MEMO To: Cindy Petkac, Union Station Redevelopment Corporation

329 Race Street
Philadelphia, PA
19106
215.923.2834 TEL
215.923.2835 FAX
bcausa.com
MEMO
To:
From:
Date:
Project:
Cindy Petkac, Union Station Redevelopment Corporation (USRC)
Lauren Drapala, Building Conservation Associates, Inc. (BCA)
Dorothy Krotzer, Building Conservation Associates, Inc. (BCA)
July 16, 2014
Union Station, Rostral Columns
Conditions Assessment and Treatment Recommendations
At the request of Cindy Petkac, Building Conservation Associates, Inc. (BCA) has prepared a
memo on the present condition of the rostral columns at the east and west entrances of the
south elevation of Union Station in Washington, D.C. The conditions assessment was
performed as part of the Historic Preservation Master Plan that BCA is currently preparing for
Union Station. The portion of the assessment related to the rostral columns has been extracted
from this larger effort and presented in this memo so that USRC may provide information on
the condition of the columns as part of a grant application to District Department of
Transportation (DDOT).
Lauren Drapala and Julianne Chianese-Wiesner of BCA performed a site visit on July 10, 2014 to
inspect the granite bases, balustrade, cast iron columns, light fixtures and decorative sculptural
elements that comprise the four rostral column installations. This assessment was documented
primarily through on-site photography. This memo will summarize the conditions observed and
provide general, prioritized recommendations for treatment. It should be noted that, in several
instances, additional investigation, testing and review by other consultants (such as a structural
engineer) will be required in order to more fully develop the scope of work for repair.
Both the east and west entrances on the south elevation of Union Station contain a set of
symmetrical column installations. For the purpose of discussion throughout this memo, the
installations have been identified with alphanumerical references. (Figure 1) There is a primary
walkway that corresponds to the arched opening of the station entrance, which is flanked on
either side by large cast-iron composite order rostral columns, crowned with decoratively
gilded eagles propped atop spherical bases. There are circular lighting fixtures on both sides of
the column at the lower third of the shaft. The column sits on a granite base, approximately 66”
tall by 60” wide, which is connected to a granite balustrade, approximately 122” long, which
terminates at a smaller base for a light pole. The smaller base stands at the same height as the
balustrade, approximately 40” tall, and supports a cast-iron light pole with a glass spherical
lighting fixture atop. The west entrance is flanked by column installation 9A (Figure 2) at the
west and 9B (Figure 3) at the east, while the east entrance is flanked by column installation 10A
(Figure 4) at the west and 10B (Figure 5) at the east.
Each element of the column installation will be discussed, followed by a discussion of conditions
that are specific to individual elements, if noted. This survey only considered material condition
issues related to the rostral column installations. The electrical systems for the related lighting
components were not evaluated as part of this survey.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Overall Condition
Granite Base and Balustrade
The granite bases and balustrades of both column installations have a high degree of integrity.
However, there are areas of deterioration and conditions requiring repair, some of which can
be considered significant. In general, the west column installation (9A and 9B) exhibits worse
conditions than the east column installation (10A and 10B), with several through-masonry cracks
that will require partial disassembly in order to repair. Some cracking is significant and will
require review by a structural engineer to evaluate the cause of the cracking.
In both column installations, there are many open joints, which have allowed water to enter the
structure resulting in displacement over time (from either freeze-thaw phenomenon or
corroding internal anchors). (Figure 9) There is evidence of multiple repointing campaigns
through each of the stone installations.
