Having touched very briefly on the historical significance, the variety of styles and even the challenges in finding the early iron bridges, it is time to consider how to assure that they are all still proudly carrying water or spanning it two centuries from now. That leads to the basic question: exactly how many are there left of these bridges and aqueducts and what condition are they in at the present time?
There is no definitive, comprehensive inventory of the surviving iron bridges. From references in the many books written at the time of the first iron bridge bicentennial and since, especially the Civil Engineering Heritage guide books, one arrives at a figure of about 200. Thirty years later, such a list needs to be updated. Domestic bridges on private land and on land held in public trust by various institutions as well as those in Ireland are the most likely sources for additions to a current inventory. Others bridges have been demolished or dismantled and that needs to be noted.
It is the author's intention to compile such a comprehensive list from many sources and then to visit each site to take color digital photographs of the bridge from different angles as well as to take its GPS coordinates both for identification purposes and to facilitate future visits. A truly comprehensive list will always be a moving target, but it is important to make a base line in time and in current information to build on in the future. The author is approximately half way through this process of visits and documentation and would welcome information on any obscure bridges that should to be included.
Such a digital file can eventually contain everything known about one bridge: digital photographs, engineering plans, anecdotal notations, maps and diagrams, and any other relevant data. Such files can be stored, edited, accessed, shared, and have back-up security at the fraction of the cost of maintaining and handling and copying paper files. Additions and corrections are easily done with the date noted and by whom if helpful.
Of equal advantage is that these files can be cross-referenced by geographical area, by builder, by site or by type of design, and accessed partially or in whole for reference and comparison from anywhere in the world for teaching purposes or for research. The policies of access and copy write and editing can still remain the sole prerogative of the governing body of the non-profit entity under whose auspices it will be maintained, hopefully in perpetuity. {8, 11}
The contents of such an archive would be an effective tool for preservation. A website devoted to old iron bridges and aqueducts would be of common interest to a number of organizations whose members see these bridges all the time, but probably are not aware of their significance, such as canal boaters, tow path hikers, fishermen, industrial archeology and rail road buffs to name 'outsiders'. For those who live with these old bridges, for whom they are hiding in plain sight, it would be a point of pride to know more about them. There are organizations who care for historic properties such as the National Trust, English Heritage, Cadw, and British Waterways who apparently have no master list of their own for the bridges in their care, so that this inventory would be of value to them.
The goal here is to have as many people as possible within as great a variety of interests and professions as possible who appreciate these bridges and who would therefore be a potential advocacy group for their preservation. {11}