The Friends of Hemlock Gorge

The Restoration of Echo Bridge: 2007 Documentation

The Rehabilitation of Echo Bridge in the Hemlock Gorge Reservation has been a long term concern of the Friends. A major restoration of the stone work was completed in 1992, and the Echo Platform was repaired and restored in 2004, but restoration of the Railings remains to be done. An early cost estimate was provided to the Friends in 1997 -- click here to read it. The following information regarding this unfinished project was provided to the Friends by Marianne Connolly at the MWRA in early 2007 and gives some idea of how the scope and complexity and cost of the project have increased.

Attachment A

Echo Bridge

 Historical Background

 Echo Bridge, officially known as the Charles River Bridge extends over the Charles River and connects the City of Newton and Town of Needham.  The pedestrian bridge serves as a conduit for the MWRA’s Sudbury Aqueduct and was constructed by the Boston Water Board in 1877 at a cost of $200,000.  The bridge is 500 feet in length, 15 feet wide, with seven arches, five of which span 37 feet and one that spans 38 feet.  The seventh and largest arch that spans the river is said to be the second in size on this continent and one of the largest stone bridges in the world.  There is a remarkable echo (hence its name) within the arch with the human voice being rapidly repeated upwards of 15 times.   On April 9, 1980, Echo Bridge was included on the National Register of Historic Places designated by the Department of Interior through the Massachusetts Historical Commission (36 CFR 60).  

 Previous MWRA Maintenance to Echo Bridge

 The MWRA completed limited improvements to the Bridge in 1991 under the Echo Bridge Phase I Rehabilitation Contract. That contract included:

             - Cleaning, repointing and resetting of brick masonry on both spandrels.

            - Removal of the existing asphalt-paved walkway atop the bridge, and replacement with a concrete walkway.

            - Cleaning and minor repointing of granite ashlar masonry on nearly all exterior bridge surfaces, and graffiti removal.

 The rehabilitation of the bridge railings was not included in the project because the focus was on masonry repairs to protect the public from unstable brickwork and deterioration, and with minor cosmetic improvements such as cleaning, graffiti and dirt removal. The railing rehabilitation and/or replacement was to be addressed in a subsequent phase when MWRA would consider the costs, public safety and continued public access to the bridge deck.

 Previous Engineering Reports and Documentation of Echo Bridge

 Several reports on the proposed Phase II work were completed and are listed below:

 1)         1990 Existing Conditions Report - The Society for the Preservation of New England Antiquities documented the railing conditions as generally deteriorated by moisture entrapment due to various factors.  The main recommendation of the report was to remove a test portion of railing and try various repair methods on it.   

 2)         1992 Preliminary Report - MWRA outlined a Phase II scope of work that included repairs to existing railings. 

 3)         1994 Preliminary Design Report - MWRA outlined alternative methods of railing renovations with estimated costs. Please note that these alternatives focused on in-kind replacement using original materials and/or aluminum instead of cast iron, but would look exactly like the original design.  

            1994 estimate: $350,000.                    2004 estimate:             $448,000. 

            1994 estimate: $440,000                     2004 estimate:             $565,000. 

           1994 estimate:  485,000                       2004 estimate:             $620,000. 

  2007 Costs are estimated to be in the range of $ 575,000 - $750,000.     

The original design does not meet existing safety codes now in place in Massachusetts.  A Feasibility Study of the Farlow-Chaffin Park in Newton discussed the Massachusetts State Building safety codes with a particular emphasis on railings. [1]   

Echo Bridge Today

 Today, Echo Bridge continues to serve as the conduit for the Sudbury Aqueduct system and is used as an emergency back up in case of a breakdown or interruption of the primary water supply.  As MWRA struggles with capital program budget cuts, MWRA has focused its limited resources on “active” facilities.  Therefore, MWRA needs to be creative and seek other sources of funding for the railings at Echo Bridge, a back-up emergency facility.   

Community/DCR Issues and Concerns  

MWRA staff has maintained regular contact with “The Friends of Hemlock Gorge” and the DCR Superintendent of the Hemlock Gorge Reservation- Kevin Hollenbeck. MWRA has assisted the DCR in several small projects including graffiti removal on the bridge, fence replacement on the Needham side of the bridge at the first cross street (Reservoir Street) with stones and a cable gate to prevent unauthorized vehicles from entering along the Sudbury Aqueduct ROW.  MWRA carpenters also restored the stairs leading to the platform as well as the platform itself that had eroded so that visitors to the park can safely access the area under the arch. 

2007 Railing Options 

Since the $250,000 was earmarked in the state budget, MWRA staff have researched and reviewed various less costly railing options to address the safety problems at Echo Bridge.  Those options, including illustrations and general descriptions are provided below.    

