Ronaldo47

Builders's merchants used to have racks of manufacturers' documentation, but I can't recall seeing any on compression fitting assembly. I tighten until I get what feels like the right resistance. I still have a very useful set of Osma leaflets I picked up more than 40 years ago, with fully dimensioned drawings of their soil and waste fittings and comprehensive installation instructions. Most of the fittings are still in production today.

That's correct. When in the mid-1970's I replumbed my house and installed central heating, I specified the half-hard (medium wall thickness) stuff for the 15mm pipe as I needed to make slow bends in places to promote gravity circulation in the central heating circuit branches, thin wall non-bendable for the 22mm for the central heating distribution pipes and the 28mm gravity circuit to the hot water tank heat exchanger, because the thinwall was significantly cheaper than the bendable stuff and I was on a tight budget. In fact the builders' merchant delivered medium thickness 22mm pipe and only charged me for the thin stuff, so I invested in a 22mm bending spring. I did manage to put some small, very large radius, bends in the 28mm thinwall stuff to avoid having dead horizontal pipe runs in the gravity circulation circuit by heating the pipe with a blowlamp and using a home-made bending block. It did cripple slighty in places but didn't crack. The only time I have seen the fully annealed stuff being used was when the council replaced mum's incoming mains cold water pipe at around the same time. I guess nowadays plastic pipe would be used for that instead of the fully annealed copper stuff. I never over-tighten compression fittings, but I do usually apply a smear of pipe jointing compound to the olive for extra security.

When I replumbed my first house in the mid-1970's, copper pipe dimensions were specified by BS 2871. There were three classes, defined in its tables X, Y and Z . For 10mm pipe, the wall thicknesses (in mm) were 0.6, 0.8, and 0.5 respectively (the tables were not named in order of wall thickness). That BS was subsequently replaced by EN 1057, and this specifies the following wall thicknesses for 10mm pipe: 0.6, 0.7, 0.8, and 1.0 mm. More info here: https://www.engineeringtoolbox.com/en-1075-copper-tubes-d_2115.html

The air seems to be in the form of thousands of tiny bubbles and I understand is designed to break up the boundary layer between the hull and the non-bubbled water, making it more slippery.

Mr. Pedrick, ably assisted by his cat Ginger, who is usually remembered for his wacky inventions, did patent a method of reducing the drag of ships by blowing air out under the hull to provide a layer of bubbles between the hull and the water. Not such a wacky idea perhaps, as I once saw this patent cited as prior art in the search report of a patent for just this sort of thing filed by a German company. I do wonder if this technique is actually being used commercially, as the cruise ship we were on a decade ago seemed to have a strip of bubbles all along it between its hull and the sea, but possibly there is another explanation for the bubbles? In a canal boat, even if it works, I would think that the energy required to pump the air would probably be greater than any energy saved by drag reduction.

My understanding is that, because road tax is not hypothecated, motorists pay more in road tax than the government spends on roads, so motorists subsidise general taxation. Even if my understanding about road tax is not correct, I believe that it is certainly so if what motorists pay in fuel duty is included.

That's a sensible philosophy in principle, but unfortunately successive governments seem to have been doing their best to make it difficult for people to use public transport. It's fine in the large cities such as London where politicians seem to congregate, less so elsewhere. When I lived in East London in the 1950's and 60's, no-where was more than 10 mins walk from a bus stop, and most buses ran a frequent service all day from before 6AM to midnight. All my extended family in East London and the suburbs lived no more than a few minutes' walk from a local tube station, and no-one needed a car to get around. Trains used to run on bank holidays, even including Christmas Day, when the trains ran until about 2PM. We used to have christmas dinner at home and then catch a train to whichever relative was playing host that Christmas. When I moved to outer London in 1970, we were a few minutes from a station on the Liverpool Street line. Trains used to run all night, and although I then had a car, it was more convenient for a night out in the West End with friends to go by train. There was no last train home, the service was just less frequent at night, the longest gap being about 2 hours between 2.00AM and 4.00AM, but there was plenty of seating at Liverpool Street and a number of vending machines for food and drink, even one selling ice cream and lollies. There was also a night bus to Victoria every 15 mins all through the night, which I did use to get to Victoria at around 4.00AM to catch a night train to Gatwick for an 8.00AM flight departure. Unfortunately, in the run-up to privatisation, the government allowed (encouraged? instructed?) BR to cut back the less profitable all-night services to make them more financially attractive to potential franchisees. My last trains back home from Liverpool Street were cut back, firstly to 1.45AM, and later to its present 00.55AM, meaning that for a late night out I had to either take the car or else pay around £60 for a cab. I understand that It's even worse in rural areas, especially where there is not even a regular daily bus service, let alone a night bus service.. So it's not really surprising that those who do not live in large cities, still need their own transport.

