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Second Bank Conditions Assessment

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A highlift being used on the south facade.
Complete Assessment Overview
Phase 1 of the assessment survey began with the north and west elevations. The exterior masonry conditions survey was completed during Phase 2 of the project, surveying the south and east elevations in 2003. Since the work carried out on the Second Bank of the United States actually spanned two different phases, efforts were made to maintain consistency from one phase to the other; however differences did occur which helped the ACL to test the repeatability of the building conditions surveys.

Presently, all of the exterior masonry of the building has been carefully inspected, the conditions recorded, digitized drawings produced, the final product field checked and preliminary assessments formulated. Data gathered from the exterior masonry survey has been used in preparation for GIS-based diagnostic assessment and remedial and preventive intervention.

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Teams followed proper safety procedures when working on high lifts and scaffolding.
Phase 1
Phase 1 was conducted from June 7 through July 16, 1999. A total of six graduate and post graduate interns conducted a complete investigation of both elevations with the use of movable scaffolding and 60’ and 45’ high lift cranes with extending booms.

Teams alternated between recording conditions in the field and digitizing those conditions in AutoCAD over the new drawings. During the six-week field school, all elevations of the portico including the columns, pediment, ceiling, flooring, and stairs as well as the entire west elevation were surveyed and digitized. Two interns continued for a three-week period beyond the field school to check and complete the survey drawings.

conditions assessment

In many locations on the building,the stone has suffered from a wide range of conditions including soiling, erosion, spalling and staining.

In 1999 a multi-phased conservation plan was developed and initiated with Independence National Historical Park beginning with the preparation of a detailed CAD based survey of the exterior masonry conditions based on early HABS recording and the compilation of a history of past repairs and treatments to the building.

Phase 2
Phase 2 of the survey was conducted from June 2 through July 11, 2003 by a total of five graduate and post graduate interns. Movable scaffolding and a 60’ high lift crane were used for recording and documentation purposes. AutoCAD line drawings from the 1999 survey were modified and adapted to the south and east elevations to be used as base drawings for conditions recording. The drums of the columns were accurately measured while all other joint lines on the ashlar walls, steps, and floor were carefully approximated by eye. For surveying purposes, the team divided the conditions into five groups and assigned each group to one team member. This decision was made in order to ensure consistency across the survey in an effort to combat against the sometimes subjective nature of conditions recording despite detailed glossaries. All conditions recording of the entire east elevation and south portico including the columns, pediment, ceiling, mutules, entablature, floor, and stairs was completed during the six-week field school. Three interns continued for two to three weeks beyond the field school to begin the digitization process. One intern continued over the course of the fall and winter to complete digitization and lay out the final set of drawings.

Documentation in the form of digital photography was also made during time spent in the field. When an exemplar condition was found, it was photographed for use in the revised glossary. Unique conditions and complex deterioration patterns were also photographed, along with construction details that could only be seen with the aid of the high lift or scaffolding. Digitization was a three-step process using Photoshop, AutoCAD, and ArcView software.

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The columns showed the most deterioration and the final assessment created an opportunity for a second project with the Park carried out in 2011 using Surface Penetrating Radar.
Solving Problems
As a result of two different teams recording conditions, the final full survey had discrepancies. On the Second Bank, the north and south facades are almost identical, as are those of the east and west. By having the south and east facades surveyed in 2003, and the north and west facade surveyed in 1999, a comparison showed that the results of each phase differed when comparing areas of the same condition, suggesting that the system in place was not adequate to ensure consistency. Conditions, while well defined, can be subjective and are ultimately defined by the individual who is recording them. This is especially true when addressing the fine nuances that differentiate one condition from another.  As a result of this variation, the ACL adopted new guidelines for all their future surveys.

During Phase 1, individuals were asked to record the entire set of conditions within a given portion of the overall survey area. Since differences were noted from one area to the other, during Phase 2, all the conditions were divided into sets. Each person was assigned a set and was asked to record those conditions for the entire survey area. The work load was consistent with that of the 99 survey however the results were not, showing much more consistency across the entire surface.

After a thorough introduction of all conditions to the entire team, each person was asked to write comprehensive definitions for their assigned conditions and compares them with the other definitions in the group. this process helped individuals better define their own conditions.

Finally each individual was required to capture at least 3 photographs of each of their conditions which could be used in the final printed glossary. These photographs needed to clearly show the defined condition and show its full range.