There is disaggregation of the upper molding of the large granite base, which appears particularly
pronounced on the west entrance. (Figure 6) The bases also have multiple anchors that have
been installed in the granite faces, presumably used to secure previous signage, many of which
are corroding. (Figure 7) Atmospheric soiling is extensive throughout each of the bases, with
heavier surface accumulation at the east entrance (10A and 10B). Iron staining occurs most
prominently along the top rails of the balustrade and the caps of the bases. (Figure 8)
•
9A- West Column, West Entrance
- On the middle pier, there are significant cracks that extend through the north and
south faces, causing a corner of the pier to separate. (Figure 10)
- There are traces of graffiti on the east face that have not been fully removed. (Figure
11)
- Slight variation in the appearance of the balusters indicate that some balusters may
have been replaced over time. (Figure 12)
- A unique metal bracket is still embedded on the west end of the base, just under the
cast iron light pole. (Figure 13)
•
9B- East Column, West Entrance
- There are large vertical cracks through the center of each face of the large granite
base on which the rostral column sits. Many of these cracks have been previously
repaired with patching material, but they have re-opened over time. In addition,
there is evidence of leaching lime and/or salts coming from these cracks, suggesting
active water infiltration. This condition should be investigated to determine the
cause of the cracking. It should also be evaluated by a structural engineer to make
sure that the base can adequately support the weight of the column. (Figure 14)
- Diagonal cracking is visible at the upper corner of the middle pier of the balustrade,
similar to that identified on the middle pier of 9A. This through-unit crack is causing
a large spall at the corner of the pier. The source of the crack, which may be related
to internal iron anchors that are corroding in the presence of water, should be
investigated. (Figure 16)
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C -
There is isolated cracking in portions of the top molding of the balustrade. (Figure
15)
Corroded abandoned anchors are present on the south face of the middle pier of
the balustrade. (Figure 16)
Sugaring is also visible on approximately 3-4 balusters on the north face of the
balustrade. (Figure 17)
There is also an isolated loss at the southeast corner of the smaller light pole
granite base. (Figure 18)
•
10A- West Column, East Entrance
- There are appreciably more abandoned anchors in the surface of the large granite
base. Many of these anchors are corroded and resulting in staining on the face of
the granite. (Figure 19)
- Traces of black and white coatings, most likely paint, are present along the western
side of the balustrade railing. (Figure 20)
- There are isolated areas of loss at the southeast corner of the large granite base
(Figure 21).
- The balusters are consistent in appearance and texture, with pronounced iron
staining throughout.
- One baluster has been patched on its north face. (Figure 22) In comparison to the
installations at the west entrance, the central pier does not illustrate the same
diagonal cracking.
•
10B- East Column, East Entrance
- The large granite base under the rostral column is cracked on the north and south
faces along the upper profiled molding. The cause of the cracking was not identified
during this preliminary survey but may be related to the way in which the rostral
column is anchored and the possible corrosion of the anchor. (Figure 25).
- There is isolated loss of granite from balusters (Figure 23) and the base of the cast
iron light post (Figure 24).
- The balustrade appears to have moved over time, likely due to pervasive open joints
that have allowed water to enter the assembly (causing any internal anchors or
possibly causing internal pressure from free-thaw phenomenon). (Figure 24)
Cast Iron Columns and Light Posts
- The cast iron substrate is in good condition on all columns, although there are many
small areas of surface corrosion where the paint is flaking and peeling. (Figure 26)
- Corrosion is most prevalent at points of junction, at metal-to-metal connections as
well as metal-to-stone connections. (Figure 27) These areas have a propensity to
collect water.
- The light posts, and to a lesser extent the rostral columns, contain many metal
brackets previously used to hold signage. These brackets have been sensitively
installed and have been fastened to the poles through tension rings around the
perimeter of the columns. Many of them are corroding and resulting in further
staining of the decorative cast iron and granite bases. (Figure 28)
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C -
The access panels for the light pole base are often not secured in place and have
become places where trash is placed. (Figure 29)
Light Fixtures
- Three opaque white spheres are installed in each column installation, with the two
smaller globes on either side of the rostral column (Figure 30) and one larger globe
on the top of the light post (Figure 31).
- These glass spheres are further enhanced with metal straps that follow the vertical
and horizontal curvature of the globe. These elements are intact in each of the
installations and appear to be well preserved although generally soiled, based on
observations from the ground.