I guess it depends on what the surface is like. If you have a smooth metalled surface, a two-wheeled sack barrow will be fine, but if the surface is unmade or rutted, a single wheeled barrow with a large pneumatic tyre may be more practical.

The article does not make it clear what proportion of the heat pumps are air source and which are ground source, but all the specific examples given are ground source. +++++++++++++++ Ole Øystein Haugen, a retired metalworker who lives just outside Oslo, convinced three of his neighbours to get ground-source heat pumps after he got one himself seven years ago. ++++++++++++++++++ Likewise, the early Swiss and US examples quoted are ground source. Unless you are in a permafrost region, in the depths of winter, the ground temperature at moderate depth will always be above freezing and therefore warmer than the air above it, and in mountanous regions, the rocks will often be warmed by geothermal heat emanating from the earth's core or, in the case of granite, by natural radioactivity. Climate can also be a factor. In the northern USA and Central Europe, especially in mountainous regions, the humidity in the depths of winter is often very low indeed, meaning that there is little water vapour in the air to form ice on the cold heat exchangers of air source heat pumps. Brits who are acclimatised to the damp climate of the UK will normally suffer from dry throats when taking skiing holidays in the mountain resorts of Austria or Italy, due to the lack of moisture in the air.

A poster on this forum mentioned that a heat pump manufacturer's information was that a water temperature greater than 5°C was essential, which is greater than typical canal water temperatures established by measurements taken during winter cold snaps. Heat pumps work by extracting heat from one environment and delivering it at a higher temperature to another environment. Your domestic fridge is a type of heat pump. If the environment (canal water) from which you are extracting heat is already at a temperature close to freezing, then the act of extracting heat from it will soon cause the water in contact with the surface of the "cold" heat exchanger to freeze, which will inhibit the pump's ability to extract further heat. The ice surrounding the "cold" heat exchanger will just get progressively colder, preventing the relatively warm canal water from which heat should be extracted, from coming into contact with the surface of the "cold" heat exchanger. Heat pumps produce a certain temperature difference between their "hot" and "cold" heat exchangers, so the colder the "cold" heat exchanger becomes, so the temperature of the "hot" heat exchanger becomes correspondingly cooler. This is why air source heat pumps don't work effectively in really cold weather. I understand that air source heat pumps may need to periodically heat their exterior heat exchangers in frosty weather to melt any ice that builds up, in order for them to continue delivering heat to the "hot" heat exchanger. Otherwise the ice would become cooler than the air from which heat was supposed to be extracted. No practical experience of heat pumps other than domestic refrigerators, but I did study their theory in the thermodynamics module of my engineering degree course many years ago, and I don't think that the laws of physics have changed in the mean time.

