Lead was all around

Hancock's "Half Hour" and "Steptoe and Son", both comedy series written by Galton and Simpson in the 1960's and 70's had more than one reference disreputable characters stealing lead from roofs.  I am reliably informed that one of the murder weapons in the game of Cluedo is a length of lead pipe.   If there was a lot of lead in light entertainment, there was even more of it in Victorian and Edwardian buildings.

In the last couple of years I've more or less become my own builder and whilst renovating my house have come across a lot of lead in one form or another.  To the best of my knowledge, lead is only used for roofs and flashing in modern structures.

Lead roofing

The attraction of lead as a building material is that it is malleable and does not corrode.  From a half remembered conversation with a retired builder, there was once a specialist trade of lead workers whose principle skill was to beat lead sheet into the complex shapes drawn by architects.  The term plumber (which means lead worker) was reserved for people who worked with lead pipe.

At the time our house was built, all the plumbing was lead tubing, working with this stuff would have been hard, a 10 metre run of pipe would have been heavy and it probably needed two men to install, one to do the bending and another to support the pipe until it could be secured to the structure.  Relative to modern plastic plumbing, forming joints and connections would have been a lengthy and skilled task in which the pipe and solder(?) had similar melting temperatures.

A tee junction in lead piping

I was surprised to find lead had been used a sheath for electric cables which might have been installed around 1911.  I'm guessing, but one of the problems with early electric cabling might have been water induced breakdown of insulation.  Whilst lead was not an obvious choice of sheathing material, it would have provides some protection against water.

Lead Sheathed Cable

One of the attractive features of Victorian and Edwardian houses is stained glass windows.  These are segments of glass held together with I-section lead piping.  Over time stained glass windows can sag if they are exposed to the sun and fatigue if they are mounted in doors, thus you get a bill for restoration approximately every hundred years.

Apart from drafts rattles, sash windows are an attractive feature of Victorian houses, concealed in the frames are four counterweights, in the case of our house, there is more than quarter of a ton of cast iron in the windows, however, in grander properties with large windows, lead was used for the sash weights.

Lead would also have been present in accumulators which were used for door bells and other signalling devices and later to heat the filaments in valve radios.  Local shops offered to charge up the accumulators, maybe for a shilling, which was a very expensive way of buying electricity.

Various lead based materials were in regular use, the most common was paint.  Lead paints had a reputation for durability and the pretense of lead implied a premium product.  Whilst lead is no longer used in paint, its previous large scale use makes it necessary to take precautions when sanding down old doors and window frames to avoid inhaling the dust.  Another one was "red lead" which was a sealing compound used with iron and brass pipe fittings.

Until relatively recently tetra-ethyl lead was used in petrol to prevent "pre-ignition" and was often referred to as an "anti-knocking" additive.  The engines in early cars were large had low compression ratios, for example the Model T ford had a swept volume of 2900 cc and a compression ratio of around 4.  When lead as added to petrol, compression ratio could be increased to around 7 or 8 which increased the efficiency of the engine allowing the size of engine to be reduced for a given output.  At the end of the 1930s small cars typically had 1,000 cc engines.  At one time petrol was sold according to with its octane rating denoted by a number of stars and the higher the octane rating, the higher the price and lead content.   By the 1970s, the used of lead in petrol was seen to be detrimental to public health and its used was phased out.

Zen and the art of.......

I've always had a grudging admiration for "Zen and the art of motorcycle maintenance".  I see where it is coming from, but I once owned an aging BSA C15 250 cc single.  This bike facilitated my 50 mile./day commute for three years and a few ill-advised long distance rides whilst at university.  There is a passage in the book which describes adjusting tappets on something desirable which is parked under a shady Californian palm tree.  This is in marked contrast to placing the cylinder head of the BSA in sterile environment of my mother's oven in an attempt to replace well worn valve guides which were causing oil and petrol consumption to be about equal.  The mobile workshop which was my Belstaff waterproof never lacked a feeler gauge for tappets and points adjustment.  To be fair to the C15, once big-ends had been replaced, the cylinder re-bored and anything that generally needs to be replaced on a motorbike, like chains, clutch pads and oil had been replaced it was reasonably reliable, but I never sat under a palm tree with it feeling at one with the world.

Some decades later, I decided to confront the plumbing in my house.  The object of plumbing is to move water from some ill-defined location to a tap where one use it to clean vegetables or hatch beautiful/creative thoughts whilst languishing in a hot bath.  When the house was built in 1901, it probably did both these things well, but somehow progress got in the way and the bath water cooled and creative thoughts became a thing of the past.

Pipework which is not at one with the world

When the house was built, lead pipes fed a few taps and a gas fired geyser, a simple, functional arrangement albeit with the attendant risks of gas explosion and carbon monoxide poisoning, both of which could be mitigated by opening a window.  The first enhancement was the addition of a back boiler to the cooking range, this would have been OK, had the pipes not been made of iron and by 1949, bath water would have been a trickle of dark red fluid which gave the occupiers the appearance of  fake tan combined with poor personal hygiene.

I'm guessing, but the solution was probably a solid fuel boiler with copper pipes, whilst this was step forward, the only way of moving water around the house was "gravity feed".  The attraction of a gravity feed system is that it is cheap to install, the downside is that it is inefficient.  A pump to move water around the house improves things considerably.  The occupants of the house continued to be cold and dirty.  Sometime in the 1980s a pumped system arrived, but there were three generations of pipework in place, lead, iron and imperial copper.  It was probably cheaper to route the new pipe via London than remove the old stuff and offset the long and winding path with a massive boiler.  Nobody involved had read "Zen and the art of motorcycle maintenance".

