Holdfast Training Services Trial Blog

Since the sub-contractor went into administration a couple of weeks ago their sub-sub-contractors and suppliers have been either walking off site (like the plumbers), or going straight to McAlpine in order to get paid.

We are now paying for:

Steel

Plumbers

Drainage stores

Skips

Waterproofing materials

Timber and consumables

Muck-away

Almost everything else

PC Harrington are still paying for:

Concrete

Some labour

The drainage is now being installed by Realtime.  Since we needed them to start immediately they had us over a barrel at least initially so they’re currently working on day rates.  A price will be agreed soon but in the mean time they’re making hay while the sun’s shining.  The contractor is throwing blokes at the job, which is great for our progress and great for his profit.  We pay £31 per hour for the drainage supervisor.  He probably earns half that at best.  The rest is overheads and profit. They are working totally risk free.

More concerning is that we’re having to supply timber and consumables.  Even B&Q won’t give PC Harrington any credit!  We’re also now supplying pull-out bars for the slipform.  Irritatingly they’re on a 1 week lead time.  We were only told they couldn’t get them yesterday, but they need them tomorrow.  Obviously this can’t be done.  We asked for the quantities and we’re told the engineer would do the take off for us.  This means they hadn’t done the take off.  That means not only had they not placed the order themselves, but they had no intention of doing so.

In a progress meeting yesterday PC Harrington told us that their recovery program would be issued 48 hours late.  They can’t even program when their program will be published.  They also gave us a list of what works they will complete in the next two weeks.  They told us how far behind they are today but had no idea how they would be looking in two weeks time.  Their forward planning is terrible.

There are some great things about working in civvi street: they are very efficient and know their stuff, the other day I was running late and didn’t shave before work, no one cared that I wouldn’t be able to get a proper seal with a respirator!

There is also some really annoying stuff.  The accuracy of their written work is terrible.  If I have to read another ITP describing me as a Mace representative when I work for McAlpine I might scream!  And their ability to plan beyond what their having for lunch is woeful.  I use to laugh at the term “military precision” having seen some pretty slap dash planning, but at least it was planned, which is a start!

Rant over.

UPDATE – We are now also buying their stationary.  Today we had an order for 30 reams of A4 paper!

I never thought I’d say this, but I really do long for Eurocodes.  Whilst the plethora of EC books for design exercises in Phase 1 may have seemed confusing, whilst being in the USACE office I now realise just how thorough and user friendly they all were.  I can almost picture (longingly) the flow charts we used for steel design.

Instead, I am presently hamstrung by a Steel  Construction and Design Manual (SCDM) that is 3 inches thick and literally made of cigarette paper.  Not only is there no easy flow to the manual and its contents, but it sits in isolation with no sponsored design examples. Instead there are a plethora of Design Guides that are not up to date, therefore do not reference the SCDM accurately.  In some case, such as one of my projects (a supporting structure design for overhead cranes), US structural engineers use a Canadian design guide that is more thorough…and to add injury to insult, it uses metric units rather than imperial! Added to that is the choice of which design philosophy to use, and the one you have decided to use may not be the one that the Design Guide explains and/or uses in its design examples.  That said, though my design calculations seem to take an inordinate amount of time for me to consistently detangle my knickers, it has forced me to go back to first principles!

Two design philosophies exist in the USA: Allowable Strength Design (ASD) and Load and Resistance Factor Design (LRFD).  Both are strength based philosophies, though ASD was historically stress based. My first question was: What on earth is the difference and which one do I use?

1.  When considering the steel yield vs displacement graph, the combined force levels (i.e. load, moment  shear) for ASD design are kept below Fy, by taking the nominal strength Fu and dividing it by a factor of safety (aka permissible stress design).  For LRFD, the combined force levels are kept below a ‘computed’ member load capacity which is a product of Fu multiplied by a resistance factor (aka limit state design ~ Eurocodes!).

2. ASD treats live and dead loads equally, thus uses one FOS for both live and dead loads – this accounts for uncertainty in load and capacity.  Consequently it is simpler to use and more conservative.  LRFD however recognises the inconsistencies of dead and live loads thus allocates a higher FOS for live loads than dead loads as dead loads are believed to be more accurately calculated….  LRFD also recognises inconsistencies in material properties and construction tolerances.

So, though LRFD is proven to be a more ‘efficient’ approach in that it harnesses more of the strength capacity of a member, legally we can use either method for steel frame design.  ASD has historically been significantly quicker than LRFD for preliminary design although recent editions of SCDM have become more thorough for ASD.  I honestly believe that having uses ASD, it appears quicker than LRFD (not that I have done the latter yet) but it is still far slower than EC….largely due to the complexity of the Design ManuaI (and because imperial units are driving me insane!)  And that is the reason that every engineer has told me why old-school US structural engineers are steering well clear of adopting LRFD (not the units piece).

The same goes for timber and masonry design; concrete is the only one where LRFD is mandated (by the ACI).  But to add even more confusion, USACE has mandated LRFD for certain design work such as hydraulic steel structures. Then, I have also found, that product catalogues will vary in what methodology they have used for their allowable loads – this makes things incredibly tedious.  All in all a disjointed approach across all  the institutions!