Shelf collapse

[pete_mcfarlane]

Nothing wrong in principle with glueing stuff together. Ask any Mosquito pilot.

Unless they were in India or the far East, where Mosquitoes had a tendency to come un-stuck due to the humidity degrading the glue. I think this was eventually resolved, as the Vampire and Venom didn't have the same problem. 

 

 

[PatB]

 The piratical assumption of the term designer by someone who is only a stylist.

 

There's altogether too much of this 'form over function' crap going about, well illustrated in the UK by the wobbly footbridge event on the Thames. I recall the collapse of a largely glass footbridge over a hotel atrium some time in the last millenium in the USA, and live in daily expectation of similar events. The high capacity resort 'cruise ships' top my list of very likely to fail someday with very unpleasant consequences, others may have similar junk in mind...

 

The hotel walkway collapse was a result, IIRC, of inadequate design by engineers who should have known better, not architects/stylists with ideas above their station. I could be wrong, though. The book I have which goes into some depth on the failure of the suspension system is in a box somewhere so I'm relying on an increasingly unreliable memory.

 

And that's from an engineer who's had his share of headaches trying to make the pretty pictures of architects actually work in reality.

[PatB]

Unless they were in India or the far East, where Mosquitoes had a tendency to come un-stuck due to the humidity degrading the glue. I think this was eventually resolved, as the Vampire and Venom didn't have the same problem. 

 

Well, the casein glue they were stuck with was dairy product based ad so rather attractive to adhesive munching microbes. I believe this was the motivation for the development of acid catalysed urea formaldehyde adhesives, which were much more durable. They do degrade in heat and humidity but take longer to weaken dangerously. They're banned in Australia for aircraft construction for this reason, but still permitted in the US. Mind you, the US allow all sorts of stuff on an "at your own risk" basis that other jurisdictions see fit to regulate, so I'm not sure if that tells us much .

[meil]

Well, the casein glue they were stuck with was dairy product based ad so rather attractive to adhesive munching microbes. I believe this was the motivation for the development of acid catalysed urea formaldehyde adhesives, which were much more durable. They do degrade in heat and humidity but take longer to weaken dangerously. They're banned in Australia for aircraft construction for this reason, but still permitted in the US. Mind you, the US allow all sorts of stuff on an "at your own risk" basis that other jurisdictions see fit to regulate, so I'm not sure if that tells us much .

The glue developed for the Mosquito was Aerolite 360 and it's still used in the construction of wooden aircraft.

[Spitfire2865]

The hotel walkway collapse was a result, IIRC, of inadequate design by engineers who should have known better, not architects/stylists with ideas above their station. I could be wrong, though. The book I have which goes into some depth on the failure of the suspension system is in a box somewhere so I'm relying on an increasingly unreliable memory.

 

And that's from an engineer who's had his share of headaches trying to make the pretty pictures of architects actually work in reality.

The Regency disaster was actually due to the builders.  The original design was for a support rod through the beam, however it was installed as two separate rods through the beam, so instead of the rod supporting the weight (which it could), the beam was stressed and gave way.  Studied the Regency disaster back in school as part of my engineering.  

 

One of my professors once told a story from when he was working on aircraft design.  His plans called for a welded joint in a certain orientation.  The welder thought otherwise and the welder's improvised joint didnt work when tested.  

[34theletterbetweenB&D]

The hotel walkway collapse was a result, IIRC, of inadequate design by engineers who should have known better...

I will never for a moment claim engineers always get it right, but when it goes wrong it is rarely because no proper skill and calculation went into it. (Our local 'big one' is the Comet airliner, and the memory is still alive among the dwindling band who were there.) Personally I was very glad during the active engineering design phase of my career to be developing product which might cause major inconvenience, and potentially significant financial losses, in event of failure; but negligible chance of directly causing injury or death.

 

I once managed to do the thick end of a million quid worth of damage in a production plant by trusting a highly regarded component supplier's spec. which was a tad embarassing. I should have stuck to my instinct and insisted on a full trial before production implementation, but the commercial side had already sold the new product capabilities before the development work had started, and the heat was on. Fortunately the VP of our division was newly pushing the concept of 'bias for action' so I sold it under that clause...

[PatB]

The glue developed for the Mosquito was Aerolite 360 and it's still used in the construction of wooden aircraft.

Indeed it is, and very successfully too. Just not in Oz. The options here are epoxy or resorcinol. I'm not sure what we do about vintage aircraft built before the ban. Regular inspections I assume.

[peach james]

The hotel walkway collapse was a result, IIRC, of inadequate design by engineers who should have known better, not architects/stylists with ideas above their station. I could be wrong, though. The book I have which goes into some depth on the failure of the suspension system is in a box somewhere so I'm relying on an increasingly unreliable memory.

 

And that's from an engineer who's had his share of headaches trying to make the pretty pictures of architects actually work in reality.

The as designed for the Hyatt bridge was fine.  It was the as constructed that was the problem...

https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse

[meil]

Indeed it is, and very successfully too. Just not in Oz. The options here are epoxy or resorcinol. I'm not sure what we do about vintage aircraft built before the ban. Regular inspections I assume.

And I believe the Oz restored mosquito has used epoxy impregnation of the plywood. If only that had been used originally we would have any number of flying aircraft now.

[eastglosmog]

I will never for a moment claim engineers always get it right, but when it goes wrong it is rarely because no proper skill and calculation went into it. (Our local 'big one' is the Comet airliner, and the memory is still alive among the dwindling band who were there.) Personally I was very glad during the active engineering design phase of my career to be developing product which might cause major inconvenience, and potentially significant financial losses, in event of failure; but negligible chance of directly causing injury or death.

 

I once managed to do the thick end of a million quid worth of damage in a production plant by trusting a highly regarded component supplier's spec. which was a tad embarassing. I should have stuck to my instinct and insisted on a full trial before production implementation, but the commercial side had already sold the new product capabilities before the development work had started, and the heat was on. Fortunately the VP of our division was newly pushing the concept of 'bias for action' so I sold it under that clause...

Just been involved with sorting out a similar problem - manufacturer trusted the (supposedly) certified frost resistance of a material only to find it failed after rain and a freezing night.

[Classsix T]

And I believe the Oz restored mosquito has used epoxy impregnation of the plywood. If only that had been used originally we would have any number of flying aircraft now.

We'd have DeHavilland Mosquitos in abundance in 2018 if they'd used different adhesive in 1944? me.

 

C6T.

 

Honestly, that's top drawer .

Edited May 17, 2018 by Classsix T

[The Stationmaster]

The glue developed for the Mosquito was Aerolite 360 and it's still used in the construction of wooden aircraft.

 

Known to some, like my dad, who used it in aircraft construction as 'beetle glue' (oddly he was 'directed' by the Ministry of War Labour out of an aircraft factory [Miles] where he was on skilled work to less skilled work such as barrack huts etc)

[The Stationmaster]

And I believe the Oz restored mosquito has used epoxy impregnation of the plywood. If only that had been used originally we would have any number of flying aircraft now.

Like we have any number of flying Wellingtons, Halifaxes and Beaufighters you mean?