It's reasonably easy to protest against airport expansion, you just turn up and wave a placard around and maybe make a some new friends.  It's much nobler to tackle one's own plumbing.  Over the past two months I have ripped out a century of pipework and replaced it with short, insulated runs and to my surprise/relief we have reduced our CO2 emissions and enjoyed the luxury of a hot bath.

Sadly, when I sit in the bath, I still do not feel at one with the world, but I still appreciate where "Zen and the art of motorcycle maintenance" was coming from.

Electric Cars - Would you start from here?

This post started as an attempt to understand electric cars.  My first impression was that electric cars are a set of trade-offs.  On a rough like-for-like basis, electric vehicles are expensive, maybe costing £20k - £30k compared to £10k - £15k for a similar petrol fueled one.  The return is you swap tail pipe emissions for smoke stack emissions but get a more diverse fuel mix which includes nuclear, coal, gas, wind and solar rather than petrol.  Fuel costs are lower, in part due to the lower tax on the fuels used in electricity generation relative to those for automotive use.  The nature of the energy use is significantly different, a high proportion of the energy purchased for electric vehicles reaches the wheels, the conversion losses having taken place at the power station, whilst for a petrol engine the energy loss and related pollution takes place at the vehicle.  A big attraction of electric vehicles is the potential for improving air quality in cities.

Automobiles have been with us for more than a century.  Treat this graph with caution because it was compiled from a random collection of vehicles which I might have owned, i.e. bottom of the range family vehicles.  There is a well established trend of increasing weight and power which has largely been offset by improved efficiency.  A Fort Model T of 1920 weighed in at roughly 500 kg with 20 HP (from a 2.7 liter engine) giving approx. 20 mpg, my Mark 1 Mini (1,000 cc) from the 1970s weighed in at 650 kg,with 35 HP, giving 42 mpg.  The box that my wife uses for her commute to work weighs 1,200 kg and may have a 50 HP engine and returns roughly 50 mpg.  Clearly, there has been a significant advance in petrol engine efficiency over the last century.

The electric equivalent of my wife's box might weigh 1,500 kg and have another 20 HP.  Is this time for a rethink of what we want from a car?

Hi-tech batteries, hydrogen and fuel cells have the potential to partially displace petrol as the dominant automotive fuel.  Exactly how this might take place depends on climate, in Arizona, solar panels work well, in the UK offshore wind offers greater output.  Wind and solar energy sources are weather dependent, but most cars spend 95% of their time parked waiting for something to happen, that something could be the availability of some form of sustainable energy.  With an increased number of charging points and a connection to the internet of things, a parked car could hunt around for an appropriate energy supplier.  Take this one step further and add-in peer-to-peer energy, a parked car might do a deal with the owner of a roof top PV array to buy electricity that might otherwise go unused.  There are a lot of technologies emerging which could be joined up in some interesting ways.

My first impression when looking at electric cars that I might imagine buying was that the manufacturer was trying to safeguard the buyer from change, they just looked like the one that had just been traded-in only the new one came with an electric plug.  Maybe, the optimum electric vehicle is a lockable golf buggy costing less than £10k and a range of 100 miles and very low running costs.  For a lot of people this concept would work.  Most car journeys are short and usually involve one person, maybe up to four on the school run.  This concept would not be attractive to those who see the car as a modern day cod piece, but if I were still a thrusting young project manager, I might lust after a Tesla S.

Back in the 1950s there were a number of small, light cars which were a common sight on the roads, the best known is the Bubble Car:

Variations on the theme included the Messerschmidt KR200.  These vehicles weighed roughly 250 - 400 kg and were powered by small two stroke engines.  Motor cycle and sidecar combinations met the same need, whilst I have met a couple of ladies who liked them, most didn't.  However, real enthusiasts did manage to transport a family of four, dad driving, mum on the pillion and two children in the sidecar.  A lot of motor cycle frames from the 1940s and 50s had sidecar lugs as standard.

A modern day equivalent of the Bubble car might be the Renault Twizzy which would meet the motoring needs of a lot of people, just that they don't know it.

Postscript

By chance I came across this description of what it was like to start a Model T:

"If Mr. Smith's car is one of the high, hideous but efficient Model T Fords of the day, let us watch him for a minute.  He climbs in by the right hand door (for there is no left hand door by the front seat), reaches over to the wheel and sets the spark and throttle levers in a position like that of a clock at ten minutes to three.  Then, unless he has paid extra for a self starter, he gets out to crank. Seizing the crank in his right hand (carefully, because a friend once broke an arm whilst cranking), he slips his forefinger through a loop of wire which controls the choke.  He pulls the loop of wire, he revolves the crank mightily and the engine at last roars, he leaps on to the trembling running board, leans in, and move the spark and throttle to twenty five minutes to two. Perhaps he reaches for the throttle before the engine falters into silence, but if it is a cold morning, perhaps he does not.  In that case, back to the crank again and the loop of wire.  Mr. Smith wishes Mrs. Smith would come out and sit in the driver's seat and pull that spark leaver down before the engine has time to die."

Let's all be grateful that cars have evolved to the point where you push or turn something and pull away.  However, in the process we have lost contact with the engineering on which the car is based and less able to understand and evaluate choices.