Initial Historic Bridges CoP Discussion Thread

Folks - I would offer two observations based on over ten years of Historic Bridge advocacy in Indiana:

First – we must find an economic incentive for consulting engineering firms to consider rehabilitation. Most of my work has been to preserve county owned bridges and in almost every case the cost associated with rehabilitation has been less than replacement. (Although we have found the need at times to fund alternative studies in order to show the true cost of rehabilitation) Simply stated, it is in the economic self interest of the consulting engineering firm to propose replacement. In order to provide an incentive in Indiana, we have worked to have Low Volume Road design standards that make available BR funds for bridge rehabilitation, thus eliminating the need to compete for limited TEA funds and have proposed lifting the restriction on the number of rehabilitation bridge projects that can be underway within a county.

This coupled with:

Second – there is a need to separate the historic review process from the engineering work of bridge replacement / rehabilitation. The combination of these functions results in a “fox guarding the hen house” arrangement; where the economic incentives can overshadow the preservation review process. This could be as simple as a policy change where once a project is identified that involves an historic bridge, the section 106 and 4(f) review work is funded and under the control of FHWA; not the bridge owners. This would establish the appropriate “client “ relationship.

Finally, neither of these comments should be considered critical of consulting engineering firms - I have worked with a number of good firms over the years; but offer I would offer the observation based on over twenty five years in management: “tell me how someone is rewarded and I will tell you how they behave”.

Paul

MAINTENANCE.  Ken Harwood hits one of the nails on the head.  By the time many historic bridges come up on a project list, they are suffering from deferred maintenance.  Not only that, if they have received maintenance, that maintenance has sometimes been detrimental to the integrity of the resource – for example, well-intended, but inappropriate welding, repointing, patching etc. that makes it hard or impossible to rehab when the time comes.

This critical area of FUNDING & TRAINING FOR APPROPRIATE MAINTENANCE has been largely overlooked, in part, because project development is driven by Section 106 and 4(f).  This is both an issue in the regulatory and funding streams as well as an organizational issue within state DOTs because maintenance and operations are usually separated from planning and design where most project development takes place and where historic bridge expertise lies.  We need to find ways to target funds to historic bridge maintenance and training, as well as reach and educate the maintenance and operations side of the DOTs.  Some DOTs have begun to realize this and are including maintenance programs or at least "best practices for maintenance" in their historic bridge management plans, but whether those maintenance components are implemented and have the desired impact it is too soon to tell.  Did we lose an opportunity with the stimulus package because so few states have “maintenance” ready plans for historic bridges.  Do any of the community know of a state that has a historic bridge maintenance plan and actively promotes and uses it?  Which states have Programmatic Agreements stipulating the use of appropriate maintenance to govern specific historic bridges or populations of bridges?

I may have misdirected this reply by giving it a title: "Secretary of the Interior's Standards," so I'll try again.

This follows up on the important topic of "purism" in bridge rehabilitation, first raised by Frank Griggs and pursued by several others, including Steve Olson, Joseph Pullaro, and Ann Miller.  Frank mentioned that "the best is often the enemy of the better." 

When a National Register-eligible bridge is affected by federal funding, the lead federal agency (usually FHWA) must follow Section 4(f) of the DOT Act of 1966 and Section 106 of the National Historic Preservation Act (NHPA) of 1966. Both laws seek to avoid harm to historic resources, and the State Historic Preservation Office (SHPO) is a consulting party in this analysis.  SHPOs must try to apply the Secretary of the Interior's Standards for Rehabilitation to their analysis of the proposed project.

For anyone not familiar with these Standards, see http://www.nps.gov/history/hps/tps/tax/rhb/stand.htm.

In general, I don't think that these Standards require a purist approach to bridge rehabilitation, though they do urge retention of the maximum amount of original material and replacement in-kind whenever possible.  That could mean rivets instead of bolts, but not necessarily.

The big problem is that the Standards were written for buildings.  They apply awkwardly to bridges.  This was perceived when the First National Best Practices Conference for Covered Bridges was held in Burlington, VT in 2003.  That conference adopted the Burlington Charter for the Preservation of Historic Covered Bridges.  The  charter was accompanied by a resolution asking the National Park Service (which defines the Standards) to "adapt the Standards to historic covered bridges."  This effort is reportedly underway, but it may be arduous work.

