Eiffel Over

Category: Engineering and architecture

  • God’s architect: Saint Antonio Gaudi?

    Thanks for Mary for finding this article about the camapaign to confer sainthood upon architect Antonio Gaudi, creator of my favourite building site in the world: La Sacrada Familia in Barcelona. I say building site because the colossal cathedral is not due to be finished for another twenty to forty years.

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    It is well known for its UNESCO protected facades, but it is the columns that flank the impossibly tall and narrow nave, sculpted like impossibly slender trees that are astonishing. All imagined and engineered without finite element analysis or any other modern day computer wizardry. The grounds for Gaudi’s beatification are his pious lifestyle and his divine inspiration (attempts at finding a “miracle” to confirm his saintliness – a prerequisite on the saint application form – have resulted in some pretty hilarious and far-fetched tales. See the article for more). I have no doubt that Gaudi lead a pious life and there is no doubt that having a new saint on the block will help with the construction of this cathedral: every drop of concrete has been paid for by private donations and gate fees so a few extra pilgrims would do no harm. It would be a shame however to confuse mastery of the mechanics of materials for divine inspiration. A wander around the crypt at the at the Sagrada Familia demonstrates some of Gaudi’s technical mastery through his models (details of which deserve a post of their own).

    The same could be said of other ‘devinely inspired’ engineers and architects: Christopher Wren for St Paul’s, Michelangelo for St Peter’s, Imohotep and his step pyramid (Egypt’s first). They may have prayed a lot but they are also all great engineers!

    Finally, I wonder about the wisdom of granting sainthood to an architect/engineer. The bible is not exactly full of praises for worldly construction afterall…

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    Engraving The Confusion of Tongues by Gustave Doré

  • Flying the TGV from Paris to Strasbourg

    It’s not just about the trains.  It’s about the track, the gentle curves, the tunnels, the soaring bridges…

    click this link to fly the route of the TGV Est Européen from Paris to Strabourg in 5 minutes, stopping at all the major bridges along the way, naturally…

  • Trainspotting: TGV at 578 kmph

    Choose life, choose reducing your carbon footprint, choose highspeed train travel instead of flying

    Thank you SNCF, for making trainspotting cool, at least for a day. Yesterday, a especially modified train with bigger wheels and go-faster stripes set a new train speed record of 578 kmph. The only thing that is faster on rails is the Maglev train, which doesn’t  even touch the rails, and at that, only goes a few kilometres per hour faster.

    It is fair to ask whether this record attempt was worth the 30 million Euro price tag. Travelling along France’s more minor train routes, there the decay and tattiness to be seen that is indicative of the large sums of money that have been diverted into the TGV programme. That said, France’s highspeed network is a great asset: where there are highspeed lines, flying simply takes longer. The development of the highspeed network has also pumped large sums of money into structures research, especially in the domain of bridge design. This record is in part another stage of that research process. The data recorded from sensors on the trains, tracks and bridges will help improve the understanding of these components under the intense vibrations that a train travelling at these sorts of speed can generate.

    There is no doubt however that a significant reason for spending so much money on this attempt is the hard sell. France wants to export highspeed technology to South Korea and even to the United States. It is just possible that a train that travels at over 300mph is enough to make even the US, where internal flights rule the day,  sit up and take notice.

    Check out this trainspottingtastic coverage from France2:

    [youtube=http://www.youtube.com/watch?v=8skXT5NQzCg]

  • TGV in 354mph record attempt – 1pm

    As part of the preparations for the eagerly anticipated TGV Est-Européen, which will operate from June 10th between Paris and Strasbourg, the SNCF are hoping to break their previous high-speed train record. As might be expected, in France this is a media event. I heard it mentioned twice on the breakfast time news and it will be broadcast live on the lunchtime news. Read more here…

    Also, I spotted this on the arrivals board last night at the Gard de Lyon. Anyone waiting for a friend on the 19h06 train might be waiting a long time…

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  • Wobbling la Passerelle Simone de Beauvoir

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    I was invited on Wednesday to go and help wobble the Passerelle Simone de Beauvoir (previous posts here and here). The wobbling was being sollicted in order to conduct ongoing tests on the bridge’s dampers. The tests were being conducted by the CSTB (France’s centre for building science, where I almost ended up doing my projet de fin d’études).

    Bridges such as this one, and infamously, London’s Millenium Bridge, are susceptible to wobbling caused by the excitation of one of the bridge’s natural frequencies by the pedestrians who use it. As well as forcing the bridge deck up and down with their footsteps, pedestrians also exert a sideways force as they alternatively plant their left and right feet on the deck. This sideways movement is of a similar frequency to the transverse vibrational mode of lightweight bridges such as this one and the Millenium Bridge. When a bridge does start to shake noticeably, there is a tendency to ‘lock-in’ whereby pedestrians synchronise their steps with the vibration in order to stabilise themselves, but in doing so, give more energy to the vibration. The first time that this lock-in phenomenon was observed was at the opening of the Millenium Bridge.

