Readers letters

Letters - January 2015

PE

The skills debate, the Swansea Bay tidal lagoon plan, that visit to a comet, high-speed rail and other topics

History of invention: The story of aeroengine development makes fascinating reading

How Rolls-Royce played Wilde card

One of the most remarkable facts to emerge from Phil Ruffles’ exemplary textbook dissertation on the RB211 turbofan engine is the technical prowess of Sir Frank Whittle (Books, PE December). 

He filed a patent for a bypass jet engine as early as 1936. Whittle’s first jet engine ran on 12 April 1937. The RB211 turbofan first ran 30 years later on 31 August 1967. However, it took Rolls-Royce nearly 25 years to bring its three-shaft RB211 bypass engine to fruition from the first patented designs.

More elusive is: who invented the RB211 crucial fan which posed such an engineering challenge? Alec Collins, programme manager of the RB211, notes that the original concept of the wide-chord fan came from Geoff Wilde, who had been in charge of the compressor design office and as early as 1950 produced a transonic blade design. When Wilde became head of advanced project design, transonic fan blades became necessary and, because of the high bypass ratio, also long. 

To reduce blade weight – and hence the disc and containment ring – the blade chord also had to be low. This necessitated a mid-height support (snubber) on the adjacent blade to avoid vibration problems.

Snubbers irritated Wilde; positioned at the point where the airflow was sonic, they caused large losses. Wilde foresaw the huge advantage of wide-chord fan blades with good vibration properties that did not require snubbers. The downside was their weight if made from solid titanium.

In 1966, Wilde tasked two of his team, including Mark Poucher, to devise how a lightweight, wide-chord blade could be made. The duo produced six solutions, including a titanium honeycomb structure (used on the RB211 535E4) and a blade of two halves with internal machining then bonded together. The sixth idea called for a carbon-fibre reinforced resin blade – or Hyfil blade. 

Many leading engineers in Rolls-Royce approved of the carbon-fibre blade, but Wilde maintained his disfavour. He reasoned that resins then available were too brittle; the blade while strong enough would be liable to impact damage, which turned out to be the case.

So Wilde invented the wide-chord blade – for which he held the patent – and effectively the three-shaft, high bypass ratio engine. But the Hyfil blade, although devised by his team, was not claimed by Wilde but by many of the people associated with its detailed design. The Hyfil blade did not cause the downfall of Rolls-Royce as many in the media at the time suggested for, as Ruffles says, a back-up titanium blade had been developed.

Events proved that the rewards from Wilde’s wide-chord fan blade were massive: a 2.5% improvement in specific fuel consumption. The wide-chord RB211 turbofan first appeared in 1984, 10 years before its competitors. Wilde’s three-shaft, wide-chord fan concept continues today, almost 50 years later, on the highly successful Rolls-Royce Trent engine family – the third-generation RB211. 

And by the time the carbon-fibre blade was made to work – on the General Electric GE90 nearly 30 years later – resins had improved to the point where they were both strong and resilient.

Rolls-Royce began work on fibre-reinforced plastic blades in the late 1950s and used them in the RB162 lift engine in 1961. The advent of carbon fibre, developed by the Royal Aircraft Establishment at Farnborough, was seen as an ideal substitute for the earlier fibre due to its high strength. Rolls-Royce elected to make its own fibre, namely Hyfil, but discontinued it.

John Mortimer, Whaddon, Bucks

Hitting brick walls

I am writing to you in response to the article entitled “Must try harder” (PE November). As a female chartered mechanical engineer who is looking to return to work after a career break to bring up two children I have become increasingly frustrated when reading articles like this and the many articles that have been in media in the last six months or so. 

When I read “there is a skills shortage”, “we need females in engineering”, or “women are missing out” I just want to scream.

I am keen to return to the engineering world to continue my career and my love of engineering but continually hit brick walls with companies and agencies as I am looking to balance work and life (as are many working mothers). 

I believe that it is important to bring up your own children and teach them your values and be there for them. But I know that I could offer an engineering company all my skills, maybe for only a short working day, and make a difference. Finding a company that shares this attitude is proving a challenge, to say the least.  

I have been told that I am unique as companies want my skills but not my availability. I wonder if you can understand why I am frustrated.