The plea really ought to be broadened to "adapt the Standards to all historic bridges."  The Standards figure in most or all federally-funded historic bridge rehabilitation reviews, and SHPOs must try to apply them appropriately.  In some cases, especially where the SHPO has no staff engineering expertise, this may lead to an inappropriately purist approach, not tempered by a sense of what is practical and cost-effective, and not meeting the necessary engineering criteria to keep the bridge in question in service for another 50 or 100 years.

We need to address the incompatibility of existing federal rehabilitation standards with historic bridges.

I agree w/ James Garvin.   As I recall, VaDOT actually developed a corollary document to the SoI Standards for bridges, 20 or more years ago.  Not sure I could find it now.  Anyone remember?

Track federal and state funding for replacement, repair, rehab, and bridge maintenance.

No one seems to be tracking the flow of money into each of these areas.  The FHWA has said that they do not distinguish, nor do they require reporting from the states, about the proportion of funding is used for replacement vs. rehabiliation.

It seems to me to be fundamental to infrastructure policy to know where the money has been going.  This is a nontrivial excercise, and would require a great deal of work, not least to come up with some agreed upon definitions.  For example, what is maintenance?  Still, I think this is one of the most important metrics for good policy-making.

As usual I agree with Jim's comments. My main problem has been with SHPOss who try to add on their own preferences to the Dept. of Interior standards. While it is possible to fight them on these issues and maybe win they slow down the process so much that interest is lost and prices keep on increasings. One of my complaints was on an 1859 Cast and Wrought iron bridge that had collapsed into a river damaging many of the cast iron members and bending and breaking some of the wrought iron members. We were very faithful to restoring cast iron verticals using ductile cast iron but with the same geometry. We used some welding on other cast iron parts and wrought iron members. On some missing wrought iron parts we replaced them with mild steel. This was fine with the SHPO and in keeping with the inttent of the standards but some other SHPO may not have agreed with these solutions. The main problem was on site work. I had restored a Moseley WI bridge on the campus of Merrimack college and placed it over a pond that we built. Since the project was done with private funds (contributions, etc) we had no problems with any SHPO. On the subject project we were going to build a similar pond as the bridge was to be built near its original site, which was over the Erie Canal, on a plain adjacent to the NY State Barge Canal. In designing the pond the SHPO rejected our solution and told us what it would take to get his approval. We fought this as it had nothing to do with the restoration of the bridge and was beyond his area of espertise. He was not a registered professional engineer, but he insisted nonethe less. Eventually we gave in just to get his signature. Another item was handicapped accessibility. We gave our best effort to provide handicapped accessiblity around the pond and under the bridge but due to the steepness of the earthen ramps we could not provide access to the bridge deck. We tried to distinguish between the actual towpath stone dust surface and the handicapped paths, on the flat, for which we used gravel. He did not like this solution and recommened his own, still outside of his expertise, and slowed the process down so much that we again had to go against our professional judgement and accept his way. I have no problem with listiening to suggestions or demands from SHPOs but when they try to impose their preferences under the guise of the federal standards they add nothing but time and cost to a project. This response will not please many but it was a case of SHPOs doing more than applying "the Secretary of the Interior's Standards for Rehabilitation to their analysis of the proposed project."

Greetings:  Regarding Eric's call to amend 23 U.S.C. 144(o), this is long-overdue.  Efforts to amend provisions of that law, specifically the federal funding limits (estimated costs of demolition) placed on bridges removed from highways, began in 1993, and we haven't made much progress to date.  Rather than focus on minutia at this stage (bolts vs. rivets), let's look look at the larger picture.  We need a creative national initiative to encourage states to develop programs that identify alternative uses and sites for historic bridges at risk.  That program should also serve as something similar to a clearing house, keeping tabs of bridges at risk and moving quickly to prevent crisis-mode decision making.   Obviously funding is a key part of that, but creating public awareness about  the value and feasibility of such a program is just as important.  And, it should be coordinated with national programs aimed at building footpaths and bicycle paths, and also programs aimed at reclaiming urban or community growth centers.  Those are places where opportunity exists.  The national program should also explore ways to keep the costs of adaptive use reasonable - competitive with the costs of building or purchasing a new bridge for bicycle or pedestrian purposes.  Vermont's prototype for restoring a 45-foot metal truss bridge adapted to a footpath in Hinesburg, designed and managed in-house in 1995, cost about $32,000 (not including the costs of agency overhead).  Today, a similar project developed by a consulting engineering firm might cost about $500,000.  I suspect the true costs are somewhere in the middle, but the gap remains substantial.  

