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Tuesday 26 September 2017

A Random history of energy economics (2) - The Horse and the Lorry

By 1900 railways were the most important element in Britain's transport infrastructure, but they only provided town-to-town communication.  The distribution of goods within a town was done with men with barrows and horses with carts.  In the rural areas "carriers" moved goods and people around with horse drawn wagons.  Horses were widely used well into the 1930s by which time motor transport was firmly established.

I came across some figures comparing the cost of coal distribution from depot to customer by 30 cwt truck and a horse and cart in 1931.  The figures seem to relate to an adequately funded and well run coal business.  Two points about the graphs, first they are for 1931 and are not comparable to costs in 2017 and that the original data is in pounds, shillings and pence which was converted decimal pounds for the benefit of Excel.  I have doctored the data a little for the sake of comparability.  In 1931, the price of domestic coal was between £1.50 and £4.50 per ton depending on the grade, local terrain and market conditions.  Anthracite was the premium product whist Bituminous coal was cheaper, also coke from gas works was widely used.


Both the horse and truck were depreciated over four years and  funded by money at 5%, the horse cost £90 and the truck £250.  The cost structures for both modes of transport is broadly similar, the exceptions are higher capital related costs of the truck, the legal requirements for a license and insurance and maintenance.  Food for the horse and fuel for the truck are similar as are the wages of the driver.

The big difference is the level of productivity, the horse shifts 38.5 tons/week, whilst the truck can do 49.5, but the unit costs are similar at around £0.20/ton.  I suspect that there was a lot of variation within the industry.  If only one man was employed to work with the truck, he would have to work harder than the bloke with the horse and cart, the references I have seen to coal sacks at this time suggest there were 1.25 cwt ( very roughly 62kg or very heavy, I struggle with 25kg bags of sand).  This might have been OK for a youngish man shooting coal into a cellar with street access, much less for an older one shifting the bag from the street to coal store in the scullery at the back of the house.


Some random reading suggests that the domestic coal market was split into three sectors.  At the top end would be customers that bought coal in large quantities, say greater than half a ton, possibly belonging to a "coal club"  which spread the cost more or less evenly over the year, trucks would give an advantage to merchants serving this group.  Those serving customers purchasing less than half a ton and paying the current market price might have a cost advantage from the potentially lower costs of the horse and cart.  At the bottom end of the market would be those purchasing small quantities of coal, possibly as little as 7 pounds would pay high prices to men with barrows.



Thursday 21 September 2017

A Random History of Energy Economics (1) - Gas Engines in the Home

Over the past year I've been acquiring a few copies of the "The Model Engineer and Amateur Electrician" at car boot sales.  I now have about 15 examples dating from 1899 to 1919.  Models make up a large part of the content, but there is also an informed debate on technology as it was evolving.  At the bottom of one page is a note that a Frenchman has observed that a platinum wire is heated with an electric current and then placed in a jar of methane continued glow.  I'm guessing that this curiosity was an early version of the catalytic converter found on most modern cars.  There are notes on telephones and wireless telegraphy and a discussion of the ideal way of storing energy to power motor vehicles, electricity is was thought to have potential and compressed air to be a bad idea.  Electric shock treatment must have been fashionable as some advertisers claimed it was better to be shocked by their apparatus than that of a rival company.  With hindsight X-Rays were not something the citizen scientist should be encouraged to mess with.  The classified ads can be intriguing, there is a suggestion that a vicar had a model gunboat to sell and why would someone expect to exchange an accordion for a lathe?

In the diversity of items advertised, three occur frequently, these are gas engines, dynamos and accumulators.



In 1905, electricity was still a luxury product costing may be 4d - 6d per kwh (roughly 50p in today's money) and many urban areas did not have a supplier and remote households had to generate their own electricity if they wanted it.  Gas, however was a mature technology, many gas companies had been established between 1820 and 1850 and most urban areas had a gas works.   In some coastal towns, the coal was supplied by brigs from Newcastle running themselves aground on the beach  and being re-floated after their cargo had been hauled away by horse and cart. The cost of gas might be something like 2s 6d and 3s per 1,000 cubic feet, depending on the nature of the gas this would be roughly 10p/kwh today.

At the turn of the century gas was increasingly being used for heating and cooking, but the principal application was lighting. Whilst gas lighting was better than candles, it could make the air in a room foul, the products of combustion being carbon dioxide, carbon monoxide and water vaoiur plus anything else the gas company could not get rid of.  Gas mantles required cleaning  and lighting, whilst electric lamps were clean and available at the flick of a switch.  Doctors wrote letters extolling the benefit to health of electric lighting.  It's not easy to make a like for like comparison with the cost of gas and electric lighting but it seems that electricity was perceived as being 5 - 10 times more expensive.



Fractional horsepower gas engine/dynamo sets provided a source of electricity where a public supply was not available and possibly a means of getting a supply at a lower cost.  At the time of writing, I'm still attempting to identify a property which had such an installation.  At a guess, a common configuration would be to have the machinery in a shed where it was used to charge accumulators which were in turn connected to the lighting circuits in the main house.  Voltages seem to have been in the range 4 - 12 volts and accumulators could be relative large, say more than 50 AH.

After 1900, the public electricity supply expanded rapidly, but in most places this was AC, whilst the use of DC in the home decreased, cars and motorbikes created a new demand and low voltage dynamos were used to charge automotive batteries.  Early radio sets also needed a DC supply.

The magazine has several references to water engines, for owners of landscapes which were suitable for the construction of small dams and there a few mentions of "hot air" engines, I take this to mean "Stirling" engines, but so far no description of the workings of these devices.