Bull Run Dam 2 Tower Improvements Project
Selected Improvements
Preliminary Scope of Work
For
Services Provided by
Montgomery Watson Harza
Revision 02
Note: The following provides a general description of the proposed preliminary scope of work for services by Montgomery Watson Harza (MWH) to assist the Bureau in implementation of design and construction of selected improvements at the Bureau’s Bull Run Dam No. 2. Refer to MWH memo dated May 29, 2002 for the list of selected improvements.
This scope assumed that the Work will be specified, bid, and performed by a single General Contractor, using specialized subcontractors as needed.
I. General Design
I. Civil/Structural Design
A. Platforms to Access Raised Electrical Equipment for PMF Protection
In order to provide access to electrical cabinets and controls raised to above potential PMF reservoir levels, platforms will be designed for both the North and South Tower. MWH will develop designs and perform calculations. Detail design and calculations will be performed in accordance with industry standards and details developed.
B. Other Structural Modifications
Details will be developed and calculations performed, as necessary, for the following miscellaneous features:
• New handrails to OSHA standards
• Ladders and platform(s) at North Tower for access to the roof and 10-ton crane
• Cover plates over deck openings
• Raise the gate vent pipes
• Improve north wall at South Tower
• Water sampling equipment and Appurtenances
C. Field Examination
An engineer and a technician will visit the site to make measurements, make field notes, take photographs, and discuss potential improvements with project personnel. The trip will last just one day and it is assumed that the Bureau will provide access to the towers.
2. Mechanical Design
A. Gate Lifting Beams
The North Tower gate lifting beams will be reviewed and conceptual designs prepared to replace the existing (bent) lifting beams. It is assumed that the lifting beams will be “reverse-engineered” from the existing lifting beams. MWH will provide detailed designs and calculations.
B. Gate Hoists Controls
A design will be prepared for replacement of the controls for the North Tower gate hoists. The work will include addition of limit switches to prevent future damage to the lifting beams.
C. Miscellaneous mechanical work.
A design and performance specification will be developed to replace the North Tower gate wheels with stainless steel wheels using greaseless bearings; to replace all hoist wire ropes; and for painting of the cranes/hoists.
D. Field Examination
A senior mechanical engineer will also attend the site examination discussed in Section I.1.C above, for the same general purposes.
3. Electrical Design
A. Power/Communication cables
Calculations will be performed to determine the maximum electrical load demands at the North and South Tower, and maximum voltage drop under different loading scenarios. These calculations will be used for final sizing of the main feeder cables and the local distribution cables.
Cable vendors will be contacted to determine cable construction criteria for the new power/communication cables. It is proposed that fiber optic communication fibers be embedded in the new power submarine cable. Construction criteria will need to be finalized to ensure proper physical protection, moisture protection, for the power cabling and the embedded fiber optic communication cabling. Proper techniques for terminating the cables will also be investigated. Detailed routing, installation, and securing the cables will be designed and specified by MWH.
Modifications required at the existing Generator Building will also be investigated. Requirements for new feeder protection and integration with the existing 440 volt system will be determined.
B. Power Distribution Equipment
New power distribution equipment will be designed and specified for local power distribution at the two towers. Equipment to be detailed and specified by MWH will include new power distribution panelboards, transfer switches, lighting transformers, lighting distribution panelboards, and miscellaneous raceway and cabling. Equipment will be designed based on the electrical load and voltage drop calculations, latest edition of the National Electrical Code. The design will also include plans and specifications to relocate the equipment above the PMF elevation to prevent outages during flood conditions.
C. Instrumentation
The existing water sampling system will be augmented with a microprocessor based probe type system. Vendors will be contacted to assist in determining the best arrangement of sampling probes and monitoring equipment, and how best to interface with the new communication system and the existing monitoring equipment. Details and specifications for properly integrating with the existing system will be developed and provided.
D. Field Examination
A senior electrical engineer will also attend the site examination discussed in Section I.1.C above, for the same general purposes.
II. Design Drawings and Documents
General: It is assumed that Contract Documents will be developed in CSI format, with Divisions 0 and 1 prepared by the Bureau, except for the technical bid forms, which will be prepared by MWH. MWH will prepare the technical specification sections, which will be coordinated with City Standard Construction Specifications. This scope includes Bureau review at the 50% and 95% level of completion and teleconference reviews at the 50% and 95% stage. A contracting package, including the latest design drawings, specifications and calculations will be furnished the Bureau for their review at completion of the 50% and 95% design. Select existing drawings will be used as reference drawings of the overall project arrangement and specific features and equipment.
