Coal/town gas and natural gas have different compositions that burn differently. A burner optimized for one may work poorly or not at all with the other. Natural gas is the most common utility-supplied residential gaseous fuel today, but that was not always the case. And that switch required a massive retrofitting or replacement of home appliances.
All gas equipment in Great Britain (but not Northern Ireland) was converted (by the fitting of different-sized burner jets to give the correct gas/air mixture) from burning town gas to burn natural gas (mainly methane) over the period from 1967 to 1977 at a cost of about £100 million including the writing off of redundant town gas manufacturing plants. All the gas-using equipment of almost thirteen million domestic, four hundred thousand commercial, and sixty thousand industrial customers were converted.
That seems quite the lift. I would like to learn more about how the UK (and other places) rolled out the change. You can’t exactly gradually switch a street over. And from what little I know about gas distribution infrastructure, I’m not sure you can even gradually switch a city over. I’m assuming people had to do without gas for some time if their burners were swapped before or after the fuel switch.
If the new gas was in a new distribution system, (Some areas, especially toward the end of the conversion, took the opportunity to replace their old cast iron pipes) street-by-street changes would be doable - on change day, they’d disconnect the street from the old gas main, connect it to the new, and a small army of gas service people fans out to switch out the jets, check for leaks, and light the pilots. For any buildings where nobody was home, they’d probably shut off the gas at the meter, and deal with them whenever they’re ready.
The wiki link you give implies that there was a robust door-to-door process of checking and changing as it says many dangerous appliances were removed from service as part of the changeover.
The biggest challenge would be in knowing that everyone in a given neighborhood is on the same local gas pipe.
I am reminded of a story about when the Pacific Northwest switched from 50 to 60Hz (termed cycles at the time). There was all kinds of publicity and after sending out cards with an appointment time on it, utility agents went to each home to explain in detail what needed to be done to get ready. One house had a note on the door I had an emergency errand to do. Please leave the 60 cycles on the porch.
They made doubly sure to mark that address down for a return visit.
There was also the day, fifty-something years ago, when Sweden switched from driving on the left to the right side of the road. (And there are a few other countries that made such a switch.)
I was in Sweden in the summer of 1966 and they were already planning this. They were putting up a second set of street signs on the opposite sides of the streets. They were all covered. They planned to go out overnight Saturday into Sunday and switch all the coverings to the old signs.
I suspect one reason Sweden switched was Denmark and, probably more importantly, Norway were right hand dives. There were no border controls between those countries. When driving from Sweden to Norway in a rural spot, there was simply a very small double barrier with a sign that read keep left followed by one that said keep right.
I think it took a couple of years from there. Also, from the article, you’ll not that they converted each home in a multi-step process. It’s possible that as they got more experienced, they may have converted “one burner” before switching the gas, rather than waiting until after switching the gas.
I know that some of the conversion took longer than expected because of difficulties converting ‘strange’ ovens that nobody expected to find. For people using the standard locally-made white goods, replacing the jets was easy. As they got further into it, I think they were spending more time upfront identifying what equipment each home had.
I was marginally involved in the big switch from coal to natural gas. Fitters were recruited and trained all over the country and supply depots were set up with all the parts that would be needed. Leaflets were posted through every letterbox and it was much publicised through all the media.
In the event, it all went fairly smoothly. The gas was turned off at around 9 am (after breakfast) and for the vast majority of homes, it was back on by the time the kids got home from school.
Many people took the offer of a subsidised replacement appliance, and I believe that there was a scheme in place to replace older equipment in poor households at no cost.
I also remember when some places had to switch their electric supply from DC to AC. They were in areas around large factories who generated their own supply and were not then linked to the National Grid.
It helps that gas wasn’t really used for heating until after the switch, at least here in the US. Town gas was limited to lighting, cooking, and domestic hot water for the most part, which is easier to convert than all those things plus large boilers and furnaces. It appears that widespread natural gas was available pretty soon after WWII here, and most buildings from that time period installed gas heat. Older buildings seem to have converted their old coal or oil furnaces/boilers in the 1960s.
