Holdfast Training Services Trial Blog

This blog aims to provide an update on site progress, as well as demonstrating the wide range of tasks that seem to land on your lap as an engineer.  Apologies if it is a bit long, not had a lot of time recently to blog.

My main area of responsibility (the pipeline) is nearing completion, with the filling for the hydrostatic testing taking place as I type, should take around 3.8 days.  My involvement in this has been limited to developing the test procedure alongside the subcontractor and client, as well as ensuring the relevant standards are followed and John Holland isolation procedures are adhered to. It did however give me the opportunity to wheel out some P=ƿgh action when the client asked why we were not going up to the full test pressure (answer – because the pressure gauges are not at the lowest point). Other areas I have recently taken on include the intake and outflow at both the sea and project end, as well as the lining of the lagoon structures and all the associated pipework.

The intake and outflow for the pipeline at the sea end is a $1m package of work which has recently been awarded to Guidera O’Connor. I have been responsible for developing the scope of works, getting the designs to IFC stage, introducing the subcontractor to the project and on boarding their construction team. The design currently ties in with existing infrastructure at Alinta power station. A few weeks ago the power station announced its closure in 2016; previously this was due to be in 2030. This clearly has some major impacts on our project:

• Firstly the site is to be returned to the condition it was prior to the power station, including the inlet channel that we are building on and the control rooms that we were going to use for power. Currently this has been passed back to the Client to come up with a solution through negotiations with the land owner.
• Secondly the Environmental Protection Authority sign off for the brine discharge from our site was based on the outflow of the power station for diluting and mixing, prior to the water entering the sea. Further models are now in development by the University of New South Wales to analyse the impact.

A potential positive is the fact that the government is under pressure to do something about the number of unemployed persons in the area and as a result there are already discussions for a second Sundrop Farm project in the area, clearly this will be dependent on the commercial success of this one. At the moment we have been to soldier on with the current designs, with the hope that the Client comes through in the end otherwise we will have some major variations coming our way.  I have included some photos of the existing infra structure firstly to show the state of disrepair that we are expected to link into and secondly to balance the fact that the remainder of this blog is civil based.

The contract for the lining of the ponds was awarded to Fabtech and was valued at $750,000 – at first I thought this would be a relatively pain free scope of work. After interrogating the drawings I discovered a whole can of worms in the form of buried services.   Basically I have spent the last two weeks trying to find out who is responsible for what services, taking items out of various scopes of works and awarding variations to Fabtech in order to progress works as they are already onsite and we can’t afford any delays. In the process I have found gaps in both the design and procurement packages, which always makes you popular on site. One of the most surprising gaps at the moment is that there is still no plan for the waste water across the whole site, even though the subcontractor for buried services starts next week.

The big recent event on site was the pour of the Solar Tower foundations; I have included some pictures below for all the civil types out there. In total the pour was around 550mᵌ, it began at 0300hrs and lasted until 2000hrs. The planning and preparation involved in the whole pour was quite impressive and was greater than what I witnessed on some military operations, with standby pumps, plants and trucks identified across the state and put on reduced notice to move. Inside the reinforcement you can see the ring of 200 bolts, 4.5m long which will eventually hold the base of the tower.  The photo’s below show the template holding the bolts getting lowered in to place, the start of the pour and the end of the pour (yes it is raining).

Other random things I have been running with include dealing with some asbestos that was discovered whilst excavating the pipeline writing an Acid Soil Sulphate (ASS) plan and the redesign the pipeline as it crossed through an area that locally has become known as the ‘bog’. The area in question was a concern as the pipe transitioned from an area of pale brown sand to an area of grey clayey sand before going back to sand. From John Morans lessons the mention of clay clearly sent alarm bells ringing in my head. As a result I was then tasked with organising a geotechnical investigation to try and establish an estimate of the long term settlement (which came back as 50mm over the 100m) and then amend the construction method and design to bridge the gap whilst ensuring there was enough flexibility to prevent the joints from opening up at a later date. All very civil orientated but I suppose it prepares me for future roles as a PQE in the Royal Engineers. What was a shock was the fact that this whole episode came as a surprise to everyone, despite the fact that the area can be clearly seen on Google earth. The photo below shows the result of a test pit, which started out as 1m wide by 3m deep trench about an hour before.