In addition to evaluating various railing designs, MWRA has been grappling with the issue of whether we retain the historical railing by installing a new railing either in front of or behind the existing railing in an attempt to preserve the railing as a relic (similar to the Fitch’s Bridge concept in Groton).  Safety is our primary concern and MWRA worries about the historic railing falling into the public way, Charles River, and/or the DCR park below if a new railing is placed inside the existing railing.  The existing historic railing is in such poor condition that leaving sharp edges exposed to the public presents other safety problems if the a railing is installed on the outside of the existing historic railing.   MWRA seeks guidance and feedback from MHC and the local historical groups on how best to handle this safety concern.  One solution would be to remove the existing railing entirely as part of the upcoming work.  The removal costs have been estimated to be approximately $25,000.   

Option A

Architectural Railing System

 Option A is an architectural unobtrusive railing design.  Details include four foot long panels, 3.5 feet high, with 2 inch posts and  a continuous smooth handrail.  Materials are black thermoplastic reinforced metal designed to withstand high traffic areas.   Advantages are that the system is maintenance free, very durable, and structurally sound.  The installation method calls for a plate mounted anchor system into the existing granite.                    

Preliminary Estimated Material costs:                                $70,000 - $86,000

Estimated Design Costs                                                        $15,000 - $20,000

Estimated Installation costs:                                                

(Due to location and difficulty for access)                           $25,000 - $35,000

Total Estimated Project Costs                                              $110,000 - $141,000

Option B

Aluminum Stainless Steel Horizontal Wire Railing

This is a similar design that will be incorporated into the Fitch’s Bridge Repair project in Groton, MA.  The design provides views to the historic railing (if it is retained) and tends to be maintenance free.  The handrail systems are completely fabricated and infill areas assembled before shipping.  Various colors are available, but in keeping with the original color of the existing railing, MWRA proposes to keep the railing a black color.  Details include eight foot long panels, 3.5 feet high, with 2 inch posts and a continuous smooth rounded handrail.

Preliminary Estimated Material costs:                                $45,000 - $60,000

Estimated Design Costs                                                        $15,000 - $20,000

Estimated Installation costs:                                                

(due to location and difficulty for access)                           $20,000 - $30,000      

Total Estimated Project Costs                                              $80,000 – $110,000               

Option C

X Panel Railing Design – Georges Island

This railing has recently been installed by DCR on Georges Island in Boston Harbor.  It was custom made and according to staff at DCR, the installation was more complicated than anticipated.   The railing needed to be retrofitted with mesh panels to improve safety conditions.   The panels are 6 feet long, 3.5 feet high, with 2” steel posts.   The railing top and bottom is made of steel stock.   

Preliminary Estimated Total Material costs:                      $220,000 - $260,000

Estimated Design Costs                                                        $ 25,000 - $ 35,000

Preliminary Estimated Installation costs:                            $ 35,000 – $ 45,000                                        

Total Estimated Project Costs                                              $280,000 – $340,000 

Please note:  These images do not reflect the meshing that has been installed to be compliant with the Massachusetts State Building Code.

Option D

Glass/Plexiglas Railing

The glass/Plexiglas design allows a full view of the historic railing if it is determined that the historic railings remain.    Materials tend to be heavy and the modern design is not consistent with the historical fabric of Echo Bridge.   Glass panels are highly prone to graffiti and vandalism and scratching.    

Preliminary Estimated Total Material costs:                      $55,000 - $75,000

Estimated Design Costs                                                        $15,000 - $20,000

Preliminary Estimated Installation costs:                            $30,000 – $40,000     

Estimated Total Project Costs                                              $100,000 - $135,000

MWRA Recommendation

MWRA looks forward to discussing the railing option designs with staff within the MHC Office and with the local historical agencies in Needham and Newton.   MWRA evaluated the four railing options from a safety, aesthetic, and cost perspective, and concluded that Option A, the Architectural Railing System is the preferred option.  As stated above:

  1. The installation of this railing system (or something similar) will improve safety conditions at the Bridge.
  2. The thermoplastic reinforced metal design is attractive, durable, and has low maintenance costs.  
  3. The design will blend into the historical fabric of the Bridge

[1] The Bridge railings must meet the railing design criteria as state in AASHTO “Guide Specifications for Design of Pedestrian Bridges.”  The railing height for pedestrian bridges (walkways not considered bicycle paths) is 3’ – 6.” In addition, the maximum opening in the railing cannot exceed 6 inches with the bottom 27 inches of the railing and 8 inches above the 27 inch level.  The Massachusetts State Building Code sets 4 inches as the maximum opening in a railing. 

Page last updated April 12, 2007

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