Nissan Huts

Sorry, but actually it has been known about for many years!! When I was jungle training in Malaya in 1955 we knew better than to cross our rope bridge in rhythmic marching steps.

No, it’s not the quite the same thing.

In fact when I worked with one of the Arup Engineers who was on the Millenium Bridge design team, several years ago, I querried the exact same thing, as my Dad had always told me years ago about the ‘break step’ order when marching over bridges.

Runways, hangars, fuel storage tanks….

Yes yes i know that…. but i think we may have swayed off topic (more than the wobbly bridge in London)

IIRC, soldiers were/are always told to break step when crossing any bridge.

Actually, Synchronous Lateral Excitation wasn’t really known about as such until what happened with the Millenium Bridge, and as a result the British Standard Code for Bridge Loading has been updated to reflect the research done by Arup to solve the problems with the bridge.

Sorry, but actually it has been known about for many years!! When I was jungle training in Malaya in 1955 we knew better than to cross our rope bridge in rhythmic marching steps.
It seems to me that today’s engineers have to go through their own learning curve of basic mistakes, they take no notice of us old hands. I have worked with many graduate engineers all gleefully re-inventing their particular wheels.
Geoff.

“Actually, Synchronous Lateral Excitation wasn’t really known about as such until what happened with the Millenium Bridge”

– I find this hard to believe?

Well it’s true.

Have a read…..

http://www2.eng.cam.ac.uk/~den/ICSV9_06.htm

I don’t believe that a temporary building , i.e a porta cabin , or caravan/moblie home, is restricted to 28 days, as there wouldn’t be a building contract finished in the whole land! (without somewhere to have a tea break).

You misunderstand the term ‘temporary’ when applied to the actual structure and the term applied to the use of the structure, they are not the same. It’s ONLY temporary in terms of the regs for usage, if it’s there less than 28 days, otherwise the regs apply.

I’ve seen footage of a bridge in the US swaying in the wind, I would have thought that was lateral exitation, surely the problem with the footbridge was a much to do with harmonic frequencies, generated by the people using it

The Tacoma Narrows bridge collape was due to Mechanical Resonance from wind loading, not Synchronous Lateral Excitation from imposed loading….there is a difference.

“Actually, Synchronous Lateral Excitation wasn’t really known about as such until what happened with the Millenium Bridge”

– I find this hard to believe?

Engineering is a matured discipline these days. As per Stuarts example states, there have been many other occurences of dynamic behaviour destroying building structures over the years. My fathers company for one, designed and installed building dampers to cure a resonance problem in an already finished multi-million pound development. It is more a case of the civil engineer didn’t do his job thoroughly in the first place.

It has always been ironic to me that a Civil engineer trains for many more years, and requires higher levels of qualifications, gets better paid, needs Chartered status, etc, etc, than their mechanical or aeronautical counterparts. Buildings are built ontop of suitably created foundations for the terrain, with very large safety factors incorporated into their designs. Mech/Aero engineers have put men on the moon… need I say more?

DC

And building regs relate to historic aviation how exactly??????

Runways, hangars, fuel storage tanks….

And building regs relate to historic aviation how exactly??????

I don’t believe that a temporary building , i.e a porta cabin , or caravan/moblie home, is restricted to 28 days, as there wouldn’t be a building contract finished in the whole land! (without somewhere to have a tea break).

I’ve seen footage of a bridge in the US swaying in the wind, I would have thought that was lateral exitation, surely the problem with the footbridge was a much to do with harmonic frequencies, generated by the people using it ;as I say I’m no expert, ( “X is an unknown quantity, and a spurt, is a drip under pressure”).

I’ve added a photo of one I made earlier, (about 5 years earlier!) a variation on a theme, but essentially the same.

Whilst I am no expert

Obviously:rolleyes:

I have always regarded Nissen huts as “temporary accomodation”, (I use the word “temporary”, in the planning context, i.e something that can be moved in sections, or as a whole, or else easily dismantled).

