The text presented here is not precisely as published by OUP, but modifications are minor. Illustrations are another matter. Where images used in the original book were not my copyright, I have in most cases been able to substitute links to sources on the web. See Image Acknowledgements.
Note. When this text was submitted as part of a PhD thesis in 1996, the Notes were greatly extended. As the reader may prefer to ignore them, they have been collected into separate web pages. They are a mixture of: simple page references; additional examples or quotations to justify generalisations; and some afterthoughts. As there are so many, the existence of a Note is indicated discreetly in the text below in the form [7.x]. (These are not links.) [Notes to Chapter 7.]
Introduction.
An attempt will be made here to examine the significance for structural design of certain themes developed in previous chapters. It has been postulated, inter alia, that:
- the likely response of people to built form must be treated as an important consideration in engineering design.
- this response will depend on the personality, mood, and education of observers, and vary according to whether they are engineers, architects, critics, formalists, classicists, or non of the above.
- it is important to consider not only the formal qualities of a building or structure, such as proportion, scale, rhythm, or unity; but also possible emotional reactions such as awe, intimidation, excitement; the impact of historical and political associations; moralistic responses; the reactions inspired by perceived symbolism; and the effect of perceived similes with like forms.
- it is important to integrate these considerations with practical ones such as transmission of force by the most 'direct' route consistent with space requirements, optimum use of material, least cost [9.1], satisfaction of functional requirements, best distribution of space for use, and good control of the internal environment in terms of HVAC, lighting, and acoustics.
The 'cost' of aesthetics.
The suggestion that aesthetics (defined in its widest sense) be treated as a serious criterion in engineering design raises certain questions. Engineers disagree as to whether a consideration of aesthetics will necessarily increase the cost of a project. If it does, we must ask whether aesthetic values are important to more than a small minority. Is it worth the cost to please this group? Are designers in any case entitled to spend other people's money on aesthetics, given the subjectivity of the designer's (and everyone else's) views on the matter?
Some bridge designers maintain that consideration of aesthetics adds between five and seven per cent to capital cost. An example is provided by the Moseltalbrücke in Germany (Fig. 9.1). This is a pier and beam bridge in which the length of the spans was varied for aesthetic reasons to maintain the proportions of the bays, rather than keeping them constant at the economically optimum length. [9.2]
Fig. 9.1. The Moseltalbrücke, Winningen, Germany. The central span frames the view of the valley. Side spans were varied to maintain similar proportions. (Engr: Leonhardt und Andrä.) [Photo: Structurae.]
It is easier to envisage cost-free aesthetics if it is sought in qualities other than formal elegance. Effects based on character or sublimity, and the intellectual and emotional factors discussed in Chapters 4 to 6 offer alternative ways of making a positive contribution to the built environment. The secret is, of course, to look for qualities of form that are intrinsic to a particular design situation, taking into account economic as well as technological considerations.
Most people would agree that consideration of aesthetics imposes certain non-monetary costs in demanding a greater intellectual effort in design and in requiring trade-offs against qualities such as structural logic or efficiency of functioning.
The question thus arises of who is to finance improvement of the built environment for the general good and how will such decisions be made. [9.3] In the public sector, this can be achieved if government instrumentalities are able to argue successfully with politicians that there is public support for it. Fortunately road and bridge engineers in public authorities have so far been able to do this to a large extent. In most cases the advice of architects has been taken. The result has been of great benefit, although in some cases it could be argued that a robust functionalist approach might have been more appropriate than a self-conscious search for 'beauty'.
In the private sector, aesthetics may be considered by large companies which are philanthropic and affluent or wish to foster their image as responsible 'citizens'. It is possible to demonstrate that even in accounting terms, good appearance may have measurable value. Business clients consider it profitable to employ architects to design their factory buildings because it creates a distinct identity, raises the morale of the workforce, and impresses clients and customers. Munce (1960) makes this point in relation to the British mining industry. [9.4] Members of the professions find it worthwhile to rent offices in 'prestige' buildings which project an image, perhaps of dynamism or conservatism, for which they wish to be known to their clients. Finally, given the current level of concern for the rural and urban environment, a careful consideration of visual impact is often necessary in order to ensure that a structure gains the approval of the planning authorities. [9.5]
It is hoped that after reading this book, the reader will agree that the aesthetic merit of built form is of intrinsic importance to all, especially if defined in the wider sense, and that it is worthwhile to pay a certain premium.
