W912P519B0003-0005 Amendment 5.pdf

W38XDD01291495

AMENDMENT OF SOLICITATION/MODIFICATION OF CONTRACT

Except as provided herein, all terms and conditions of the document referenced in Item 9A or 10A, as heretofore changed, remains unchanged and in full force and effect.

15A. NAME AND TITLE OF SIGNER (Type or print)

30-105-04EXCEPTION TO SF 30

APPROVED BY OIRM 11-84

STANDARD FORM 30 (Rev. 10-83) Prescribed by GSA

FAR (48 CFR) 53.243

PROJECT:: Barkley Pow er Plant Turbine Generator Rehabilitation, Kuttaw a, KY

PURPOSE: The purpose of this amendment is to:

1. Publish the final set of Q&A to the solicitaion.

2. Extend the bid opening due date from Wednesday, September 2, 2020 at 1:00 p.m. Central Time to Tuesday, September 8, 2020 at 11:00 a.m. Central Time.

3. Provision FAR 52.204-24 and clause FAR 52.204-25 are hereby deleted and replaced in their entirety.

4. Provide revised bid schedule, revised technical specifications and reference draw ings as separate attachments.

5. DFARS 252.236-7001, Contract Draw ings and Specifications and FAR 52.232-3, Alterations in Solicitation are updated.

6. There are no revisions to the Wage Determinations; listed for informational purposes only.

1. CONTRACT ID CODE PAGE OF PAGES

1 39

16A. NAME AND TITLE OF CONTRACTING OFFICER (Type or print)

16C. DATE SIGNED

BY 21-Aug-2020

16B. UNITED STATES OF AMERICA15C. DATE SIGNED15B. CONTRACTOR/OFFEROR

(Signature of Contracting Officer)(Signature of person authorized to sign)

8. NAME AND ADDRESS OF CONTRACTOR (No., Street, County, State and Zip Code) X W912P519B0003

X 9B. DATED (SEE ITEM 11)

18-May-2020

10B. DATED (SEE ITEM 13)

9A. AMENDMENT OF SOLICITATION NO.

11. THIS ITEM ONLY APPLIES TO AMENDMENTS OF SOLICITATIONS

X The above numbered solicitation is amended as set forth in Item 14. The hour and date specified for receipt of Offer X is extended, is not extended.

Offer must acknowledge receipt of this amendment prior to the hour and date specified in the solicitation or as amended by one of the following methods:

(a) By completing Items 8 and 15, and returning 1 copies of the amendment; (b) By acknowledging receipt of this amendment on each copy of the offer submitted;

or (c) By separate letter or telegram which includes a reference to the solicitation and amendment numbers. FAILURE OF YOUR ACKNOWLEDGMENT TO BE RECEIVED AT THE PLACE DESIGNATED FOR THE RECEIPT OF OFFERS PRIOR TO THE HOUR AND DATE SPECIFIED MAY RESULT IN

REJECTION OF YOUR OFFER. If by virtue of this amendment you desire to change an offer already submitted, such change may be made by telegram or letter, provided each telegram or letter makes reference to the solicitation and this amendment, and is received prior to the opening hour and date specified.

12. ACCOUNTING AND APPROPRIATION DATA (If required)

13. THIS ITEM APPLIES ONLY TO MODIFICATIONS OF CONTRACTS/ORDERS.

IT MODIFIES THE CONTRACT/ORDER NO. AS DESCRIBED IN ITEM 14.

A. THIS CHANGE ORDER IS ISSUED PURSUANT TO: (Specify authority) THE CHANGES SET FORTH IN ITEM 14 ARE MADE IN THE

CONTRACT ORDER NO. IN ITEM 10A.

B. THE ABOVE NUMBERED CONTRACT/ORDER IS MODIFIED TO REFLECT THE ADMINISTRATIVE CHANGES (such as changes in paying office, appropriation date, etc.) SET FORTH IN ITEM 14, PURSUANT TO THE AUTHORITY OF FAR 43.103(B).

C. THIS SUPPLEMENTAL AGREEMENT IS ENTERED INTO PURSUANT TO AUTHORITY OF:

D. OTHER (Specify type of modification and authority)

E. IMPORTANT: Contractor is not, is required to sign this document and return copies to the issuing office.

14. DESCRIPTION OF AMENDMENT/MODIFICATION (Organized by UCF section headings, including solicitation/contract subject matter where feasible.)

10A. MOD. OF CONTRACT/ORDER NO.

2. AMENDMENT/MODIFICATION NO. 5. PROJECT NO.(If applicable)

6. ISSUED BY

3. EFFECTIVE DATE

21-Aug-2020

CODE

US ARMY CORPS OF ENGINEERS-CELRN-RC-N

DIRECTORATE OF CONTRACTING

110 9TH AVENUE SOUTH, RM A405

NASHVILLE TN 37203

W912P5 7. ADMINISTERED BY (If other than item 6)

4. REQUISITION/PURCHASE REQ. NO.

CODE

See Item 6

FACILITY CODECODE

EMAIL:TEL:

W912P519B0003

SECTION SF 30 BLOCK 14 CONTINUATION PAGE

SUMMARY OF CHANGES

SECTION SF 30 - BLOCK 14 CONTINUATION PAGE (SF 30)

The following have been added by full text:

Q AND A 3

W912P519B0003 Barkley Turbine Generator Rehab Questions and Answers Amendment 0005

51. Can you also confirm if an electronic version, preferably Excel, of the bid schedule can be provided?

ANSWER: An Excel version of the revised bid schedule was provided as a separate attachment with Amendment 0004, issued on July 31, 2020.

52. Section 48 13 13.01 26 Paragraph 1.5.4 – Speed and Runaway Speed The specification requires that “the maximum runaway speed of the rebuilt turbine shall not exceed the generator design runaway speed of 144RPM when operating on-cam at all heads from 18 to 60 feet with no load on the generator except windage and friction.”