Here’s a question. Is the heat output of town gas vs. natural gas close enough that appliances could be converted beforehand and still work, even if at a reduced capacity? Like if you hook up a propane appliance to natural gas I think it still works, just not very well. Or would it not even stay lit? On the other hand if you hook up a natural gas appliance to propane you can burn your house down.
My understanding is that it’s not so much a difference in heating value but that you need a different fuel air mix.
The number I hear today is that up to 20% hydrogen in natural gas will work ok with a natural gas burner. The composition listed in that wiki article is 50% hydrogen. So I think both burners are incompatible with the other mix
I hope that this switching was done in the summer, when at least home heating wasn’t necessary. Or maybe this was done when most British customers were still using coal for home heating.
Regarding the electricity switch from 50 cycles to 60 cycles: In California, the utility company offered to convert customers’ synchronous electric clocks (the kind that plug into a socket) at no charge. The motor had to be replaced with one designed for 60 cycles. The utility had quite a job replacing the motors in all of the different styles of clocks. ( And - Electric utilities used to adjust their cycles in the small hours of the night to keep these clocks on time.)
IIRC there was some change to legislation for selling second hand appliances, it became an offence to sell old ovens on the old jets.
Lots of folk were buying new items so there were loads of them being dumped - this created a market for shysters to resell them, they got them for nothing and anything they made was a plus.
Not everywhere. I knew a Norwegian who described driving from Oslo to his family home on a farm in the NE corner of Norway that was only 100 meters from the Russian border. The one-lane rural road that he mostly drove on snaked in and out of Sweden without any signage. He would be driving late at night and see a headlight coming and have to guess whether to pull off to the right or left. I once wrote this story to uncle Cece who included it in one of his books.
Someone mentioned the switch from 50 to 60 cycle power. Really, only clocks and other timing devices would be affected. But I once had a girlfriend who lived in a DC powered apartment in Manhattan (around 103rd and B’way). The apartment had a DC-powered AC generator sitting in a closet (and making a racket) to power the various appliances that didn’t operate on DC. Lights didn’t care of course, but most things did.
Getting back to the OP, I still recall the day sometime in the late 1940s that some guy from the gas company came round to adjust our stove. I would’ve been around ten at the time and do not remember how they dealt with the entire city of 2 million. I imagine it was a block by block and rather slow operation. But I don’t recall any time that we couldn’t use the stove.
Coal gas heating value depends on a lot of factors but is generally around 500 BTU/FT3 (scf to be technically correct) while natural gas is around 1000 BTU/FT3. propane is around 2500 BTU/FT3
Given the same pressure entering the burner, a burner designed for Natural gas will give a very small small flame with coal gas.
I seem to recall that there was a lot of concern over pilot lights more than the main gas jets.
I think that natural gas pilots need more gas than coal gas pilots and the big concern was that there could be a lot of pilot flames going out and causing a build up of gas in enclosed spaces.
Not that it’s relevant but … impact printers. If it was advertised as 6 pages per minute in the USA, it did 5 pages per minute in Australia. Because the motors advancing the print head and pages were synchronous.
It may have helped the gas switchover in the UK that gas supply was a nationalised monopoly.
As for the uses of gas, domestic central heating wasn’t that common still at the time, most gas heating was by radiant gas fires, and water heating by smaller individual boilers/geysers in kitchens and bathrooms. I have no idea how they managed with big institutional central heating set-ups, but I don’t recall any major problems being mentioned in the media.
In Melbourne, becoming a state-sanctioned monopoly happened partly as the result of conversion, but starting with a bunch of independent, not-interconnected gas-generation facilities, and replacing them with a much cheaper supply from a pipeline, happened even though the coal-gasification plants which were being bought out were all independently owned and operated.