Aesthetic accountancy.
If the sufficiently educated observer expects aesthetic delight from all aspects of the design process including the logic of structural action, aesthetic worth must then be assessed on a number of unrelated scales. It is unlikely that a building will score well on all of these simultaneously. One which is beautifully proportioned geometrically may offend our sensibilities by the irrationality and awkwardness of its load-bearing structure. If the true functionalist approach always worked, this would not be so, but as we have seen, it rarely does. Thus from an engineering standpoint it becomes necessary to strike an optimum balance: to find some sort of harmony between cost, efficient functioning, and aesthetics. (Minimum scores might be demanded on certain scales.) The only point of dispute amongst engineers might be the degree of importance to be accorded to the matters discussed in this book.
Ove Arup has referred to this sort of assessment as 'aesthetic accountancy'. [9.6] Trying to assess aesthetic merit on this basis will undoubtedly be difficult because it is necessary to allot relative weighting to the various parameters and to weight them further against cost and efficiency. However, difficulty in execution is no excuse for abandoning a principle, and engineers are accustomed to making decisions under such conditions. [9.7]
Engineers and aesthetic design.
If visual aesthetics is to influence the design of built forms in which it has traditionally been ignored, the engineer must decide whether to cope with this alone, or engage an architect as 'aesthetic consultant'. In the latter case, it must be agreed to what extent the engineer will take part in the 'aesthetic decision-making', and what weight will be given to this parameter. The answers will probably depend on the nature of the project, particularly the level of industrial content, and on the client's interest in aesthetics. If there is a desire for a particular architectural style, either on the part of an engineer-principal or a client, it would be essential to work with an architect, and appearance would play a large part in determining form.
As we have seen, some well-known people have been troubled by the prospect that engineers might involve themselves in aesthetic matters. One view is that the noble savage would then be tainted by the sophistication of the art world. An anonymous writer in the journal Cahiers d'Art, concerned by the influence of the Werkbund, complained in 1926 that
"The work of the Engineer, pure in its origins, begins gradually to be adulterated by aesthetic pursuits. The crane … is soaked in romantic Expressionism. It would be a great pity if Engineers refused to recognise that their work is not meant to communicate emotions." [9.8]
Le Corbusier wrote:
"shall we see engineers trying to turn themselves into men of aesthetic sensibility? That would be a real danger … An engineer should stay fixed, and remain a calculator, for his particular justification is to remain within the confines of pure reason."
Corbusier's argument is that we lack the passion necessary to produce works of art. [9.9]
There are many engineers who would agree that we should not meddle in aesthetics. The more pragmatic see art, and even a general concern for good appearance, as irrelevant to real engineering design. Others see it as a legitimate part of structural design, but are content to provide a purely technical service to the architect whom they see as an artist: a sort of sculptor with a unique talent which no engineer could hope to emulate. This attitude was expressed forcefully by several engineers in the ASCE debate over the design of Roger Taillibert's stadiums for the Montreal Olympics (Civil Engineering - ASCE 1976). A consultant who had worked on the project, Klaus Ostenfeld, said, "if we agree that these structures are to be considered sculptures with a certain function, esthetics should be left to the architect", and later, "if we agree [to that] I think another objection to these structures - cost - cannot be discussed either". [9.10]
This attitude may be valid for a small number of leading architects, but few engineers can accept that vast sums of public money should be spent on creating sculptures which do not perform their intended function as buildings.