Decorative Eagle Sculptures
- Each rostral column serves as a pedestal for a sculpture of an eagle with wide
wingspread perched atop a sphere. These cast metal elements have been finished with
gold (either gilding or paint, or a combination of both), with one exposed horizontal
cast iron band around the globe. The eagles appear to be in sound condition, although
the finishes are fairly deteriorated, resulting in flaking and inconsistent finish across the
sculpture surface. (Figures 32-33)
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Recommendations for Treatment
The following prioritized recommendations for both rostral column installations are based on
the conditions observed during the visual inspection performed by BCA. In many instances,
additional investigation, testing and review by other consultants (such as a structural engineer)
will be required in order to more fully develop the scope of work for repair.
Granite Base and Balustrade
• The causes of the cracks in the granite piers and bases of column installation 9A and 9B
should be investigated. It is possible that the cause of related to either corroding
internal anchors or freeze-thaw phenomenon associated with water entering the
assembly through the numerous open joints in the stonework. For the column base in
particular, a structural engineer should be consulted to evaluate the cause of the cracks
present on every face of the base and determine whether there is any concern about
the base being able to adequately support the weight of the cast iron column.
• Once the cause of the cracking in the granite bases and piers is diagnosed and
addressed, the cracks should be repaired. In order to repair the cracked piers, partial
disassembly of the balustrade will be required. The top rails above the cracked piers will
need to be removed in order to access the piers. The piers will then need to be
removed or repaired in situ by installation of a dutchman piece at the corner (in the
location of the cracking).
• Re-assembly of any removed pieces should include re-setting using stainless steel pins
set in epoxy or lead.
• Smaller cracks in the stone that are more superficial in nature can be repaired through
injection with a cementitious grout or a patching mortar. Any losses in stone should be
compensated, either with a cementitious patching material or a stone dutchman repair.
• Because multiple pointing mortar campaigns are present on the structure, a mortar
analysis should be completed to determine an appropriate restoration mortar. Once an
appropriate re-pointing mortar has been identified, both column installations should be
completely re-pointed.
• The granite should be cleaned in an effort to remove surface soiling, ferrous staining on
the upper stone courses and traces of graffiti. Tests should be performed to determine
the best means of cleaning the stone.
• Abandoned anchors that are corroding should be removed from the stone and these
openings should be patched with a composite patching mortar that matches the
appearance of the surrounding stone.
Cast Iron Columns and Light Posts
• The original finish scheme of the cast iron columns and light posts should be
documented through paint analysis so that it can be replicated as part of the restoration
work. The existing finishes should also be tested for the presence of lead paint.
• The surface of each cast-iron element should be thoroughly scraped and/or abraded to
remove any loose or unstable paint on the surface. Similarly, areas of corrosion should
be thoroughly prepared to expose sound, stable metal substrate.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C •
•
•
Any gaps or openings in the cast-iron should be sealed with a sealant intended for use
with metal. Joints between metal and stone should also be sealed with an appropriate
metal-to-stone sealant to prevent water entry.
Cracks or small losses in the metal should be filled with a metal-filled epoxy that has the
ability to be shaped or tooled.
Access panels should be secured in place with appropriate, locking hardware.
Light Fixtures
• The glass spheres should be removed during the preparation and re-painting of the castiron surfaces of the columns. During this time, they should be thoroughly cleaned on
the interior and exterior. Once re-finishing of the columns has been completed, the
lighting fixtures should be re-installed, with any necessary electrical infrastructure
improvements needed to make the lighting system operable.
Decorative Eagle Sculptures
• The eagle sculptures appear to have multiple finish campaigns. A thorough finishes
analysis should be completed to determine the original finish scheme so that it can be
replicated as part of the restoration.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 1. Site plan of Columbus Plaza, identifying unique components, unscaled. The rostral
columns are noted, the west entrance at the upper left corner (elements 9A and 9B) and the
east entrance at the upper right corner of the image (elements 10A and 10B).