Table 4 then lists a matrix of runaway speeds for the turbine with the existing runner at various heads and operating conditions: “Off-cam (Loss of oil pressure)”; “On Cam”, and “Max false blade position”. The table indicates that the turbine will exceed the generator design runaway speed of 144RPM when heads are 36 feet or greater, and the turbine goes to runaway from “Max false blade position”.

The final paragraph states “It is recognized that the existing runner design has a maximum false blade runaway speed that can exceed the generator design runaway speed rating of 144 RPM. The design target for maximum off-cam (loss of oil pressure) and on-cam runaway shall be 144 RPM.”

Please clarify that the Government is stating that the rehabilitated turbine design, with the new runner, may exceed the speed of 144RPM at runaway from any operating condition except “On Cam” and “Off-cam (Loss of oil pressure)” – which we understand to mean the maximum speed the runner will runaway to if there is a sudden loss of blade and gate hydraulic oil pressure resulting in the blade and gate positions to move off-cam.

If this is the case, please acknowledge that the Government will assume the risk that the new turbine could exceed the generator design runaway speed under other conditions, including “Max false blade position”. This creates the risk of failure of the generator from overspeed, and the Contractor cannot be held responsible for any associated liability.

Please clarify and confirm.

ANSWER: Table 4 of Specifications Section 48 13 13.01 26 provided estimates of runaway speed over a range of operating head and various operating head conditions. These values have been revised based on OEM model test results. As revised, the specified maximum runaway speed of 144 rpm is exceeded at heads of 44’ and above and under false cam operation (i.e. flat or closed blade angle). It should be noted that these OEM model runaway values were based on slightly different tailwater elevations than are presented in specifications, which represent current conditions. A copy of the model test is provided for reference. The goals of replacement runner specifications is to obtain runaway speeds less than the specified maximum under all operating scenarios. At net heads of 44’ and above, the replacement runner design should not introduce an increase in false cam runaway speeds beyond those presented in Table 4.

Runaway conditions are rare events, and off-cam runaway are even less common. Nonetheless, given the potential consequences it is prudent to design or implement measures for such worst case scenarios. As such, provisions for limiting runaway have been incorporated in specification revisions.

These include:

‐ Limiting minimum blade angle. Procurement documents for existing OEM runner limited minimum blade angle to 16.5 degrees. A similar limitation will be incorporated in replacement runner design.

‐ Increasing minimum blade angle will also be considered. It is recognized this may result in off-cam operation and associated potential loss of efficiency and/or increased pressure pulsations when operating at part-load.

‐ Replacement of blade servomotor or significant increase in servomotor stroke is beyond scope of rehabilitation effort. The existing servomotor stroke (nominal 5 inches) and blade operating range (10 degrees) is expected to be similar in replacement design.

‐ Limiting wicket gate openings at higher heads.

53. Section 48 13 13.09 26 Paragraph 3.2.6(a) – Repair 48-Inch high by ¼ to ½ Inch Deep Area of Discharge Ring The Specification requires the removal, by in-place machining, of a minimum depth of ¼ inch of the existing discharge ring within a 48 inch height band, and then the replacement of the removed material by overlaid stainless steel weld cladding of sufficient thickness to insure a minimum of ¼ inch residual stainless steel thickness when machined to the original design shape, and a maximum thickness of ½ inch only for a band of up to 12 inches in height within the total 48 inches.

Since it is not possible for offerors to know the condition of the discharge ring, including the residual material and its cylindricity and runout, and to insure that offerors are bidding the same scope for this work, please clarify that the bid price is only to include a uniform ¼ inch machining depth and uniform ¼ inch depth weld overlay – plus minimum stock for machining – over the 48 inch height band, and that additional weld overlay will be considered change work and compensated as per the Excess Work Options or Change Order to compensate actual additional cost.

ANSWER: The specification requires up to ½ inch machining. For the purposes of bidding, assume the worst case, the Contractor may be required to remove and weld overlay up to ½” inch of stainless steel. However, it is expected that in most areas only ¼ inch depth is needed.

54. Section 48 13 16.00 26 Paragraph 2.11.4 – Stator Clamping System (OPTIONAL) There is no CLIN on the bid schedule specified for this item. Please advise the correct line item numbers for us to provide the prices for this option.

ANSWER: Please reference the Government’s response to question 51. CLINs 0192, 0302, 0408: “Stator Clamping System, Unit [x]” were added to the bid schedule for the optional replacement of the stator clamping system.

55. Section 48 13 13.24 26, 2.4 “brake cylinders shall have the same nominal dimensions and bore as existing. The brakes shall retain the same operational stroke as the existing brakes”. Please provide the brake drawing.

ANSWER: No brake drawings are available. The Contractor is responsible for inspecting and measuring the existing brakes to reverse engineer the replacement brakes.

56. SECTION 01 78 00 3.1.1 first sentence states, contractor shall vectorize all reference drawings. In the same paragraph, line 9 states minimum of 80 drawings. It is our understanding that the bidder to include price for 80 drawings in the bid. If the Government request for more than 80, separate payment will be made as change order.

Please confirm.

ANSWER: Specifications section 01 78 00, paragraph 3.1.1 has been revised to state:

“The Contractor shall vectorize all reference drawings identified on G-002 and G-003 and any components modified by the Contractor, so the end result is one complete set of drawings with any modifications from the contract. The Contractor shall submit a list of drawings to be vectorized.”

57. Technical Specifications/05 59 13/Para. 1.1 /Page 3

Please clarify if the purpose of this section is to provide new draft tube gates similar to those shown on OEM drawings (Q9-79/680, Q9-79/680.1, Q9-79/681.1, Q9-79/681.2, Q9-79/682.1 and Q9-79/682.2).

There is no reference to those drawings in this paragraph. Moreover, there is no description and no dimensions for those gates in this paragraph.