It is probably safe to say that few structural engineers would wish to become involved in formalistic design of the type of building which is now the preserve of the architect. Few would wish to take responsibility for beautifying the exterior of utilitarian buildings such as power stations. They would probably agree with architects that it is best for both professions to specialize in their present roles, with the exception of a few particularly gifted individuals such as Nervi, Candela, and Calatrava. This situation could change only if major changes were made to the training and organization of both professions. Otherwise, the best that can be expected is that engineers and architects should try to understand one another better, the engineer being encouraged to take a greater interest in, and to have a greater sympathy for, aesthetics. Many calls have been made by leading designers for such co-operation and several firms have introduced innovative organizational structures in order to achieve it in practice. [9.11]
The elusive objective of aesthetic design.
Because the terms 'beauty' and 'aesthetic merit' have so many different meanings for different people, it helps to ask what it is that engineers are seeking when they desire that their built forms should be 'beautiful', or 'aesthetically pleasing'.
The previous chapters may have suggested some reasons why the answers to these questions are so elusive. Contributing factors include the great variety of influences which affect the aesthetic response of the observer, and the fact that the observer contributes so much to the perception and appreciation of aesthetic objects. Added to this is the fact that even if we feel we can reach some agreement on what constitutes beauty, and analyse it to some extent, this is still a very different thing from being able to create it on the drawing board.
It is sometimes the case, especially with certain types of bridge, that there is a correspondence between the general form suggested by technological considerations and that suggested by the principles of formal composition. This is perhaps the reason why bridge engineers often favour a formal beauty or 'elegance of line' which has much in common with that sought by the aesthete. However, it must be accepted that in many cases of engineering design, economic and functional considerations render it inappropriate to allow formal considerations to play a significant role in the determination of the basic form of a structure.
It is then worth looking at the additional responses which people experience to built form. As noted in earlier chapters, many thinkers agree that there are different types of beauty, in addition to the widespread ideal of formal elegance. It could be that the form dictated by economic and technological considerations has potential for a more robust form of beauty. It could have more forceful qualities, such as the air of purposiveness and efficiency attributed to many machines. [9.12]
An example of contrasting forms of beauty is provided by two bridges which cross the River Murray side by side at Echuca in Victoria (Figs 9.2 and 9.3). As regards their setting in the environment, the new bridge accords with the 'strong contrast' approach. The old one seems to blend in well, although this may be because the observer locates it within an image of nineteenth-century Australia derived from historical and literary sources reinforced by the local tourist industry. [9.13]
Fig. 9.2. The functional road-and-rail bridge at Echuca, Victoria (1878). Its robust charm seems not to conflict with the environment. Nostalgia is a factor.
Fig. 9.3. The elegant prestressed concrete railway bridge at Echuca (1989) shows the influence of architectural composition and detailing. (Engrs: Maunsell and Ptnrs with V/Line. Consulting Archt: Brian Stafford.)
The new prestressed concrete rail bridge is of the elegant, formalist style favoured by modern bridge engineers. An architect was closely involved with the design. A white concrete was specified. Cut-back joints between the precast segments articulate the major spans and provide scale. The three main spans are of 'U' cross-section, but the lower corners of the U are dissolved in wide chamfers and there is a careful transition from mid-span to the piers. These measures achieve an interesting play of sweeping, slightly curved lines, planes, and shadows. Great attention was paid to the difficult detail where the ends of the U-shaped portion meet the shallower I-sections of the approach spans.
The old road and rail bridge of 1884 shows no sign of having been influenced by an architect. The massive cylindrical piers, painted red, and their black cross-bracing are completely functional, having forms designed for ease of construction and strength. The timber trusses are standard functional members. (The lateral portal frames are a later addition.) Nevertheless, the old bridge has great character and charm and is as beautiful in its own way as its elegant neighbour.
This suggests that, just as different sorts of music suit different occasions and different moods, it is possible for us to enjoy different species of beauty in built form. It should be possible for the same person to enjoy the structural exhibitionism of a pavilion at an Expo site, the dynamism of a tent or shell, the repose of a classical box, or the charm of an old railway bridge.
