Written by Harry Valentine
Large ferry ships provide essential transportation services to populations in many parts of the world, sailing relatively short distances across the Irish Sea, Baltic Sea, Mediterranean Sea and numerous channels and straits. In these cases, competing road and/or rail transport may be non-existent while in other cases, the distance across water is considerably less than by rail or by road. While some ferry designs are best sailed in relatively calm waters, other designs are able to withstand the rigors of sailing for short distances across open sea.
Ferry ships built with rear doors at the stern appear to be more suitable for operation in rougher seas, than designs built with doors at the bow. Whole most ferry ships carry road vehicles other ferry ships include railways lines to allow sections of train to come on board. The train-on-ferry concept worked well for several decades, the result of several different nations using the same 56.5” (4’ 8.5”) railway gauge. These nations engage in international trade and include:
- United States and Canada
- China (Shanghai)
- Middle East (Riyadh, Cairo)
The railways of several other nations with trading capacity operate trains on meter-gauge (3’ 3.4”) and 42” (3’ 6”) railway gauge. Rail vehicles designed for meter-gauge can interchange on the 42” gauge. The nations include:
- Brazil (Rio de Janeiro and Sao Paolo)
- India (Southern Region – Kerala region)
- Argentina (several rail lines into Buenos Aires)
- Southern Africa (42” gauge)
Oceanic ferries may initially sail amongst trading nations that use the same or compatible railway gauges. At a later time, there may be scope to include multiple gauge railway lines at some international intermodal ports, for the purpose of allowing easy future trade amongst nations.
Port Rail Lines:
There is generous vertical height clearance at most oceanic intermodal ports, allowing containers to be triple and quadruple stacked when moving at low speed in the port area. Special flatcars with diminutive-size rail wheels may move stacks of containers on to and off oceanic ferries that may include 2-gauges of rail lines, similar to the multi-gauge rail lines in some regions of Australia. Technology from the railway industry could allow for operation of diminutive wheel size on rail lines aboard ship and in the port.
Railway lines on the Toronto subway trains connect via overlap joints that allow the rail wheel to pass smoothly between rails. The railway interchange points along high-speed lines include a “moving frog” that eliminates the gap in the points where rails cross. Such technology would allow multi-stacked containers to move between ship and an off-ship, container-transfer area at the port where containers would be transferred by crane to/from trains and/or trucks. The off-ship container transfer system would reduce ship time at port.
When at port, the oceanic ferry would be moored in a special lock where water would be pumped out to allow the ship to rest on a special floor. Such an arrangement would allow for loading and unloading of the ferry, without change in elevation relative to port rail lines. The oceanic ferry may be a single barge-ship with a stern door and include electrically driven propellers (azipod), bow thruster and bilge pumps that receive power from forward mounted engines.
An alternative arrangement may carry the engines in a separate twin-hull catamaran unit towed by the ferry. Power cables and remote control cables would link between ferry and power generation unit. The ferry ship would use the power to operate a forward bridge and activate azipod propulsion, bow thruster and bilge pumps. The twin-hulls of the catamaran unit would be placed at the edge of the propulsive stream produced by the propeller, a method of reducing hydraulic drag.
The ocean ferry may be a barge that a remotely controlled push-tug would propel and steer from the stern, from a forward bridge on the ferry. The concept may be further developed into an oceanic train of 2-barges with rail lines on board. It may be based on the design of the intermediate sailing unit that would form a section of the Seasnake (www.seasnake.net) oceanic ship-train technology. The volume aboard a 2-section barge-ferry would compensate for space lost to railway lines, multi-level floors and railway wheels.
Wide Option Rail Flatcar:
In the history of railways, one unique railway technology involved a special over-wide railway car that straddled over 2-parallel sets of railway tracks. There would be scope at intermodal ports to make provision for over-wide railway flatcars to carry stacks of containers at low speed over short distances, to and from an oceanic ferry ship. The over-wide flatcar may carry containers up to 4-lengthwise by 4-abreast by 5-high, using multiple rail-wheel assemblies that include lateral-suspensions that compensate for width variations between the 2-sets of tracks.
When being moved, the combination of an air plenum chamber under each over-wide flatcar and a supply of compressed air may carry some of the weight of the flatcar and its load of containers. Such operation would greatly reduce wear and tear on the rails and the wheels under the flatcar. Magnetic track brakes are well proven in municipal passenger railway transport service and would be included under the flatcars.
The transfer of containers between over-wide flatcars and conventional railway equipment and/or trucks would occur at a section of the port/terminal that is remote from the intermodal container ferry ship. Cranes with multiple vertical supports on rail wheels and a bridge-type cross-member would be designed to simultaneously transfer multiple containers in a single movement, from over-wide carrier to multiple trains parked on parallel tracks.
Automated computer control would be essential to such operation. An automated conveyor-on-rails placed between the over-wide carrier and the trains could re-locate containers, placing them according to final destination on the proper section of a particular train. There is much scope to undertake further research to refine the logistics of an automated container transfer system.
It is possible to install railway lines on to inland river barges as well on barges built with ‘unrestricted’ hulls that allow for deep-river and some ocean travel. Such technology would allow for interlining between international ocean carrier and domestic maritime carrier at select intermodal ports, where stacks of containers carried on rail wheels (possibly assisted by air pressure) may be transferred between carrier modes. The barges would sail to smaller, nearby coastal ports and inland river ports where stacks of containers may be rolled off and on barges, interlining with local truck transport.
Over a period of many years, several researchers have examined idea on how to move large groups of containers on and off ships at intermodal ports. While there may be some merit to using a crane that moves 1-container per transfer movement, these is potential economic benefit to simultaneously moving multiple containers on or off a ship in minimal time.
Numerous researchers located around the world are exploring various methods by which to reduce ship time at port, while increasing the number of containers that may transfer in less time between different transportation modes.
Harry Valentine can be reached at firstname.lastname@example.org