ANSWER: Added drawing list to paragraph 1.1, “SCOPE

This section applies to the fabrication of the draft tube gates. Contractor shall provide one set of draft tube gates. A set of gates constitutes 3 gates, each with 2 segments. A total of 6 segments. The gates shall be fabricated as per contract drawings listed below.

Q9-79/680A Q9-79/681A Q9-79/682A Q9-79/683A”

58. Technical Specifications/48 13 13.09 26/Para. 3.2.29.3/Page 15

Please clarify if this minimum thickness is applied to the full length of the insert.

Progressive reduction of thickness at the bottom would be suitable to avoid having a step in the discharge ring or machine the full thickness of the existing discharge ring.

ANSWER: The discharge ring insert has been de-scoped and machining of the discharge ring is the base requirement per Specifications section 48 13 13.09 26.

59. Technical Specifications/48 13 16.00 26/Para. 3.33.2 (d)/Page 46 The measured sound emissions from the rewound generator shall be equal or better than value measured before the outage.

ANSWER: The specification paragraph is updated to reflect post rewind sound levels no greater than pre rewind.

60. Technical Specifications/01 22 00.00 26/Para. 1.3.1/Page 5 & 48 13 13.07 26/Para. 3.1.1/Page 7 Please clarify that bid item No. 0124 in price schedule is optional as described in the specifications.

ANSWER: Contract Line Item Number (CLIN) 0124 is not an option item; it is part of the base CLINs. Paragraph

3.1.1 in Specification section 48 13 13.07 26 is discussing spare guide bearings.

All operating generator guide bearings are base CLINs. Spare bearings have an inspection in base scope and refurbishment as options. CLINs 0558 to 0559 (options) cover the spare generator guide bearings. The turbine guide bearings are replaced, so refurbishment of the existing bearings is not included.

61. Technical Specifications/01 22 00.00 26/Para. 1.3.1/Page 7 & 48 13 13.04 26/Para. 3.20.6 b./Page 30 Please clarify if bid item No. 0137 in price schedule is mandatory or not. If yes, please clarify the related scope of work since it is not described in the specifications.

ANSWER: CLIN 0137 is part of the base CLINs. Additional specification wording has been added to paragraph

2.21 in Section 26 05 00.00 26 of the Technical Specifications.

62. Technical Specifications/01 22 00.00 26/Para. 1.3.1/Page 12

Please clarify the scope of work associated with bid item No. 0180 in price schedule.

ANSWER: There is a similar CLIN for Units 3, 2, and 1. This CLIN covers wiring replacement in Specifications section 26 05 00.00 26.

63. Technical Specifications/09 97 02/Para. 1.1.1/Page 4

The existing semi-spiral case is made of concrete and is out of the scope for refurbishment of hydraulic structures.

The actual condition and surface finish is unknown and are necessary to validate our hydraulic calculations.

ANSWER: Condition of concrete spiral scroll case was available for viewing during the June 19, 2020 physical site visit.

64. Please consider to give an access to Contractors to the spiral case during the mandatory site visit. If not, please include detailed pictures of actual condition with the final version of specifications.

ANSWER: Please reference the Government’s response to question 63.

65. Technical Specifications/22 00 00.00 26/Para. 3.14/Page 16

Please clarify the related scope of work and the associated bid item in price schedule.

ANSWER: Specifications section 22 00 00.00 26 paragraph 3.14 is updated.

66. Technical Specifications/48 13 16.00 26/Para. 2.11.4/Page 21

Please clarify the associated bid item in price schedule for this optional scope of work.

ANSWER: Reference CLINs 0177, 0283, and 0393 on the bid schedule.

67. Technical Specifications/48 13 16.00 26/Para. 3.11/Page 31

Please clarify the associated bid item in price schedule for this mandatory scope of work.

ANSWER: CLINs 0176, 0282, 0392, and 0500 “Removing abandoned rotation exciter parts, Unit X” have been updated to “Rotating Exciter Modifications” to include installation of replacement collector rings on the updated bid schedule provided as a separate attachment to Amendment 0005.

68. During the Virtual Pre-Bid meeting it was mentioned that the Contractors should note the interim project milestones listed in Section 01 32 01.00. The first interim milestone listed in paragraph 3.3.7 is unclear: “NTP+365 Design complete and shop drawings approved for runner model”

Did the Government intend for the milestone to be for the Prototype Runner design/shop drawings in lieu of the runner model?

ANSWER: This particular milestone is the maximum calendar days the Government expects to complete the design of the runner model with approved drawings. This milestone can occur anywhere between Notice to Proceed (NTP) to NTP+365. However, the contractor will submit the "initial project schedule" submittal 01 32 01.00_ 3.4.2 that will lay out all major activities for the duration of the contract. Items such as prototype design, manufacturing milestones, and design milestones will all be determined by the contractor and agreed to by the Contracting Officer’s Representative (COR). Naturally, items such as prototype design must be completed somewhere around the NTP+365 to begin manufacturing in order to commence Unit 4 at NTP +730 on time.

The Interim Milestones in Specifications section 01 32 01.00 paragraph 3.3.7 are high level milestones that have many perquisites in order to keep the entire contract moving in a timely manner. All milestones can be achieved prior to the maximum days listed, but not after without contracting action.

69. CLINs 0132, 0238, 0348, and 0462 is for refurbish, or replace, the draft tube unwatering valves, and the turbine 12 inch depression valve (Ref. drawing 220333 – 12” Air Valve). However, Section 22 00 00.00 26 called to “replace”. Please clarify if it’s refurbishment or replacement. Mechanical Equipment and Piping.

1.1 GENERAL INFORMATION

d. Replace the four draft tube unwatering valves and actuators.

e. Replace depression air valves.

3.8 DRAFT TUBE UNWATERING VALVES

Refurbish the 14 inch draft tube unwatering valves on each Unit….

