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Texas floods
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 Texas floodswww.bbc.com I recall when I was 'Engineer - Regulatory' at Blacktown city Council, one of my jobs was to assess proposed developments for flood risk. I recall one development that was specifically intended for seniors; that designation allowed some benefits in terms of floor space ratios, so it was popular with developers. But this development was in a flood path. The calculated depth and velocity of water through the site exceeded what was considered 'acceptable' even for able-bodied residents, and would be even more dangerous for seniors. I recommended against approval. The developer asked for a meeting with the Town Planner. I was asked along. The developer raised several arguments, all of them special pleading rather than based on engineering and safety. At one point he simply said that strict compliance can't be achieved, so his proposal should be approved despite 'a minor non-compliance'. That was when I replied "We can't do it safely, so we have to do it some other way!" You might be surprised (or you might not!) to hear that I was later censured for that 'unprofessional' comment. |
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Bob Can you provide me with a few of their email addresses, ole boy? |
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Mo I had a bit of a habit of refusing to approve unsafe design 'solurtions'. The first was when I was designing cable tunnels for a power station. These were typically around 2 metres wide and from two to five metres in headroom, and often both sides were stacked with cable trays except at opening or junctions. A fire in one of those would produce thick, black, acrid, poisonous smoke. Combined with lighting being lost. Policy was to place stair wells at no more than forty metre spaces. These would be easily detectable in the dark by someone crawling along the floor to stay beneath the smoke layer. Not only the gap in the side wall would show its location, but the light coming down the open stairwell would also indicate where the nearest stairwell was. There were stretches in this power station where that would have required some re-arangement of equipment or re-routing of the cable tunnels, at significant expense. So I was told that a swing ladder with a pop-open hatch above would suffice. I refused. First, because the lack of light down the stairwell would not be there to show a person which way was their escape route; secondly, someone crawling along the floor in the dark wouldn't be able to feel for the gap in the side wall so he wouldn't know where it was, so he would miss it; thirdly because even if he knew where it was (for example, by a patterned floor), he would need to stand up into the smoke to pull the ladder down, using considerable strength while breathing heavily from both exertion and panic; fourthly because the space above where this was needed was where a vehicle would often be parked, stopping the pop-up from opening. For some reason this job was transferred to another engineer to design. |
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jonheck 15-Jul-25, 00:47 |
bob |
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Bob Sounds cheap enough to me, bob, but a few ropes would be cheaper and a flashlight might help if it could penetrate the the smoke before one passed out. The site could even make money by gouging the people for flashlights --- something like flashlight dispensing candy machines that only take a $100.00 bill for a piece of junk, huh? Ya need to think out of the box more, Mate. |
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Mo 15:30 I had a couple of problems with that particular supervisor back when I was a design engineer in my late twenties. Those cable tunnels had always been designed as a pair or retaining walls with the floor as a common base. This allowed cables to be fed in from above instead of pulled through with a winch. This also meant that the walls had to resist the ground pressure and heavy vehicle loads on both sides, so they had to be very strong. I had also seen during my time on site building a previous station that these open cable tunnels caused a great deal of inconvenience by making access through the site more difficult for cranes, cement trucks and delivery of the huge steel sections required for the boiler house. That was for cable tunnels up to three metres deep. The tunnels on this new station were more than 5 metres deep, and the bending moment at the base of a cantilever goes up by the cube of the depth, so these would need to be enormously strong. So I DID think outside the box. I started designing these tunnels as complete box sections, with the roof in place as part of the original construction. This not only braced the tops of the walls apart, but also allowed the roof slab to provide effective stiffening of the top of the walls against surface point loads such as cranes and heavy vehicles nearby. And with this small but stronger roof, vehicles could pass over the tunnels instead of having to go around or need temporary bridges. The down side was that the cables would need to be fed trough by winch rather than laid in from above. But I knew that the cable-layers were accustomed to winching anyway, and it was not much more difficult for them if they knew that had to plan for it from the beginning. It also allowed standardisation of many components such as formwork, and reinforcement was also made lighter so that even in the deepest tunnels the same bars and bends could be used, just varying the spacing as required to meet the load. Also, I didn't just design each section individually, but produced charts for the draftsmen so they could read off depth and that would show them what reinforcement size and spacing was required. Simpler for them, easier for me to check and approve, and easier for the construction crews to lay out the reinforcement correctly if they had only two sizes of bars (16mm and 28 mm are not difficult to tell apart and spacing is easy to measure!). This new approach effectively halved the cost of the tunnels, as well as making construction more convenient. But golly did I get a blast when the boss first saw something so 'simple-minded' compared to previous practice! He came around to accepting it when the guys in the Construction section approved of it, but in one way that only made it worse. He didn't like that he had made himself look foolish. Perhaps that was another reason why I was taken off this job. After that came the basement to the Electrical Services Centre! Similar story, where I didn't just scale up the 'traditional' approach for the same 'cube-of-depth' reasons, but chose a radically different paradigm. Finally, he hauled me into a 'Disciplinary Interview' over some sick leave, complete with a guy from HR there to let me know my employment was at risk. The lesson is that safe design is good design; you just gotta think! |