Figure 2. The south face of element 9A, at the west entrance on
the south elevation of Union Station, 2014.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 3. The south face of element 9B, at the west entrance on
the south elevation of Union Station, 2014.
Figure 4. The south face of element 10A, at the east entrance on
the south elevation of Union Station, 2014.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 5. The south face of element 10A, at the east entrance on
the south elevation of Union Station, 2014.
Figure 6. Disaggregation of the profiled granite molding on the rostral
column base.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 7. Multiple anchors have been installed in the granite base. These
elements are corroding, resulting in staining of the granite.
Figure 8. Extensive soiling is present throughout
the granite portions of the installation. There is
predominant staining on the top moldings of the
bases and balustrades from corrosive ferrous
elements, including the columns themselves.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C (
Figure 9. Open and cracked mortar joints are
pervasive throughout the stone bases. The
open joints allow water into the junctures
between stone elements.
Figure 10. Cracking through the middle pier of
the balustrade on element 9A. This image
shows the north face of the pier, but this
condition also extends into the south face.
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Figure 11. Traces of graffiti, or possibly
adhesive from prior signage, remain on the
east face of the large granite base on element
9A. Corroding abandoned metal anchors are
also visible on the surface of the stone.
Figure 12. Variations in the appearance of elements on the balustrade on
element 9A indicate that some elements may have been replaced. The
arrows highlight two elements that appear different from each other.
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Figure 13. Metal bracket on the west face of
element 9A.
Figure 14. Vertical cracking and leaching of lime and/or salts is visible
on every face of the large granite base of element 9B. This image
shows the south face, which has been previously patched, but is
currently cracked.
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Figure 15. Isolated cracking in the upper profiled molding of the
large granite base, at the southeast corner of element 9B.
Figure 16. Cracking through the middle pier of the
balustrade on element 9B. This image shows the
south face of the pier, but this condition also
extends into the north face.
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Figure 17. Disaggregation of the baluster bases on the north face of
element 9B.
Figure 18. Loss of granite at the southeast corner of the smaller light
post base of element 9B. The damage is most likely the result of impact.
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Figure 19. Abandoned ferrous anchors in the east face of the granite base
of element 10A.
Figure 20. Black coating (most likely paint) on the western portion of the
top railing of element 10A.
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Figure 21. Loss of profiled granite base molding at the southeast corner of
the large granite base of element 10A.
Figure 22. Iron staining of balustrade from ferrous corrosion in element 10A.
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Figure 23. Loss of granite at the top of a
baluster in element 10B.
Figure 24. Loss of granite at the northwest
corner of the smaller light post base in
element 10B, indicated by red arrow. Visible
open joints in this area also indicate slight
movement of the balustrade railing from the
light post base (blue arrow).
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Figure 25. Vertical crack running through the center of the top granite piece
on the smaller light post base in element 10B. The crack is both
visible on the north face (shown above) and south face.
Figure 26. Small areas of surface corrosion are
visible in areas of flaking and peeling paint
throughout the columns.
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Figure 27. Detail of corroded cast iron base of a light post at the junction
between the metal and stone. This area is particularly prone to water
infiltration and pooling and should be sealed.
Figure 28. Metal brackets are used to hold
signage on the light posts, and to a lesser
extent, the rostral columns. The light post on
element 10A (shown) is the only feature
surveyed with a sign attached.
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Figure 29. Unsecured access panel at the base of the light post.
Figure 30. Detail of the two smaller lighting fixtures on the east and west sides of the rostral
columns.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 31. Detail of the larger spherical light fixture on the top of the light pole columns.
Figure 32. Decorative eagle atop the rostral column of element 10B. The design complements
the sculpted eagles on the south elevation of Union Station.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C Figure 33. Detail of the decorative eagle atop the rostral column of element 10A. Note the
inconsistent finish across the sculpture, and presence of bird activity that is likely contributing to
the deterioration of the finish.
B U I L D I N G C O N S E R V A T I O N A S S O C I A T E S I N C