23B0001 Q and A.docx

23B0001 – Install HF Antennas – Q&As Question: Refer S-200, S-201, S-202 and S-203 what size is the W8 vertical bracing shown on drawings?

ANSWER: The main tower braces are vertical “X” braces made up of W8 members. It looks like the labels dropped off NKB’s final submission. They should be as follows:

All 4 sides at lowest level (0’ to 10’): W8x28 All 4 sides at all other levels: W8x18

There are some miscellaneous braces that are W6 and they are as labeled on the plans, but the main braces are all W8’s.

Question: Who is the manufacturer / basis of design for the Antennas?

ANSWER: The basis of design for the antennas is the MAS-5 Multiport Antenna System by Antenna Products

Question: Is the contractor installing a structural steel antenna on all three sites or just only one?

ANSWER: antennas will be installed at the Stockbridge and Tanner Hill test sites (2 antennas total). On the Irish Hill test site, there will be a walk-up tower to be constructed not an antenna.

Question: Can the AISC erector certification be waived?

ANSWER: Comment from NKB is as stated; Recommend the AISC Erector criteria in the spec can be modified to add:

“or firm with minimum 5 years’ experience with comparable projects and a field quality control plan that includes 100% 3rd party inspection/testing of field welds that are larger than 5/16” fillet and periodic inspection/testing of 5/16” and smaller welds and all bolted connections.”

Question: Both Tanner Hill and Stockbridge call for the proposed Electrical panels to be NEMA 4X. Irish Hill does not state a NEMA 4x is required. The Specification section calls for only a NEMA 4 which is not stainless Steel as the 4x Panel would be. Are the [2] new panels on Irish Hill site to be NEMA 4 or 4X?

ANSWER: Please provide the 4x panels.

Question: Is there counterpoise grounding required for the towers?

ANSWER: See information provided in Specification 26 41 13, 26 05 26 and also drawing E-501-S, Electrode Ground Grid detail, these provide information on grounding of structures.

Question: The existing standard at the sites for the Fiber optic termination is type LC. Are you looking to install type SC terminations?

ANSWER: LC is now fine in the outside plant, but the panel and inserts should be as follows: A 4u Corning CCH enclosure with 12 fiber (6 port) inserts. We do not want the density of 24 fiber (12 port) inserts. No substitutes on the corning enclosure or panels.

Question: Was there a Geo Tech report available?

ANSWER: Provided in the narrative document from CME Associates.

Question: Were marking lights required on the antennas?

ANSWER: For bidding purposes, contractor shall consider beacon indicator light to be provided.

Question: Will the antenna be installed as delivered or does the marking similar to the jib tower need to be painted on as well?

ANSWER: For bidding purposes, painting shall be assumed to be installed.

Question: Plan calls for lightning protection but no information on it in drawings?

ANSWER: Narrative states antennas are to be prewired and purchased with lightning protection.

Question: Will the transformer that is to be removed, be exposed of by the contractor or turned over to AFRL?

ANSWER: For bidding purposes, consider transformer needs to be de-commissioned and recycled. Refer also to hazardous material sampling report in specifications.

Question: Are the feeders of building 1605 encased in concrete?

ANSWER: NKB believes they are not but cannot confirm the extent. For bidding purposes, feeders can be assumed they are encased in concrete.

Question: Are the septic tank and leach field included in the building demo?

ANSWER: Please refer to sheet C002-T for details for septic tank and leech field.

Question: What is the utility cover on the back side of B1605 near the location of the new transformer and pad?

ANSWER: Nothing is depicted on record drawings and after observation inside, it is determined to be abandoned and filled with fill material.

Question: Location of transformer and pad may impede into the existing asphalt at rear of B1605. Any plans for this?

ANSWER: Specific transformer location to be coordinated during construction. For bidding purposes, contractor shall assume saw cutting of existing asphalt in order to install transformer and associated equipment pad.

Question: Will there be bollards surrounding the new transformer and pad at the rear of B1605 ANSWER: Yes, bollards shall be provided in accordance with transformer pad detail shown on Drawing E501-T.

Question: Will the propane tank on the back side of B1605 be removed and exposed of as well?

ANSWER: Propane will be removed by the contractor but the tank is full at present time. Coordination is needed before removal/demolition to ensure fuel is transferred beforehand.

Question: What is the cable type at the UGE manhole across the road of B1640 at Irish Hill?

ANSWER: For bidding purposes, contractor shall assume lead (XLPE) type insulation.

Question: Are lights required on the walk-up tower?

ANSWER: General purposes lighting is shown on Drawing E101-I. For bidding purposes, contractor shall assume beacon indicator light to be provided.

Question: P60 of CDs references movable shelter – is contractor responsible for installing this?

ANSWER: No, gov will be installing later on. Pad, utilities, gravel, etc. to be installed by contractor.

Question: Movable shelter – provided by GOV or purchased by contractor?

ANSWER: Gov providing at a later date.

Question: HF Antennas from Antenna Products – are the antennas provided on site by GOV or purchased by contractor?

ANSWER: Antennas to be purchased by contractor and installed by contractor.

Question: Walk up tower at Irish Hill – provided by GOV or purchased by contractor?

ANSWER: Materials purchased and fabricated by contractor.

Question: Please provide manufacturer and model for walk up tower.

ANSWER: No manufacturer for the walk-up tower. Materials to be purchased by contractor and erected/fabricated by contractor on site.

Question: I found a discrepancy between the Communications trench length on drawing C200-S and EY100-S.

Following are the trench lengths for the same 4” Communications conduits:

1. C200-S Shows conduit length at 711’

1. EY100-S Shows conduit length at 300’ Which Drawing is correct?

ANSWER: from the designer:

“After some double checking with Site Civil, the scale on C200-S should be adhered to.

To clarify the fence line radius is approx. 100 feet;

The fence line on the EY100-S drawing scales at about 89 feet; it should be 100 feet as shown on the Civil.”