3.9 DEPRESSION AIR VALVES

Replace the 12 inch depression air valves located within the turbine pit.

See reference drawing 220333 12" Air Valve - Hydraulic Turbine.

ANSWER: The Technical Specifications are changed to reflect the requirement to refurbish air valves, replace 16” spiral case valves, and replace 14” draft tube valves. Scope is included in specification SECTION 22 00 00.00 26 paragraph 1.1, paragraph 3.8, and paragraph 3.9. CLINS 0132, 0238, 0348, and 0462 are updated to reflect this change.

70. Please clarify work scope for scroll case unwatering valve. The scroll case unwatering valve is included in CLINs referenced in above question, however, these valves do not appear in the Technical Specification. Please provide technical information and drawings of the existing draft tube and scroll case unwatering valves locations.

ANSWER: Specifications section 22 00 00.00 26, paragraphs 1.1, 3.8, and 3.9 have been revised to replace the 16" spiral case valves and 14" draft tube valves. This change is also included drawing Q9-79/500 piping diagram.

71. CLIN 0113 and 0164 Provide new Draft Tube Man Door and refurbish door frame for Unit 4, appears to be duplicated. Later section 22 00.00 26 Measurement and payment section 22 00.00 26 called 0113 as “Reserved”.

Please confirm the CLIN 0113 is not required to price.

ANSWER: CLIN 0113 is a duplicate and has been changed to “Reserved” in the bid schedule

72. CLINs 0164 (U4), 0270 (U3), 0380 (U2), and 0494 (U1) called for Draft Tube door frame to be refurbished.

However section 48 13 13.04 26 item 3.16 indicates for replacement. Please clarify if it is refurbishment or replacement?

ANSWER: CLINs 0164 (U4), 0270 (U3), 0380 (U2), and 0494 (U1) are changed in the bid schedule and measurement and payment section of the Technical Specifications to make clear the draft tube man door AND door frame are to be replaced.

73. Section 41 01 20.76. Below the Hook Devices. Paragraph 1.1 Description of Work, indicates that the drawing for the Main Lifting Beam (drawing 850-1). We could not locate the drawing in the specification. Please provide drawing for Main Lifting Beam.

ANSWER: Drawing 850-1 is added.

74. Optional CLINs 0208, 0316, 0421, and 0526 Head Cover Sealing Flanges O-Ring Groove Modification. Base work scope covered under Section 48 13 13.04 26 Existing Turbine Component, Refurbishment and Replacement, at paragraph 3.10.2 Machining of Stay Ring Flanges, reads: “Machine up to 0.080 inches off the surface of the stay ring flange to restore the flange to a flat and level condition. The machining shall include restoration of the O-ring groove on the lower flange, Detail H on drawing 227930…”. But there is no detailed description for the optional O-ring groove modification. Are the optional CLINs above and base scope CLINs 0141, 0247, 0357, and 0471 redundant? If not, please provide more details scope of work for optional item groove modification.

ANSWER:

The CLINs previously noted as 0208, 0316, 0421, 0526 and 0166, 0272, 0382, 0496 have been removed and incorporated into CLINS 0140, 0246, 0356, 0470 on the updated bid schedule provided as a separate attachment to Amendment 0005.

- CLINs “Head Cover Sealing Flanges O-Ring Groove Modification (OPTION)” (0208, 0316, 0421, 0526) were changed to “reserved”

- CLINs “Machine Head Cover Flanges in Shop” (0166, 0272, 0382, 0496) are now used for a different bid item

- Updated CLINs “Head Covers and Facing Plate Inspection and Refurbishment” (0140, 0246, 0356, 0470) to say “Also included is the machining of a new O-ring groove and the restoration of existing O-ring grooves and flanges”

- 48 13 13 .04 26 para 3.15.1.c and 3.15.8.c have been updated to clarify scope.

75. Painting of draft tube section below the discharge ring overlay. Section 09 97 02 Painting: Hydraulic Structures

– Paragraph 3.5 Painting Schedule reads:

“i. Draft tube section below the discharge ring overlay (approximately El. 294.5') and above the bottom of the of the new draft tube man door repair area (approximately El. 286.5')” Contract drawing M-003 Discharge Ring Anchor Pattern, shows the 48 inch overlay band starting at approximately

28.5 inch below the bottom ring facing plates.

Being distributor centerline Elevation at 310.00 Feet, and the bottom ring facing plates at 58 inches below the distributor centerline, the bottom of the 48 inch overlay band will be at Elevation 298.8 [310.00 – (58/12) – (28.5/12) – (48/12)] = 298.795 Feet. The elevation discrepancy results in approximately 340 square feet difference.

Please confirm the correct elevation, below the stainless steel overlay weld, the draft tube painting should start.

ANSWER: Paragraph 3.5 of Section 09 97 02 is updated with the correct elevation.

Section 09 97 02 Painting: Hydraulic Structures – Paragraph 3.5 is updated in the Technical Specifications.

76. Please clarify if the painting of the entire generator air housing exterior surface, including access stairway and railing, should be painted.

In Section 09 97 02 Paining: Hydraulic Structures – Paragraph 3.5 Painting Schedule – System No. 21, the sentence “The External Generator Air Housing color selection shall be approved by the Government.”, leads to believe that the air housing should be painted however, the generator air housing is not specifically listed in the components to be painted.

ANSWER: The intention of this requirement is for the generator to have the same color scheme as before rehabilitation. System 21 paint is required on the ferrous portions of the air housing, hand rails, cover plates, exciter housing, oil head components, Kaplan oil pipes, etc. The ferrous portion extends from the generator floor to the top of the oil head. Requirement for the hand rails to be PPG Betonel Bleu has been removed, the color of the hand rails shall match the existing color. The wording for System 21 has been updated in Section 09 97 02 of the Technical Specifications.

