Cannon Carriage Fabrication and Replacement

The City of Cambridge would like to invite you to submit a bid for Cannon Carriage Fabrication and Replacement. If submitting electronically, Bids are to be submitted through the Procurement Portal at https://procurement.opengov.com/portal/cambridgema. Bids are to be submitted no later than 11:00 am on Thursday, April 9, 2026.

Project Details

• Reference ID: COC-IFB-FY26-30854
• Department: Historical
• Department Head: Charles Sullivan (Executive Director)

Important Dates

• Questions Due: 2026-04-02T15:00:00.000Z

Addenda

• Addendum #1 (released 2026-03-31T21:29:31.459Z) —

  Please use the See What Changed link to view all the changes made by this addendum.

• Addendum #2 (released 2026-03-31T21:53:16.439Z) —

  Please use the See What Changed link to view all the changes made by this addendum.

Evaluation Criteria

• PROJECT BACKGROUND —

  The City of Cambridge is seeking quotes from vendors to fabricate three reproduction Revolutionary-era wooden cannon carriages replacing deteriorated carriages presently located on Cambridge Common. The project must be completed no later than June 30, 2027.

   

  The intent of the project is to construct new carriages based on U.S. Navy plans to support cannon weighing as much as 6,000 pounds. City forces will remove and store the cannon tubes. The successful vendor will take possession of the existing carriages and construct replacements using new wood and existing wheels and hardware. The vendor will deliver the completed carriages to Cambridge Common and assist City forces to reinstall the cannon tubes on the new carriages.

   

  1. All work is to be done at the direction of the Executive Director of the Cambridge Historical Commission or an authorized representative (“Owner”), who shall have sole authority to approve work performed by the Contractor, make field changes, and approve requests for payment.
  2. Unless otherwise noted, the specifications are intended to include everything obviously requisite and necessary for the proper completion of the work whether each necessary item is mentioned herein or not.
  3. Work herein specified shall be executed in accordance with all governing ordinances, laws, and regulations that meet all local conditions. Additionally, any changes and/or additions in the work necessary to meet these ordinances, laws, regulations, and/or conditions shall be made without additional cost to the City.
  4. The Contractor shall not assign or subcontract the whole or any part of this work without obtaining the prior written consent of the Owner.
  5. The Contractor shall provide and pay for all transportation required to deliver and remove from the site all materials and equipment, as required for all the work shown and specified.
  6. The Contractor shall furnish all such equipment, tools, and labor necessary to expedite the work in a professional manner.
  7. The work shall comply with all local and state laws and ordinances, and with all the established codes applicable thereto. The Contractor shall take out all required permits and arrange for all necessary inspections. Fees for Permits given by the City of Cambridge shall be waived. Payment of any other fees and expenses in conjunction with the work under this contract shall be assumed by the Contractor.
  8. The City shall have the right to require alterations of, additions to, and deductions from, the work described in the specifications without rendering the contract void. All such items shall be covered in the form of an amendment issued by the City. 
  9. The City of Cambridge reserves the right to reject any or all bids if it is in the public interest to do so.
  10. If the Contractor refuses or fails to execute the work with such diligence as will ensure its completion within the agreed time and as specified in the contract documents, the City, by written notice to the Contractor, may terminate the Contractor’s right to proceed with the work.
• SCOPE OF WORK —

  The selected Vendor will construct three new wooden cannon carriages, fabricating the wooden structures from new material and reusing existing hardware when feasible. The intent of the replacement project is to provide new carriages that will be more authentic than the existing ones, safely bear the weight of the cannon, and resist deterioration for an extended period of time.

   

  The cannon for which the carriages are to be constructed include the following:

   

  Marks	Weight in Pounds (as reported)	Bore	Length
  Crown, G.R., #19	6,072	6 ½”	9’7”
  Crown defaced, #1293	5,637	6 ½”	9’8”
  Crown defaced, #22	3,192	4 ½”	9’1”

   

  After the British Army evacuated Castle William (Fort Independence) in 1776 the cannon were transferred to the Massachusetts Arsenal at Cambridge. In 1875 the Legislature granted the cannon and their carriages to the City of Cambridge, which placed them on Cambridge Common.

   

  In 1927-1931 the Charlestown Navy Yard, tasked with restoring and rearming the U.S.S. Constitution, selected the largest of the Cambridge cannons as a prototype and cast 18 reproduction cannon to populate the ship’s gun deck. The carriages fabricated by the Navy were similar to those shown in historic photos but more robust than those presently in use (see Attachment A.).

   

  New carriages are to be designed according to the pattern of carriages fabricated for the U.S.S. Constitution, with certain exceptions as noted below.

   

  The City of Cambridge’s Historical Commission is the Owner for the purposes of this project.