To share my love of engineering I am a Stem Ambassador and working with my son’s school on the Bloodhound project. I do as many activities as I can. It is fantastic sharing my love of engineering with the children. Our schoolchildren have so much to offer and are so keen to learn how their day-to-day work can be used.

I would be interested to have some constructive advice on how to return to work, whilst bringing up your children with your values and whilst supporting your husband who is also a chartered engineer.

Rachel Rawlings, Northwich

Steer clear of black holes

The debate around the skills gap is an interesting one (Editor’s Comment, PE December). What skills are the gaps in?

You refer to the letter to the London Evening Standard by Nick Pollard, chief executive of Balfour Beatty Construction Services. I worked alongside Nick earlier in his career and hold him in high regard. Raising the issue as he has is a positive sign of leadership so often lacking these days. 

Of the organisations cited elsewhere in your editorial, I ask how are they failing to attract the skilled people they need? Is it because of the predominant use of black hole recruitment processes, lack of relevant engineering key words in the computer search algorithms, or that skilled people don’t want to work for companies who constantly whine about the perceived skills gap in place of engagement with and investment in said skilled people?

A black hole recruitment process is where you attend an event you were invited to, to learn of career opportunities with organisations that are stating they are facing skills gaps. You then apply through the black hole portal as advised, and you hear nothing back, and have no response to follow up calls and emails. Evidently this process doesn’t work as those companies employing that method continue to whine that they can’t get skilled people.

There is another method – the ‘headhunter’ employed by the company they can’t identify, that want to know everything about you, including your inside leg. You pass that first hurdle and the second, the telephone interview. Then you get to the final panel interview where you travel 300 miles to the location that is not where the job is based. The panel espouses how skilled you are, how they need people like you and bid you farewell until they make their decision. You hear nothing for weeks, and calls are not returned. You are eventually contacted to be told you are overqualified and too experienced.

Our heritage and history shows from the creation of modern wealth resultant from the Industrial Revolution that a mixture of skills were developed through myriad academic, education and empirical routes. Our wealth-creating forebears of the Industrial Revolution and their endeavours would not pass muster with today’s commercial focus on narrow short-term profit.

Keith Parkin, Hampshire

Questionable sums

The letter from Alex Herbert regarding the cost of electricity from the proposed Swansea Bay tidal lagoon suggests that the power produced will be among the “cheapest in the country for most of its 120-year life” (PE December). This seems to be at odds with the requirement from his company, Tidal Lagoon Power, for a guaranteed payment of nearly £180 per MWh for 35 years. 

Given that the press have criticised the proposed deal for Hinkley Point nuclear power station because of a guaranteed price of around £90/MWh, how can the lagoon be justified? 

Given that the lagoon project is much simpler technology than a nuclear plant, with obviously less risk, why is this cost so high? This cost presumably will merely be passed on to electricity consumers in the form of higher bills.

Bernard Hex, Mumbles, Swansea

Unrecognised achievement: Comet mission was a triumph of engineering

Misleading TV reporting

From the TV coverage of the recent Rosetta rendezvous with a comet and the landing of a scientific package, the general British public would not appreciate that what they were watching was a major achievement of engineering/technology. All the references were to the science and this is typical of the BBC reporting of such events. 

This probably reflects the lack of knowledge of the news compilers and reinforces the lack of understanding by the public. In the interest of educating the public and the youth of our country and to encourage more young talent into engineering/technology, our institutions and the Royal Academy of Engineering should be making a co-ordinated continuing approach to the BBC at the highest level to improve the balance and accuracy of their reporting of these events and their lax use of the title ‘engineer’. 

The BBC has a tremendous influence on the culture and attitudes of the public and eventually over time this could have an effect.

Gordon Quinton, Reading

Unwelcome forests

Your survey on wind turbines and solar farms suggests one of two facts, either how few of your readers live in Cornwall or how many of your readers live in areas that have yet to experience the industrialisation of the countryside with forests of wind turbines and/or blankets of solar-panel power stations (8 Questions, PE December).  

Let’s stop calling them farms and parks just to give the impression that they are green and natural additions to rural life.

Dr Ben Dobson, Newquay

First act: The Savoy Theatre in London gave electric light its public debut

Further illumination

Joseph Swan and Thomas Edison had both been involved in the development of electric lighting, from different sides of the Atlantic and with a degree of rivalry (Archive, PE December). 