Friends who have recently bought a small EV as their second car are pleased with it and its range of over 200 miles. They have had a high power charger installed at home, but tell us that the instructions are to use a slow charge after two three fast charges to keep the battery in good condition. If an all- electric boat needs similar treatment, then it would need periodic access to a land-based charger, as a battery boat-based charger isn't going to want to wait around for hours to provide slow charges. Perhaps some battery technoligies can cope with multiple successive fast charges. Even boats that are not used in winter would need an effective heating source to cope with the vagarities of the English weather. At Easter 2008 (which fell in April that year) when we hired a 60' boat for a week, overnight snow meant we would have liked to keep the diesel heater running all night, but after 8 hours it stopped working as the auxilliary batteries were discharged. The boat's instructions did say the heating could only be used continuously for 8 hours. If an ordinary bank of auxilliary batteries can only power a diesel heater for 8 hours, I shudder to think how much battery capacity would be needed to provide all night electric heating in sub-zero temperatures.

The government's Green Marine document, which only addresses sea-going (marine!) craft and says nothing about inland waterways, other than navigations used by sea-going craft, only considers electric propulsion to be suitable for a limited number of vessels, such as short-distance ferries that can be recharged between trips when in dock. It seems to put its faith in new, undiscovered or yet-to-be-developed technologies such as Ammonia, for use in the type of vessel where storage space for fuel is not going to be a problem, and really only considers vessels that travel between ports where they can refuel. I very much doubt that any proper consideration has been made by government to inland waterways, the type of journeys made by canal boats (in particular, those with nothing corresponding with a home port), or the physical contraints affecting small vessels such as canal boats that mostly do not go from port to port like marine vessels and do not have enough space for low-energy-density fuel to provide a range equivalent to diesel . Politicians do tend to make decisions based on policy first, and only consider the details of how to implement it afterwards, especially where the implementation and its cost will be the responsibility of someone else well after the next general election. When I was in the Civil Service, a session in one of the Civil Service College courses I was sent on, highlighted numerous examples of this practice and the consequential financial costs to the taxpayer. Edit: P.S. Have the government published a a document corresponding to the Green Marine one that does address the inland waterways ? I haven't heard anyone mention such a thing.

Re metrication, a couple of years ago, having been unable to find a UK source, I was able to buy a replacement glass chimney for my old oil lamp from a German supplier whose details I had got from a post on this forum. Amongst the info on their website was the fact that wick widths were expressed in fractions of an inch, not English inches, but inches of the old French foot (from memory, equal to just over 13 British inches) that was used before metrication was introduced in France following the French Revolution. Funnily enough, driving along the A128 this morning, I passed a newly-opened warehose complex near its junction with the A127 that has large lettering on the wall of one of its buildings, announcing how much space is available in terms of 100's of square feet (and only in square feet). Unfortunately not an uncommon scenario. A few years ago, Northern Rail had a "consultation" about the type of seats to be used in their fleet of new trains. A stand was set up at a busy station with examples of three different types of seat and the public were invited to try them and express their preferences. The design that absolutely nobody preferred was the one used, no doubt because it was the cheapest.

We occasionally burn logs in our open fire obtained from the fallen and felled-as-dangerous trees in the heavily-wooded conference centre, owned by a charity, where my wife works as a volunteer. They used to just burn them on bonfires in the grounds because the trees do not produce wood of any economic value, other than as fuel. We only light the fire on special occasions or in the rare periods when we have really cold snaps.

I understand that it is thought that the majority of condensing boilers are in practice operated in non-condensing mode in order to get the radiators hot enough, especially where fitted as a replacement for a non-condensing boiler. Before condensing boilers were introduced, central heating systems were usually designed for a circulating water temperature higher than the condensing temperature to optimise radiator dimensions, and a system designed at the outset for use with a condensing boiler would need significantly larger radiators to compensate for the lower water temperature. This is like the problem you would have when replacing a gas boiler with a heat pump: you would also have to fit much larger radiators to compensate for the significantly cooler circulating water temperature.

A columnist in "Modern Railways" , when discussing government's reluctance to invest in conventional electrification because some new, innovative, cheaper method of propulsion might be invented in the future, has been referring to this as the "bionic duckweed" solution.

And level crossing gates either had to be close-barred or else fitted with wire mesh. That is, until they started replacing conventional hinged gates by lifting barriers.

Mum's armchair was right next to the radiator, and so did receive its radiant heat.