Question_and_Answer_Log_Updated_8-2-2018.pdf

JECA 219033 - Build Safety Compliant Cave Tour Structures Solicitation No. 140P2018R0015

QUESTION AND ANSWER LOG updated 8-2-2018

Questions Received from Various Contractors NPS Responses:

1 1. Please state if CPAR’s evaluations may be submitted in lieu of Past Performance Questionnaires for given projects for which the contractor may have a CPAR’s evaluation on record?

Yes, CPAR's evaluations are thorough and can be submitted in lieu of Past Performance Questionnaires.

2 2. Sheet C1 – please clarify if stairs noted as 1D and 61 U are correctly designated.

The same stairs on sheet C13 are noted differently.

The designations are correct, C1 is showing demo of the stairs while C13 is showing new installation of the Bridges 1B1 and 1B2 in the same location.

3 3. Is the contractor permitted to maintain the staging area designated on sheet C2 between Phase 1 and Phase 2?

Yes, as long as there is access maintained for NPS to utilize the portal as emergency egress route and nothing is left that will hinder park access and operations.

4 4. If contractor is permitted to maintain staging area stated on sheet C2 between seasons, please state any limitations on quantity of equipment and materials that may be stored between seasons?

The park reserves the right to determine what can be left in the park between seasons.

Any equipment that may cause an environmental issue cannot be left in the park.

5 5. Is the temporary airlock permitted to remain in place between Phase 1 and Phase? Yes, As long as it does not hinder access to and from the cave. If the contractor wishes to leave the temporary airlock in place between Phase 1 & Phase 2 they will be responsible for any necessary maintenance on the temporary airlock between the time of Phase 1 ending & Phase 2 beginning.

6 6. Please confirm contractor can access electric power from NPS electric system in the cave to provide temporary electric power needs for the project?

There are 27 outlets at various locations within the cave, all outlets are 120V receptacles. See attached "wiring diagram" for outlet locations.

7 7. Please designate locations on a plan sheet of the cave where electric power can be accessed by contractor?

See attached "wiring diagram" .

8 8. Please designate number and size breakers available for contractor at each location of power?

Any modifications to use the power panels by the contractor will be at their expense.

Any modifications to access or use power panels by the contractor shall be restored after completion of the project. Based on the photos of the existing breaker panels there may be 5 spare 20 amp breakers at Transformer #2 for use but Transformers #1 and #3 appear to be full.

9 9. Please confirm if 220v electric service is available in the cave? The power panels are capable of accepting 220v circuits, existing receptacles available for use are all 120v.

10 10. If power available in the cave will not meet requirements for the project and contractor is required to bring in power from outside, please confirm contractor is permitted to bring temporary power line through the air lock? Please designate how this penetration should be made if permitted.

If additional power is needed the contractor shall bring it in through the air lock. If needed the penetration shall be made adjacent to the existing penetrations on the east side of the exterior portal door through the concrete wall. The contractor would have to run the cable through a drilled hole and then seal that hole airtight around the cable.

11 11. If temporary power is brought through the airlock please confirm extent of repair that is required to restore penetration after project is complete?

Any penetration through the air lock shall be resealed to an air tight condition following completion of the project.

12 12. Please designate if water source referenced in section 015000 will be available through winter/cold weather conditions?

See spec section 015000 paragrach 1.3 B. Assume water will be available near the visitor center (more specifically by the maintenance building) through winter/cold weather conditions.

QUESTION AND ANSWER LOG updated 8-2-2018

13 13. Water is stated in section 015000 that it will need to be hauled from the visitor’s center to the portal entrance. This presumes water will be stored in tanks near the portal entrance until needed for use. Given the cold weather time frame of this project, water in the tanks will freeze and not be usable to the contractor without expensive efforts to maintain the tanks above freezing temperatures. Please state if it is permitted to store water in the cave target room in large tanks to be used for concrete mixing operations?

Water cannot be allowed to (inadvertantly) contaminate the cave environment.

Limited, careful storage of water would be acceptable within the temporary air lock so as to prevent freezing. No concrete mixing is allowed in the cave or portal or temporary airlock due to the need to prevent cement dust from contaminating the cave environment. Remember that the cave "breaths" through the portal during pressure changes.

14 14. Ready mix concrete is not deemed a viable option for this project given ACI time requirements for placement after initial mixing. Site mixing of concrete outside the cave portal in the cold weather conditions will have many challenges. Furthermore, mixing outside the portal requires additional travel time for placement of concrete that may be limiting if adhering to ACI time requirements for placement. Please state if mixing concrete in the cave is permitted given proper protection for dust and water is provided by the contractor?