77. Thrust bearing oil sump exterior. Section 09 97 02 Painting: Hydraulic Structures – Paragraph 3.5 Painting Schedule – System No. 25. Since the thrust bearing oil sump is integral part of the generator lower bracket (Reference drawing 718E340 Lower Bearing Bracket), please specify the boundaries delimiting the thrust bearing oil sump, providing estimated surface area to be blasted and not painted (thrust bearing oil sump interior surface), and estimated surface area to be blasted and painted (thrust bearing oil sump exterior).

ANSWER: The scope includes the face of the lower bracket that supports the access hatches to the thrust bearing, the access hatches themselves, and accessories that were painted before. The scope also includes the top portion of the thrust bearing tub including hatches, covers, pipes, and accessories that were painted before. The Contractor is responsible for determining the estimated area from the available drawings or from the physical site visit held on June 19, 2020.

78. Please consider including “Performance base payments” for the following bid items:

• 0118, 0229, 0339 & 0453 Design, Manufacture, Test and Deliver 63,605 hp Kaplan Runner Assembly

• 0119 Furnish Turbine Model

• 0172, 0278 & 0388 Furnish Complete Set Of Stator Coils Including Supplies and Accessories for A Complete New Winding Including Factory Testing

• 0177, 0283 & 0393 Furnish and Install New Stator Core References: 52.232-32 PERFORMANCE-BASED PAYMENTS (APR 2012), and 252.232-7013

PERFORMANCE-BASED PAYMENTS-DELIVERABLE-ITEM BASIS (APR 2014)

The above CLINs are long lead items with a high value and “Performance Base Payments” is more suited than “Job Price Payment.”

ANSWER: The Government will pay in accordance with FAR Clause 52.232-5, Payments under Fixed Price Construction Contracts.

For CLINS 0118, 0229, 0339 and 0453 progress payments can be made under construction clauses for major completion of work outlined in the cost loaded schedule and determined by COR.

79. As stated in Section 48 13 13.04 26 paragraph 3.25.2:

“The servomotor shall be capable under maximum or the most unfavorable head of moving the turbine blades smoothly a full opening or full closing stroke in 18 seconds, with a supply of oil at 300 psi pressure in the governor oil pressure tanks.”

It is assumed that 18 seconds is the current travel time for the very limited tilt range (10 deg) of the existing Kaplan turbines at Barkley. This results in a current movement speed of 0.55deg / second (10 deg / 18 seconds).

Due the requirement for draft tube pressure pulsation below 7% of rated net head across the operating range (Section 48 13 13.00 26 paragraph 3.1.11 (d) ), the blade tilt range must now be significantly increased to cover the low flow range on-cam (lower minimum tilt value than current minimum tilt).

In order to move across the full new larger tilt range in 18 seconds, the rate of change of blade tilt will have to be significantly increased (blade deg/s). An increase in this rate can be undesirable from a transient standpoint and would also likely be problematic for the existing governor controls since the oil flow rate through control valves and piping would have to be significantly increased (possibly beyond the capability of the existing governor).

Would it be preferred to maintain a rate of blade movement that is compatible with the existing governor to maintain current maximum acceptable oil flow rates? If so, what is the maximum oil flow rate that would be compatible with the existing governor?

ANSWER: Replacement of blade servomotor or significant increase in servomotor stroke is beyond the scope of the intended rehabilitation effort. The existing servomotor stroke (nominal 5 inches) and blade operating range (10 degrees) is expected to be similar in the replacement design. To improve runaway characteristics, increasing the minimum blade angle may also be considered. It is recognized this may result in off-cam operation and associated potential loss of efficiency and/or increased pressure pulsations when operating at part-load. See changes to minimum horsepower requirements and pressure pulsation criteria provided in Specifications Section 48 13 13.01 26, paragraph 3.1.11.d and Table 3.

80. In addition to question above, there are several other requirements on the specification cumulatively necessitate additional forces or travel for the blade servomotor beyond the capacity of the original design, such as:

a. Roller bearings, which were present in the OEM design, are prohibited according to Section 48 13 13.04 26, 3.25.1. Bronze bushings have a higher coefficient of friction, and therefore require additional force to operate.

b. Increase in turbine output to 63,605 hp. increasing the maximum output adds additional forces in the runner linkage which requires additional servomotor force.

c. The hydraulic balance of the blades is required such that the natural tendency is an opening movement at all positions, according to Section 48 13 13.01 26, paragraph 3.6.3.2.e. This requirement places a higher dependency on one side of the servomotor, which increases the amount of force required from the servomotor.

d. Due the requirement for draft tube pressure pulsation below 7% of rated net head across the operating range (Section 48 13 13.00 26 paragraph 3.1.11 (d), the blade tilt range must now be significantly increased to cover the low flow range on-cam (lower minimum tilt value than current minimum tilt). This increase in blade tilt translates directly to an increase of servomotor travel.

e. Operation at extreme minimum net head of 18 ft. conditions away from the design point tends to lead to higher loads on the blade mechanism. The requirement for the servomotor to be capable of moving the turbine blades at 300psi at any unfavorable head or condition (Section 48 13 13.04 26, paragraph 3.25.2) requires exceptional force from the servomotor, compared to load cases closer to design head and flow.

The specification makes no reference to an upgrade of the governor system due to changes stated above on the turbine. Neither does the Specification provide any information related to governor sizing and controls.

Since the equipment necessary to remedy this situation is not included in the scope specified in the Solicitation, and the Government is soliciting bids to be selected by lowest price, how are offerors expected to communicate the governor requirements of the rehabilitated turbine? If this information is intended to be part of the offer, how should it be communicated, and how will it be evaluated?

Alternatively, is there one or more of these parameters that could be relaxed to avoid impact to the governor?

ANSWER: The existing runner model test has been included as a reference document in Section 01 95 00 attachment 11. The intention of the contract was re-use of the blade servomotor.

