Guest bri.s Posted April 23, 2016 Share Posted April 23, 2016 Jut saw this on a media site and wondered ,does this really happen and if so how often and why http://img.ifcdn.com/images/544e2a2be84ee9fa39dcb4a48827117cff4981e594ab5a9faa8436895d1f1ef1_1.gif Brian Link to post Share on other sites More sharing options...
Andy Y Posted April 25, 2016 Share Posted April 25, 2016 It was a controlled test to monitor what happens when a vacuum is created inside a tank wagon. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted April 25, 2016 RMweb Gold Share Posted April 25, 2016 Somehow I don't think this one I photted at Pecos, Texas in Sept 2004 was actually controlled! Link to post Share on other sites More sharing options...
RMweb Premium Andy Hayter Posted April 25, 2016 RMweb Premium Share Posted April 25, 2016 Yes this sort of thing does happen although I have never seen it happen to a rail tanker before - which is not to say that it cannot happen. Typically you start to pump out a tank (or rail tank wagon). There should be a mechanism to allow gas (often nitrogen when handling flammable materials) into the tank so that the pressure remains at normal atmospheric pressure. If that mechanism does not work (someone forgot to open a valve), and if the pump has enough umpff to keep emptying the tank then a vacuum is formed in the tank and the result is as you have seen - sudden and catastrophic implosion. Link to post Share on other sites More sharing options...
RMweb Gold unravelled Posted April 25, 2016 RMweb Gold Share Posted April 25, 2016 There was a final series Mythbusters episode attempting to replicate this. A bit long winded, and they only got collapse after trying with a dented tanker. Videos at: http://www.discovery.com/tv-shows/mythbusters/videos/tanker-crush-videos/ Dave Link to post Share on other sites More sharing options...
Guest bri.s Posted April 25, 2016 Share Posted April 25, 2016 Interesting stuff guy thanks , I've seen another not railway but saw this the other day http://youtu.be/ETdsuvi91VQ Thanks Brian Link to post Share on other sites More sharing options...
Fat Controller Posted April 25, 2016 Share Posted April 25, 2016 We used to live in Penkhull, Stoke, overlooking what was then the Marcroft works. At the time (late 1970s), a large part of the work they carried out was overhauls and repairs on all sorts of tanks. Whilst we'd quite often see examples where something had hit the tank and dented it, I can only think of perhaps one example of an 'imploded' tank. Link to post Share on other sites More sharing options...
Broadway Clive Posted April 25, 2016 Share Posted April 25, 2016 In "Oil on the Rails" by Alan Coppin, whilst describing how the 1927 14 ton RCH spec wagon discharged via a bottom outlet stool he mentions how forgetting to open the cap could cause a partial vacuum to cause barrel plates to buckle. He was told that an unofficial repair method was to use hydraulic pressure to reflate it! Link to post Share on other sites More sharing options...
Austrag Posted April 25, 2016 Share Posted April 25, 2016 It is quite easy to do with oil tanks. I saw one at a RAF station in Germany where the loco delivered a few tanks of oil, the storeman forgot to release the upper valve lid and gravity did the rest when the lower valve was opened. Red faces and a big bill was the order of the day. Link to post Share on other sites More sharing options...
RMweb Gold Joseph_Pestell Posted April 26, 2016 RMweb Gold Share Posted April 26, 2016 Happens not infrequently in the wine industry too as we use quite lightweight steel tanks. Link to post Share on other sites More sharing options...
Mark Saunders Posted April 27, 2016 Share Posted April 27, 2016 The same can happen wth covered hoppers the opening of the doors can cause a sudden vacuume and the lid implodes! I believe some of the GBRf biomass hoppers had a similar problem when discharged with the lid closed! The HEA's when converted to CEA's had anti vacuume slots put in the ends in a similer way to the salt PGA's had a pipe added! Mark Saunders Link to post Share on other sites More sharing options...
Jenny Emily Posted April 28, 2016 Share Posted April 28, 2016 Wasn't there a tank wagon dumped at Cadishead in the 1980s that had imploded in this way? Link to post Share on other sites More sharing options...
RMweb Premium Northroader Posted April 28, 2016 RMweb Premium Share Posted April 28, 2016 I've seen it done at Aberthaw power station around the 1970s. A bogie oil tank was being emptied, and the staff didn't open the top lid before they started. It collapsed in much the same way as the one in the American picture, but no, it wasn't blown back out again! Link to post Share on other sites More sharing options...
RMweb Gold Happy Hippo Posted April 28, 2016 RMweb Gold Share Posted April 28, 2016 One used to (still can) be able to use vacuum to refill boilers of the externally fired pot variety. At the end of the run blow out the fire and everything started to cool down, this created a vacuum in the boiler. Opening the boiler level plug, and connecting it's drain pipe to a water supply, would draw water into the boiler, and re fill ready for the next jaunt around the garden, without resorting to re filling by removing the safety valve and using an old teapot or similar. Of course, if one forgot to close the regulator at the end of a run, the vacuum would be equally adept as sucking the contents of the displacement lubricator back through the regulator. This would then coat the inside of the boiler with unused steam oil and the rather messy condensate from the bottom of the lubricator. Link to post Share on other sites More sharing options...
w124bob Posted May 4, 2016 Share Posted May 4, 2016 Somehow I don't think this one I photted at Pecos, Texas in Sept 2004 was actually controlled! Texas so it might just have melted a bit! Link to post Share on other sites More sharing options...
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