That Sinking Feeling
Comment on FB: “We need a proper deep water berth that big cross channel ferries as well as Cruise ships can use.”
Do you ever get a sinking feeling when people say things without doing any research? I’m fortunate in having a network of correspondents who are more knowledgeable about these matters than I am, and this is what they had to say.
Out of their Depth
Guest post by Adam Gardiner
Another case of people making comments without doing their homework. Our ability to provide a deepwater berth is limited by virtue of 3 factors. (1) our tidal range that creates a huge difference in the depth of water and therefore large ships would likely ground by mid water (ii) to dredge a deep water channel would require the removal of thousands of tonnes of rock - the only method of achieving that being explosives and (iii) that channel would need to extend almost 3 miles into the bay into natural water in order to allow large cruise liners to navigate entry. That is why they currently moor south the Demie Des Pas light in deeper water and tender their passengers ashore.
You can see from Google earth that the current natural channel into the harbour is relatively narrow - and shallow - and map shown on the FB thread (copy above) shows the mean depth of water in the channel as being 5.2 metres - or just 17 ft in old money. The larger cruise liners can draw anything between 20ft to 30ft.
I got most of that information from an acquaintance with considerable expertise on the Jersey coastline and shipping. He said that while all technically possible, detonating multiple charges in our approaches would cause considerable disruption to our general shipping traffic and thereafter the channel would require constant dredging to keep it open. Costs would be significant to start with - £multi-millions, notwithstanding ongoing dredging costs and the environmental harm it would cause.
A solution may lay in extending a causeway out into deep water - reclamation. That would not be cheap and could, environmentally speaking, be very harmful and also further affect the already compromised tidal flow in St. Aubins Bay.
There have also been suggestions to use the Ronez harbour to berth large liners. The water is deep enough but to construct a terminal on what little level land is available plus the duplication of passport/immigration/C&E services not to mention local road structure make the proposition unviable.
Like the bridge to France (but unlike the large ferries and liners) these suggestions are all out of their depth.
Comment on FB: “We need a proper deep water berth that big cross channel ferries as well as Cruise ships can use.”
Do you ever get a sinking feeling when people say things without doing any research? I’m fortunate in having a network of correspondents who are more knowledgeable about these matters than I am, and this is what they had to say.
Out of their Depth
Guest post by Adam Gardiner
Another case of people making comments without doing their homework. Our ability to provide a deepwater berth is limited by virtue of 3 factors. (1) our tidal range that creates a huge difference in the depth of water and therefore large ships would likely ground by mid water (ii) to dredge a deep water channel would require the removal of thousands of tonnes of rock - the only method of achieving that being explosives and (iii) that channel would need to extend almost 3 miles into the bay into natural water in order to allow large cruise liners to navigate entry. That is why they currently moor south the Demie Des Pas light in deeper water and tender their passengers ashore.
You can see from Google earth that the current natural channel into the harbour is relatively narrow - and shallow - and map shown on the FB thread (copy above) shows the mean depth of water in the channel as being 5.2 metres - or just 17 ft in old money. The larger cruise liners can draw anything between 20ft to 30ft.
I got most of that information from an acquaintance with considerable expertise on the Jersey coastline and shipping. He said that while all technically possible, detonating multiple charges in our approaches would cause considerable disruption to our general shipping traffic and thereafter the channel would require constant dredging to keep it open. Costs would be significant to start with - £multi-millions, notwithstanding ongoing dredging costs and the environmental harm it would cause.
A solution may lay in extending a causeway out into deep water - reclamation. That would not be cheap and could, environmentally speaking, be very harmful and also further affect the already compromised tidal flow in St. Aubins Bay.
There have also been suggestions to use the Ronez harbour to berth large liners. The water is deep enough but to construct a terminal on what little level land is available plus the duplication of passport/immigration/C&E services not to mention local road structure make the proposition unviable.
Like the bridge to France (but unlike the large ferries and liners) these suggestions are all out of their depth.
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