I find it hard to believe that current building regs, can be applied to them, as in their original state, short sections could be craned, as the floor joined the walls together, and if clad and bolted, the front and back walls joined the floor to the ceiling (so to speak); probably a bit heavy to move ,if front and back walls were brick!

I’m a bit rusty regarding current Bldg Regs stuff, but IIRC, to be ‘tempraory’ a building structure can only be exempt from the Regs if it will be there less than 28 days.

And a wartime Nissen hut will have the regs applied to it IF you are moving it, as it doesn’t matter than it was an existing structure where it was originally put up, as it becomes a new build at the location where you now want to put it up.

I bet that piece of cr@p foot bridge over the Thames passed current regulations ; “it was alright, until people started to walk on it”…..

Actually, Synchronous Lateral Excitation wasn’t really known about as such until what happened with the Millenium Bridge, and as a result the British Standard Code for Bridge Loading has been updated to reflect the research done by Arup to solve the problems with the bridge.

Whilst I am no expert, I have always regarded Nissen huts as “temporary accomodation”, (I use the word “temporary”, in the planning context, i.e something that can be moved in sections, or as a whole, or else easily dismantled).

I find it hard to believe that current building regs, can be applied to them, as in their original state, short sections could be craned, as the floor joined the walls together, and if clad and bolted, the front and back walls joined the floor to the ceiling (so to speak); probably a bit heavy to move ,if front and back walls were brick!

So what are we saying then, “something that has stood for over 60 years in all weathers, without any maintenance what so ever” is potentially dangerous, or is it that the design, (that allowed these buildings to stand for over 60 years in all weathers etc etc) is inherently flawed?

Neither really Stuart – its more a reflection on the increasing ‘factor of safety’ levels that have become rooted in modern structural design.

So what are we saying then, “something that has stood for over 60 years in all weathers, without any maintenance what so ever” is potentially dangerous, or is it that the design, (that allowed these buildings to stand for over 60 years in all weathers etc etc) is inherently flawed? I bet that piece of cr@p foot bridge over the Thames passed current regulations ; “it was alright, until people started to walk on it”…..

So now they fall down, whereas before they didn’t?

No -its simply that getting old designs to show compliance with modern codes of practice can be rather dififcult

That Engineer with a capital E please, and it’s doesn’t matter whether one uses a computer programme to do the analysis or a calc pad, pencil, and slide rule (not that ANYONE uses them these days:rolleyes:) as the rules of analysis are still the same as they have ever been…..what’s changed is the relevent codes of practice, and you can’t get around that no matter how you do the sums.

Yes exactly :rolleyes:

So now they fall down, whereas before they didn’t?

What ever you do don’t let a structural engineer run it through a computer for Building Regulations approval – computers say they fall down!

You need a qualified engineer who can work it out the old fashioned way – paper, pencil and slide rule!!

That Engineer with a capital E please, and it’s doesn’t matter whether one uses a computer programme to do the analysis or a calc pad, pencil, and slide rule (not that ANYONE uses them these days:rolleyes:) as the rules of analysis are still the same as they have ever been…..what’s changed is the relevent codes of practice, and you can’t get around that no matter how you do the sums.

We have saved the last one from Stansteds Birchhanger site, It is still in situ at the moment, as it contains the electrical switchgear for the old industrial estate. Once EDF have cleared it, we will take it down, and rebuild it elsewhere😉

I have mentioned before in another thread you started 668, You will need planning permission!

Nissen Huts

Nissens & Romneys are still manufactured in Holland by J Snoie BV
Also G T Evans in Wales
They are available in sizes from 16ft span upwards in any length.

A new build is the way to go – Ive done several now – the second hand ones are fine if youve got a free building and endless time – the originals can be prone to metal fatigue high winds and snow loads they can be prone to collapse. A New build kit will save you in the long run.
For larger Spans the Romney up to 36 ft Standard or 40ft with a roof plug are fine a much more robust building than the Nissen.
A 60ft by 24 is around £8000 Romney £12000
Add about the same on again for a proper concrete base.

Regards