No concrete mixing is allowed in the cave or cave portal or temporary airlock due to the need to prevent cement dust from contaminating the cave environment. Mixing will need to be done outside the portal entrance. The contractor may choose to build a temporary structure right outside the portal entrance to protect against the elements.

15 15. Please state if there are any limitations or restrictions to use of water or requirements for containment of water in the target room if water is permitted to be brought into the cave for storage and use?

See response to item 13 above.

16 16. Section 011100 states that contractor may not drill into or set bolts into cave walls except where shown on the plans without permission from the contracting officer. It was discussed at the site visit that the contractor may be permitted to set anchors necessary for rigging in discrete locations of the cave walls that are not deemed sensitive or of higher resource value. Please confirm contractor will be permitted to set anchor bolts in discrete locations necessary for rigging requirements to perform work on this project.

The Contractor will be able to set anchors in discrete locations agreed upon in advance by the on-site Resource Management staff. Each location shall be approved in advance by the NPS.

17 17. Assuming parameters of use for each application will need to be understood, please state what protection materials are generally approved for use on or near cave walls and ceilings when crew are working in proximity to walls and ceiling? For example, is rigid foam insulation approved for protection? Is soft poly foam, or polyethylene foam approved for use? Is plywood approved for use? Are moving blankets approved for use?

Rigid foam will not be acceptable due to the fact it is brittle and fragments may contamintate the cave. Specs call out padded blankets for use in these applications so moving blankets would be preferred, plywood can be used in certain areas as needed.

Other potential methods and materials would be considered. Goal here is to prevent damage to important cave features, and not contaminate the cave.

QUESTION AND ANSWER LOG updated 8-2-2018

18 18. Sanitary facilities are stated to be located outside of the portal entrance in section 015000. We understand and agree to have sanitary facilities in this location for use by the crew. Workers at their stations in the cave will have to travel a long distance multiple times per day to utilize these facilities outside the airlock unless other means of providing relief stations for workers can be provided inside the cave. If no relief stations can be provided inside the cave near various work stations, this will add a tremendous cost to the project to provide for extended bathroom breaks multiple times per day for each worker. A suggestion used on a similar project for NPS is to allow use of disposable, leak proof, sanitary convenience bags that can be used in temporary privacy shelters set up in the cave at various locations strategically placed to limit needs for workers to travel great distances to use the restroom. See link for info.

on recommended convenience bag for such use.

http://www.traveljohn.com/products/disposabale-urinal/ Convenience bags are available for both liquid and solid waste. If this is permitted workers should be required to remove their own waste daily from the cave. Please state if use of convenience bags and relief stations in the cave as described above is acceptable given a proper plan is submitted by the contractor and approved prior to implementation on the project.

Thank you for bringing this real issue to light and for the suggestion. The solicitation requirements are amended as follows: Ref. 015000 paragraph 3.2E. Add note 4.

"The Contractor shall develop for NPS review and approval a 'HUMAN WASTE MANAGEMENT PLAN' that ensures that ABSOLUTELY NO HUMAN WASTE is introduced to the cave environment and/or left in the park boundaries. It is assumed that use of convenience bags in the cave will be necessary. "

19 19. Please designate if there are special considerations for animal species that may inhabit the cave?

There are no animal species in this cave area.

20 20. Are there any limitations on use of equipment that generates vibrations? For example, electric or pneumatic hammers for rock/concrete removal/demolition. If there are limitations, please designate if the limitations are cave wide or only through certain portions of the cave?

It is recommended that vibration causing equipment shall be the smallest size necessary to complete the work. If contractor equipment is found to be causing vibration damage in the cave alternative methods will have to be utilized. The contractor will have to take care in areas that may have loose or stacked rock that vibration may disturb.

21 21. Work hours are stated in section 011100 to be M-F 7:00 a.m. to 5:00 p.m.. This is a 10 hour window for work daily. With 1-2 hours of check-in, set up and travel time into the cave daily to get to work stations and nearly the same to shut down at the end of every shift this leaves 6-7 hours of productive work daily not counting for lunch and other breaks. With lunch and other breaks accounted for, productive hours are limited to 5-6 hours daily. If the work day can be extended to allow the contractor to be onsite as needed, the contractor can manage most effective work shift hours and most efficiently execute the project. Please state if contractor will be permitted to work hours necessary to complete the project most efficiently and in a timely manner, or if the 7:00 to 5:00 time will govern through the duration of the project.

