How could this hub work?Wednesday, September 18, 2013
I am annoyed to see Dr Omar Davies declaring that "one of the things I would love is some proposal, in addition to Mr Warmington's..."
Is he really bankrupt of ideas? Even with a PhD in some kind of geography? The PNP and JLP both seem to be eager to dig up Goat Islands at the behest of the Chinese.
If the question is asked, what's desirable in creating a port? Slow or no currents, good approaches and exits to deep water, flat ground for the port beside the sea, rail access over relatively flat ground to population centres for workers, airport facilities or potential for such, and seismically inactivity?
A couple hours examination looking at a Shell road map of Jamaica, a mariner's depth charts ("Jamaica including Pedro Bank" Defence Mapping Agency (DMA) 26120, stock no 26AC026120) and Google Earth shows potential sites for a port. Macarry Bay to the west of Alley, and Carlisle Bay between Rio Minho and the community of Rocky Point.
Sea currents? Robertson Shoal and the piece of Jamaica poking out into the sea, Rocky Point, already slows the westward currents. If more protection is needed, an artificial extension of the shoals to the southwest might do the job.
Good approach and exit? Say dredged to the Nicamax/Chinamax depth of 90 ft (15 fathoms or 27.4m)? A channel wide enough to accommodate two-way traffic from the 15 fathom contour from the south, through what looks like a channel to the southwest of Alley, evidenced by landward protrusions of the 10 fathom and 6 fathom contours, would reduce the amount of dredging and sea bottom disturbance. By the way, if the dredged material is of good quality, it could be used to reclaim some of the coastal water to enlarge the proposed port, reducing the land requirement, and avoiding the environmental problem of disposing of the dredged material at sea. Information about the Kingston Harbour experience with the effects of dumping dredged material at sea can easily be had from the fishermen of Port Royal, Grenwich Farm and other fishing beaches.
The approach to Goat Islands would seem to be longer from the 15 fathom contour, west of Bare Bush Cay, west of Pigeon Island, bending right to Goat Islands, dredging all the way.
Flat ground for the port? Google Earth shows a large enough unpopulated area to the west of Alley and a smaller area between the Rio Minho River and the community of Rocky Point.
Rail access? There's a spur to Port Esquivel already, which could be extended, on the flat, to the south of the Brazilletto Mountains, parallel the B12 road, south of Lionel Town to the coast and the proposed port.
Potential airport access? The old Vernam Field is just around the corner. Closer than to Goat Islands. That's a hop, skip and jump away from Macarry Bay. Goat Islands are over 20 miles away from the proposed port at Macarry Bay and further from the Norman Manley International Airport.
Seismically inactive? I'm not sure, after all I'm just a mechanical engineer. However, the map showing the faulting of Jamaica, "Geology Jamaica", geological data prepared by Mines and Geology Division, Ministry of Mining and Natural Resources. Originally compiled by N McFarlane (1977), edited and corrected by S Brookes (1984), A J Geddes, director of Geological Survey Division, doesn't show much except that it's on alluvium. I might guess perhaps deep underneath there could be faulting. A Goat Islands facility would be partially on reef/white limestone and partially on alluvium.
You'd love some other proposal Dr Davies? Well, here's one that only took me a few hours of thought. You go flesh it out with your experts.
Damage to the environment? Some is likely to be unavoidable. Environmental Impact? Young fish swimming across the deep ship channel where they would be susceptible to predation, ship noise, run-off in an area where a few rivers enter the sea, etc. At least it's not in an environmentally protected zone.
This plan is vastly superior to the Goat Island port proposal, and I think that the government would be ridiculous to dig up the Goat Islands.
Howard Chin, PE is a registered professional engineer and member of the Jamaica Institution of Engineers.