1. PennDOT Management
Plan for Historic Metal
Truss Bridges
Kris Lammi Thompson
PennDOT Cultural
Resources Specialist,
Districts 4-0 & 5-0
2. Historic Metal Truss Bridge
Management Plan
• Historic Metal Truss Bridges-rapidly
diminishing resource
• Bridge Inventory (2001):
– 863 total trusses
– 303 eligible/listed
• Population today:
– 601 total trusses (in BMS)
– Loss of 262 (30%)
– 47 eligible/listed lost (16%)
3. Historic Metal Truss Bridge
Management Plan
Gannett Fleming/Transystems
Project Team-PennDOT Central
Office, District CRP, FHWA, PHMC,
PennDOT Bridge & Highway Units
Protocol for Determining
Preservation Potential
4. Historic Metal Truss Bridge
Management Plan
Determining which Bridges to Assess:
Protocol for Defining Levels of
Significance
Historic Trusses on TYP
Historic Districts
5. Met with PennDOT Districts
What is the incentive for local bridge
owners to rehabilitate a historic
bridge?
6. Met with PennDOT Districts
Fiscal and technical assistance for
counties and municipalities?
9. Historic Metal Truss Bridge
Management Plan
• Management Plan Document- Draft in July
– White Paper
• Purpose/Objective
• Overview of Approach
• National Context
• Benefits
• Effective Management Plan Practices
– District Meeting Summaries
10. Historic Metal Truss Bridge
Management Plan
• Management Plan Document (Cont’d)
– Summary and Results
• Research Summary
• Coordination
• PHMC Historic District Assessments
• Levels of Significance for Population
• Prioritization for Individual Assessments
• Implementation Plan
11. Historic Metal Truss Bridge
Management Plan
• Management Plan Document (Cont’d)
• Appendix Items:
– Protocol for Defining Levels of Significance
– Protocol for Determining Preservation Potential
– Database (outline)
– District Summary Tables (truss lists)
12. Local Significance and Bridges
• Interagency Funding/Cooperative
Agreement
• Bucks/Chester Counties
• Guidelines
• Potential Contexts
• Public Outreach/data gathering
13. Local Significance and Bridges
Completed or In Progress:
•Public Meetings held Fall 2011
•Background Research Conducted
•Context Development
•Comparison with other states
14. Historic Metal Truss Bridge
Management Plan
Questions?: Kara Russell:
krussell@pa.gov or
Kris Thompson:
krthompson@pa.gov
Editor's Notes
This initiative started as we, working with PHMC, began to see the degree of loss among the population of historic metal truss bridges. Approximate numbers—difficult to be precise but accurate current counts is something we hope to have as part of the project outcomes
*Contracted with GF through CO open-end who subcontracted with Transystems *Project team assembled which includes a CRP rep., PHMC reps (Cheryl Nagle and Barbara Frederick)., CO Bridge Rep., Highway Project Delivery Rep., The effort is built on methodologies Transystems has used successfully in other states such as Maine and OH We are proposing an individual assessment model (vs. ranking system) based upon the AASHTO Guidelines for Historic Bridge Rehabilitation and Replacement ( which AASHTO endorsed/published in 2007 and which our CR handbook uses as guidance for Rehab. Feasibility Analysis Reports. The methodology is outlined in the document “Protocol for Determining Preservation Potential”. It is built on the notion that a bridge must be made “adequate” (a term used in the AASHTO guidelines) for the transportation use. It is predicated on developing a defensible and reasonable purpose and need statement and implementing a balanced approach to the consideration of preservation and need. The protocol also attempts to balance consideration of safety and also cost.
The management plan effort involves applying the protocol for determining preservation potential to historic metal truss bridges in the plan. Insufficient funds to evaluate all historic metal truss bridges +No need to evaluate bridges already preserved/recently rehabilitated or major river crossings where rehabilitation will be thoroughly considered anyway due to cost of replacement Assessment priority will be built on two things—level of significance and whether or not a bridge is on the TYP. If on TYP but not too far along in 106 ideal for consideration—this is a linking and planning tool! Recognition that some bridges are more significant that others—Trans. developed a methodology for determining a hierarchy of significance. Highest level called “Exceptional”, middle “High” and lowest “average”. This hierarchy of significance is important in helping to prioritize bridges for evaluation but also for determining what can be done to the bridges, such as in a rehab., without affecting historic integrity. Each historic metal truss bridge has been ranked as having an average, high, or exceptional level of historic significance.— currently in internal review and then we’re going to reach consensus on rankings with PHMC. The protocol facilitates evaluation of bridges within populations of similar bridge types/designs within their appropriate specific national, state, or local contexts. PHMC has assisted us by working with our CRPS in assessing historic district potential for areas surrounding these bridges. These aren’t official DOEs but for planning purposes in knowing if a truss bridge would contribute to an historic district surrounding, or adjacent to, a truss bridge. This is factored into the significance assessment and also the approach for evaluating preservation/rehabilitation options.
