First off - since we started out with this little project - there has been a slight change
and we have moved on to Plan B - without missing a beat.
Here is the amended description.

Well we can blame the whole thing on friend Bill Saville - who 'just mentioned' - that he'd seen an ad in the local paper for a Water Tank Company nearby - and thought it could be an idea for me to call and ask them if they had any old or removed steel water tanks - they were throwing out.
Thinking of course that a round water tank - could make a perfect mould for a round mooring block - which we all know is a far superior 'sucking to the muddy bottom' shape for a mooring - than the usual square blocks that most people use.
Just ask anyone - Penny included - and they'll tell you that it's the surface area that's 'stuck in the mud' that's just as important as the weight.   And that once a mooring has settled in - you can just about pull the barge under before you'll break the stuck mooring free from the bottom.
So sure enough - as is my usual luck in these matters - I walked in to the place - stopped a bloke who was just walking out - told him my idea - and wouldn't you know it - he said:
'As a matter of fact, I've got one in my factory yard at Windsor
and if you want to come and get it - you can have it.'
So . . . . there was only one thing to do . . . . . .
ring Uncle Maurice immediately
(well 2 really - when you include - drive out there and get it - and bring it down here
well that probably makes 3, or 4 actually - but who cares - when you're crazy anyway)
Now you might be saying to yourself - 'that's a BIG tank on a little ute'
and you'd be approximately right - but this is the usual way water tanks are transported
and when on it's side - the tank fits perfectly in to the back of the ute - and easily secured.
And it's not such a little ute - but that water tank measures about 2.6m (9ft) across
and in case you were wondering - they charged us the full truck fare on the M4 too.
We had no difficulty getting it all the way down to the nearby shipyard that afternoon
and with a few hands it was soon rolled out - and ready for the 'next stage'.
Just take a look at the colours and the corrugated iron patches on the old sheds
in the late afternoon - the old shipyard is a fascinating place.
Here is a view back up the other way - in this back lane of the yard.
I did all the calculations - to work out the volume of the tank
and how much it would weigh when cut at various sizes
but I could just as easily have used the on-line calculator - I found
Naturally, you would of course have known from your school days (Ha)
that the formula is Cylinder Volume =  x Height
So here it is:
 X 1.3 X 1.3 X .6 (High) = 3.18 cu M
Concrete weighs app 2.2 ton per Cubic Metre
SSSoooo . . . . . . 3.18 X 2.2 = 6.996
So if we cut the tank at just .6m (2ft) high and fill it
then it will weigh 7 tons
(and will be about the biggest mooring block ever dropped in the bay)

So the very next day - we were in to it.
Keith had welded up an 'artwork' of offcuts from Sam's scrap bin to go in the middle. 
And I had no trouble cutting right around the tank with a 1mm cutting disc in about 15 mins.
The next thing was to just roll the section to a suitable spot and start to mesh up the inside
and wire in more reinforcing bars all over the place - to strengthen up the finished block.
And of course one of the large 2" steel Navy links was tied in - with heavy bars through it
as the main lifting ring - and the attachment link for the heavy ground chain - later.
It took a few hours - but we took it easy - as I was feeling pretty tired - and before long
the entire structure inside the tank was finished - and ready for concrete.
This is 2 photos combined - and there is a larger more detailed shot available here:
And that is still where we are right now.   Waiting for the concrete.
I have visited the local Cement Plant and they have promised to drop off the leftover
concrete each day - no problem - and to fill the tank for me
as they usually just dump about 10-12 cubic metres each week anyway.
But this whole week has gone by - and despite another visit - and again being told they would start dropping it off that day - we have come to the end of the week - and it's still empty.
So, if nothing should be dropped over the weekend - it looks like another visit around there
on Monday - to see if there's any problem - but they all seem quite happy and helpful.
It's just that I'm running out of time for the block to be put out - and will have to go
in on Wednesday - and ask for an extension of time - which I'm told will be given.
There's still more to report - and another trip out west to pick up some giant ship chain
which I'll tell you about next time.
So bye for now
Sydney, Australia