    This sort of vibration is unlikely to cause any damage to the bridge itself but it does make the people onboard feel quite uncomfortable. It is therefore an issue of serviceability. In order to reduce its effects, such bridges are installed with tuned dampers designed specifically to damp out these effects. And in order to check if these dampers are working or not, it takes a group of fifty or so enthusiasts (usually engineers) to jump up and down to see just how much they can get the thing to wobble. I tell you, we got some funny looks from passers by…

  • Berlin Wall lost in translation – can anyone help?

    I am correcting a document that has been translated from French into English and I have hit upon a term that keeps cropping up, and I simply don’t know what it is in English.

    In French the term is ‘Paroi Berlinoise’. I always see it translated as ‘Berlin Wall’. In my (admittedly limited) experience as an engineer, I have never heard of a ‘Berlin Wall’ unless it is a type of reinforced concrete structure with graffiti on one side that typically has a design life of, say, forty years.

    I don’t think this is what this document is talking about. Can anyone help? (It maybe useful to know that ‘paroi’ is a word tpyically associated with perimeter foundation walls; for example, a ‘paroi moulée’ translates as diaphragm wall)

  • Project update – meeting the architect and virtual handshakes + one for those who moan about London Underground

    At the beginning of the week, the architects for the project that I am working on flew into town for an intensive week of meetings. Most of yesterday was spent shuttling back and forth between our offices and La Défense for meetings about the building’s structure. For me it was a great chance to get to know the project team before the video conferencing kicks off in ernest (despite Margaret Atwood’s invention that allows her to do book signings wherever she wants in the world from the comfort of her own home, it is still not possible to shake hands over the internet). For the moment there are still a number of questions to answer about the building’s facade but once those are answered there will be a rush to design the floor which, for the moment, is where my project is going to be focused. I therefore have the sense that we are in the calm before the storm.

    During a coffee break, I tried to strike up a non-engineering/architecture conversation with the architects. Struggling fora topic, I suddenly remembered that my favourite US online radio station, KCRW, is broadcast from the same town as their headquarters. They listen to my favourite show in their office on the otherside of the world, every morning. Doesn’t the internet make the world small?

    In other news, old calculations that I had made on the cost of another tower have come back to haunt me. It is not that they were wrong, it is just that I was suddenly required to present my results without any notice. I was therefore glad that I had left a decent paper trail so that I could quickly see how I came to the result two weeks ago. This is basically thanks to my new strategy: to date absolutely everything, to put the date in the name and print it in the header and to include a table of modifications for each time I use a calculation sheet. This may all seem obvious now but it wasn’t when I started off. I have since been asked to carry out a cost calculation on the tower that is the focus of my project. Since cost will be an important part of the choice of floor design, I will be able to tie the overall cost calculation into my project. And now that I have the method sorted, it hopefully shouldn’t take too long to calculate. The only trouble is… none of the floors are identical…

    + one for those who moan about London Underground – spare a thought for those who ride the L in Chicago – from a new blog find: Anonymous 1%

  • Pounds per square inch?? (project update)

    Today I started getting into the nitty gritty of how to stop a floor from vibrating. When dimensioning the floor slab of a building, one of the considerations is to check whether the natural frequency of the floor is in the same frequency range as that for footsteps. If the two frequencies do coincide the latter could resonate with the first causing the floor to shake.

    Today I have been looking at an American document that brings together the different ways of estimation this interaction. Most of the results are based on empirical evidence of what seems to work. This lack of rigour is fine with me, and is common in engineering. The thing which has really held me up is the units: all the calculations are in pounds, feet and inches! Could there be a more unhelpful system of measurement?

    Curious about this archaic standard, I started hunting around on Wikipdedia and found a wealth of information on the origins of both systems. Apparently, the only countries still to use imperial units of measurement are the USA, Liberia and Myanmar, although, I might add that here in the office my colleagues were surprised to here that in the UK we also use the metric system.

    I urge anyone who is similarly disposed towards the imperial system, to use this site to help them out.

  • Opening of the Cité national de l’architecture et du Patirmoine

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    Last night Lorenzo (a fellow engineer from work) and I blagged our way into the opening of the permanent exhibition at the newly refurbished Cité National de l’architecture et du patrimoine, France’s national architecture museum. Neither of us had thought to check if this was and invite only event and indeed, it was. Luckily, a few charming smiles and a couple invitations made themselves available from the large group loitering outside the front door and then we were in.