   

  Work to be Performed

   

  A. Removal and Transportation

  • City forces will remove and store the cannon tubes offsite.
  • City forces will load the carriages on the Vendor’s vehicle.
  • The Vendor will thereupon assume custody of the carriages and will be responsible for securing and transporting them safely to its place of business. In so doing the selected Vendor will protect persons, the site, and surrounding structures, such as light poles and benches, from injury resulting from the removal.

   

  B. Preparation of Working Drawings

  • The Vendor will measure the old carriages, whose dimensions may differ from one another to accommodate the different configurations of the cannon (for example, cannon #3 has a smaller diameter than #1 or #2). The City will provide measurements of the cannon as requested by the Vendor.
  • The Vendor will disassemble the old carriages and assess the metal components for incorporation into the new carriages. It is assumed that forged and cast components such as cap squares, cap square bolts, split keys, and wheels will be salvaged and reused.
  • With the following exceptions, wooden components of carriages will conform to a drawing prepared by the U.S. Navy titled “1927-1931 Restoration/U.S. Frigate Constitution/Gun Carriages for 24 ^PDR Gun.” dated October 2, 1930. Vendor must conform to the detail for “Carriage for 24 ^PDR Gun – English Type.”
  1. If necessary, and with Owner approval, plans may be adapted to allow reuse of significant original hardware.
  2. Omit eye bolts, rings, and restraints appropriate to shipboard deployment.
  3. Omit coign (coin) and substitute fixed wooden block to maintain cannon at a slight elevation when on level ground.
  4. Adapt axle design to accommodate present wheels and axle consisting of 6" outside diameter x 5" inside diameter x .500" wall thickness DOM (Drawn Over Mandrel) steel tube conforming to ASTM A513 Type 5, sealed with friction fit same-species wood plugs secured with linchpins as shown on the plans. The length of the wooden plugs should be a minimum of 1.5 times the inside diameter of the tube. The exposed tube between the cheeks is to be boxed on top and sides with 5/4” lumber same as used in the cheeks. Submit documentation of proposed axle design for Owner approval.
  • Submit detailed shop drawings of the carriages including lumber sizes, dimensions, grades, edge treatment, surface treatment, finishes, and connection joinery details. Shop drawings may take the form of paper drawings or electronic PDF files. Note any differences between the carriages for the different guns.

   

  C. Materials and Fabrication

  • New wood to be air-dried dimensional White Oak (Quercus alba), graded FAS (Firsts or Seconds), free of heart center (FOHC), or approved equal. The carriage sides (cheeks) and frame shall be built up from 6” (nominal), 5½” thick (actual dimension) members, as measured after drying to a moisture content of approximately 20% and surfaced four sides. The lumber shall not be warped, and shall be free from visible checks, splits, worm holes, bark pockets, and knots. Finger-jointed, glued, or laminated stock will not be accepted. Submit samples and mock-ups of lumber materials, including surface treatment and finishes.
  • Alternative species that will be considered by the Owner include Sapele (Entandrophragma Cylindricum); Black Locust (Robinia pseudoacacia); Ipe (Handroanthus serratifolius); and Cumaru (Dipteryx odorata) in equivalent quality, grade, moisture content, and finish as specified for White Oak above. Vendor must submit samples and documentation demonstrating suitability for the intended purpose. 
  • Lumber shall be graded by a grader certified by an approved lumber grading agency or a qualified individual who has completed a lumber grading training course. Lumber shall bear a grade stamp or a certificate of grade from the lumber grader.
  • Keep lumber dry during delivery and storage. Cut and stack lumber so as not to encourage the growth of sap-stain, fungi, mold or mildew. Stack lumber with stickers and spacers between bundles to allow air circulation. Provide reasonable protection during transportation, storage, and processing to avoid marring, staining, or the accumulation of excess moisture, dirt and foreign matter.
  • Components shall be fabricated in strict conformance to approved shop drawings to join tightly and in proper alignment at the time of assembly. Fabrication prior to receipt of approved shop drawings shall be at the Vendor’s risk.
  • Vendor may propose bedding materials to inhibit penetration of moisture between components. Vendor must demonstrate compatibility of bedding materials with the selected wood species.
  • The cheeks of all three carriages shall be fabricated to the same profile. The widths of the carriages and diameters of the trunnion saddles shall be adjusted to the varying dimensions of the cannons.
  • Assess all metal components for reuse. Propose replacements for all components with an estimated useful life of less than twenty-five years, duplicating the original in dimension and appearance when practical to do so.

   

  D. Finishes.

  • New or reused metal components shall be sand-blasted to remove rust and either a) hot-dip galvanized to ASTM A307 and coated with an organic zinc-rich primer such as TNEMEC Zinc 90-97 or b) epoxy coated with an approved finish before assembly
  • Prime all wooden surfaces (including bored holes) before assembly with a mix of 50% oil-based stain, 35% boiled linseed oil, and 15% balsam turpentine, brushed on until refusal. Wipe off excess and allow to dry for 24 hours.
  • After assembly apply two coats of gloss black oil base stain. Propose manufacturer’s specification for owner approval.