Contractor shall conduct its work ON-SITE (i.e. inside the cave) M-F between 7 a.m. and 5 p.m. This is to ensure the availability of NPS project representatives (CMR, resource monitor, emergency personnel). Contractor's OFF-SITE work not limited to these hours.

22 22. Possibility of weather shutdowns of the roads were discussed at the site visit.

Please designate if contractor will be permitted access to work in the cave if the park is otherwise shutdown for weather/sun concerns

Per sheet C2 of the drawings and notes herein, the contractor fully responsible for maintaining its access to the portal entrance. Even if the park was shut down to visitors, work could continue in the cave during contract work hours provided NPS project staff available.

QUESTION AND ANSWER LOG updated 8-2-2018

23 23. If the contractor loses days to weather as stated above, are those days added to the completion time at the end of the project?

No, the contractor must account for a reasonable amount of delays associated with typical winter weather into the schedule. The end dates for each phase as described in the plans will not be changed due to weather delays. Completion dates are critical for the park to provide access to park visitors during the busy seasons.

24 24. Detail 1/C33 designates “Rocks & boulders along path to be moved/restacked for installation of new curb at direction of Contracting Officer or representative”. Will C.O.

or COR be present at all times to give direction per location on how rocks will be moved? Will rocks & boulders be required to be moved any distance from their current location? Extent & distance of rock removal and moving is necessary to understand extent of work associated with this process. Please provide clear direction on extent of rock removal and moving inside the cave.

Rock removal & relocation is expected to be (on average) within 50’ of their current location. NPS will have a full time CMR and also a resource protection staff member assigned to this project that will be able to give direction on how rocks are to be moved at each location.

25 25. Please confirm if all rebar for new concrete is not to be hot dipped galvanized or epoxy coated? Detail 3/C33 references use of epoxy coated rebar. There are no other references to epoxy coated or hot dipped galvanized rebar in the specifications or drawings.

Standard rebar shall be used in all locations. No epoxy coated or hot dipped galvanized rebar will be required.

26 26. Please designate if there is a minimum depth to compacted fill/leveling material designated in details A/C33, 3/C33, 4/C33, & 5/C33?

No minimum depth is required. Material is just intended to fill voids and provide a solid, compact, level bottom for the curb & sidewalk.

27 27. Please clarify if there is compaction and compaction testing requirements for leveling fill referenced in A/C33, 3/C33, 4/C33, & 5/C33?

No compaction testing will be required on this material. Compaction is expected to consist of tamping by hand tools (weighted tamping bar) or mechanical methods to ensure material is properly consolidated and will not settle out leaving voids.

28 28. Concrete retaining walls designated on sheets C27 & C28 associated with details on sheet C38 show concrete retaining placed against rock formations of the existing cave wall. Please clarify if contractor is permitted to place polyethylene sheeting against the cave wall and pour concrete for the retaining wall against the polyethylene sheeting?

Per the details the contractor shall excavate the existing rock walls as shown and pour the concrete directly against the cave walls at these locations. Polyethylene sheeting will not be required.

29 29. Given the magnitude and complexity of this proposal will NPS extend the August 2nd deadline for RFP submission by one week to allow more time to coordinate pricing?

The NPS has extended the proposal due until August 16th. See amendment to solicitation on www.fbo.gov.

30 1. It was discussed at the site visit that 3D laser scanning has been completed in the cave and in the development of the contract drawings. Please confirm the data files be made available for use by the contractor upon award?

Data files can be provided to the successful contractor after award if so desired.

31 2. Is it possible for NPS to provide a sample of the data file referenced in above question to the bidders at this time? This is requested because 3D models are created with varying levels of accuracy. It will be helpful to examine the files for potential usefulness prior to preparation of our final pricing for the project.

No sample at this time, scan was developed to .375” accuracy at each scan location.

The amount of electronic data is substantial.

32 3. Sheets S16, S18, S20 have notes designating certain structural members for demo and install to be noted in BOLD print. The sheets do not contain bold print so it is not clear which members are to be removed and installed. Please clarify with new sheets that clearly designate which members are to be removed and replaced.

Sheets are accurate as submitted, supporting members & columns to remain appear as lighter grey on these sheets.

