It’s time to slow down the flood waters
When will they ever learn? No doubt we will have politicians saying that “we have to learn lessons”. They have said this after each of the recent flooding events, including in Gloucester, Somerset and the Thames Valley. They may have learnt lessons, but they are not very good at putting them into practice.
There are reports published with suggestions for solutions, but little seems to have happened. We also get this “one in every 100 years” theory trotted out. As a young design engineer, whenever anything did not quite work out, I would say to my design director “well, in theory...”. He would immediately reply “if your theory and fact disagree, there is something wrong with your theory”!
While we may not be able to completely stop the very worst flooding, it has been known for years that the solution lies upstream in the river system. Any engineer will tell you that the best place to solve a problem is at its source. This flooding is no different.
There needs to be a concerted effort to improve water retention upstream by planting trees and other vegetation which make for a slower release of the water. Attention needs to be paid to rivers too. Stop the river straightening works, and allow them to meander, even forming oxbow lakes. This will also slow the water down.
If needs be, government has to get into serious discussion with landowners to persuade them of the greater need.
We also need to recognise the importance of traditional flood plains. Stop trying to drain them to build houses on them. Strange how these houses are then prone to flooding! This responsibility lies with planning authorities.
I know that governments are not good at long-term planning beyond the next election, but they need to get their act together, and carry out work other than the immediate flood defences.
Bill Gibson, Fylde, Lancashire
Let’s back these reactors
If you exclude those with a vested interest in the renewable energy industries or in the gas turbines required for when the wind doesn’t blow or sun shine, there is near consensus on this letters page that intermittent renewable sources are not going to bring about a carbon-free future.
Rightly, other letter writers are concerned about nuclear safety, waste and economics. The good safety record of inherently unsafe high-pressure water-cooled reactors has been achieved using expensive reinforced containment vessels, back-up cooling systems and a complex stringent regulatory system.
This magazine has mentioned Energy Process Developments’ report on the feasibility of developing a pilot-scale molten salt reactor (MSR) in the UK. It concluded that work over the last decade has made a compelling case for MSR feasibility, particularly in regard to inherent safety and low-cost modular production. They are ready now for prototype development without the need for more science.
MSRs should be relatively cheap, mainly because they work at atmospheric pressure and can fail-safe when cooling systems fail. Xenon gas which inhibits fission in solid fuel reactors bubbles off so long-lived actinides fission, leaving waste that only requires a few hundred years’ storage. Current nuclear waste can be used as fuel.
One design in particular, Moltex Energy’s Stable Salt Reactor, was recommended for urgent funding. The patented design employs convection currents rather than active pumping in the most corrosive and radioactive part of the reactor, thus eliminating materials challenges within other designs.
After 30 years’ active interest in green energy, I see this direction easily eclipses all other paths to a carbon-free future. I would urge all engineers with an interest in this field to investigate for themselves and to lobby our institutions and government to invest now. The UK could lead the way.
Jon Michaelis, Buxton
Cut-price energy
With regards to the Editor’s comment on energy provision (PE November), the wholesale price of electricity (£44/MWh) is not a sensible comparison to make when considering the strike price of £92.50/MWh for Hinkley Point C. There is no power station on earth that could be built for £44/MWh.
I suspect that current spark spreads are around about zero (they certainly were a year or so ago) which means that £44/MWh would probably pay for not much more than the gas consumed by a combined-cycle gas turbine.
John England, Stratford-upon-Avon
Flower power
I totally agree with the letters by Harvey Holmes on the future of coal and by Colin Warburton on the pitfalls of privatisation (PE January).
The consideration of carbon capture in the debate on fossil fuels has always struck me as one of the greatest follies of recent times. Why do this when technology can be applied?
If you research “close coupled field” technology, you will find many surprising things. Who would possibly believe that a low-energy source of electrons could break the molecular bonds of CO2 to release carbon and oxygen – perhaps only plants, which have been doing this forever, whilst seemingly releasing electrons into the ground.
The same technology could, of course, improve all engine exhaust emissions – how relevant today.
Food for thought and, potentially, very green research.
David Lancaster, Macclesfield, Cheshire
Secretive science
Dr A A Griffith at the Royal Aircraft Establishment started research work on axial-flow gas turbines for aircraft propulsion in 1926, several years before Sir Frank Whittle commenced his work (Letters, PE January). Unfortunately, Griffith’s work was classified as secret until November 1976; he should be fully recognised.
Discussions took place between the aircraft establishment and the steam turbine department of Metropolitan Vickers (Metrovick). The first British axial-flow jet engine was designed and built in the steam turbine department at Trafford Park and was tested in December 1941. This engine, the Metrovick F2/1, was installed in the prototype Meteor in 1943.
The German BMW and JUMO axial-flow jets were in full-scale production in 1943.
In 1945, the Ministry of Aircraft Production placed an order with Rolls-Royce for the Avon with an axial-flow compressor and with Metrovick for a similar engine, the Sapphire. Dr D M Smith, of Metrovick’s steam turbine team, designed compressor blades that did not stall. In 1948, the ministry instructed that the design be handed over to Rolls-Royce to cure the problems with the Avon compressor blades.
