Questions_and_Answers__2.docx

PRE-BID WALK THRU REPLACE CASS STATIONS T-38 AIRCRAFT

QUESTIONS

1. The Statement of Work does not address the need to remove and replace Concrete Panels at the Head of each Aircraft Shade Row. The existing air line that runs parallel to the Apron Road is Fiberglass Air Line that is brittle and subject to fracture and has failed in the past. It would be necessary to intercept a stub out of that line between each Air Manhole and the end of the Aircraft Shade to stub it up to go overhead on the Shade rafters. This is not practical for the following reasons:

0. The splicing/repair of this class of Fiberglass is a “lost art”

0. A hole at least 5’x5’ in the apron would be required for this splice if possible

0. RAFB does not allow for the removal of part of an Apron Panel with patch back

0. Several of the Shut off valves that feed each row are reported to be inoperative or leaking and replacement is favored

0. Partial apron panel removal would not allow for the installation of the new:

4. Stub Up for Fiber Optic Cable

4. Stub Up for 400 Hz Power

4. Stub Up for spare communication conduits

For Rows 1, 8,9, 10, and 11; the Apron panel between the Manholes and the end of the Aircraft Shade were replaced. The Air Shut Off Valve was replaced with new, and HDPE Pipe was installed between the Air Manhole new Valve and stubbed up to allow that Air Piping to progress Overhead. New PVC conduits were installed between the Electrical Manhole for the Fiber and the 400 Hz. The 400 Hz conduit was converted to Aluminum as it progresses to the open.

Response:

The replacement of concrete slabs for each row has been address in the revised SOW. The Government is not asking to replace any lines not already covered in the statement of work.

1. The Statement of Work does not address the requirement to modify the 400 Hz panels that currently serve the CASS Islands in Rows 2 thru 6 and will provide power to the central transformer in those rows.

Response:

The existing 400 Hz electrical panels are adequate to provide power for new 20 kVA stepdown Transformers

1. The Statement of Work does not provide information as to wire size or type for the new 400 Hz Main distribution feeds to the affected Rows 2 thru 6 Distribution panels or the indicated replacement for Rows 1, 7, 8, 9, 10 and 11.

Response:

Contractor shall specify the wire size to comply with NEC and UFC. Voltage drop shall be considered into the calculations.

1. The Statement of Work does not provide information as to wire size or type for the feeder between the Row Distribution Panels and the central transformer installed in each row to be modified.

Response:

Contractor shall specify the wire size to comply with NEC and UFC. Voltage drop shall be consider into the calculations.

1. The Statement of Work does not provide information as to the wire size or type for the sub feeder between the central transformer in each modified row and each new CASS station relay controlled by the local touch screen Response:

Contractor shall specify the wire size to comply with NEC and UFC. Voltage drop shall be consider into the calculations.

1. Plans do not dimension the distance between the rows or the length of the Aircraft Shades to allow determination for Conduit or Wire quantities for the project.

Response:

The site plan will be provided. Appendix D provides a site layout of the Shelter Rows.

1. The schematic for the “New CASS System Diagram” has the Call Out for Note # 5 indicated at both the location of the hose and the underground path of conduits

The diagram has been revised. Note 5 has been revised.

1. In the schematic reference above, the Part numbers for the “Customized” hose do not indicate the Vendors, only the part numbers. Please indicate those Vendors to allow identification of acceptable hose assembly.

Response:

The revised SOW will include all the missing information.

1. Section 5.5 (Construction) indicates that the conduit for the Fiber Optic in the Shade rafters shall be “Aluminum”. The only Aluminum conduit that we saw was the 400 Hz Conduit.

Fiber optic cables shall be in PVC conduits

1. The plans nor the Statement of Work indicate that the stub ups for the 400 Hz power and Fiber Optic are in a Classified Area and require Seal Off’s.

The stub ups for the 400 Hz power and Fiber shall be classified area

1. Section 2.4 Description of Work indicates that the new CASS module shall communicate with the master control via “Hardwire”. We observed Fiber Optic, but no hardwire control cable.

Response:

Section 2.4 reference to “Hardwire” is incorrect and should be “fiber optic cable”

1. Please indicate the output voltage of the 400 Hz Convertors that will be stepped down by the new transformers to be installed Response:

The 400Hz Frequency converters output will be approximately 517 VAC PIV and the 20KVA Transformers will step that voltage down to 115VAC.

1. Will the Government salvage any items other than the CASS stations as indicated in 4.4 or is the Contractor expected to dispose of all material Off Base?

All old CASS Stations will be removed and shall be relocated to an area specified by 12 FTW AGE shop while all other debris (construction) will be removed by the Contractor.

1. The project will include several occasions when the entire CASS system will be disabled such as:

13. Installation of new 400 Hz distribution cables

13. Installation of replacement Air Valves/Lines Will it be necessary that this work be conducted during “No Fly” occasions of weekends, holidays, or nights?

Response:

Each row can be isolated at the electrical panels adjacent to Hangars 3, 4, and 5. Therefore, when construction work is being completed “Row by Row”, each row can be isolated until project is completed row by row without having to completely shut down or disable all Rows 2 through 6 during construction. It is not recommended this project require work to be conducted during “No Fly” occasions or weekends, holidays or nights. In the advent of a total isolation of CASS system is required to shut down CASS operation, then it must be coordinate with 12 FTW/MX and flying operation will resume with backup portable AGE equipment if needed.

1. Once the Government takes Beneficial Occupancy of a Row and the Contractor proceeds to the next Row, will the Warranty Period for the occupied row start or does the warranty period start once the entire project is accepted?

Response:

Warranty period will start with beneficial occupancy of each row. Contractor will need to document the warranty dates for each row on the warranty letter, required in final closeout docs.

1. The schematic for Demolition indicates that the Contractor is to “Cap Off’ level with finished apron elevation the existing air and electrical lines under the CASS Islands. In order to cap them off level with the top of the apron, it will be necessary to remove and patch concrete around the conduits that rise above the apron. Is this patching to be done by the Contractor?

All work shall be done by Contractor. Additionally, refer to SOW, Section 5.1 Contractor shall re-establish the pavement joints to include dowel bars, backer rods, and silicone joint material. Contractor shall re-compact base materiel to 95% proctored density before placing pavement.