    The Cité is housed in one of the wings of the Palais de Chaillot, that splendidly curving art deco building opposite the Eiffel Tower on the other side of the Seine. Unlike any other architecture exhibit that I have visited, this one had not one model of a building. Instead, the main exhibition space, itself a long and wide curving corridor, was filled with fifty odd floor-to-ceiling screens onto which a series of short films were being projected. Every film was about a project, but every film had been shot differently: some showed in speeded-up time a building going up, others showed people flowing in and out, the building through the different seasons. There were images taken from satellites that showed whole areas being redeveloped. My favourite was a series of photos taken from a balcony, of an American city skyline. The photos start in the 60s and go on, lets say one a month until the present. As the images tick pass, the downtown skyscrapers grow like mushrooms after a rainstorm. One by one the pop up out of a hole in the ground, until eventually, one pops up right in front of the balcony and the view is completely obscured.

    It is not just buildings that are showcased. One video was taken from a car driving across the Milau Viaduct. Another, from a helicopter flying over an offshore wind farm.

    I think that the exhibition rather successfully shows the dynamic side to buildings. How they change, during their lifecycle, fro, construction, to use, to decay, to demolition and also how people interact with them. None of these aspects are static and so the moving image is an ideal medium for communicating them. My one criticism of the exhibit is that in the dark room where the videos are projected, it is difficult to read the programme that tells you what the projects are. Maybe you are just supposed to know already. I wonder?

    The free lemony champagne was worth the effort it was to get through crowds of people in order to see the exhibit. It is hardly surprising that on the opening night I saw a lot of architects and not a lot of architecture. I shall therefore definitely be making another visit before too long.

  • Metro Entrance Gare St.Lazare

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    The other morning I found myself in northwestern central Paris around the Gare St.Lazare. This is not my normal stomping ground, so I took the time to go and have a look at the striking curved-glass metro entrance that was built as for Paris’ newest metro line, the driverless 14.

    The architects and the engineers on the project were Arte Charpentier and RFR respectively.

    The glass has a double curvature: that is to say, like a dome or the saddle for a horse, the glass curves in two different directions. The lateral stability of the structure is assured by the fine metal cross-bracing that can be spanning diagonally across the frames. The frames are in stainless steel, a material that, thanks to its many different crystal faces, reflects light from many different aspects.

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    Unfortunately I didn’t have the time to have a closer look at how the various elements are joined, which is always the devil in projects such as this where transparency is the goal.

    You can see a slideshow of photos of the Gare St.Lazare station entrance from my engineering photo site by clicking here.

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  • Zen and the art of building maintenance

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    I am in the throws of reading Zen and the Art of Motorcycle Maintenance by Robert Persig. In my view it is a philosophical book that challenges the reader to find beauty in technology, in maths and in reason. I am no book reviewer, so I will only add that Persig uses the motorcycle as an analogy for different ways of thinking. In particular, he talks about the idea of an ‘intellectual knife’: the tool with which we slice up a problem into its components before we set about resolving it. So each evening on the metro, I have been reading about different ways a motorcycle can be divided up in order to explain its different functions, and it has struck me how similar this exercise is to what I am doing at work in order to calculate the cost of the cost of a skyscraper.

    One way to add up the cost is to start at the top left-hand corner, and work your way down to the bottom right-hand corner, counting up all the lumps of concrete and steel along the way. This method would be ideal for a bungalow but not for a high-rise as for starters it fails to take into the repetition in the structure. So the first use of the knife is to cut the building up into repeating chunks. Now in the case of this building, like the Gherkin, this building is curvy, so no two floors are identical. The knife is therefore used to cut the building up into chunks whose dimensions are broadly similar, so that mean values for these chunks can be used.

    Am I boring you yet? Then look at the photo. I put it in to spruce up what on the surface might otherwise be an apparently boring entry. It’s the view from my office (prizes for anyone who can spot the Eiffel tower). Refreshed? Right, lets carry on…

    So we have our broadly similar chunks of building: can’t we start counting? Well yes, but if you want to automate the process you have to put into Excel. I do want to automate it because this project is constantly changing and I want to quickly be able to modify the calculation. This is really where the headaches begin. So often have I marched into writing an Excel spreadsheet only to find that when I am waste-deep in it, it becomes very complicated, difficult to verify and impossible for anyone else to follow. This happened to me last week on this same project. I spent the weekend thinking that there must be a better way. Before I started again I set out the main things I wanted to achieve when doing the calculation again. It has to be easy to enter the data, easy to modify the data, easy to verify the results and easy for somebody else to follow.

    If there are any readers left, I want to illustrate the problems that these objectives can cause. I won’t go into how I solved them because whereas the objectives are general and can be applied to the automation of other engineering problems, the solution is specific, of less ‘interest’ to others, and I have that recorded in the form of the spreadsheet itself.

    Starting with entering the data, it is very well to count up all the similar columns but how can you be certain that they have all been counted. One answer is to create a big grid with all the stories, to cut and paste in all the similar elements and then to count them all up. Whilst this approach starts off very pleasing to look at, (I think this approach uses Excel well) it quickly becomes unwieldy. In order to simplify things, it is necessary to only put in the absolute minimum of information, putting the rest of the information perhaps on another sheet. The risk here is that the sheet quickly becomes difficult for someone else to follow. The other problem with hiding information elsewhere is that it also becomes difficult to modify quickly.