*Started with District meetings to get a sense for how districts feel—would a management plan benefit them; type of plan that would benefit and also info. gathering on how districts consider truss bridges now in decision to rehab. vs. replace -consensus was there is need for management plan and agreement with approach proposed -several districts felt that it would only be successful with local bridges if there was a “carrot”-funding to encourage the rehab. choice for a bridge the project team feels could be rehabbed and meet needs. *District meetings also included field views with Transystems Historian and Transystems or Gannett Fleming Bridge Engineer +CRPs to begin gaining understanding of remaining population anticipation of significance ranking and assessment priorities. We saw many many bridges w 3 or 6 ton postings such as this Pratt Pony, one of several similar on Huntingdon Ck. in Luzerne Co. that feature Phoenix columns. Most of these are not on the TYP but are highly significant ,if not of exceptional significance. The "Phoenix Column" (patented by Samuel Reeves in 1862 during the Civil War), was a hollow cylinder composed of four, six, or eight wrought iron segments that were riveted together into a single column. The result was much lighter and stronger than the usual solid cast iron columns of the day [8] and advanced the ability to build massive structures without the usual brutally heavy load bearing walls. Taller and taller buildings could now be built on narrow urban plots, helping facilitate the creation of the skyscraper and high stress load bearing bridges. Phoenix Iron Works/ Iron Company
The field views clearly illustrated the biggest problem (that all bridge engineers are aware of)—inadequately maintained locally owned bridges. Most of the historic trusses, particularly the highly significant ones, are locally owned. We saw many bridges hanging on at 3 tons., many of which end up in a cycle of open, closed, minor repairs to bring back to 3 ton min., This one in Berks county was recently closed following inspection. (Wiley’s Br. on Bower’s Rd.) Clear problem with lack of cleaning, esp. connections and bearings, which would help with longevity. Several districts mentioned the difficulty with funds for cleaning but also associated DEP permitting. We are realizing that a successful management plan may need to come with a maintenance set-aside for local bridges determined to be preservable (and meet needs).
In some cases, as with Messerall Rd. Bridge in Beaver Co., need for reopening is not clear—with clear alternatives in the roadway network, and if a bridge could only be rehabilitated to 6 or 9 tons without affecting its integrity, the question becomes is the need great enough to justify the rehab. for this limited capacity?; demolition is not a priority either so many just sit barricaded indefinitely. So, the individual assessments and how need is defined is going to be key. The assessments will also help establish what is controlling the rating, and how easily the bridge could be reopened (repair needs analysis). When a bridge is not going to be reopened we’re going to work with PHMC, and other partners to hopefully find off-system uses.
We are also going to look at “abandoned” bridges, including former road/highway bridges (to the degree we’re aware of them—some are in BMS, some aren’t) Why?: 1) they may affect significance level of on-system bridges; 2) there may be opportunities—even better opportunities given that timing is not an issue-for preservation. Preservation of any truss helps with PHMC and CP coordination in terms of sentiment that trusses are being preserved. Many on-system, but highly significant bridges, will be better candidates for off-system adaptive reuse than for rehab. for continuing vehicular use. We want to have a good inventory of bridges available for/better suited for reuse so that we can market them early. AGAIN—Anticipate a partnership with PHMC and locals to find adaptive reuses.
Management Plan document in internal review—to be shared with task force team, including PHMC next.
PHMC has been helpful in conducting historic district assessments
In 2011 an agreement was signed between PennDOT and PHMC to provide funding to PHMC to support a joint initiative to identify potential National Register areas of significance for local bridges in Chester and Bucks counties under Criterion A of the National Register of Historic Places Criteria for Evaluation. The joint initiative will also establish guidelines and standards for documenting significance and will identify potential contexts for evaluation. The funds provided to PHMC will also be used for public outreach efforts to elicit local opinions about important transportation resources and to identify local sources of information to support National Register evaluations; PennDOT is also providing additional funds to support a consultant who is conducting primary research and help draft the guidelines Intent of this initiative is to use these 2 counties as a starting point for a statewide reevaluation of historic bridges (once funding can be established) using established criteria. Initiative comes out of a task force that included representatives from local historic preservation groups who expressed concerns with the 2001 statewide historic bridge inventory in terms of consideration given to local significance for bridges
Copies of the 2 protocols, sample assessments, district meeting minutes and other pertinent info. on the management plan effort can be found on the P drive. We are asking Environ. Managers and staff to look at the protocols, and esp. the sample assessments and let us know if they would be useful or of any suggested changes/improvements.