QUESTION AND ANSWER LOG updated 8-2-2018

33 4. Section 05 52 05, paragraph 1.4.B.3 states “Certification that railings have been designed and fabricated to meet the loading requirements specified.” This paragraph implies that all railings are subject to a delegated design and stamped structural plans by a third-party PE that must be developed by the contractor. Similar language is included in paragraph 2.3.6 and 2.3.7. Please confirm it is the intent of this paragraph to make new railings subject to a delegated design requirement for the contractor.

Contractor shall certify that railings will meet the loading requirements specified. If Supplier/fabricator will not certify the railings then the contractor will need the third party PE to certify.

34 5. Various railing manufacturers specified in section 05 52 05, paragraph 2.1.A do not supply guardrail/handrail products that meet requirements of the contract documents including the buy American Act and/or products with the specified wall thickness in paragraph 2.3.B and that are type 316 stainless steel. Please provide direction for a single approved handrail system as the basis of design to be utilized for the project, or provide direction if the contractor should assume the handrail system will need to be entirely custom fabricated to meet specifications as they are written currently.

Guardrail/Handrail shall be built per the specifications. If the contractor cannot find a supplier that can meet the specifications then the rail will have to be custom fabricated.

35 6. Section 05 52 05, paragraph 2.3.A.4 states that handrails can be fabricated by connecting members with concealed mechanical fasteners and fittings, unless other indicated. Please indicate/clarify by elevation drawings (sheets C35 & C36) which typical joints on the handrail system are expected to be mechanically fastened versus joints that are to be welded; and which joints typically must be welded and finished.

Concealed mechanically fastened joints that produce flush, smooth, rigid, hairline joints will be allowed in handrail segments over 10’ in length. If mechanical fasteners do not produce hairline joints acceptable to the CO the contractor will be required to weld and finish all joints.

36 7. Please state if the continuous handrail shown on sheets C35 & C36 can be a bolted assemble onto the guard rail posts, or if the handrail must be welded to the handrail posts.

Bolted connection to the guardrail posts will be acceptable.

37 8. Section 05 52 05 paragraph 2.3.B states that vertical posts of the guardrail/handrail should not be spaced more than 4’ C/C. Note 1 on sheet C36 states that new guardrail should be connected to existing platforms/stairs/bridges using the same bolt holes as existing rails. General observation of the existing handrail post layout indicates that existing posts are not 4’ C/C and are in fact spaced further apart than 4’ C/C. Meeting both of these requirements at the same time is not possible without adding considerable quantity of posts and significant changes to the post layout. Please provide direction on how contractor should plan to install new posts 4’ C/C and reuse existing blot holes at the same when the two directives are in conflict.

Contractor shall plan to reuse existing bolt holes whenever possible. It is understood that new bolt holes will be required for new posts to meet the 4’ max spacing per the plan details and specifications.

38 9. Sheet C35, detail 7/C35shows elevation view of the combo guardrail with no bottom rail when used on horizontal surfaces. Sheet C36 shows combo rail for stairs with a bottom rail. Please confirm if stairs will have a bottom rail and horizontal rail structures will not have a bottom rail.

Combo rail on the stairs shall have a bottom rail. All other combo rail locations do not require a bottom rail.

39 10. Section 05 52 05, paragraph 2.3.E states that handrail finish should be stainless steel mill finish. Mill finish can be highly irregular. Please confirm if all finished surfaces should be mill finish?

All stainless steel finish shall be mill finish. Per specifications all stainless steel items shall be passivated during fabrication per ASTM A380.

QUESTION AND ANSWER LOG updated 8-2-2018

40 11. Will contractor be permitted to stage materials and equipment along the portal entrance path to the Target Room that is approximately 370’ between Phase I and Phase II to reduce the amount of demobilization required between phases if the pathway is maintained in an open and clear manner for persons to travel the pathway without obstruction?

Yes as long as a minimum 4’ wide pathway is maintained down the center (max headroom) for egress. Any equipment that may potentially contaminate the cave shall not be left in the portal. Any equipment that may potentially contaminate the natural environment shall not be left in the staging area either.

41 12. Please confirm according to detail 2/C2 that contractor will be permitted to entirely utilize 40’x250’ area designated for staging? At the site it was discussed that the contractor should keep the road open to thru traffic. If this is required this will dramatically reduce the effective size of the staging area given the topography of that area.

There will be no through traffic on the dirt road outside the portal entrance. There will need to be access maintained to the portal entrance for emergency egress.