    One might conclude that ease of modification is at the cost of simplicity. However with careful application of the intellectual knife, I don’t necessarily think that this is so. Experience of this sort of calculation, something that I don’t have much of, would give an idea of which variables are more likely to vary and so which ones should be easier to change. For example it may be that the thickness of the core walls are much less likely to change than the thickness of the floor.

    Moving on from the depths of dullness and back towards a level of interest that might only correspond to vaguely dull, the one thing I haven’t talked about is how to check you got the right answer, because after all, that’s all that matters. Verifying my procedure and checking that it gives me a reasonable answer has taken me so long (most of the week in fact) that I wonder if using a computer has saved me any time (remember citizens that that is what computers are for…). Trying to unravel what a string of cell names in a formula actually means is the bane of my nascent working life! It doesn’t help that I have no sense of what the answer should be.

    That all changed yesterday when I spent the afternoon looking at the final cost add-up of another building designed by this company. By looking at what the price of the foundations was as a percentage of the total cost, say, I instantly had a ball park figure to head for. I then used this rubric to look for where my answers were way off par. Sure enough, where there were discrepancies, there were mistakes.

    It makes me wonder why bother doing any of this calculation afresh. The two match up so well that surely one could take the price of the first, modify for inflation, add a bit, and be done.

    To conclude, after a week of work on this calculation, I am happy with the result. I have gone into some detail about what I have done because for one thing, a great deal of reflection would quickly have been forgotten as soon as I move onto the next thing. I fear the hours that can be spent in front of computer screen with nothing to show for it. I hope that at the very least I will be able to apply what I have learnt here to the next problem, and more ambitiously that the fruits of my labour will be a rethink of the way that these problems are tackled, which strikes me, albeit as a novice, as inefficient.

    It seems entirely appropriate that ‘Zen and the Art of Motorcycle Maintenance’ has inspired me to think in depth about what I am doing. It is unfortunate for me however that motorcycles sound a lot more sexy than volumes of concrete and Excel spreadsheets. Thanks for reading.

  • Bending beams and counting the cost

    During these first few weeks of my placement I have been carrying out some fairly entry-level calculations on a forty-five storey tower. These follow on nicely from courses in concrete and steel design that I took during my first term at ENPC. However, while these courses were based on the new Eurocode regulations (currently being adopted in the U.K. and in France), the company I am working for is in a transition period during which it is using the new code for some projects and the old French code for others.

    During the first few days I therefore had to get my head round these older regulations that I had never seen before. In particular I was getting hung up on the issue of how much a beam should bend in service. While a bending beam may not necessarily break, it may cause temporary walls to crack and finishes to become damaged: hence the limits on how far a beam can deflect in everyday use. Both codes have similar limits for this deflection; the only difference is in how you calculate the deflection. The Eurocode is a lot more flexible (read vague) on how to perform this sort calculation than the French code. I spent a long time going into the detail of how to apply the French code and got quite confused. Everyone that I asked had their own way of doing it but no one seemed to have a definitive answer (this was not helped by the fact that those who do know are rushed off their feet). In the end, I found that these technicalities accounted for minor differences and I was able to move on. I remain unsatisfied however with my methodology.

    Once a methodology is established, calculations can be automated with Excel. Everyone has their own Excel sheets to speed things up. Or at least that is the idea. When the sheet is up and running, it is very easy to rattle off calculations, but getting it to work is the difficult part and I sometimes wonder whether the time taken verifying the code doesn’t add up to more than it would have taken to do the calculations by hand. It is also very difficult to follow your working in Excel, and even harder to follow someone else’s. The biggest challenge is making these automated calculations readable to others.

    As well as the program for dimensioning beams, I am now on the second version of a program that will work out an approximate cost for this tower. Something that started relatively simply has spiralled out of control, hence the second version. I hope to be able to report progress tomorrow!

  • The end of bridges and the beginning of projects

    After seven and a half years, I had my final exam as an undergraduate last Friday.  As final exams go, it counted for a minute part of my degree – a far cry from my chemistry finals five years ago.  Assessment at ENPC is continuous with marked courseworks and the occasional test.  The “Conceptions Parasismiques” exam last week was only significant because it was my last engagement at the Ecole des Ponts, for tomorrow, I start my placement in a French company.

