surely any half baked engineering company could have a replacement strut already fabricated ready for the paint shop by now, council will have working drawings in there archives still. what a waste of time these uni trained 'engineers' are , taken 2 days to decide a replacement is needed
glad i live nowhere near it
budgel,
Sep 21, 10:54am
It is a structural member that weighs several tons in a bridge that is still in use. This is not a 'shoot from the hip, she'll be right' situation. They are doing the right thing by approaching it carefully and with due consideration for the forces involved. Public safety is worth spending some time on in my opinion.
Took more than 2 years to repair/ upgrade it - excellent for my (non uni) mech engineer husband who earned some big money working on it. Paid the mortgage off. These things aren't quick, by any means.
bill-robinson,
Sep 21, 11:28am
i love all these home schooled structual engineers that can knock up a bit of stteel work and fit it overnight.
sr2,
Sep 21, 11:45am
Transport Services appear to once again have been caught with their pants down. Why on earth did they not already have a BCP (Business Continuity Plan) and team in place to to cope with such an emergency? I've been on BCP teams for a number of companies where we are continually improving contingency planning and holding annual or 6 monthly simulated exercises to train the people and test the plan - it's not rocket science and is commonplace in business.
If it had happened in Japan it would have been fixed over the weekend!
lyrad,
Sep 21, 11:50am
Misleading video, alot of work had obviously been done previously to get it to that point.
alowishes,
Sep 21, 11:53am
And it would be a tangled wreck in the bottom of the harbour in five years.!
boby11,
Sep 21, 12:31pm
Its a 22 metre long main stay especially coated against corrosion.The half baked el-cheapo engineering firm would probably get the bolt holes wrong and the dimensions wrong for when its preloaded.
sr2,
Sep 21, 12:54pm
I think he would have been working on the 'clip-ons' repair; they are effectively separate bridges each side of the older, main span.
We're very lucky they are semi-independent structures, otherwise the buffoons would have had to shut down the whole bridge!
mrfxit,
Sep 21, 12:56pm
Seriously tho, should only take one to two weeks to measure build plans and build the replacement strut, Fitting. . is a whole different ball game. With todays laser measuring tools & a lifetime of building bridges in NZ and overseas, it should be all done & painted within a month. Bureaucratic bollocks & a mountain of over the top safety protocols, will see it extend to 6 months at a minimum
kazbanz,
Sep 21, 1:54pm
Ok so I'm "there" as in had to drive past the damaged "strut' several times over the weekend. The centre lanes are ALL blocked off. However what was noticeable every time I drove past was that there were zero staff there doing any work with the one exception being one guy on a hirepool cherry picker doing -well not a lot. Yes its a pretty darn big chunk of steel but its pretty clear there was no intention to carry out any work until today.
tgray,
Sep 21, 2:35pm
Upper harbour alternative route down to one lane in places, due to roadworks.
s_nz,
Sep 21, 2:38pm
It was covered in today 1pm press conference. There are a lot of people working on this, just they are working out of public sight. In terms of physical inspection the bolted connection that failed is below bridge deck level, so not viable from the road.
Plan is to come up with a temporary patch up that can allow an additional one lane each way to run on the bridge. Then to work on a permanent solution.
I'm not a structural engineer, but have worked alongside many as a mechanical engineer.
They have already drilled new holes in the bent member and replaced sheared bolts to reduce the change or further damage to the bridge.
Engineers will have the original plans for the bridge, and these days it is often faster, cheaper & safer to have a 3d scan of the area done than to be up in a man-basket with a tape measure. That area's pretty small. a 3D scan could be done in under an hour.
From there all the info goes back to an engineering design office. Engineers then work out if surrounding members have been damaged via overloading, and if not, get to work designing a temporary fix, and re-rating the bridge for less lanes of traffic. They then get on with designing a new strut, and a means to install it.
Note that the strut is load bearing, so can't simply be unbolted and swapped out without risking the bridge falling down. Also it needs to be installed under tension which can be very challenging.
It is only when the design for each the temporary & permanent fix is complete, materials sourced (quite a challenge as it need to have similar thermal expansion properties as the existing bridge), Workshop fabrication competed etc that you will see big action on the bridge itself.
Easy to criticize the process for being too slow, but this is the correct way to go about it. Could easily rush the job, skip proper engineering analysis and peer review, and ultimately cause the whole bridge to fail (possibly bringing down one of both clipons as it falls).
For those posting time lapse of rapid construction in china. Firstly most of these jobs are only possible because of heaps of offsite preparation & planning. Also it is not hard to find cases where bridges & buildings have catastrophically failed due to construction issues in that country.
The Harbor bridge is to important for us to compromise on quality.
richardmayes,
Sep 21, 3:44pm
Murphy was an optimist.
apollo11,
Sep 21, 3:48pm
There are companies that do this sort of thing day in and day out. If it's mainly just cut plate, it could be same day turnaround and on the overnight truck. Welding would require an extra day or so, depending on how much there is to do.
apollo11,
Sep 21, 3:50pm
Or you find out that there were many 'unrecorded revisions'. It the job was handled electronically then it's likely the cut files are on someone's computer, somewhere!
alowishes,
Sep 21, 4:06pm
Don’t forget the bolt holes - they’ve all got to be in the right place.
kazbanz,
Sep 21, 4:14pm
snz--sorry mon but there was not a lot going on from under the bridge either. -In fairness --Visible from the road under the bridge at city end.
sr2,
Sep 21, 4:17pm
If you look at the photo's you'll see one end is already 'unbolted' - the bolts have all sheared off!
apollo11,
Sep 21, 4:18pm
CNC will put them where you want them- as long as the drawings are spot on. Removal of the damaged piece and installation of the replacement would require a bit of nutting out though.
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