42 13. Upgrade and continual maintenance of the access road to the portal entrance noted as sections B to C and C to D to meet SDDOT standards designated on Sheet C2 is a significant undertaking relative to the magnitude of this project. It will represent a significant cost to the project as currently specified. Please confirm it is the intent of this project to meet the standards of the SDDOT construction and maintenance guide for use of this .8 mile section of access road for the project.

The only thing noted to meet SDDOT standards is the base rock material that the contractor MAY choose to use to maintain portions of the access road during the contract performance period. The contractor is fully responsible for maintaining access to the portal for construction and/or NPS emergency operations. This is a performance specification.

43 14. Please state if cut away overburden necessary to construct sections of road designated as B to C and C to D on Sheet C2 can be stock piled and left in place onsite or if the contractor is required to haul offsite all cut away overburden from construction of the road to DOT standards?

The contractor will be responsible (performance requirement) for making improvements to the access roadway only to the extent that it is passable for construction operations. Temp road improvements do not need to meet DOT standards. This may require importing weed-free materials (subject to NPS approval) to stabilize muddy sections. Any excess dirt generated by the contractor during roadway stabilization (unlikely) would need to be hauled off site.

44 15. At the site visit it was discussed that USFS was responsible for winter plowing of snow to make access road 277 accessible. Please confirm frequency of plowing and timeliness of plowing after a storm event to open the road up for access by the contractor.

Reference sub-sheet number C2 of contract drawings. Reference "matrix" statement, "THIS SECTION OF 2 LANE ROAD IN GOOD CONDITION IS MAINTAINED BY USFS. BE

AWARE OF STEEP GRADES AND TIGHT SWITCHBACKS. INQUIRE WITH USFS IN REGARDS

TO THE FREQUENCY OF SNOW-PLOWING, ETC." Solicitation amended this sheet with a note as follows: "Please note that NPS has subsequently contacted USFS and determined that USFS WILL NOT be snow-plowing this segment of road (A to B) during the winters; therefore, it is fully the contractor's responsibility to snow-plow this segment of road for access to the portal entrance. NPS has obtained USFS permission in this regard. Again, the contractor is FULLY RESPOSIBLE for mainting access for its construction operations. The NPS has not specified "how" to do this. This is a contract performance requirement."

45 16. If frequency and/or timeliness of plowing by USFS is not sufficient to meet access needs of the contractor and contractor is losing critical time due to lack of access to the project is the contractor permitted to plow road 277 with their own equipment? If so, how will the contractor be reimbursed for this cost?

See response to item 15 above.

QUESTION AND ANSWER LOG updated 8-2-2018

46 1. Ref: General. Working in the cave presents many unique challenges such as protection of the natural elements of the cave, access to the areas of work, safety of the workers, scheduling, availability of resources and many others. In order to effectively plan for these logistical challenges, we request an extension of the bid due date of 2 weeks.

Solicitation amended as follows: "The NPS has extended the proposal due until August 16th. See amendment to solicitation on www.fbo.gov."

47 2. Ref. Factor 3, Key Personnel. Please clarify whether the Site Safety Manager role may be fulfilled by either the Site Superintendent or the Quality Control Manager as long as the individual’s qualifications meet the requirements of both roles.

Yes Safety Manger may be fulfilled by either the Superintendent or QC Manager.

48 3. Ref. Factor 3 Key Personnel. Please clarify whether the Project Manager must be on site at all times during work activities.

Project manager does not have to be on site at all times, Site Superintendent must be on site at all times during work activities.

49 4. Ref. Spec Section 015000. Is there water for construction use available at or near the portal entrance to the cave or must it be transported from the visitor’s center or offsite?

Water must be transported from the visitor’s center area (maintenance building) or from sources outside the park.

50 5. Ref. Removal of Rocks. There will likely be a surplus of rocks that are removed but not restacked as part of the sidewalk and curb installation. Please confirm that any surplus rock, not including manganese which will be removed, may be left in the cave in locations to be coordinated with the Contracting Officer.

Rocks shall be relocated from cut areas to fill areas and/or left in the cave within 50’ of the location they are removed from.

