Holdfast Training Services Trial Blog

For those that don’t know I am working on a demolition and rebuild project in Woking. One of the main challenges during my phase 2 has been the live shopping centre and services running around and through the site. As John would say RISK!

Well yesterday that risk was realised when the demolition subbie struck a live water main. I was on site minding my own business when I got a shout and went over to see a 6″ pipe distributing water at some pressure. The pipe had been exposed the day before so it could be isolated in the next few days.

The location of this strike could not have been worse. It is on slight high ground with 3 key low areas around it.

To the left is the demolition site where machines are digging out existing foundations, back filling and constructing a pile mat onto. For those just going through this on phase 1 I’m sure you can reel off the problems flooding a site conducting those activities pose.

To the right ground beams and concrete substructure walls are being cured ready to be back filled and loaded with the GF slab. Again water is not helpful.

Behind is the live shopping centre. As we have demolished part of the shopping centre, the only thing separating the elements and the public is a temporary protection tunnel and crash deck. It has been weathered but would not stand up to a flood, this flooding would mean closing the shopping centre.

What happened next. Well I instantly went into PITCHPOLE mode and started using demo arisings to create a barrier between the water and the shopping centre. We then had to make a pretty hasty decision what to do with the water so dug a trench to encourage the water along the side of the piling mat.

I phoned the M&E engineer for the area and he managed to stem the flow by isolating a valve but couldn’t turn off the entire flow due to it being on a ring main serving greater Woking, they cannot do without water. We made some phone calls and got a large pump on site within 10mins to match the flow of the leak and have stemmed the flooding. Affinity water are not coming onto site until the end of the week so this pump must be run 24/7 until they isolate the ring.

I’ve been reflecting on our actions and the impacts and if we could have done anything better. As it is we chose to protect the live shopping centre and the concrete curing. We have potentially jeopardised the piling mat by diverting the water towards it, a plate bearing test happening on site today may shine some light to whether this has actually caused damage.

I constantly was suggesting leading a trench into a live foul drain and letting gravity help but there is little appetite to do that considering the disruption it would cause to current works. Also there is the consideration of overwhelming the foul system.

Hey Guys – I hope to use this blog to pose a problem only – generate discussion, and follow up in comments or a blog to let you know what I did about it.

Firstly and briefly  – I am attached to the Gold Coast Seaways Project – we are upgrading two pump stations that serve to release recycled water on the Gold Coast out to sea.  A map showing project activity can be found below.  It consists of two pipelines (northern and southern) and we will have left each of them able to shift future flows of up to 6300 L/s.

Project overview map

And it is in Queensland Australia……

Sorry

Since arriving on site back in April; I have noted that the Engineers on the Project are flat out and separated from one another by geography as well as function.  It is almost like 7 separate projects (each headed by an Engineer) rolled in to one headed by the PM.  Meaning that interdisciplinary teamwork is difficult at best.  I have made good progress in breaking down some of these barriers and managed to get my hands on to some interesting Scopes of Work(SoW), from a range of areas.

However, as a result I have become the go to engineer for that extra little scopes that no-one else wants, some of which I have politely avoided.   But I have picked up some pretty interesting little tasks from underwater construction to lifting with no head room.  I might pick up on some of those in a later blog; for the time being structural strengthening!

My main task is to deliver mechanical installation at 2 pump stations; I am teamed with an electrical engineer and a mechanical engineer, but no structural engineer.  I have some big pumps and motors to move around the place, some of which have been noted by the designer to exceed the load limits of the existing infrastructure and therefore the preliminary work to the main event (the E&M) is a bit of civil and structural.

This particular task was to install 5 columns and 2 beams to strengthen the mezzanine floor (drawing below) which will be loaded with the new motors later in the year; no big deal?!?!?

Structural Drawing Snapshot

I was to:

• Read the drawing to put together a scope of works package.
• Submit to potential subcontractors.
• Assess the tenders and award the subcontract.
• Manage the subcontractor through to completion of works.

Problem:

• I don’t know where to start with checking the drawings.
• Any changes I might want to make for practical reasons (clash with my pumps), might not comply with the engineering.
• RFIs raised by the subcontractor will likely push beyond the bounds of PET fundamentals phase.

That said – it’s just management; right?  I have done management since joining the Army. This scope is dwarfed by many of the others on the project (magnitude of time and cost) – can I assume that the complexity of engineering is minimal?  The designer has already designed it, so I don’t need to do much more than just get someone to fabricate and assemble?

Questions:

• How should I comply with UK SPEC to ‘identify personal limitations, disclose them appropriately and ensure that the implementation of this scope is not hampered by my lack of knowledge’?
• Have you got examples of out of discipline work that you have had to manage?

Finally – it did get installed – and hasn’t fallen down (yet) – so can’t have went too badly.

The Finished Product (anyone spot what’s missing?)