Prospects for a Ship Carrying Mega-Ship
By: Harry Valentine
A concept in lateral thinking developed by Dr Edward de Bono may be able to reduce fuel and labor costs in commercial marine transportation, specifically in barge and container operations. Ships benefit from the concept of economy of scale, that is, a ship that measures 120-feet across the beam and 1200-feet from bow to stern may carry some 3 to 5-times the volume of a ship that measures 75-feet across the beam and 600-feet from bow to stern. There are waterways such as the St Lawrence Seaway that can only grant passage to the smaller ships that travel to multiple inland ports following the arrival at the mouth of the St Lawrence River.
The trans-oceanic movement of container ships involves voyages between multiple ports that are within close proximity to each other, at the points of origin and destination. Multiple ships may arrive at the entrance to the Irish Sea after having sailed from the St Lawrence River or any of several American East Coast ports such as Boston, Newark, Halifax, New York City, Baltimore and Philadelphia that are in close proximity of each other. The ships that arrive at the Irish Sea may be destined for the combination of ports at Glasgow, Dublin, Belfast, Liverpool, Bristol and Cardiff. Likewise, a group of ships arriving at the southern North Sea may destined for Oslo, Rotterdam, Edinburgh, Goteborg and perhaps Hamburg.
Multiple Ships may also sail between several Asian ports that are within close proximity and across the Pacific Ocean and multiple American West Coast ports. The combination may include the ports of Seattle, Vancouver, San Francisco and Prince Rupert on one side of the voyages and ports at Seoul, Shanghai, Tai-Pei and Hong Kong on the other side. While there is definite economic merit in sailing the new generation Panamax series-2 size of ships, the smaller ship can offer the option or more frequent departures if there were way to reduce the fuel and manpower costs involved in sailing multiple small ships.
Floating Dock Technology:
The ship builder based in Holland builds a ship technology known as a floating dock that can partially submerge and move itself under the keel of another ship, the empty its ballast tanks of water to raise the ship out of the water. While the floating dock technology was originally intended to repair ships away from port and including on the ocean, there may be scope to further develop the technology to reduce fuel and manpower costs in the trans-Pacific and trans-Atlantic container trade. The lateral thinking technique developed by de Bono may combine the concepts of a floating dock, an oil tanker and a ferry ship.
One possible result would be a semi-submersible ferry ship built to the size of an oil tanker equipped with rear doors built to the size of navigation lock doors that can open. The ship may measure 200-feet across the beam and 2400-feet between the bow and the stern, 2-parallel “dry-docks” capable of holding 3-vessels each that measure 75-feet across their beams ands 600-feet between their bows and sterns. Sailing separately, all 6-ships would present a combined beam of 6 x 75 = 450-feet to push against ocean water. The combination of the cross-section and length presented by the super carrier would assure something in the order of a 50% savings in fuel consumption on a trans-oceanic voyage.
The super carrier could operate with the same manpower required to operate any one of the smaller ships, while undertaking the trans-oceanic portion of the voyage, while local crews may operate each of the smaller ships on the shorter voyages to each port. During the trans-oceanic section of the voyage, reinforces bags filled with compressed air would exert pressure between the hulls of the smaller ships and both sides of the “dry-dock” sections of the fully enclosed super carrier. The pressure between the inside of the hull of the super carrier and the smaller vessels being carried on board could reduce structural stresses on the hull of the super carrier.
Electrically driven propellers mounted on azipods may provide propulsion for the super carrier that may carry the engine in the forward section of the ship, near the bow. There may be potential to use creative thinking to design the engine installation into some other location aboard the super carrier. A wider super carrier could carry the engine closer to the stern, perhaps even use direct engine – propeller propulsion and eliminate the electrical aspect of ship propulsion.
Near Ports:
An eastbound super carrier may arrive in the Irish Sea and partially submerge to allow the onboard ships to be floated out on to the sea, from where they would sail to ports at Dublin, Belfast, Glasgow, Cardiff, Bristol and Liverpool. On a westbound super carrier may arrive at the mouth of the St Lawrence River where it may partially submerge to float out ships destined for Montreal, Ogdensburg, Toronto and other Great Lakes ports. The following table may summarize the points of origin/destination as well as nearby ports:
Future Research:
While the new generation Panamax Series-2 ships offer a definite economic advantage over smaller vessels over longer voyages, there may benefit to extending the usable economic life of the smaller container vessels. The ability to carry multiple smaller vessels aboard a single mega vessel on extended trans-oceanic voyage offers potential cost savings in fuel consumption and manpower requirements. Such a vessel may be used on shipping routes that involve frequently scheduled sailings in each direction, allowing the mega ship to carry multiple smaller container vessels in both directions. The concept of a mega ship built to a width greater and greater length than that of on oil tanker will require substantial further research to resolve the structural and propulsive challenges.
Harry Valentine can be reached for comment at [email protected] or
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MarEx does not necessarily endore the opinions herein.