51 6. Ref. Spec Section 030900 Due to the very small quantity of concrete that will be placed daily, casting test cylinders every day as required by 03 09 00 Paragraph 3.4.B would result is much greater material waste, and additional cost to properly cure and transport the large number of cylinders for testing at a laboratory. Please consider modifying the concrete testing requirements. We suggest the following in lieu of the daily strength test specimens. Prior to production concrete placement, trial batches will be run on commercially available, prepackaged concrete mixtures to determine the appropriate quantity of water and mixing time in the proposed type of mixer to gain specified strength and other properties. No partial bags of product will be used, which will ensure consistent mixture proportions. QC personnel will witness all mixing and verify that the correct amount of water is added and that the mixing time is correct.

Less frequent periodic testing may be done to verify.

Solicitation amended as follows, "Concrete testing frequency can be reduced to one test per each CU YD placed for the first 3 CU YD placed in each phase. If test results for the first 3 CU YD are all meeting the specification requirements then the contractor can reduce the testing frequency to one test per each 10 CU YD for the remainder of the phase If the test results for the first 3 CU YD do not meet specification requirements the Contractor shall continue testing each CU YD placed until three consecutive tests yield passing results and then reduce testing frequency to one test per 10 CU YD for the remainder of the phase. Contractor shall be aware that all locations placed between the test samples will be subject to corrective measures if the test results do not meet specifications."

52 7. Ref. Solicitation. In order to maximize the time before the bid date, please consider allowing proposals to be submitted via email with hard copies to follow the next day

Solicitation amended as follows: "The NPS has extended the proposal due until August 16th. See amendment to solicitation on www.fbo.gov. "

53 8. Ref. Structural Drawing S27. The lint collection system is designed using a 3/16’' thick Stainless Sheet Metal. Our Stainless Steel supplier cannot perform the break work that these sheets need to fit the situation in the cave. Also materials will be hand-carry into the cave, the extra weight is not necessary. Would government consider using 14 Gauge, 1/8” thick Stainless Steel metal for the collection system design?

Solicitation amended as follows: "14 gauge, 1/8” thick Stainless Steel will be acceptable for the lint pans."

QUESTION AND ANSWER LOG updated 8-2-2018

54 9. Ref. Specification Section 05 50 50, Paragraphs 1.4.B and 2.5.: Referenced Specification Paragraph 2.5 requires an independent testing agency to inspect and test all structural steel work. In addition to visual inspection of all welds, the Specification requires 50% of full penetration welds, and 20% of fillet welds to be tested with liquid dye penetrant or mag particle. This requirement will add significantly to the cost as the independent agency will have to be present for the majority of the shop and field fabrication in order to conduct the required tests. Much of this time will be spent standing by and not productively. As required by referenced Specification Paragraph 1.4.B, the welders will be certified in accordance with AWS, and they will be following a welding process that is developed in compliance with AWS. Therefore, please consider modifying the Specification to waive the requirements for dye penetrant/mag particle testing, and allow the certified welder to conduct visual inspections of welds completed in accordance with AWS compliant procedures.

Solicitation amended as follows: " Delete 05 50 00, 2.5.C.1.b &c. The contractor will not be required to perform the dye penetrant/mag particle testing on the items in this section."

55 10. Specification Section 05 50 50, Paragraph 2.5.C.. The Referenced Specification requires the independent testing agency to inspect structural steel which has been erected. Please confirm that this inspection can be done once at the end of each working season.

This inspection can be done once at the end of each working season.

56 *1-Specification 05 50 00 C.2.b call for the grating to be 11/16" OC spacing of the Bearing bars, however drawing S12 note 6 call for the Bearing bars to be less than 1/2" gap. These are two different grating type one would be 11SGCS4 and the one with less than 1/2" gap would be a 7SGCS4. Which one is required? *2-These platform for this same area does not indicted a serrated surface if a slip resistant surface is required on the 7SGCS4 we would recommend and OnGrip Spray Traction surface.*3-Specification 05 50 00 C.5 Grating shall be notched for G-clips so the bolt heads are flush with the top of the adjacent grating. The notching of the Bearing bars will compromise the structural integrity of the grating. Thus we would recommend using Anchor Blocks on the 19SGCS4 grating and Countersunk lands on the 7SGCS4 or 11SGCS4 grating. See attached details.

1. 11/16" OC spacing is correct. Bearing bar spacing is a maximum of 1/2" for Bridges 1B1 & 1B2 and Platform 1P. 2. Spec 05 50 00, 2.3.C.4 calls for the 11/16" grating in the locations noted in #1 above to have a slip resistant surface coating.

3. Platform grating shall be fabricated per specifications with the G-clips or equal that can be removed from the top of the grating and don't require additional holes drilled into the top of the support members.

Sheet1