 

 

 

 

On Patrick Sparks's question as to the Virginia document relative to the Secretary's Standard's: VDOT, through the Virginia Transportation Research Council, has produced numerous bridge surveys and related documents.  In 1985 Howard Newlon produced a paper called Some Considerations Relating to the Need for and Development of Rehabilitation Standards and Guidelines for Historic Bridges, but this was not published as a report and is not available in electronic format at this time.  The most current Virginia document which includes application of the Secretary's Standards for historic bridges would be A Management Plan for Historic Bridges in Virginia (2001), of which I am principal author.  To access this electronically, you can go to the AASHTO historic publications site (i.e., the "other" site that Terry coordinates), or go to the Research Council reports site at http://vtrc.virginiadot.org/PUBS.aspx and type in the title.  The overview on the Secretary's Standards with application to historic bridges is on pp. 13-16 of this report.  

Note also that maintenance is an important component of our historic bridge management plan.  Detailed recommendations for each bridge are not included in the published version: these are worked out with the district bridge engineers who oversee the specific structures. 

 

There are many important issues, including funding and technology. It is hard to choose a single most important issue, but among the top issues is the owner's expectation regarding the finished project.

This is an issue for all repair, restoration, and retrofit projects, not just historic structures. Too often the owner does not have a clear vision of what he wants to accomplish. He knows he has a facility that does not meet his needs, but does not set a target for the finished product. Too often a bridge owner's assumption is that when the work is done he will essentially have a like-new bridge. This is no more true for historic bridge restoration than for auto repair - if you take your old car to the shop to get the transmission fixed you don't normally expect to get a new car back.

As design professionals, part of our job is to help the owner define his objective. Another part is to help the owner make the necessary value judgments regarding his project, balancing costs versus the outcome.

I have to agree with the suggestion that maintenance may be among the most serious issues for historic bridges. I have long said that a lot of preservation can be accomlished with the right attitude. Most local engineering authorities need an attitude adjustment when it comes to historic bridges. What to do? Might it be possible to create incentives for developing maintenance standards fro hsitoric bridges? Otherwise we're left trying to salvage "too-far-gone" structures. I would suggest we need to promote this concept for statewide bridge preservation plans as a high priority.

David Simmons' comment is equally correct if the work "historic" is removed. Dept's of Transportation are terribly underfunded, and tend to treat the "worst first." This exacerbates the trend to replace bridges instead of rehabilitating them.

I agree that maintenance guidelines for historic structures would be helpful, as some of the maintenance requirements and techniques for older structure components (pins, riveted connections, timber, bearings, and masonry) are different than those for current structures.

Perhaps a good place to start is a synthesis of current practice, if that has not been done already. That might help get existing information out to the bridge owners.

I can't refrain from replying to Frank's posting in which he references the Moseley bowstring he worked on. It relates to the issue of riveting which he and others have raised. As some of you may know, I took on the history of the Moseley truss as a research project a number of years ago. I set out to try and determine the origins of the tubular bowstring and then answer the question of how it was constructed and erected. A critical question was how field connections were made. It was all a part of an effort to more completely understand the history of the form in order to better understand how to best preserve such structures. The work led to an article in the Society for Industrial Archeology's journal IA in 1993. The Merrimack College "restoration" overseen by Frank wholesale replaced original rivets with bolts and basically destroyed all evidence that would help answer that question. Thus a well-intentioned "strengthening" of a bridge led to a serious diminishing of its historic value. So before decrying those who promote rivets as wild-eyed purists in our efforts to preserve, let's give some credit to a system that has worked admirably for decades or even centuries and is being revived in Michigan through an National Center for Preservation Technology and Training (NCPTT) seminar. Riveting doesn't have to be "more expensive." Bolters work by the hour too.

