State-so-confused-on-PortFrom previous letter, a couple of pieces of constructive criticism have been received.
About dredging, evidently many people find it difficult to relate to Mm3 (millions of cubic metres).
Per previous letter, maximum anchorage space is for just five ships at 5000m E-W by 1000m N-S. Looking more closely at report by Hatch Ltd to Dept Major Projects Victoria, reducing draft of ship to 14.9m, to match (!) Hastings, it also adds regulatory clearance of 1.8m below keel.
Westernport has tidal range as much as 3m and depths on charts are from mid tide level, so to allow ship movement in all states of tide, depth needs to be 14.9 + 1.8 + 1.5 = 18.3m. Charts show maximum depth contour 5 to 10m.
There are a few holes and skinny channels which are deeper but let’s presume that depth average is 8.5m which means dredge of 10m.
For anchorage this means 5000 x 1000 x 10 = 50Mm3.
The channel 30,000m long, needs to be widened to at least 500m, so that monster ships, as tall as a city high rise, can be prevented from slipping sideways and running aground, so 30,000 x 500 x 10 = 150Mm3. So total dredge is 200Mm3.
To make sense of big volumes, in mainstream media, they talk about number of Sydney Harbours or Olympic swimming pools, neither of which is meaningful.
Recent bulletin from PoHC (Port of Hastings Corp), allocates some space labelled “Potential Offshore Dredging”, with two additional optional spaces, the goal being hardly more than 1km square, or 1000 x 1000 = 1M, divided into 200Mm3 volume means that placing dredge here will amount to a rectangular pile 200m high!
Didn’t the Minister for Planning recently get knocked back for approving a CBD high rise project as high as this because it was too close to Tullamarine?
Do our ministers need minders who are capable of arithmetic other than that used in never ending growth type economic forecasts?
If a 200m high lump doesn’t suit some people then how about, since it’s proposed as a container port, let’s resolve it to how many containers.
The volume of a standard TEU container is a little less than 40m3 (cubic metres).
Divided into dredge volume of 200Mm3, tells us that this volume is 5million containers or two years’ worth of nothing but dredge through Melbourne container terminal.
Is it to get trucks to Appleton Dock the reason our Premier thinks he need East-West Link, at $8billion?
Justification for 1.8m clearance below keel, mentioned above, is some kind of maritime standard thingo, to allow for wind and/or wave/current action, of which there’s big lumps in Westernport.
Even this looks a bit shaky when you consider that these monster ships are nearly 50m beam.
Very simple calculation shows that the flat bottomed edge will be scraping bottom of harbour with as little as four degrees of roll.
Another gem from report about Corner Inlet is allowance of 90 to 120 minutes for ships to travel 13km to clear end of shipping channel.
For Hastings, this means three to four hours.
For a round trip, this means eight hours, which means just three ships per day, when plan calls for eight per day, assuming no days lost for regular dredging or any other “externalities”.
Here’s another observation from Port Phillip, the Heads are only about 2.5km across.
For such a small size, how about a concrete wall across the whole entrance, with lock access to the Bay, almost as exciting as Panama. Portsea could get its beach back. Fish and penguin ladders can be a tourist attraction. A road along the top can shift more tourists, bigger, faster. Minister Hunt’s dream about tidal power could come true, 24/7 reliable, not intermittent like wind and solar. Bay level could be higher, to save dredging. Container port at Point Wilson would be a complete no brainer. And the whole thing would be safe from climate change and sea level rise. And they all lived happily ever after.
Is Premier Napthine really going to burn the whole $110million before conceding that maybe, just maybe, the whole Hastings thing has been a misguided fantasy, from the very beginning?
He’ll end up doing as much as Mr Baillieu, but at least he was quiet about what he wasn’t going to be able to deliver.
Bernie McComb, Cowes