    At this point it would be helpful to mention how I would be finishing my degree if I were back in the UK.  In their final year, students at Imperial are expected to take on a full course-load of lectures and tutorials and at the same time, to conduct independent research that is to be written up at the end of the year, somehow in the middle of revising for final exams.  In contrast, the system at Les Ponts, which I might add is a system which seems to be typical among other European engineering courses that I have heard about, requires that its students undertake a “projet de fin d’études”.  Rather than being conducted in parallel with studies at the university, the PFE takes place in a company or a laboratory.  In either case, the student is offered a placement during which they can undertake research at the same time as being involved with the day-to-day work of that enterprise.  The placement is also paid, albeit at minimum wage level.  Final year students are close to being qualified and so should know their stuff.  This system offers them the chance to experience the work environment and also offers cheap labour to the companies involved.

    Getting a placement is something of a magic art, and the following words are intended for the eight or so Imperial students coming to ENPC next year.  What is not entirely clear with the PFE is whether it is the students who should be approaching companies with ideas for a project or whether students should be contacting the companies and asking them what they have on offer.  One thing is for certain: if you tell an engineering company in France that you are from the Ecole des Ponts et Chaussées and you are looking for a PFE, they know what you are talking about.

    In order to get my first experience of the professional world, and of speaking French proper like, I went to an event back in November called the Forum Trium, a careers fair where engineering companies and financial firms battle it out to solicit the interest of students from one of a number of grandes écoles in Paris.  I turned up with the worst CV in the world, officially, and proceeded to distribute copies of it evenly across the hall.  Most employers were looking for people interested graduate jobs, but my name was noted nonetheless.

    I left the event no closer to finding a project.  Term plodded on and the PFE slipped down my list of priorities until just before Christmas, when I found that a fair chunk of my French friends had found placements, and what’s more, they were going to be working on topics that not only interested me, but were with companies I would have dearly liked to have had a place with.  I was no closer, however, to understanding how this application process should work.  By the time term started in the New Year, I had landed on the idea of investigating the ways in which the carbon footprint of a building can be measured (more about this in the future).  The project would have taken place at the local building research institute near Les Ponts.  The whole project was conceived over a series of coffees with a couple of members of staff from the department.  I was all set to accept when I received a phone call from a director of Setec TPI who invited me to an interview.  It seemed that one of my awful CVs from the Forum Trium had made it onto his desk.  He was looking for an English speaking engineering to join a team working in collaboration with an American architect on a new skyscraper at La Défense.  Unshaven, I turned up that afternoon for the interview and was offered the place.  In the space of a week I had gone from having nothing to having a choice of placements.

    In the end I chose Setec.  My project there will be an investigation into the role of skyscraper floor design in the overall stability of the building, both during construction and in service.  But I didn’t choose this placement for the topic; rather I chose it for the experience of working in a French engineering office environment, and the opportunity to work on one of Paris’ most prestigious projects.  If the last four months of study have been good for my French, I am hoping that this placement is going to do wonders.

    In conclusion then, what would I recommend to next year’s students when it comes to looking for a placement?  Well, I would definitely advise going to the Forum Trium and introducing yourself to as many companies as you can.  Since I accepted my offer at Setec I have been offered two more placements (including one with SNCF that would have given me free TGV travel for the rest of the year!!) and both of these directly from the Forum.  My other piece of advice is not to be scared to approach companies yourself and say, what project could you offer me.  They expect to get calls from people like you, so you may as well get in where you want to before everyone else does.  The chances are that the early you get involved, the more likely you are to get to choose a project that really interests you.

  • Womb with a view

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    Paris is slowly encircling itself in tramways. The latest tramway to open, connecting the disparate ends of several metro lines is the T3, which skirts inner Paris’ southern border. As part of the project, the RATP commissioned a series of art installations on or in the vicinity of the route. So it was with travel card in hand that I went, albeit a little too late, one Saturday afternoon, to see what I could see, so to speak.

    The trip became somewhat of an art-hunt for all I had to help me was a cutting from a newspaper giving some approximate locations, and a metro map. Unfortunately, I was not able to experience the murmuring benches as the park they were in had shut. And I simply couldn’t find the installation called “Mirage” (even though Mary swears blind that she did). One of the best installations, in my opinion, was realised using just light. Where the tramway passes under the TGV lines coming out of Montparnasse, the bridge’s beams and columns are lit up in orange and blue at night time reclaiming an otherwise threatening space (and showing off the beautiful metalwork on the columns which must have been lost in darkness even during the day).

    The tour finished with a sculpture on the middle of the bridge. This installation is by Sophie Calle and Frank Gehry (with RFR as engineers) and consists of a twisted metal alcove or shelter with a telephone inside. According to a sign inside, only Sophie Calle has the number and she occasionally calls the number and to talk with whoever maybe passing by. The sculpture is a a shelter from the wind, a womb high up over the river, isolated, yet connected. If you have a few hours to spare in the south of Paris, I recommend taking the time to take the tram.