Even so, a joint enterprise called the Edison and Swan Electric Light Company was set up in 1883, and it had an office in London. It was a couple of years before the Savoy Theatre in London became the first public building to be electrically lit. The performance of the lights at the Savoy was as expected but the generator turned out to be inadequate and was replaced.  

It is noted in the article that Swan became a member of the IMechE in 1884. At that time the IMechE existed alongside the Society of Telegraph Engineers and Electricians, which in 1889 became the Institution of Electrical Engineers.

J C Jones, Aberdeen

Costume drama

Archive got its facts slightly wrong (PE December). Swan’s fairy lights were not used to illuminate the Savoy Theatre but were used as part of the costumes of the fairies on stage in the Gilbert and Sullivan comic operetta Iolanthe. Hence the term fairy lights.  

The theatre was illuminated by Swan’s bulbs but of larger size than the fairy lights used on stage. A double first in fact! 

Irvine Bell, Lytham St Anne’s, Lancs

Hands-off management

How refreshing to read Dr David Landsman’s remark about Tata (“Passage from India,” PE November) that “We do recognise there are geographical differences, and it’s important to let managers manage in a way that suits the location.” 

Would it not be wonderful if central government applied this to local government and the NHS?

John Stoton, Barnham, Sussex

Safety will be built in

I feel compelled to respond to the anti-nuclear letter from John Sharp (PE December). Nuclear site licensees have an absolute obligation to meet the risk and public safety criteria defined by the law and enforced by the Office for Nuclear Regulation. There is no credible case that these legal commitments can be circumvented to increase profitability. 

 It is very probable that some of the new small reactors will use small particulate fuels that have high proliferation resistance, rather than large multi-pin fuel assemblies. However, even if light water designs are used, the technology is well-established/low risk. And small reactors would have additional passive safety features compared with large designs, permitting them to be sited close to population centres.

 In addition, small reactors are able to operate at full power for at least two years before refuelling.  This is a great advantage for isolated communities that are not grid-connected but who seek the same 99.98% continuity of supply that is available to the rest of us and is almost impossible with renewable generation. 

Paul Spare, Davenham

Risks posed by HS2

I’m afraid that Dr Peter Primrose is misinformed about High-Speed 2 (Letters, PE December). HS2 would be largely disconnected from the current network, so train paths could only be freed up at the expense of cities like Coventry (which are considered to be over-provided). The plan is to release one train path an hour through the West Midlands, where traffic is limited by platform space, junctions, and franchising restrictions, not track capacity.

With regard to airports, HS2 was backed by the aviation lobby as it was thought likely to increase flights from Birmingham and Manchester, not reduce them.

The original supporters of HS2 stressed the importance of the direct link to HS1, but that is dead and buried. It’s doubtful that HS2 will even reach London Euston.

Primrose should realise that HS2 is a building project, not a transport system. We’re six years into it, yet not a jot has been done to tackle the risks that a mechanical engineer would pick out. My list would include the mitigation cost of the selected greenfield route, the reliability of a system planned to send every train to the north of the country up a single track at the rate of 18 an hour, the dependability of the points on the network handling that traffic at 400km/h, and the reliability of the overhead line equipment carrying 300 trains a day, each drawing up to 800A. 

When it comes to mitigating the 100dB noise, the civil engineers offer walls and tunnels. I’d like to think a mechanical engineer would have spent the last six years integrating the aerodynamics of the train with line-side wind deflectors.

But then again, if Stephenson or Brunel were asked to design a system for service in 20 years’ time, they’d probably take advantage of developments such as superconductivity, nano-technology and mechatronics. 

Don’t expect a happy ending for HS2. 

Richard Lloyd, Coventry

Email your views to pe@caspianmedia.com or write to The Editor, PE, Unit G4, Harbour Yard, Chelsea Harbour, London, SW10 0XD. please include your full name and address










Share:

Read more related articles

Professional Engineering magazine

Current Issue: Issue 1, 2025

Issue 1 2025 cover

Read now

Professional Engineering app

  • Industry features and content
  • Engineering and Institution news
  • News and features exclusive to app users

Download our Professional Engineering app

Professional Engineering newsletter

A weekly round-up of the most popular and topical stories featured on our website, so you won't miss anything

Subscribe to Professional Engineering newsletter

Opt into your industry sector newsletter

Related articles