I have been trying to consider what view to take about the Trans Siberian and Golden Gate Bridge proposals – and also, in all fairness, to revisit my own proposal re The Panama Canal! We could easily fill our "top 50" with "Grand Projets" from the 20th century alone! How then could/should we assess and rank them? We have the UNESCO criteria and they are going to have to measure up against 1 or more of
i. to represent a masterpiece of human creative genius;
ii. to exhibit an important interchange of human values, over a span of time or within a cultural area of the world, on developments in architecture or technology, monumental arts, town-planning or landscape design;
iii. bear a unique or at least exceptional testimony to a cultural tradition or to a civilization which is living or which has disappeared
iv. to be an outstanding example of a type of building, architectural or technological ensemble or landscape which illustrates (a) significant stage(s) in human history;

However, as Meltwaterfalls pointed out, the criteria are not really very tightly defined or strictly applied – every year we see that sites which present themselves well, go "with the flow" and have the right allies get in however thin their justification against the criteria.

And the current List isn't a great deal of help regarding good "models" for "Great" 19th or 20th century civil engineering. There are no really "top class" constructions – All I could find were Vizcaya Bridge (Criteria i, ii), 4 Lifts (iii, iv), Semmering Railway (ii, iv), Mountain Railways of India (ii, iv) and Rideau Canal (i, iv) plus a few modern buildings with a degree of novelty in their "engineering" aspects – Centennial Hall (i, ii, iv) and Sydney Opera House (i). Where are the Gothic Cathedral equivalents of the 19th and 20th centuries – not there I am afraid. And these "criteria assignments" don't exactly help! How on earth did the 4 Lifts get accepted as "bear(ing) a unique or at least exceptional testimony to a cultural tradition or to a civilization which is living or which has disappeared"? Apparently it was on the basis that they "bear exceptional testimony to the remarkable hydraulic engineering developments of 19th-century Europe" (ie a civilisation which has disappeared?). Hmmm? It would appear that the Vizcaya Bridge "represents a masterpiece of human creative genius" on the basis of being the first Transporter bridge – which is just about fair enough I suppose but sets a fairly "low bar" for "creative genius"! But why does the Rideau Canal also receive this same "creative genius" accolade? I can find nothing particularly "innovative" about its design etc.

If the current List doesn't provide too much guidance for us in determining what engineering projects should be in our Top 50 list what "assessment parameters" can we develop from the criteria? I suggest the following

a. Degree of innovation involved in design and construction (i, ii)
b. Impact of design/construction on later similar developments (ii)
c. Impact of its existence on society/culture (and whether only "regional" or "worldwide") (iii, iv)
d. Extent to which it is iconic and "of its time" (iii, iv)

Using these I would assess
Golden gate Bridge
a - fairly high. It was for some years the longest suspension bridge
b - fairly high
c - really only regional around the Bay?
d - definitely

Trans Siberian
a – I don't think so. USA + Canada had already done "trans continental"
b – No
c - Only regional on Russia
d - Not really

Panama Canal
a – High/Unique (in engineering and organizational terms). Others had tried and failed!
b – I don't think so
c - Worldwide impact
d – Demonstative of Growth of US power

On that basis GoldenGate Bridge and Panama Canal would be in our Top 50 but not Transiberian.
Views??

I don't think I can support the Golden Gate Bridge Proposal, for although it is iconic, its technical advances were limited to it being bigger than the proceeding largest Suspension Bridge.

This is where I am in a sticky situation as many of the great breakthrough engineering feats of the industrial revolution mostly occurred in Britain, and we can't propose sites from our own country (by the way this was the only one from the UK I thought would be worthy of a Top 50 space).

I have long thought of attempting to get a cohesive tie around projects spread throughout the country into some sort of 'Infrastructure of the Industrial Revolution in the Britain' style proposal.

This would include projects such as; the Menai Straights Birdges including the world's first suspension bridge (and perhaps their miniatures in Conwy), Pont-Cysyllte Aqueduct, Clifton Suspension Bridge, Selected parts of the Great Western Railway (Box Tunnel, Maidenhead Railway Bridge, Paddington Station etc), Leeds-Liverpool Canal, Stockton-Darlington Railway, Forth Rail Bridge, Selected parts of London's subterranean infrastructure e.g. Thames Tunnel and parts of the Metropolitan Railway line, perhaps the already inscribed Ironbridge of Ironbridge Gorge and early steam railway in Cornwall, maybe more.

Now I think it is very disparate and unfocussed, but I am thinking that serial sites such as the Belfires of Belgium and France and Pilgrimage Routs to Santiago are developed over a long period of time and contain different facets, maybe for coherence it could be reduced to the works associated with just Brunel? But with some work it would be something that would meet the four criteria set out by Solivagant and to some extent I think it could claim to be the maximum that each criteria could achieve.

a- These were the first of nearly everything, first 'railway', first suspension bridges, first Iron bridge, first underwater tunnel, first underground railway.

b- The influence of these projects essentially redefined the building of infrastructure throughout the world not just limited to the region or British Empire.

c- These were the means by which the industrial revolution redefined production and society, which has had an effect on almost every corner of the world. They enabled Britain to become the predominant world power of the age.

d- These contain several iconic projects most notably the Forth Rail Bridge but also Clifton Suspension Bridge, Menai Straight's Bridge, the 'Tube'

I think this would make it worthy of a place in the Top 50 missing in my opinion. But of course I am not proposing it as I am excluded from proposing a site in my home country.

In addition I support the Panama Canal proposal, for both the technical achievement and also as a display of the economic and political emergence of the USA.

I am willing to adopt Meltwaterfall's (non)proposal and propose it myself. I find his arguments convincing.