Engineers will continue to appreciate particular qualities in built form which are not apparent to others such as the beauty of elegant structural action clearly revealed, just as the classicist is able to enjoy the finer points of a Renaissance facade which are lost on others. [9.14] They will also bring to the appreciation of built form attitudes which are especially those of an engineer: appreciation of the degree of 'engineering morality'; admiration for 'a good job well done'; a sense of the ugliness of an inelegant and inefficient approach to design; and a distaste for expenditure on 'useless' ornamentation or on 'unnecessary' features.
The prevalence of symbolism and 'message' in engineering and industrial structures has not been truly represented in the architectural literature, for obvious reasons. The bridge has received its fair share of attention, being a potent symbol for many people. Dramatic forms such as shells and tents have received a more moderate amount of attention. However, industrial structures have been neglected. They so permeate our environment that non-engineers fail to perceive them. They are of little interest to the average architectural critic, and symbolism is of little interest to the average engineer. There is thus no established discourse to guide the designer who might wish to consider these factors in design.
Although some post-modern architects claim to be able to design intended meanings into built form, it is debatable whether they successfully communicate with anyone apart from people who have read the right books. Few engineers would even contemplate attempting such communication. It would obviously require a long immersion in the subject, and years of patient observation of built forms and of responses to them before communication with the bulk of the population could be attempted with any hope of success. Moreover, as was pointed out in the section on language [Chap.5, Section on 'Insights into the appreciation of built form'] the significance of symbols changes constantly, and often very rapidly. At the same time, designers must beware of creating the sort of 'inadvertent symbolism' of which Charles Jencks has provided so many examples. [9.15]
In situations where engineers have major influence on the choice of form for a structure which may last for many decades, they may wish to prepare a 'classical' design in the best sense of the word. This means not a structure speaking "the language of Greece and Rome", but one with spare, elegant lines, in which there is a minimum of elements having potentially transient meaning or appealing to sectarian or personal interpretations. However, for many other occasions they may feel free to allow the basic character of a more complex and less elegant form to emerge, and may find that this is still valid after many decades.
Aesthetics is strictly a matter of enjoying a work of art (using this term in its best and widest sense). But, can one expect to enjoy a coal-loader or a sewage plant? Obviously not in the same way as a painting, or the more intentionally significant built forms such as the temple, cathedral, and town-hall. However, engineers are able to perceive and enjoy many aspects of these projects, such as the ingenuity, flair, and elegance displayed in the problem-solving (or problem resolving) aspect of design. Again there is not space in this book to discuss in detail the appreciation of engineering design.
Load-bearing structure is often discussed in architectural theory, but comment is not always well-informed. It is not surprising that classicists and formalists rarely discuss what engineers have to say on the matter, because this is published in periodicals that they do not read, using a terminology that they would not understand. The basis of classicist objections is that the vast majority of people have little real understanding of structural action and of the technological determinants of structural form. The layperson's perception is founded on everyday experiences which may not be applicable to full-scale structures in steel and concrete. Therefore designers should limit themselves to structural forms which can be understood by those untrained in the discipline. The argument may be faulted in the classicists' own terms because they maintain that years of training are necessary for the full appreciation of classical art. This must apply equally to the enjoyment of the 'art of design of built form', and the creation of elegantly conceived load-bearing structure. The only qualification is that even engineers cannot fully understand the action of some structures until they have seen drawings showing hidden members and details, ground anchors, or reinforcement. [9.16]
Their other major argument for devaluing "construction truthfully expressed" is that the reality of structural action often conflicts with the visual impression inspired by the form. Geoffrey Scott notes that whereas spires actually press downwards with considerable weight, for the poet they "soar" upwards. For the psychologist of perception they draw the eye aloft. Referring to the "constructive properties" of a building, Scott notes, "in so far as they are vivid, they must exist as appearances". [9.17]
He points out that the dome of St. Peter's in Rome is reinforced near the base with hidden circumferential chains, and that some "modern critics" have suggested that its form should have been like that of the Byzantine dome so as to avoid tensile stresses in the masonry (Fig. 9.4). However, it would then have seemed "relatively lifeless, meaningless, and inert". In contrast
"The sweep of the lines of Michael Angelo's dome, the grand sufficiency of its mass, arouse in us … a spontaneous delight. The further considerations, so distressing to the mechanical critic, remain, even when we have understood them, on a different plane, unfelt." [9.18]
Fig. 9.4. Contrasting forms of masonry domes. The former is better adapted to the mechanics of masonry but the latter is favoured by classicists for aesthetic reasons.