  • American bridges number 1

    There’s one thing that they do particularly well at the Ecole des Ponts et Chaussées (School of bridges and roads), and that is teaching how to build bridges and roads. I had my last lecture today in a course called construction métallique. It has been one of the hardest courses I have taken here but has also been one of the most enjoyable. As well as covering all the theory of how metal structures ‘work’ we have also looked at a range of specific examples, including the Stade de France, the pyramid at the Louvre and the Milau Viaduct. Today’s final class was given by an expert on metallic bridge construction and he had the following to say about America’s brutal motorway bridge design.

    In France they keep it simple: put two metal beams across and then fill the gap between the two beams with a concrete deck. I say simple because it is very easy to work out how strong each beam needs to be, and that, after all, is what we engineers are paid for, right? In the USA however, things are not quite so straight forward. Famously low budgets for construction have lead to the use of lower quality materials and so there is a greater chance these bridge beams could fail. Each state has it’s own set of rules (which must make for nightmares when trying to build an interstate highway) but in all states, they are so worried about the strength of their beams that instead of allowing just two, they require five.

    When I was living in the States, I noticed how brutal the motorway architecture could be. And now I think I know why. It is very difficult to make five enormous steel beams under a bridge look elegant. There is also no architectural budget, so all you get is the bare minimum. This five beam system also makes it very difficult for the engineer to work out what is going on. For reasons that I won’t go into here, when you have five beams under a bridge, it is complicated to calculate which is supporting the car and which is sitting there looking ugly. The ultimate irony is that if they spent a little more on materials, they would of higher quality and so they could use much less.

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    A ‘brutal’ New Jersey bridge across an esturary close to New York

  • Meet Mr Alphand

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    When Haussmann was busy tearing down and rebuilding large swathes of Paris, he wasn’t doing it all by  himself.  His chief engineer was this fellow, M Alphand.  In this portrait by Alfred Roll, he is standing on the building site of the Petit Palais in 1888.  Appropriately, it is now hanging in pride of place in the Petit Palais.  As far as our history of art lecturer is aware, it is in the only portrait of an engineer in Paris.

    The Petit Palais is an interesting place, although not as immediately so from a structural point of view as its glass-domed big brother opposite, the Grand Palais.   This mock classical building has frescoes on its ceiling that, first time round, failed to draw my attention.  On a second lap however, I was invited to take a closer look at these paintings.  Sure, there were the cherubs floating around, but the clouds in which they were flying were not in fact clouds, but smoke rising from factories in one corner, and a steam train in the other.  Progress!

  • The International Tunnel of Tangiers

    This afternoon’s lecture on earthquake engineering was a struggle. The mountains of photocopies that we were given didn’t really match up with what the lecturer was saying, which had the effect of further lowering Friday afternoon lecture attentiveness. I was however paying attention when the expert before us showed us a map of Europe showing the magnitudes and location of the major earthquakes that have hit the Mediterannean region. The largest seismic event shown I seem to remember wiped Lisbon off the map in during the 1700s. A line of seismic events can be drawn from the mid Atlantic, through the Straits of Gibraltar, joining the dots all the way to Naples, neatly following the southern edge of the Eurasain tectonic plate. When there is an erathquake Eurasia and Africa move relative to one another along this fault line.

    So why am I giving you this geography lesson? Well I have just read in the ICE newsletter that a company has made a bid to build a tunnel under the Straits of Gibraltar (http://www.ice.org.uk/knowledge/spec_news.asp?ARTICLE_ID=1622). At 44km it will be longer than the Channel Tunnel. What’s more, the depth of the tunnel ( the Channel Tunnel is relatively shallow at only 50 odd metres below sealevel ) and the fact that the tunnel will have to pass through several different types of soil make the project barely feasible.

    But there is no mention of what steps are going to be taken to make the tunnel earthquake proof. What is going to happen when the bit of the tunnel in the Eurasian plate moves one metre up down left or right relative to the African plate? As far as I am aware, tunnels aren’t like buses; they don’t come in ‘bendy’. (http://www.tfl.gov.uk/tfl/press-centre/image-gallery/gallery.asp)

    Finally I would like to know what the tunnel is going to be called. I think that the Gibraltar Strait Tunnel – or even the Gibraltar Bendy Tunnel (geddit?) is unfeasible because it contains the word Gibraltar and so I am sure it will kick of a squabble between the British and Spanish governments. The Algerceras tunnel is a no go because no one outside of Spain will be able to pronounce Algerceras. Which leaves the only other option. The International Tunnel of Tangiers. It is catchy and whats more, it reclaims Tagniers’ former standing as an international city. Unfortunately I don’t think my name is going to stick as it I think it will be a long time before a tunnel linking ‘North’ and ‘South’ is named after a place in Africa.

