ICE Council approving a four year programme to help global cities resist climate change effects is disappointing in the context of “Shaping the World” (NCE 14 May). The fact that about 4bn of our 7bn neighbours now live in cities should not distract us from the very uncomfortable truth that humanity will not survive if the ignored and abused countryside surrounding these agglomerations is not lifted to the very top of our priority list.
We have recognised, as an urbanised community, the importance of water for the better part of 200 years, and we have lately, but not too late, added the condition of our atmosphere to our list of vulnerabilities.
Most people have not recognised as yet that all this, and the urbanisation it supports, is entirely dependent on a few centimetres of topsoil stretching across maybe 10% of the earth’s surface. Nor have they recognised that we are busy destroying that minute resource at an extraordinary rate.
The answer does indeed lie in the soil, as comedian Kenneth Williams’ character Arthur Fallowfield used to tell us. He didn’t do the detail but one senses he knew that 12 units of energy put in for every one taken out as agricultural production was not a plausible equation.
As a practitioner in public health engineering, I can see very clearly that this issue is for us, the civil engineering profession. We must not be lured into high rise simply because that is where the fees obviously lie, but seek out and signpost the crossroads where energy, water, waste and farming industry interests meet. Beyond doubt, it lies outside the cities, and I don’t think it will be necessary to starve while we search for it and for the way to re-harness some of these great forces in nature.
- John Douglas email@example.com
Get out of the smug warm office
David Cummins’ letter is a poor message for young engineers (NCE 23 April) and if this is the best a transport planner is able to portray the future is bleak indeed.
It conveys, dare I say, a quite narrow smug view from a warm office. Even the end paragraph is extraordinary. How could an engineer worth his salt never visit site? Presumably he is not a chartered engineer?
During the 1960s, a year in a design office and a year on site was the basic requirement to sit the chartered professional review. This was excellent training to learn the craft.
Although today examinations have changed to suit current technology, surely site visits are normal, not least to enlighten and widen the scope of the individual’s ability to comprehend on site just what it is he or she is creating in the confines of an office?
Do musicians, doctors, or airline pilots not have hands on experience before being allowed to ply their craft and perform their careers? How did Telford, Stephenson or Barnes Wallis succeed without site exposure?
How does CPD fit into this equation?
This is like a chef who prepares food without ever tasting before serving the customer. This cannot be good civil engineering practice.
- Tony Wills (M) firstname.lastname@example.org
Letting the train take the strain
Colin Davies (NCE 23 April) may be pleased to hear that 10-year-olds were still being sent on trains 60 years after him. When we moved to South Wales in the 1990s our son and daughter, then seven and nine, were happy to be put on the train in Cardiff and collected by their maternal grandparents an hour and a half later in Leominster.
It could go wrong. The next year, we sent them to their paternal grandparents in the Lake District. This required a change at Crewe. Confused by a late arrival at their platform, the children boarded a train to Liverpool. Having realised their mistake, they got off again at Runcorn. The station manager let them use his phone to tell us what had happened, before putting them back on a train to Crewe, to try again.
They survived, of course, and it hasn’t put them off travelling. The serious point is that such trips are no more hazardous now than they were in the nineties or the thirties. It is only a shaky grasp of relative risks that makes some parents think it safer to drive their young children in a car, than to pop them on a train.
- Gabriel Hyde (M) email@example.com
Right solution in the end
It is heartening to see that the Bermondsey Dive Under (NCE 23 May) is coming to fruition some 20 years since it was originally proposed. Particularly pleasing is the use of precast arches with brick faced spandrel walls to match the existing viaducts, although this form of construction is not as unusual as suggested. Standard BR “Conarch” units have been widely used for reconstructing arch structures, although probably not on such a large scale as at Bermondsey.
However, this method was not suitable for the scheme design produced for the original Thameslink 2000 project in 1997, owing to the much shorter line closures then available. Consequently earth embankments and reinforced soil structures were proposed, built up to formation level beneath the viaducts prior to the track possessions for demolishing the arches.
A major improvement introduced by the 1997 scheme design was to enlarge the dive under to accommodate four tracks so that the relocated
down slow line could pass under the Thameslink fast lines to suit the track arrangement south of New Cross Gate, that is slow lines on the outside, fast lines in the middle.
This eliminated the considerable cost of a proposed flyover to take the down slow over the fast lines just north of New Cross Gate station which, had it been built, would have seriously compromised the construction in 2008 of the new East London Line viaduct and the adjacent maintenance depot.
- Dick Watts (M Retd) firstname.lastname@example.org
Equality: not just about women
Does anyone else see the sad irony that the promotion of equality and diversity only really focuses on women? Surely a diversity of race, sexuality, and culture should also be promoted within our “pale, male and stale” industry?
- Natasha Watson email@example.com
Editor’s note: You’re absolutely right Natasha, and NCE will be broadening the debate in the coming weeks - keep an eye out.
A tale from South Africa: ITER’s seismic ancestry
I note with interest the article on BIM: Nuclear Fusion (NCE 14 May) and in particular the use of seismic bearings to support the upper raft. Similar reinforced elastomer pads topped by sliding plates were used for the first time in 1978 on Koeberg Nuclear Power Station in Cape Town. The seismic bearing system was intended to isolate the nuclear island in the case of an earthquake.
Koeberg was built as a design and build project for South Africa’s Electricity Supply Commission - Escom - by a French consortium of EDF, Framatome, Alsthom and Spie Batignolles. On site civil construction was done by the Koeberg Civil Contractor consortium, Spie-LTA-Murray & Roberts.
Excavation for the nuclear island foundations went down to bedrock and the lower foundation slab was poured with starter bars for about 500 concrete pillars. Onto the finished pillars were placed and grouted 1,820 reinforced elastomer pads, three or four per pillar depending on load, each topped by a cross-grooved bronze plate. Onto each of the neoprene/bronze pads was placed a stainless steel plate fixed by Nelson studs into a precast concrete slab. The stainless steel plates had been machined after the Nelson studs were welded to avoid heat deformation of the finished plate.
The story is that there was only a nominal earthquake when the plant was initially tendered. Then the geologists discovered a fault, and the design requirements increased to an SSE of 0.3g or about 7 on the MMS scale.
The Americans and the Dutch went away to recalculate and reprice. The French took a chance and said they would do it for the same price, and came up with this solution. Happy days.
- Colin Le Geyt (M) firstname.lastname@example.org