(a) Hagia Sophia, Istanbul. Original dome 537. Present form 562. (Designers: Anthemius of Tralles and Isidorus of Miletus.) [Drawings: Wikipedia (Scroll down for cross-section of original design).]
(b) St Peter's, Rome. Dome 1591. (Archts: Michelangelo and Giacomo della Porta.) [Drawing: Bryn Mawr College.]
Note, 2004: Compare cast-iron in the service of Art, in the dome of the US Capitol. [Drg: PBS (scroll down for cross-section).]
As far as engineers are concerned, the real difficulty with appreciating structural action is that it rarely dominates the design. 'Structure' hardly exists in the abstract. One must ask 'Structure of what?', or 'Structure for what?'. Structure must often be distorted in order to avoid encroaching on the architectural spaces it helps create. This is a completely rational trade-off of one parameter against another, and 'honesty' must be measured on all axes of the 'design space'. To use a suspended roof to cover a domestic dwelling and to expose its sweeping line would be structurally honest, but not economically honest. The same is true when structure is consciously displayed despite the fact that economic considerations dictate a type of cladding which would obscure it.
Thus for engineers, the aesthetic object is not merely the external form of the building. It includes its internal working, and perhaps more importantly the 'design' itself in the engineering sense: the manner in which conflicting requirements have been optimized within given constraints. That said, the engineer will be eager to ensure that the structure is not objectionable to people who have no understanding of these matters, as a result of visual ugliness, or through conveying inappropriate 'messages'.
Towards an aesthetic of engineering design.
Having attempted to summarize the different meanings of beauty and its relationship to function, we are in a better position to look at the ways in which engineers who wish to disregard the advice of Le Corbusier might become more closely involved in aesthetic design. To do this is not to devalue the contribution that architects make to the design of built form, but to anticipate a new aesthetic which might be more suitable for industrial structures than those derived from classical and modernist principles.
It is a help to categorize possible situations in matrix form Table 9.1). On one axis is plotted the nature of the project, grading from 'heavy industrial' to 'architecture as an art form'. On the other is plotted the nature of the relationship between the engineer and the architect (if any) grading from 'no architectural advice whatsoever', through to 'architect as artist' with the engineer as helpmate or servant.
If the engineer chooses to work as helpmate to an artist, little more need be said here. The engineer will perhaps be able to use the material covered in this book in order to take a detached interest in the aesthetic aspect of the project, and to better understand and respond to the architect's requirements.
The majority of structural engineers will continue to work as consultants to architects who have a direct commission to produce a distinctly 'architectural' result. They might then take the initiative of suggesting a range of possible technological solutions which do not conflict with the architect's overall vision or, better, which provide potential for artistic development. A familiarity with the material covered in this book (and a knowledge of the various strands of architectural thought) would be of great benefit in this case. The experience of working with an architect who is interested in sculpture, self-expression, post-modern language, or the imagery of 'high-tech' will obviously be quite different from that of working with one who is committed to an ideal functionalist version of high-tech.
Many architects object strongly to attempts by the engineer to play an active role in aesthetic design, even if this is limited to polite suggestions. For both these reasons, it is advisable where the situation permits, to form a working relationship with an architect who is compatible in terms of personality and attitudes. Of course, many engineers will not have this choice, either because they are employees, or because they cannot afford for business reasons to be selective.
