 crew -- 8,900 people altogether.

By contrast, the ship we were on was older and not quite so large, yet twice as large as we prefer.  (Norwegian Cruise Line's Norwegian Epic that began service in 2010.  Length = 329.45 m (1,081 ft), beam = 40.64 m (133 ft), capacity 4,100 passengers and 1,724 crew.)

Both ships are of the current (since around 1990) state of cruise ship evolution featuring many decks heaving verandas.  Rather than being sleek, such ships tend to have brick-like profiles, aside from a touch of frontal streamlining and topside detailing.

Without getting very technical, in the field of fluid dynamics, there are two main categories of fluids -- compressible (such as air) and non-compressible (such as water).  Below-the-waterline hull shapes have to deal with non-compressible water, and moving through water takes up most of a ship's propulsive energy.  However, some energy needs to be spent on pushing air aside.  In both cases, appropriate design can yield more efficient use of power -- better fuel economy, if you will.

An aerodynamic problem for cruise ship designers is the large amount of frontal area created by all those veranda decks.  Modern cruise ships are far less sleek than, say, pre-1990 cruise ships that tended to lack veranda decks.  Since marketing factors demand large, aerodynamically inefficient frontal areas, all naval architects can do is try to streamline front ends as best they are allowed by engineering and even some marketing (passenger-enjoyment-related) considerations.

I find it interesting to compare the World Europa's frontal design to that of the Norwegian Epic and to pioneer industrial designer Norman Bel Geddes' early 1930s design for a streamlined ocean liner.

Photos below are all mine.  Those of actual ships were taken at the Grand Harbour 15 May 2024.  Those of Geddes' ship model were taken at London's Victoria & Albert Museum 22 May 2018.


World Europa has just cast off.  Those horizontal window bands on the white zone create an attractive, 1930s-like "speed-lines" streamlining effect.

This shows the pleasing frontal shaping to good effect.  The aerodynamic smoothness begins to break down at the bridge that necessarily requires side extensions used for observation while docking.  Its forward projection breaks the airflow pattern, partly negating the otherwise smooth profile curve.  Above the bridge are what appear to be a few luxury suites -- note the baffles separating them.  The top decks contain passenger amenities and aerodynamic efficiency breaks down here despite those swoopy curves.

Geddes' design is essentially an extended teardrop.  Smokestacks are housed in streamlined shells.  The bridge, however, necessarily interrupts the general flow.  The lower hull design looks streamlined, but is inefficient by today's standards that require a bulbous element on the sub-waterline prow that serves to punch aside that non-compressible water.

Its length would have been about 1,088 feet (332 m), almost exactly that same as World Europa.  Capacity would have been 2,000 passengers and 900 crew -- about one-third that of the MSC's ship due to having half the number of decks and a lot less frontal area.  A very pleasing design, though likely impractical in some technical respects.

Prow area of the Norwegian Epic.  The bow is conventional and would disrupt air flow to some degree due to its break for the deck.  I'm not sure if it is high enough to prevent green water splash in a serious storm -- though cruise ships are usually scheduled to avoid seriously bad weather.  The superstructure is slightly curved in plan-view and sloped on the first four decks above the prow, so there is some aerodynamic benefit there.  But from the bridge upward, streamlining is minimal.

World Europa seen from more of a profile perspective.  Impressive.