Due to increased friction associated with bronze bushings and intent to reuse the existing blade servomotor, revisions to the Specifications to allow for roller bearings have been provided. Revisions to minimum horsepower requirements and pressure pulsation criteria are also provided (see response to Question 79).

Specifications Section 48 13 13.01 26, paragraph 1.4.1, 2.1.12.2, 3.6.3.2, and 3.6.8 have been updated for roller bearings.

81. Section 22 00 00.00 26 Mechanical Equipment and Piping, and subject CLINs, no drawings have been provided to estimate work associated with requirements of Section 22 00 00.00 26 § 3.3.1 Cleaning. Specification requires as follows:

a. The existing cooling and packing water piping that is not to be replaced shall be cleaned and all scale, rust, and other build up on the interior pipe walls shall be removed.

All heat exchangers shall be detached from the system during the flushing.

The interior pipe surfaces shall be cleaned by the high pressure hydro-wash method. Alternate methods of cleaning, such as using a pipe pig in straight runs of simple piping may be proposed by submittal to the Government for approval.

The proposed method shall include a description of how each pipe segment will be cleaned.

All scale, rust, and debris from the cleaning process shall be flushed out of the pipe, contained, cleaned up, and properly disposed of. It shall not be washed in to the powerhouse sump.

All piping shall be inspected with a camera following cleaning.

b. The head cover drain to the plant sump pipe shall be cleaned from its entrance into the stay ring to its exit into the drain header. Similarly, the piping up to and downstream of the eductor shall be cleaned to its exit into the draft tube.

Section 22 00 00.00 26 Mechanical Equipment and Piping, paragraph 3.3.1 Cleaning, and paragraph 3.3.3 Inspection and Replacement of Larger Piping.

Please provide powerhouse piping diagrams, piping sections and details, for generator cooling water, and turbine sump pump drainage system, to allow Contractor to assess and estimate piping cleaning, and inspection as per specification requirements. Please define limit of supply boundaries for existing cooling water, packing, and turbine/generator drain piping systems to be cleaned and inspected.

ANSWER: Added reference drawings of exposed piping for the majority the entire plant. See “INDEX OF DRAWINGS”, drawings Q9-79 560.1 THRU Q9-79/596.1

82. Reference CLIN 0115 Engineering and Installation of Outdoor Display Runner and Sign.

Section 05 50 03.20 26 Metalwork Fabrication, Machine Work, and Miscellaneous Provisions.

Paragraph 3.6 Turbine Runner Display.

Please confirm our understanding that the exposed ferrous surfaces of the existing turbine runner assembly display, and supports, shall be painted with System No. 21 in accordance with Section 09 97 02 Painting: Hydraulic Structures.

Please also specify the color for the turbine runner display.

ANSWER: The Technical Specifications are updated to add turbine display to the list in Section 09 97 02, paragraph 3.5 for System No. 21 and paint color in Section 05 50 03.20 26 paragraph 3.6.

83. Section 48 13 16.00 26 3.11 Collector ring replacement but does not include the brush rigging in the work scope. However, drawing E204 marked the brush rigging as “replace. Please clarify if brush rigging is in work scope and it will be refurbished or replaced.

ANSWER: Drawing E204 is updated to not indicate brush rigging replacement.

84. All wetted model components, from the turbine inlet to the draft tube exit, shall become the property of the Government, including tools for setting blade angle.

The model is the property of the Government, except for the model runner profiles. These profiles contain our knowledge and years of experience and R&D. The runner will be kept in GE’s laboratory and made available to the Government.

ANSWER: Specifications Section 48 13 13.00 26 requires the model be shipped to the powerhouse at the end of the model testing. The Government recognizes the runner profiles are proprietary and will not provide the model to outside entities. The Contractor may choose to label the storage boxes as “proprietary information.”

85. Fabricate a stator core segment of at least ten slots to verify dimensional compatibility of the stator coils in the stator core. Include critical features such as ends of laminated iron, clamping fingers, and surge rings.

In the dummy cores that GE makes to check the coil dimensions, the clamping fingers are omitted. The reason is that the length of the straight portion of the coil corresponds to at least the stator core length plus the clamping fingers. The tooling that GE uses on the ground insulation hydraulic presses is adapted to each project and is such that the straight length of the coil cannot be shorter than the press mold, and therefore there is no chance that the coil interferes with the clamping fingers.

ANSWER: Per Specifications Section 48 13 16.00 26, the dummy core is required to also indicate that the pitch of the coil after leaving the slot will not interfere with the clamping fingers. While the ground insulation presses are equal to slot length, the bending of the end turn may be set incorrectly or inconsistently resulting in impingement on the clamping fingers – hence the minimum dummy core constructions. A simple block to mimic the clamping finger size is sufficient to demonstrate clearance.

86. (a) Bottoming of Coils. Press the coil firmly into place with a jack.

(c) Top Packing. Press the coils firmly with a jack before installing wedges."

GE’s standard technology does not require the use of a jack to perform the installation of the coils; the coils are carefully inserted in the slots by hands to ensure no damage is caused to the coil insulation.

The typical radial wedging procedure (of the top leg) goes as follows:

•The protective band and the slot closing wedge are inserted;

•The remaining space (in front of the top leg) is gauged;

•The free ripple spring is inserted;

•The counter-wedge (its thickness is chosen depending on the space previously gauged) is driven in place using a specialized hand-held tool. The counter-wedge pre-compresses the ripple spring to ensure a radial force is always applied on the coils.

•By using go/no-go gauges, the residual deflection of the ripple spring is checked to ensure the coils are firmly wedged in the slots within installation criteria.

ANSWER: Different processes utilized by the successful bidder may be submitted for review/approval as part of the submittal process under “Stator Winding Installation Procedure.”

87. Please confirm if the stator clamping system is in base or optional scope of work. If it is optional, please clarify the associated bid item in price schedule.