Engineers who are principals on industrial projects, and wish to have the advice of an architect acting as 'aesthetic consultant', could also benefit if they are able to select a compatible architect. At the very least they might be able to select or negotiate a modus vivendi from Table 9.1. Preferably, the agreement would ensure that all factors, including aesthetics, were given a reasonable weighting. This might be expected to vary with the nature of the project, with its location, with the personnel who will experience it, with its surrounding environment, and of course with the interests of the client, the project engineer, and the architect. It would be inadvisable to appoint a classicist or a formalist to an industrial project, unless the relevant architectural effect were sought by the client. (In this case the engineer should perhaps attempt to persuade the client otherwise.) Such an appointment might impose an untoward appearance on the building. It might also increase the weighting of the aesthetic parameter in design and the likelihood of a clash between the form or envelope required for functional reasons, and that demanded by the architect. A formalist architect might however be suited to bridge design because so many bridge types have a fundamental formal elegance.
There are of course potential difficulties in any co-operation between engineer and architect. As a result of training or temperament, architects may consider it normal that they take control of the determination of form. They are likely to have problems in coping with the fact that they are not leaders of the design team in all respects. [9.19] They will probably place much greater value on appearance than an engineer, and less on technological and economic factors. Architects who are willing to play a subservient role, or to place greater emphasis on engineering factors, are less likely to produce an artistic or dramatic form if that is what is expected of them.
A possible solution to these problems would be a new breed of designers, neither architects nor engineers as we now know them, who would be aesthetically sensitive, but willing to accept the demands of function and economics as the 'resistance' of the clay which they mould in their artistic endeavours. The artistry they would display would be more of the sort described and advocated by David Billington, but with formal beauty more often included as an additional parameter in design. The new designer would be obliged to act as leader of a team because no single person could possibly have the knowledge necessary to play a detailed role in creative design on all fronts of architecture and engineering. (Jörg Schlaich has said that structural engineers are at least fifty years old before they have sufficient command of their art to be really creative.) [9.20] It is true that the quality of design and the degree of creativity achievable would be less in this case than if a genius were able to fulfil all roles simultaneously. However the results might be no worse than those produced by the traditional situation in which the architect leads a similar team of specialists. The debate on this question is endless, and it will not be pursued further here.
Finally, there will be some engineers who are sufficiently gifted, adventurous, or foolhardy, to take full responsibility for aesthetic design. Some will put their trust in functionalism, seeing functional perfection as of aesthetic value, or believing that functionalism will necessarily produce formal beauty. Gifted individuals may actually achieve the latter unconsciously, as a result of an innate formalistic sense. Others will ensure that the form of an industrial structure is determined largely by functional considerations, and will then content themselves with modifying this slightly to improve its formal qualities. Alternatively, they might be content to ensure simply that their industrial structure does not overawe or alienate its users and neighbours. The minimum of aesthetic commitment is to ensure that when a structure is prominent, either because of its size or its location, its appearance is approved of by regulatory authorities and environmental interest groups.
Conclusion.
The major objective in the foregoing chapters has been to present the 'conventional wisdom' concerning the appreciation of built form, but to do this from an engineer's perspective. The importance of the personality, life-history, and training of the observer has been emphasized. There can be no hard rules for aesthetics and little attempt has been made to tender specific advice.
A start has been made on working towards a philosophy of aesthetics which is specifically that of an engineer. In this, the designer would attempt to maximize the visual appeal and emotional significance of built form, but at the same time recognize that many other parameters must receive consideration. Engineers might look for character and power in built form, as much as for elegance or beauty. They should identify and draw out qualities that are inherent to the forms which arise from purely technological considerations. They will also recognize that aesthetic pleasure may be gained from many aspects of built form other than the visual, particularly from skill in structural design and in the transmission of force. Engineers should educate others to take a similar delight in these aspects.
Acknowledgements. Linked images, Chapter 9.
Structurae. Link.
Wikipedia. Link.
Bryn Mawr College. Link.
Public Broadcasting Service. Link.
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[Contents]
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[Chapter 8.]
[Notes to Chapter 9]
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[The art in structural design.]
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[Work of Jörg Schlaich.]
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