  • How to be dam safe

    0303-glen-canyon-dam-pan12.jpg
    Glen Canyon Dam, as featured in the popular film «Superman»

    When designing, building and operating a dam, there are a few steps that ought to be followed in order to avoid large loss of life. Here are a few that I picked up at my first lecture in a series with the title that I have badly translated as “Conception of risky structures”:

    1) Pay your workers well. The most dangerous period during the lifetime of a dam spans its construction, the filling of the reservoir and the first year of full service. Going on strike over pay during the construction is dangerous because the dam might not be ready for the winter’s flood waters and subsequently may get washed away.

    2) When checking for cracks in the bedrock on to which the dam is to be founded, looking at 50 metre intervals is not good enough. A dam in Wako, Texas collapsed when a section of the bedrock between two cracks about 49 metres apart gave way.

    3) If cracks have been found in the ground, it is unwise to leave them unfilled just because your client refused to give you any extra money to pay for this unforseen cost. To do so has led to death and destruction.

    4) If you are satisfied with the conclusions of your ground survey that there are no cracks in the ground under your dam, don’t then move your dam a few metres downstream to make your lake a bit bigger without doing a new survey. Doh.

    5) If when building, say, a 280m high dam in Italy, you notice that the mountain into which your dam has been founded has started moving(!) at a rate of several centimetres a day, don’t just carry on filling the dam and hope for the best. (In this case though the dam didn’t collapse, the mountain on one side of the lake gave way and a terrific landslide almost filled the lake that had been created, generating an enormous wave which swept over the dam and destroyed villages down-stream)

    6) Finally, if your dam once built is not a profitable venture, don’t succumb to the temptation to sell it to a group of anglers. They may use it for stocking fish. This in itself is no problem. The problems arise in the rainy season when they may lose a significant portion of their fish down the overflow pipe. To prevent this loss, they may put a gauze over the pipe to keep the fish in, but which will also unwittingly get blocked with the leaves and branches which usually accompany storm waters, forcing the flood waters over the top, destroying the dam and killing 2000 people in the town below.

    These six tips are from real examples of fatal dam failures.

    When designing a dam, don’t just be safe, be dam safe.

    282-over-the-hoover-dam2.jpg

    Rose leaning over the Hoover Dam during our visit in March 2003

  • It is nearly always a lovely day in Architecture world

    This quote is from Jonathan Glancey in today’s G2:
    “It is nearly always a lovely day in Architecture World. Happy, shiny, gym-fit young people living today’s latte-fuelled urban 24-hour lifestyle, stride through sparkling, quango-approved “regeneration” utopias. In these illustrations it never rains. The wind never blows. Snow is an alien concept.” Lamenting the fact that so many architectural renderings of future developments look blandly sunny, he rightly points out that many drawings are done with the same standard bits of software so every scheme looks much of a muchness.

    Structural engineers on the other hand could do with a little more sunny weather. While the architects are worrying about what the building will look like in the sunshine, engineers are more bothered about whether it will stand up in the wind. Those who are (un)lucky enough not to know about these things may like to know that a significant portion of a building’s structure is there to stop it falling over in the wind. And once the wind is catered for, the weight of a dusting of snow on the roof – by no means insignificant – has to be accomodated. And of course there is rain water to look out for, collecting under joints in steel and causing rust in hidden places, getting into cracks in the concrete and coroding the rebar or just making stuff rot. When all this is said, I quite like the sound of Architecture World.

    On the subject of gym-fit people walking through these shiny utopias, I am often interested by the care that goes into choosing the people that architects put into their drawings. The people in a landscape drawing I was working from for a gallery were wearing the most skin-tight jeans (These architects were obviously certain that this project would be finished before next year by which time drain pipes will habe bewly returned to fashion’s gutter). I can imagine the meetings where architects sit around a table and work out how the people in their drawings can best represent the desing ethos of the company. I imagine Richard Rogers (Pompidou centre and Lloyds of London) proposing that the people they use have all their veins and digestive systems on the outside! On a more serious note, I do know of a project where the architects were asked by the client to remove two people from their drawings because they looked too homosexual. Doesn’t sound all that utopian to me.

  • Wilkinson Ire – Successful Expedition

    It is with great pride that I report that Expedition Engineering won Thursday’s cricket match against Wilkinson Eire architects.  In a game between two teams each with a fair spread of novices and more skilled players, the tension was maintained right until the last ball of the final over.  Expedition won by two runs.

    I have to confess that despite my great improvement at the nets, my bowling was a little dismal.  When I batted I was in with Chris Wise, and we finished the batting with the pair of us not out.  Although I didn’t quite score any runs by hitting the ball, there was a no ball called when I was at the wicket – maybe my ugly mug put the bowler off and made him send the ball wide, giving us the two points that we wouldn’t have won without, I am sure!

    Though my placement with Expedition is short (too short with ever clearer hindsight – funny how with age your eye sight diminishes but your hindsight becomes sharper), there is a chance that there will be another match before I leave for France.  Next time i hope to actually score a run.  That would be a real improvement!