ANSWER: CLINs 0192, 0302, 0408: “Stator Clamping System, Unit [x]” are added to the contract for the optional replacement of the stator clamping system included as a separate attachment with Amendment 0005.

88. GE assumes that all new wiring/conduit associated with new instrumentation (RTDs, gauges, switches, etc.)

requested in the specifications will be under bid item No. 0185 in price schedule.

However, please clarify the scope of work associated with bid item No. 0180 in price schedule. This scope of work is no described in the specifications.

ANSWER: CLIN 0185 is for all general field wiring, RTDs, gauges, and switches for turn-key installation of those components. CLIN 0180 is for all other wiring entering and exiting the turbine pit and generator air housing not included under the specifics of CLIN 0185. An example is conduits cut to facilitate removal of components, and associated wiring, as described in Section 26 05 00.00, paragraph 3.5.2 of the Technical Specifications.

89. Replacement work shall include all work required to replace the existing collector ring assembly with a new one. Provide a collector ring assembly for mounting to the generator shaft. The collector ring assembly shall include the collector rings, supports, insulators, bolting hardware, etc.

Please clarify the associated bid item in price schedule for this mandatory scope of work. Please clarify if this scope of work is applicable for Unit 1.

ANSWER: Please reference the Government’s response to question 51. CLINs 0176, 0282, 0392, and 0500 “Removing abandoned rotation exciter parts, Unit X” were updated to “Rotating Exciter Modifications” to include installation of replacement collector rings. This scope of work is applicable to all units.

90. Replace the approximately twenty-seven inches of generator neutral bus bar where the neutral current transformer was removed with copper bus bar dimensionally matching the existing bus bar bolt patterns, plus any required bolting hardware.

Please clarify if this scope of work is applicable for Unit 1.

ANSWER: Specifications Section 48 13 16.00 26 paragraph 3.24.1.1 indicates removal of only Unit 2 and Unit 4 neutral current transformers, and paragraph 3.24.2.1 requires replacement of those removed sections on Units 2 and 4 only. The specification will be updated in Amendment 0005 to clarify.

91. The turbine guide bearing lubrication system will be replaced with new on a skid. The existing turbine guide bearing oil circulating pump skid has a poor design that limits access for service of the pumps and plumbing. The new system will include 1/2 HP AC and DC motors, controllers, pumps, duplex filter and sight glass. Re-route piping and conduit around turbine guide bearing and packing box for improved access. Re-route piping to eliminate tripping hazards and egress issues.

Please clarify the scope for re-routing piping and conduit around turbine guide bearing and packing box for improved access. Is there a preferred location already identified?

ANSWER: Please reference the Government’s response to question 65.

92. Item No. 0208 Head Cover Sealing Flanges O-Ring Groove Modification, Unit 4 (OPTION) Payment for the modification of each head cover flange for the addition of the an O-ring that will be made on a job basis under Item No. 0208.

Please clarify the scope of work associated with bid item No. 0166 in price schedule. This scope of work is not described in the specifications.

ANSWER: Please reference the Government’s response to question 74.

93. For the generator, the clause mentions the handrails, exciter housing, deck plates, and pipes. Are there any other atmospherically exposed ferrous surfaces of the generator that should be prepared and painted under this system (i.e. stator frame, stator housing OD, etc.) besides very small appurtenant parts (bolts, etc.)?

ANSWER: Specifications Section 09 97 02, paragraph 3.5 is updated for clarity. The entire steel exterior of the generator (stator housing OD) is included in the scope. The stator frame repainting is not in scope, except touch up paint on areas that are modified for the new laminations. Paint colors are to match the existing colors unless otherwise specified.

94. For large parts such as the lower brackets that have surfaces continuously submerged in oil and will not be repainted such as the inside of the bearing tub, is it necessary to blast?

ANSWER: Areas that are not in scope for repainting, such as inside of bearing tubs, are not required to be blasted.

95. Item No. 0122 Ship Generator Shaft and Thrust Bearing Runner to and from Contractor's Shop, Unit 4

3.5 SHIPPING (OPTIONAL)

3.5.3 Shipment of Generator Shaft

Please confirm item 122 is optional scope.

ANSWER: The word “Optional” was a typo; shipping of the thrust bearing parts are base scope items. The word “Optional” was removed from Section 48 13 13.06 26, paragraph 3.5 of the Technical Specifications.

96. Who will drain the oil from the servomotor?

ANSWER: The Contractor is responsible for draining oil from the servomotor.

97. Will the Government dispose of the oil drained by the Government?

ANSWER: The Contractor is responsible for disposal of the old oil per Section 48 13 13.10 26, paragraph 3.1 of the Technical Specifications.

98. Shall we provide a price for one or four spare shaft sleeves?

ANSWER: If this question is in regard to CLIN 0557, the price is for 4 spare shaft sleeves as an option. Base scope is replacement of the shaft sleeves that are currently installed on the turbine shafts.

99. Furnish 24 spare sets of the seals provided under subparagraph "a" above, enough to replace all the gate stem seals.

What is the bid item for these spares?

ANSWER: This is included as part of the head cover refurbishment CLINs 0140, 0246, 0356, and 0470.

100. Furnish one spare set (total for both servomotors) of the seals provided under subparagraph "a" above.

What is the bid item for these spares?

ANSWER: This is included as part of the servomotor refurbishment CLINs 0133, 0239, 0349, and 0463.

101. One packing gland is damaged and leaking and shall be replaced in-kind, except cast iron is not required, plate steel will be allowed.

On which unit?

Which bid item?

ANSWER: This requirement is removed from Section 48 13 13.04 26, paragraph 3.26.2 of the Technical Specifications.

102. Do the shafts have to be inspected on 100% of the surfaces or limited?

ANSWER: Specifications Section 48 13 13.04 26 paragraph 3.3.3 requires 100% of the shafts be inspected.

