B09_CHOH_245002_287711_Amd_5_-_061900_rev1_0005.PDF

CHOH – 245002 & 287711 06 19 00 - 1

TIMBER MITER GATES

CHOH 245002 & 287711

SECTION 06 19 00 – TIMBER MITER GATES

PART 1 - GENERAL

1.1 DESCRIPTION

A. Under this work, the contractor shall verify existing conditions, remove existing gates and miter sills, field measure reconstructed stone lock walls at the hinges, and use the field dimensions to fabricate, furnish, and install the miter sill and timber miter gates at upstream Lock 5, Guard Lock, and downstream Lock 1 with all hardware, anchors, balance beams, and butterfly valves in accordance with the contract documents and as directed by the CO. The miter gate opening and closing of these shall be demonstrated by the contractor after installation. Fit of the gates at Lock

5 and the Guard Lock shall be tight with not less than 20 gpm leakagewith leakage not to exceed

20 gpm. The downstream Lock 1 gate will be installed in the open position. The upstream lock gate at Lock 1 shall be removed, stored, and re-installed.

1.2 QUALITY ASSURANCE

A. The miter gates shall be fabricated in a shop by a Carpenter with experience in heavy timber framing. Submit a resume of experience to the CO for approval with at least 3 successful projects in which the Carpenter constructed timber frames with mortise and tenon joints. Include references with project names, addresses and owner contact phone numbers.

1.3 SUBMITTALS

A. As-constructed drawings for existing lock gates that are to be removed and replaced at Lock 5, Guard Lock, and the downstream gate at Lock 1. Drawings shall include detailing the overall dimensions of the existing gates and all timbers that comprise the gates and the miter sills. Indicate recesses in the wood that receive planking and iron fittings and valves.

B. Drawing of field measurements of existing stone recesses at the hinges to receive the quoin posts and of the miter sill.

C. A work plan for the upper gate at Lock 1 that is to be temporarily removed and then reinstalled, including a description of how the gates will be stabilized during the move to prevent warping or other damage, how the gates will be lifted, where they will be stored, and how they will be reinstalled. The existing miter sill is to remain.

D. A work plan detailing how the existing gates that are to be replaced will be removed, including how the gate hinge straps will be removed from the stones or if they will be re-used. Describe how the gates will be fabricated from field measurements of the reconstructed lock walls at the hinges and the miter. Describe how and where the fabrication will be done and field modifications and how the gates will be shipped and installed. Include a plan indicating where cranes will be located. Include a list of equipment to be used. Include a description of any field assembly.

CHOH – 245002 & 287711 06 19 00 - 2

Account for clearances of overhead utilities or structures.

E. Shop Drawings for the replacement timber gates and miter sills. The shop drawings shall detail and dimension each timber element of the gate assembly, and each piece of hardware including all bolts and anchors. A bill of materials shall be provided along with an indication of the lumber grading or ASTM designation for each hardware element. Portions of the gates which are to be field assembled shall be identified. Detail the hardware including collar straps, pivot and socket castings as well as the butterfly paddle valves that indicate all materials, finishes, and dimensions needed for fabrications shall also be submitted for approval. Include a bill of materials. Shop drawings must be approved prior to gate installation.

F. Certification of grading of timbers and planking including moisture content expected at the time of fabrication.

G. Data sheets for Non-shrink grout used for anchor bolt installation.

H. Resume of carpenter responsible for the heavy timber framing of the Miter Gates and Sill.

1.4 MATERIALS

A. Materials for this work shall meet the requirements of the 14th Edition of the AISC Manual:

1. Steel for gate hardware, valve stems, and wrenches shall meet ASTM A36 or equivalent.

The plates shall be painted with a coat of primer and two coats of a high performance latex acrylic or vinyl black paint, Federal ID 37031, semi-gloss, unless otherwise noted.

B. Anchor rods shall be Stainless Steel ASTM A316 with exposed surfaces painted black.

C. Non-shrink grout for anchor bolt installation shall be, Concrete Grouting Material and shall meet

ASTM C1107 and have a minimum compressive strength of 6000 psi in 7 days and be grey in color similar to the color of the existing stone.

D. New cast iron pivot plates, butterfly valves, and valve stems shall conform to the requirements of

ASTM A126 class B Grey Iron casting.

E. Wood planking, Balance Beam, Quoin (Heel) Posts, and Miter Posts shall be Southern Pine, No.1

Graded, and with moisture content of 12-15% as graded by SPIB. Wood planking shall be heartwood only.

F. Cross Beams shall be Southern Pine, Select Structural Graded, and with moisture content of 12-

15% as graded by SPIB.

G. Timber furnished by the Contractor shall be of sound, square edge grade, rough, and unseasoned, double end trimmed unless otherwise shown. Six inch and thicker timbers shall have three edges free from wane. The other edge may have wane not to exceed two inches. All timbers as cut and shaped shall be free from wane, rot, shakes, cracks, and checks, and splits. Timbers that have splits, checks, or shakes shall be replaced at no cost to the government.

H. Preservative Treatment: Pressure treat all timber with (CCA) Chromated Copper Arsenate to comply with American Wood Protection Association (AWPA) UC4C for Ground

Contact/Freshwater Extreme Duty use. Apply preservative treatment after fabrication of timbers.

The ends of all cuts and mortises and tenons shall be treated, including any field cuts. The surface

CHOH – 245002 & 287711 06 19 00 - 3

of any cuts made after treatment shall be retreated.

1. Minimum retention 0.6 pcf.

2. After treatment, re-dry timber to 19 percent maximum moisture content.

I. Each timber shall be clearly branded with the grade mark according to the SPIB. The timbers will be subject to inspection by the CO. Timbers that do not meet the grading requirements will be rejected and shall be replaced at no additional cost.