    It is great to be playing sport.  I forfitted that day’s gym session because I knew I would be getting some excercise at the game.  Though quite what the net benefit was, considering the beers and chips on the company tab afterwards, I am not so certain.

  • Pont Simone de Beauvoir

    My thanks go to Mary for finding this article in the Sunday Independent on Paris’ newest bridge, Le Pont Simone de Beauvoir:  http://www.sundayindependent.co.za/index.php?fArticleId=3340477

    I am fond of this bridge – not a word I would ever use for a person but entirely appropriate for a graceful structure such as this.  Last February I lead a group of 80 students on a three day tour of Paris’ engineering sites.  This is no news to most readers of this blog as I suspect that most of you were on the trip.  For the benefit of those that weren’t, the weekend was packed with an ambitious itinerary of Paris’ engineering and architectural attractions.  For me, the highlight was this bridge.

     Reading this article, I am sad, although not unsurprised, to see that the structural engineers on this project – Paris based RFR (www.rfr.fr) – are not once mentioned.  I struggle to think of a construction project where architects have been involved and not engineers.  Even the models at the end of year show at the Architect’s Association (www.aaschool.ac.uk)  this year had to be checked over by a structural engineer to make sure they were safe. 

    When it comes to bridge design, I believe there is an important part to be played by architects but that the design should be lead by the engineering.  When it comes to buildings, the engineering – the stuff what makes it stand up and not fall over when the wind blows – can be hidden away, like in the Ritz (London’s first steel-framed building) or on display for all to see like at the Pompidou centre.  With bridges however, there is no hiding the engineering.  The structural design is the language of the bridge from which all other things follow.  It’s very hard to hide it.

    I am sure that your comments will help me clarify my stance on this matter so I shall leave it there for the moment.  There is more to say however on this bridge.  Firstly, its structure should really referred to as a lenticular truss.  Thinking of it as an arch bridge supported by a suspension bridge is helpful.  Anyone who had just read that article might think that the bridge’s width was purely architectural.  It should be noted however that such a long-spanned bridge is susceptable to fluttering in the wind.  The bridge’s width helps to stabilise it from these wind induced oscillations. 

     Secondly, the bridge was not technically built in Paris, but rather on the banks of the Rhine in Germany.  The enormous central span of the bridge was constructed at a German steel fabricator, and then loaded onto two enormous barges, floated up the Rhine, along the North Sea Coast down to Le Havre, under the Pont du Normandie (my favourite bridge http://www.carte-postale.com/honfleur/pontdenormandie.htm) and up the Seine to Paris where low tide had to be waited for to get the enormous section under Paris’ low arch bridges.  The whole journey can be seen on the website of the guy who lead the strucutal desgin on the project, Henry Bardsley (http://www.henry-bardsley.com/).

    Though it has been open for a few months now, I have yet to make a crossing.  I am sure that when I do, readers of this blog will be the first to know.

  • Engineers vs Architects – it’s just not cricket

    I am forever bored of engineer vs architect debates.  They are just not cricket.  That is unless they are about cricket.  Tomorrow I will make my cricketing debut with Expedition Engineering (www.expedition-engineering.com), the company with which I am in the middle of a four week placement.  We will be playing against a team from Wilkinson Eyre architects (who were the architects on the Gateshead Millenium Bridge www.wilkinsoneyre.com). 

    This will be Expedition’s third match of the season.  Last night the team went down to the cricket nets at Paddington Rec.  The great thing about cricket nets are that they funnel the ball towards the wicket.  Given my bowling looks more akin to a throw one might use when lobbing a grenade (a technique I picked up during my extensive army training) – that is, up and over and not long and straight – I was grateful to the nets for guiding my ball towards the wicket.  As the session wore on however, I found I no-longer needed the nets, and the ball found its way close to the wicket of its own accord.  I say close becuase I never actually hit the wicket.  The batsman always gets in the way.

     Then it was time to bat.  A cricket ball is undeniably hard.  A ball deflected from my bat hit the roof frame and landed hard on my head – the noise was not unlike a walnut being cracked open.   I use a defensive stroke.  That is, if the ball is coming anywhere near me I intend to wallop it to minimise the chances of it hitting me.  If I can however, I just prefer to jump out of the way.  The problem is that this in turn leaves my wickets wide open.  I intend therefore to use a combination of the two techinques tomorrow.  I will jump out of the way while vaguely leave the bat infront of the wicket in the hope that it might protect my bales, so to speak.

     I have to say that my technique is not in line with the rest of the team.  It is a fifteen over match and we are gunning for a score of 100.  (Since I currently have no readers on this blog, I am confident that I am not giving away our tactics to the Architects!)  Work will be on the back-burner today.  Strategies needed to be plotted, and maybe even plotted out using AutoCad.

    Stay tuned to find the latest.  Unfortunately, this blog won’t allow me to provide readers with a constantly updating score board for your computers.  Sorry about that.