RMweb Gold Metr0Land Posted October 1, 2015 RMweb Gold Share Posted October 1, 2015 Just curious. Given that trainloads of cars are passing through many times a day with tanks full of petrol, why is LPG deemed to be so dangerous? Link to post Share on other sites More sharing options...
RMweb Premium phil-b259 Posted October 1, 2015 RMweb Premium Share Posted October 1, 2015 LPG is far more explosive than petrol vapour and as such the consequences of a leak would be far worse. Thus the stuff is banned from the tunnel while petrol is not - although obviously there is the fact that given most motor vehicles use Petrol or diesel, banning petrol powered vehicles would have significant implications fir revenues. Link to post Share on other sites More sharing options...
RMweb Gold Worsdell forever Posted October 1, 2015 RMweb Gold Share Posted October 1, 2015 It's heavier than air so would sit in the bottom of the tunnel and when the opportunity comes along it will go bang. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted October 1, 2015 Author RMweb Gold Share Posted October 1, 2015 Thanks guys Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted October 1, 2015 RMweb Premium Share Posted October 1, 2015 Interesting, there is no such restriction on LPG powered vehicles on the two pairs of tunnels in Melbourne. There is restriction on trucks carrying 'placarded' loads, which means chemicals of various types (as per the emergency services procedure placard), including LPG tankers. LPG powered vehicles do carry additional red stickers marked 'LPG', which are affixed to the registration plates, front & rear, so that emergency services can easily identify such fitted vehicles. The idea presumably, so that they can invoke different procedures as required. I do remember a volunteer fireman telling me, that generally LPG vehicles are considered safer, because the construction of the cylinder is much stronger than that of a petrol tank, which is much thinner. I assumed he was correct. Edit to add photo. Link to post Share on other sites More sharing options...
RMweb Premium phil-b259 Posted October 1, 2015 RMweb Premium Share Posted October 1, 2015 Interesting, there is no such restriction on LPG powered vehicles on the two pairs of tunnels in Melbourne. There is restriction on trucks carrying 'placarded' loads, which means chemicals of various types (as per the emergency services procedure placard), including LPG tankers. LPG powered vehicles do carry additional red stickers marked 'LPG', which are affixed to the registration plates, front & rear, so that emergency services can easily identify such fitted vehicles. The idea presumably, so that they can invoke different procedures as required. I do remember a volunteer fireman telling me, that generally LPG vehicles are considered safer, because the construction of the cylinder is much stronger than that of a petrol tank, which is much thinner. I assumed he was correct. How long are the tunnels - because that may have an impact on what is or is not allowed. In the UK I believe LPG powered vehicles are permitted to go through the Dartford tunnel while in mainland Europe I believe they are banned from some Alpine ones. (The channel tunnel is 26 miles long IIRC) However what you say regarding the strength of the tanks is true - and that has been precisely why LPG vehicles are permitted through Dartford Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 1, 2015 RMweb Gold Share Posted October 1, 2015 Simple point - don't forget that the Channel Tunnel restrictions owe a considerable amount to the legislation which was written very much with the possibility of terrorism taken into account. Hence numerous trestrictions and security implications which are not exactly paralleled elsewhere. Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted October 1, 2015 RMweb Premium Share Posted October 1, 2015 How long are the tunnels - because that may have an impact on what is or is not allowed. In the UK I believe LPG powered vehicles are permitted to go through the Dartford tunnel while in mainland Europe I believe they are banned from some Alpine ones. (The channel tunnel is 26 miles long IIRC) However what you say regarding the strength of the tanks is true - and that has been precisely why LPG vehicles are permitted through Dartford The 2 Eastlink tunnels are 1.6km (1 mile) & the Domain tunnel is also 1.6km, with the Burnley tunnel being 3.4km (2.1 miles). Link to post Share on other sites More sharing options...
Southernman46 Posted October 1, 2015 Share Posted October 1, 2015 Look up "BLEVE" on google and you'll have your answer ....................... Link to post Share on other sites More sharing options...
Fat Controller Posted October 1, 2015 Share Posted October 1, 2015 Simple point - don't forget that the Channel Tunnel restrictions owe a considerable amount to the legislation which was written very much with the possibility of terrorism taken into account. Hence numerous trestrictions and security implications which are not exactly paralleled elsewhere. Also, the design, and its implementation, involved a great deal of input from the Fire Service and others, to a much greater degree than in other major infrastructure projects. Link to post Share on other sites More sharing options...
Kickstart Posted October 1, 2015 Share Posted October 1, 2015 Hi I worked in Belgium for a while, and while they have a lot of underground car parks most appear to have signs banning lpg power cars from them All the best K Link to post Share on other sites More sharing options...
hammy Posted October 1, 2015 Share Posted October 1, 2015 I work with lpg being a gas fitter hate the stuff it has a wider explosive range than natural gas (gas to air ratio) NG being off the top of my head 15 to 30% gas to air. It ignites at a lower temperature than NG so not so much of a spark required. Burners way hotter than NG is heavier than air so will sink where as NG rises (fun fact if lpg leaks into a basement you can scoop along the ground with a bucket to catch the gas and take it outside being heavier than air it won't escape the bucket) It also seems to eat seals on boilers quicker than NG on glowworms the main burner seal needs changing every 5 years even though 9/10 they are not 'blowing' but on an lpg boiler normally 5 years 8/10 they are blowing Link to post Share on other sites More sharing options...