103. Is there existing paint below the shaft sleeve?

ANSWER: OEM drawing 227941 is the turbine shaft drawing that indicates the shaft was painted in accordance with OEM drawing 227962. OEM 227962 indicates a red lead primer was applied to all exposed surfaces. For the purposes of bidding, assume there is existing lead-based paint below the shaft sleeve.

104. The replacement of the chevron packing is described as base scope in 48 13 13.04 26 /3.25.4 and as an option in bid item 0193. Is it base or option?

ANSWER: Specifications Section 48 13 13.04 26 paragraph 3.25.4 shows this effort as base scope work, CLINs 0193, 0303, 0409, and 0513 are listed as base items in the bid schedule. Optional CLINS 0193, 0303, 0409, and 0513 have been deleted and moved to CLINs 0166, 0272, 0382, and 0496 in the base.

105. Since the turbine guide bearing is replaced and old one disposed, please clarify if the site still needs to be performed.

ANSWER: The Government assumes this is in regard to site INSPECTION of the old turbine guide bearing. Non-destructive testing or inspection of the disposed bearing is not required.

106. Item No. 0376 Turbine Guide Bearing Cover, Unit 2

Payment for the fabrication and installation of new turbine guide bearing covers will be made on a job basis under Item No. 0376. Payment shall include labor, material, and equipment required to refurbish the blade servomotor including honing to accommodate the new operating rod cast iron rings in accordance with the specifications.

Why is this bid item referring to blade servomotor?

ANSWER: This is a typo that is corrected, see Specification Section 01 22 00 Measurement and Payment wording for CLIN 0376.

107. The stainless steel overlay shall be applied using type 309AL material.

Should it be 309L?

ANSWER: This is a typo; Specifications Section 48 13 13.09 26, paragraph 2.1 is corrected to remove the letter “A.”

108. Do ultrasonic thickness inspections have to be done 2 or 3 times?

ANSWER: Before placing anchors, the location of the existing structure must be determined by ultrasonic checks to map the structure, in accordance with Specification Section 48 13 13.09 26 paragraph 3.2.7.

Specifications Section 48 13 13.09 26 paragraph 3.2.10 states that “Ultrasonic thickness inspections shall be performed on the discharge ring at two separate times”

If it is possible, the Contractor may elect to combine one (1) of the required inspections in paragraph 3.2.10 with the existing structure inspection, as required in paragraph 3.2.7, resulting in two (2) total inspections. Otherwise, three

(3) total inspections will be required.

109. Installation of Discharge Ring Anchors: 435, Unit 4

A minimum of 285 anchors, per unit, shall be used with the option of additional anchors, as required. As a general rule, use 10-inch centers on the anchorage pattern.

Should our price be for 435 anchors or 285 anchors or for one anchor at every 10 inches?

ANSWER: Please reference the Government’s response to question 51. CLINs 0147, 0253, 0363, and 0477 were updated on the bid schedule to be priced on a per-anchor basis with an estimated quantity of 285 anchors.

110. Provide New Draft Tube Man Door and Refurbish Door Frame Replacement Draft Tube Man Door and Frame.

Should the door frame be replaced or refurbish?

ANSWER: Please reference the Government’s response to question 72.

111. Refurbish the 14 inch draft tube unwatering valves on each Unit.

Is there a drawing of this valve?

ANSWER: Please reference the Government’s responses to questions 69 and 70.

112. Replacement pipes shall be designed for usage with the existing oil pipe lifting devices (see drawing 234490).

Should it be drawing 234990?

ANSWER: Yes, drawing 234990 shows the existing lifting devices for the blade servomotor piping.

113. Do we have to reassemble the complete runner on display including the blade operating mechanism inside the hub or only the components visible from outside?

ANSWER: The internals of the runner (levers, links, crosshead, etc.) do not have to be used. However, the runner display will need some internal method of holding the blades at the same angle and restricting movement so that the cosmetic appearance remains the same as the original runner and the blades will not move. Please reference paragraph 3.6, Specification Section 05 50 03.20 26.

114. Bronze Bushings for Kaplan Blades: 3500 psi

Bronze castings shall be of a quality at least equal to that required by ASTM B584, Copper Alloy UNS No. C90300.

Can we use higher specific pressure if we use a higher grade of bronze casting?

For example 45 MPa (6527 psi) with bushings made of ASTM B148 UNS C95800 (tensile = 85 000 psi; yield = 35 000 psi).

ANSWER: The bronze bushing requirement for the Kaplan blades is removed and changed to roller bearings.

Please reference the Government’s response to question #80.

115. Drawing 850-1 is not included in drawing package. Please clarify.

ANSWER: Reference drawing 850-1 is added to the drawing index and the reference drawing set as a separate attachment to Amendment 0005.

116. Please confirm if the intermediate shaft, turbine shaft and runner needs to be assembled to perform servomotor movement or if a dummy can be used to perform full blade rotation under internal runner pressure as required in the spec.

ANSWER: Specifications Section 48 13 13.01 26, paragraph 3.6.20 (d) is changed to allow a dummy shaft.

117. If the Contractor elects to install a runner which requires modifications to the existing head cover, bottom ring, foundation ring (stay ring), upper draft tube liner or other existing components, the Contractor shall provide all such modifications including new components, refurbishment of existing components, etc.

Please confirm that if GE elects to supply a new runner servo piston, all refurbishment requirements becomes obsolete and GE is still compliant with the spec.

ANSWER: Replacement of the blade servomotor is not anticipated as part of this rehabilitation effort, see Government’s response to question #52. The Bidder should provide price data for the CLINS of the solicitation as written.

118. It doesn't appear that the Project Detail Sheet (PDS) and Past Performance Questionnaire (PPQ) forms were included in the Solicitation. Can these be provided?

ANSWER: Project Detail Sheet (PDS) and Past Performance Questionnaire (PPQ) forms…