   

  E. Delivery.

  The Vendor shall deliver the completed carriages to Cambridge Common at a pre-arranged time and provide instructions to aid City forces in the reassembly of the cannon and the carriages.

   

  Progress Reports

  The Vendor shall provide periodic progress reports containing images and a brief summary work performed. Reports shall be transmitted electronically to the Owner every two weeks during preparation of materials and fabrication.

   

  Project Timeline

  Unless by prior agreement of the parties, the project shall be completed no later than one year from contract award date.

   

  Payment

  The contract prices paid for the base quote shall include full compensation for furnishing all labor, materials, and equipment and incidentals required to replicate the wooden cannon carriage in accordance with these technical provisions and as decided by the Owner.

Submission Requirements

• BIDDERS INFORMATION
• My business is a: (required) —

  Please select one

• Please insert the requested information: (required) —

  If a corporation, include the State in which you are incorporated in.

  If a partnership, include the names of partners.

  If an individual, include relevant information.

• Bidder's Federal ID#:
• Authorized representative information: (required) —

  Please include the name, title, telephone and email address of the authorized representative

• This bid includes addenda numbered:
• Debarment or Suspension (required) —

  The Vendor/Contractor certifies that it has not been and currently is not debarred or suspended by any federal, state, or municipal governmental agency under G. L. c. 29, § 29F or other applicable law, nor will it contract with a debarred or suspended subcontractor on any public contract.

• QUALITY REQUIREMENTS —

  An unchecked response, a failure to respond, or a failure to meet to any of the following Quality Requirements will result in a rejection of your bid. Please check each of the following Quality Requirements as confirmations. 

• Quality Requirement 1 (required) —

  Bidder affirms that they have a minimum of 10 years of experience in  the construction of carriages or mounts similar in scope to the carriages referenced above.

• Quality Requirement 2 (required) —

  Bidder affirms that they have within the last ten years fabricated at least five gun carriages or mounts similar to the carriages referenced above.

• Quality Requirement 3 (required) —

  Bidder has all necessary equipment and personnel for the safe transfer of existing and newly fabricated cannon carriages from and to Cambridge.

• Quality Requirement 4 (required) —

  Bidder maintains a fully-equipped woodworking shop containing the equipment necessary to store, handle, rough out, bore, mortice, finish and assemble the necessary components.

• Quality Requirement 5 (required) —

  Bidder has provided evidence of woodworking shop certifications from the Architectural Woodwork Institute (AWI) Quality Certification Program (QCP), Woodwork Career Alliance (WCA), Woodwork Institute compliance programs, or similar certification or evidence of experience in the field.  (Please submit any relevant documentation in the Bid submission file upload field)

• Quality Requirement 6 (required) —

  The bidder has provided references and a portfolio of images of at least five similar projects completed at their shop within the last ten years

• REFERENCES —

  Bidders shall submit a list of three references for which the bidder has supplied similar services in the last Ten Years. References shall include contact information including contact name, addresses and telephone numbers for each to inquire as to their satisfaction with the bidders’ product and service. In addition, the City reserves the right to use itself as a reference, to contact references not listed and to otherwise perform its own due diligence when making a responsibility determination. A bid maybe rejected on the basis of one or more references reporting less than excellent past performance.

  In the following Bid submission documentation field, please also attach relevant photos and documentation regarding these listed projects.

• Reference 1 (required) —

  Include contact name, address and telephone #

• Reference 2 (required) —

  Include contact name, address and telephone #

• Reference 3 (required) —

  Include contact name, address and telephone #

• City of Cambridge Standard Compliance Forms
• Please Upload the Signed Standard Compliance Forms (required) —

  Please electronically sign and upload the following documents using this URL: https://cambridgema.na4.adobesign.com/public/esignWidget?wid=CBFCIBAA3AAABLblqZhCD4UnZSN3XyfqZi9ZxGyvlhSnIlYThymiofiiHN4CtIXU4t2tYM27cVaMk7bVx6AI* 

• Non Collusion Statement (required) —

  Bidder certifies that this bid is made without collusion with any other person, firm or corporation making any other bid or who otherwise would make a bid. 

• SUBMISSION DOCUMENTATION
• ADDITIONAL SUBMISSION REQUIREMENTS (required) —

  Please attach all relevant documentation, including but not limited to reference photos/portfolios and certifications. 

• Is this contract/solicitation for a commodity or service? (required)
• Enter commodity: (required) —

  Example: Office Supplies

• Enter service(s): (required) —

  Example: Janitorial Services