J. Wire spikes for attachment of hardware shall match the field measured size of existing spikes and be hot dipped galvanized ASTM A653 G90, heads painted black. Acceptable source: Tremont

Nails Cut Spike Hot Dipped Galvanized 5.5”.

K. Wire Spikes for attachment of planking shall be 20d hot dipped galvanized, heads painted black.

Acceptable source: Tremont Nails

L. Planking for gates shall be 2” actual thickness.

1.5 EXECUTION

A. Removal of Existing Gates

1. Prior to removing the existing gates, field measure the dimensions and angles of the miter sill.

2. Remove the gates in a manner than does not cause damage to the stones.

3. At the gate hinge straps, remove the existing bolts may be reused where the nuts are removed without damaging the straps. Otherwise install new bolts by coring around the existing bolts and removing them from the stones. The existing bolts may be embedded in up to three courses. Install new bolts in non-shrink grout.

4. Remove the miter sill bolts in a similar manner to the above bolts for the gate hinge straps, where those bolts may be embedded into existing stones. Existing miter sills at Lock 1 are to remain.

5. Salvage gate hardware, straps, pivots, and valves and temporarily store them in an area for review by the CO. Provide the CO with any salvaged items requested, and dispose of the remainder.

6. For the upstream gate that is to be temporarily removed and then reinstalled, stabilize the gate prior to moving using plywood, timbers or metal straps to prevent warping or displacement. Fasten stabilizing members to existing timbers using fasteners that do not change the appearance of the gate. Plan on filling fastener holes larger than 3/8” diameter with material to match the existing appearance.

B. Fabrication

1. Prior to installation of the gates, the miter sills shall be fabricated and installed.

2. Measurement of the angles of the miter sill and the dimensions stones at the hinges are essential for proper sealing of the gate. Field measure the lock walls and the timber miter

CHOH – 245002 & 287711 06 19 00 - 4

sill and make patterns of the stone recesses in the walls at the quoin (hinge) post and the angles of the miter sill.

3. The Contractor shall coordinate with the CO to allow a visit to the timber fabrication shop during the fabrication of the gate timbers so that the CO can review the process of fabrication and the materials used. The socket and pivot castings shall be test fit and demonstrated to the CO for each leaf of the gate. The butterfly valves gates shall be assembled and test fit, and their operation demonstrated.

4. The Quoin post shall be shaped to fit the stone recess pattern. Any adjustments required due to a faulty pattern will be made by the Contractor at no additional cost.

5. The Contractor shall cut, shape, drill, and fabricate the gates. All timbers shall be cut and shaped for a tight fit. Parts of the gate which are to be field assembled shall be test fit prior to delivery to the site and installation.

6. Balance Beams shall be fabricated in the shop and test fit prior to delivery.

7. The butterfly valves shall be fabricated and shop assembled. Provide tolerance to allow adequate movement of the valve. The valves are to be fabricated to provide minimal leakage when in the closed position.

8. The pivot and socket mating casting surfaces shall be smooth and allow rotation without resistance. The castings shall be test fit in the shop prior to delivery on site. The hole for the socket in the quoin post shall be bored so that the hole is not oversized but allows for a tight installation of the socket into the post. Install quoin bands prior to installing the socket.

Install socket into the wood without splitting the quoin post.

9. Mortise and tenon joints shall be tightly fitted so that they do not allow movement and distortion of the gate assembly.

10. Tolerances of the individual components shall be as needed to obtain a nearly watertight installation (max 20gpm leakage). Any deficiencies found during any of the inspections shall be promptly repaired upon submittal and approval of a repair procedure at no additional costs.

C. Installation:

1. The miter gates at Lock 5 and Guard Lock shall be installed in the field to obtain a nearly watertight installation with leakage not to exceed 20 gpm at the miter posts and where the quoin posts contact the masonry. Any required adjustments shall be made only with the prior approval of the CO. Install gate with the following requirements:

a. Each quoin post shall be installed with approximately a ¾” gap to the stone recess over the full height of the quoin timber when the gate is in an open position.

b. The quoin posts shall be installed with a tight fit against the stone recess when the gate is in the closed position.

c. The miter posts shall be in full contact over the entire surface when the gate leaves are closed.

CHOH – 245002 & 287711 06 19 00 - 5

d. The bottom of the gates shall fit tightly against the miter sill and shall be uniformly compressed over the full length of the sill when the gates are in the closed position.

2. Install gate hinge collar straps and collar anchor bolts at the top of the coping stone. Remove existing bolts by over coring around the bolt through the stones, unless it can be demonstrated that the existing bolts can be re-used.. Use a core size as small as possible but do not to exceed 3” diameter without approval of the CO. Remove and dispose of lead, and install new anchor bolts using non-shrink grout or (gray in color to emulate lead). Shape surface for positive drainage.

3. Any painted finish that is damaged during the installation shall be repaired using touch up paint that is according to the manufacturer’s instructions.

4. At the upstream gate at Lock 1, remove temporary stabilizing elements. Fill holes used by temporary fasteners that are larger than 3/8 inches in the upstream gate at Lock 1 with wood filler that nearly matches the appearance of adjacent wood. Demonstrate that the existing gates when closed are in full contact with the existing miter sill then leave them in the open position.

5. After installation of new gates at Lock 5 and the Guard Lock, the contractor shall demonstrate to the CO the opening and closing of gates and the butterfly valves with a full head of water on the upstream side and leakage through the gate shall not exceed 20 gpm.

6. At the downstream Lock Gate 1, install the gates in the open position and these only need to be closed temporarily to demonstrate full contact with the existing miter sill.

END OF SECTION 06 19 00