RMweb Premium PhilJ W Posted October 1, 2015 RMweb Premium Share Posted October 1, 2015 It always seemed strange to me that when they ran car carrying trains through the Severn tunnel they insisted on the petrol tanks being emptied. An empty petrol tank contains a volatile vapour making it more dangerous than a full one. Link to post Share on other sites More sharing options...
DavidB-AU Posted October 2, 2015 Share Posted October 2, 2015 Look up "BLEVE" on google and you'll have your answer ....................... Any flammable liquid can cause a BLEVE. It's not unique to LPG. The 1960 Cheapside Street explosion in Glasgow was a BLEVE of whisky and rum. Cheers David Link to post Share on other sites More sharing options...
DavidB-AU Posted October 2, 2015 Share Posted October 2, 2015 To be honest the rules are ludicrous. You can take a caravan or camper van with a fixed gas cylinder up to 93 litres through the tunnel, but can't take a car with a 60 litre LPG tank. There is no restriction on LPG cars in the Gotthard or Mont Blanc tunnels, although in MB you have to declare this at the toll point and you get an extra label for the windscreen. Entire trainloads of LPG go through the Gotthard rail tunnel. Cheers David Link to post Share on other sites More sharing options...
RMweb Gold Oldddudders Posted October 2, 2015 RMweb Gold Share Posted October 2, 2015 Plenty of road tunnels in France seem to exclude LPG vehicles. I suspect unfamiliarity. Once/if LPG becomes more commonplace then rules will be relaxed. OTOH if you know there are restrictions, does it stop you considering LPG as an option for your vehicle? Link to post Share on other sites More sharing options...
DavidB-AU Posted October 2, 2015 Share Posted October 2, 2015 Plenty of road tunnels in France seem to exclude LPG vehicles. I suspect unfamiliarity. Once/if LPG becomes more commonplace then rules will be relaxed. I find the unfamiliarity bizarre. In Australia it's hard to find a taxi that doesn't run on LPG. Cheers David Link to post Share on other sites More sharing options...
RMweb Gold Oldddudders Posted October 2, 2015 RMweb Gold Share Posted October 2, 2015 I find the unfamiliarity bizarre. In Australia it's hard to find a taxi that doesn't run on LPG.CheersDavid We have LPG buses in Le Mans, where there are no real tunnels that I know of. OTOH Rouen, where the main route from the north is seriously tunneled, would not seem a good place to own an LPG vehicle. Yet. Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted October 2, 2015 RMweb Gold Share Posted October 2, 2015 It always seemed strange to me that when they ran car carrying trains through the Severn tunnel they insisted on the petrol tanks being emptied. An empty petrol tank contains a volatile vapour making it more dangerous than a full one. Not correct. If you look at my post on this thread you will see that, except in the case of motorcycles, 'a quantity of petrol may be left in the tank provided that -'. In the case of motor cycles that quantity was specified as 'not exceeding one quart', the amount was not specified in the case of cars. http://www.rmweb.co.uk/community/index.php?/topic/39204-severn-tunnel-pilning-to-stj-car-carrier-service/ Link to post Share on other sites More sharing options...
Arthur Posted October 2, 2015 Share Posted October 2, 2015 I do remember a volunteer fireman telling me, that generally LPG vehicles are considered safer, because the construction of the cylinder is much stronger than that of a petrol tank, which is much thinner. I assumed he was correct. They are, LPG is liquid because it is under pressure and therefore needs to be contained in a pressure vessel. Just compare a pressed steel Jerry can to a Butane or Propane bottle. Link to post Share on other sites More sharing options...
trisonic Posted October 2, 2015 Share Posted October 2, 2015 As an aside I believe that most (over 900) NYC buses run on compressed “natural gas". LPG is used mainly in the USA for heat and cooking of houses out in the sticks). Driving around you see various sized white pressurized tanks set away from the residence just about everywhere outside of main conurbations. Best, Pete. Link to post Share on other sites More sharing options...
Arthur Posted October 2, 2015 Share Posted October 2, 2015 Not that uncommon in rural areas here either Pete. We're well off the gas grid and are on oil, which is the more popular, but there are several houses with LPG tanks in their gardens. These tanks are owned by the gas supply company (they're not cheap) and are installed as part of a supply agreement. Link to post Share on other sites More sharing options...
RMweb Gold Metr0Land Posted October 2, 2015 Author RMweb Gold Share Posted October 2, 2015 Possibly wandering OT (but then I was the OP!) - here in west Wales there's no mains gas. Heating for most people means a choice of oil or gas, in either case stored in outside tanks. Now here's a thing - until say a year ago, oil was in a never-ending upwards price spiral and many people were seriously thinking of converting to gas (or modern wood chip burners). We have a number of oil syndicates who use purchasing power to bring down the cost of oil and since we moved here 18 months ago the price of heating oil has dropped by a third (partly due to fall in oil prices and partly due to oil syndicate) whilst gas...... Our local oil syndicate has a very active 82 year old lady who's a real tiger when dealing with suppliers as she never has less than 25,000 litres to order each month. Meanwhile people who use gas are stu##ed because they don't own the gas tank and are shackled to a supplier . Link to post Share on other sites More sharing options...
Arthur Posted October 2, 2015 Share Posted October 2, 2015 That's for sure. We've paid 50p/litre in the last last year or so for heating oil, filled up our tank last month at 30p/litre. As it hold 2700 litres, that's some saving. Link to post Share on other sites More sharing options...
RMweb Premium MJI Posted October 2, 2015 RMweb Premium Share Posted October 2, 2015 When the tunnel was opened LPG cars were rare, they never bothered working out the safety case, that was all. Link to post Share on other sites More sharing options...
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