Re: How do you install a massive iron/steel bridge with hand tools ?

Having been in the business, it is quite simple, really. Parts are procured and moved to a convenient staging point for the work to be done. Of course, logistic considerations for sizes and route restrictions have to be planned. If curves and tunnels proved too tight, flatcars with slings or other "flexible" carriers might be improvised. You do whatever it takes to get the job done. While parts are being gathered, site prep can be initiated and footings formed and poured, overhead suspension lines anchored and strung, and the construction camp built. This would likely include a forge shop for any custom work and heating the 1000's of rivets. In the end, such a project is nothing more than a full size Erector Set. What always amazes me is the remoteness and the general acceptance of such a raw life in what was then even more in the middle of nowhere than it is today. Read the story of the building of the Alpine Tunnel some time ! What a life !