1. Civil/Structural Drawings and Documents
A. Design Drawings
Drawings will developed in accordance with industry standards to allow bidding, fabrication and installation of miscellaneous structural improvements. The scope includes the following drawings:
• Site Location
• Contractor’s Work Area
• Demo plan/Civil/Mechanical for North Tower
• Demo Plan/Civil/Mechanical for South Tower
• North Tower Installation Plans and Sections
• North Tower Electrical Access Platform, Sheet 1
• North Tower Electrical Access Platform, Sheet 2
• North Tower Access Ladders and Platforms, Sheet 1
• North Tower Access Ladders and Platforms, Sheet 2
• South Tower Electrical Access Platform, Plan, Sections and Details
• South Tower Miscellaneous Details
• Standard Handrail and Ladder Details
• Cover Plate Details
B. Technical Specifications
Technical specification sections will be prepared. The civil/structural specification sections prepared will include:
• Miscellaneous Metal
• Coatings/Paints
2. Mechanical Drawings and Documents
A. Design Drawings
The mechanical items will generally rely on existing project drawings to provide as-built information for the Contractor. The scope includes preparation of the following new drawings:
• Gate Lifting Beam
B. Technical specifications
Technical specification sections will be prepared. Mechanical sections prepared will be as follows:
• Basic Mechanical Materials and methods
• Miscellaneous Metals
• North Tower Gate Hoist Controls Upgrade
• North Tower Gate Improvements
• South Tower Gate Operator
• Painting
3. Electrical Design Drawings and Documents
A. Design Drawings
An electrical power one line diagram will be furnished to indicate basic power routing. The diagram will indicate ratings, cable sizes, and conduit sizes for the primary power components.
Electrical panel schedules will be furnished for all of the distribution panelboards. The schedules will include circuit breaker sizes, physical arrangements, and connected load values.
Electrical equipment arrangement plan, elevation and detail drawings will be included. Drawings will be scale drawings showing locations of all electrical power, and control equipment. Cable and conduit routing will be shown on these drawings. The plan, elevation and detail drawings will be of sufficient detail such that the installing contractor can properly locate and install all of the electrical equipment and interconnecting cable and conduit.
Instrumentation detail drawings will be furnished detailing installation of the new microprocessor based water sampling equipment. Sufficient plan, elevation and details will be furnished for proper installation and interface of the new instrumentation equipment.
The scope includes preparation of the following drawings:
• Electrical Legend, Abbreviations, and Symbols
• Electrical Site Plan
• Power One Line Diagram
• Panel Schedule
• North Tower Power & Control Plan
• South Tower Power & Control Plan
• Generator Building Power & Control Plan and Details
• Power Cable Routing Plan and Details
• Power Cable Installation Details
• Instrumentation Installation Details
B. Specifications
Specification sections will be furnished for power, control, and instrumentation equipment. Specifications will also include installation procedures and requirements.
The following technical specification sections will be prepared:
• Basic Electrical Materials and Methods
• Submarine Power/Communication Cable
• Water Sampling Instrumentation
4. Deliverables
By MWH:
• At the 50% Design stage, provide Plans, Specification and Cost Estimates, per Section II.1-3. 10 copies for review.
• At the 95% Design stage, provide Plans, Specification and Cost Estimates, per Section II.1-3. 10 copies for review.
• Final Design, provide Plans, Specification and Cost Estimates. One reproducible hard copy.
• Electronic files of Final Plans, Specifications and Cost Estimates, final plans shall be provided to the Bureau on CD in Microstation format.
• 3 copies of Structural, Mechanical and Electrical Load Calculations
By the Bureau:
• One copy of City of Portland Standard Construction Specifications
• Access to towers.
• Copies of as-built drawings of towers.
III. Services During Bidding
MWH will provide limited technical support to the Bureau during the bidding process, including preparing draft responses to technical questions, preparing technical addenda, and preparing a technical analysis of the bids received. Because of the uncertainties in predicting the exact number and nature of issues that may arise during bidding, and uncertainties in predicting the number of bids received and the degree of detail to which bid(s) will need to be analyzed, this scope includes allowances for senior staff time as follows:
• Services during the bidding period: 30 labor hours
• Technical analysis of bids: 36 labor hours
In addition to the above, one senior engineer will attend the pre-bid site visit.
IV. Services During Construction
MWH will provide the following services during construction. Because the exact required levels of effort and support are not known at this time, the scope includes allowances for each category, assuming a 50% split between senior-level staff and staff-level engineers. The estimated levels are also based on the assumption that Bureau staff will have the lead and main role in providing all services during construction, and MWH support will be on a limited, as-needed basis only.
1. Interpretation and clarification of technical issues
MWH will provide technical analyses, interpretations of the technical specifications prepared by MWH, and other technical support as-needed.
Labor allowance: 60 hours
2. Review of Contractor’s submittals.
MWH will review Contractor’s submittals for compliance with the technical specifications and drawings prepared by MWH.
Labor allowance: 80 hours
3. Shop inspection of selected equipment or items
No shop inspections by MWH are included in the scope.
4. Short-Term Field Support
MWH will provide short-term field support during site work. Services include the following:
• One-day trip by project manager during mobilization by contractor
• One-day trip by senior civil engineer to inspect installed civil/structural improvements
• One-day trip by senior mechanical engineer to witness checkout of replaced mechanical equipment
• Two-day trip by senior electrical engineer to witness checkout of installed electrical items.
V. Permitting Support
Permits for the selected improvements will need to be discussed and negotiated with applicable agencies, possibly including the FERC, U.S. Army Corps of Engineers, and ODFW. The Bureau will take the lead on permitting issues, and MWH will provide support as requested by the Bureau. For budgeting purposes, $10,000 has been allocated for MWH permitting support, which may include items such as drafting text, participating in teleconferences, and attending meetings.