Metrovick’s steam turbine team had solved the problem.
For amplification, refer to “A steam turbine team develops Britain’s first axial flow jet engine” in Engineering Progress Through Development, by R R Whyte (MEP, 1978).
Francis Brian Cowell, Hucclecote, Gloucestershire
Rover’s role recalled
A K L McCrone’s letter about Sir Frank Whittle’s achievements contains some incorrect details (PE January). The then Ministry of Aircraft Production had in 1941 approved construction of Power Jets turbojet parts by the Rover car company.
Whittle’s complex double-inlet centrifugal compressor with high-twist blades on the W2B engine proved beyond the manufacturing capability of Rover for most of 1942, and they altered without authority the Power Jets design.
It was not until Rover’s agreement that Rolls-Royce would take over testing and manufacture of the Whittle designs in November 1942 that greater progress was made, culminating in the first Meteor flight in June 1943 with RB23 jet engines. This was very close to Whittle’s original design concept, though with Rolls-Royce Nimonic turbine blades.
Later design practice only retained the centrifugal compressor until axial-flow designs could offer a comparable pressure ratio, and were sufficiently robust.
We had a Rover gas turbine fire pump at Edinburgh University in the 1960s. It was very lightweight and powerful, but shatteringly noisy!
David Cormack, Dumfries
Renewables overestimated
Ben Sampson states that renewables accounted for almost half of Scottish energy generation, 49.7% (Global Perspectives, PE January). The actual figure is 38% (wind turbines 23%), as the Department of Energy and Climate Change figures for 2014 attest.
The figure of 49.7% is the result of dividing renewable energy produced by electrical consumption, an odd calculation which takes no account of transmission and distribution losses or exports south of the border, although it is the basis of the Scottish government’s target of producing 100% of electricity from renewables by 2020.
The press release from which the figure came was a prime example of obfuscation.
Maybe you could publish an article on how the current mix of Scottish renewables would be able to achieve a 100% reliable power supply.
George Horne, Aberdeen
Conversion confusion
Just to prove that some of us do read PE with a modicum of thoroughness, herewith a comment on the report on US-built concrete wind turbines (News, PE December). It says that a “test column is rocked with 100,000 lb of force (224.81kN)”.
According to my calculator and conversion data in “The use of SI units in IMechE publications”, 100,000 lbf equates to 444.84kN.
That aside, it seems optimistic to assume the American figure is correct to five significant figures and to quote the conversion to this degree of accuracy. Surely 445kN (or, incorrectly, 225kN) would be sufficiently precise.
This all rather supports my long-held contention that we would get along much better sticking to pounds and ounces and feet and inches rather than SI units, especially when incorrectly converted. Perhaps we will be able to do this when we leave the EU.
Gordon Latham, Worthing
Flexible working pays off
You mentioned that business should be flexible with working hours to allow people to commute before or after the rush hours (Editor’s comment, PE January). I totally agree with this – for example you could have a company that had hours of 10-6 or 8-4.
The company I work for are quite flexible with working hours and I know some people employ them to cut down their commute by over an hour. But I’m curious to know, does the IMechE employ this flexibility with its employees?
Elijah Hughes, Bristol
Picture this
To raise the profile of the profession, perhaps we could have an engineering colouring book, before the craze dies away?
I have a grandson with an interest in engineering who would enjoy one.
Alternatively, is the institution’s offer of support for an engineering-based TV series still available?
David Pullman, Oxford
Fateful final flight
I remember the R101 airship flying over my house in Billet Road, Walthamstow, east London (Archive, PE January).
You could hear the engines of the airship a long way off. My mother looked out of the front of the house and yelled “Look out of the kitchen window, an airship is coming over”. We all ran to the window but I couldn’t see out and yelled at my siblings to lift me up. My elder brother, who was six, held my body and my sister pulled up on my nappy. The sky which wasn’t that bright just went dark and slowly the airship passed over the house.
To my mind even today it wasn’t at 1,000ft. It may have been when it came down the Lea Valley but then up to Billet Road was a long climb. You could see the four engines pulling the giant through the air, and the passenger cabin. Last of all in the centre of the craft below the tail was a fifth engine.
Now the fifth engine was added to pull the airship backwards to aid in her getting to the mooring mast. The propeller faced to the rear of the airship. Standing on a platform next to the engine there was a mechanic waving down to us but no propeller on this engine moved. I believe the fitting of this engine was also a reason for putting extra gas bags in.
I remember the following day when they said that the airship had crashed but as I couldn’t speak much at that age I had to wait until the following day to be shown the large photo of the crash site in the Daily Mirror. I then understood what had happened.
Nevil Shute in his autobiography Slide Rule deals quite throughly with what went on between the two design teams. He had worked on the R100, which by the way was the only airship ever to be broken up and dismantled. All the rest either crashed or caught fire.
Bernard Poulten, Basingstoke