I can't help but reply to David's comments. First of all since I restored the Moseley Bridge with no budget and with a great deal of my own hands on labor I am fully aware of how the bridge was built. I told David the process serveral years ago. As to rivets in the Moseley I tried at the time to find someone who would replace the rivets at a low or no cost. Failing in finding anyone I chose the only method that was within in my budget and had a local hardware store give me the bolts required to replace the rivets. I would say that about 80%++ of the rivets were retained. The only place I used bolts were at the ends where I had to replace the rotted end wrought iron plates with mild steel, at the middle of the arch where the contractor who removed the bridge from the canal in Lawrence cut the arches in half to move the parts to the campus and in one spot where the plates were "kinked" in the move and I had to splice in plates I moved from the ends of the arches. I would also take exception to David's comment "The Merrimack College "restoration" overseen by Frank wholesale replaced original rivets with bolts and basically destroyed all evidence that would help answer that question. Thus a well-intentioned "strengthening" of a bridge led to a serious diminishing of its historic value." If he had ever seen the bridge he would know that I did not replace any more rivets than I had to and it was surely not "wholesale." The use of bolts was not to "strengthen" the bridge but only to put it back together again. This is just the kind of "purist" attitude that does not recognize that available funding sometimes dictates what is possible. If I waited for funding to be available the bridge would have been at the junk yard and not spanning a reflection pool on the campus of Merrimack College for all to see and cross. And finally, replacing rivets is not a permanent condition as if someone came along later and wanted to replace the bolts with rivets it can be done with no difficulty. There are many things I would have done differently if I had to do it over again but using bolts instead of rivets is not one of them. I would rather not have written this response but I just could not let David's charges stand without a response. I would be glad to explain in depth what I did to "save" this bridge if anyone is interested. I will have a paper in the ASCE Journal of Structural Design and Construction soon describing this and other Cast and Wrought Iron Bridges I have restored. It has been accepted but a publication date has not been set. I would also suggest that my article on the restoraton entitled "1864 Moselely Wrought-Iron Arch Bridge: Its Rehabiliation, Practice Periodical on Structural Design and Construction, ASCE , Vol. 2, No. 2, May 1997, pgs 61- 72" and "Restoration of Cast and Wrought Iron Bridges, Structure Journal of the Structural Institute of ASCE, September 2001, page 16-19" be read by anyone interested in the project. Frank

Driving to work this a.m., I was thinking about Terry’s original charge of ways to improve historic bridge project development and decided to brainstorm a list of what I believe has been working reasonably well, on the theory that building on what has been proven or has shown high likelihood to work is often a good strategy.  Here is the start of my list:

 

(1) AASHTO Bridge Subcommittee has adopted a fair and balanced approach to rehab or replacement decision making.  We need to encourage the use of this flexible approach.  See the recent AASHTO publication, Historic Bridge Rehabilitation or Replacement Guidelines. (tooting my own horn, since I and my colleagues at TranSystems/Lichtenstein had a hand in drafting this).

 

(2) Clearly articulated purpose and need statements, adopted at the very beginning of the planning process –  recognition as early as possible by project management  that special considerations apply to historic bridge projects, that the project is being categorized appropriately, like 3R, where there may be more flexibility, rather than waiting to address historic bridges during formal Section 106 review.

 

(3) Individual bridge-specific management plans that have the backing and buy in of SHPO, DOTs (not just cultural resources/planning section but bridge design and bridge maintenance), bridge owners (since many historic bridges are not owned by states), and community.  When complete confidence in the plan does not exist at the appropriate organizational/stakeholder level, that means it won’t be implemented or only selectively implemented.  Success usually means that the appropriate individuals have participated in the planning to understand the various perspectives, and the plans are specific to individual bridges.  Not to say that there aren’t technical approaches that are universally applicable to specific populations of bridges.

 

(3) Commitment to good maintenance strategies – for example, washing away salt and removing built-up debris – and applying them on a routine basis.

 

(4) State legislative mandates and administrative policies that articulate goals of preserving historic bridges and flexibility in application of engineering guidelines.

 

(5) Transportation enhancement funding applied to historic bridge projects.  There have been many success stories in this arena.

 

(6) Truss bridge relocation projects – private groups, trails, and parks – have an excellent record of cost-effective and community developed projects.  Good things happen when we can connect one of these groups or trail projects with an historic bridge.  See Bob McCullough’s comment about amending the way funds are made available through the estimated cost of demolition.

 

(7) A public and preservation advocacy community that is knowledgeable about the historical significance of historic bridges and brings value/expertise to the planning process.  Encouraging consistency and predictability in articulating the preservation point of view and application of procedures, and bringing constructive recommendations (not obstruction and frustration) to the table, e.g., being able to clearly articulate specifically what it is about a bridge that makes it significant, founded on sound scholarship and understanding, and those details of a bridge that can be changed without having an adverse effect.