During standard wireless site design, the A&E firm develops drawings and engineering reports to match client site development criteria within acceptable parameters for the property owner, the local jurisdiction, the RF engineer, and the construction manager and with respect to environmental compliance. Module 9 Zone-ability discusses the jurisdiction criteria for site design and Module 10 Constructability discusses practical considerations affecting site design.
Site design work is performed by the A&E firm in coordination with the project surveyor, the construction manager, the RF engineer, the attorney, the client point of contact, the site acquisition consultant, and specialty engineers, as necessary. Site drawings and reports are utilized to fulfill project due diligence standards, to process space agreements, to apply for local permits, and to prepare bid packages for site construction services. Site acquisition progress mandates creative, effective coordination of the property owner, the jurisdiction, and the A&E firm. The site sketch, final survey, and construction drawings produced by the A&E firm become exhibits to the site agreement. The final survey, construction drawings, zoning drawings, and other drawings and reports are developed for submission to the local jurisdiction with local permit applications. A construction manager oversees site design culminating with bid packages for construction service contractors.
As discussed in Module 16 Project Initiation, the A&E’s site sketch is the first output of the group technical site visit. The project team and property owner meet and confirm the proposed location for the lease area, the antenna structure, and the access route from the public right-of-way to the lease area and utility routing. If a consensus about these locations is not reached during the site visit, the project is in a state of flux until a consensus is reached.
Since facility access, the proposed lease space, and utility routing are pretty well defined for collocations on existing sites, site sketches for collocations need to include only the proposed space on the structure, the vertical cabling on the structure, and the space for the associated equipment (if on-site). This relieves much of the burden of the A&E firm for collocations that is otherwise necessary when a new structure will be built.
The preliminary survey is only an initial layout of the property based on SCIP details and field observations. The preliminary survey may include topography, displaying the contour of elevation lines, and portraying the slope of the terrain on the property. Characterizing topography on paper helps visualize the impacts of site layouts and locations overlaid on variations of terrain on the property. This perspective may be more difficult to reach while standing on the property.
Collocations under MLAs don’t typically require a new final survey if the structure owner has a valid existing survey. A new final survey will be required, however, if the current lease area of the existing site needs to be expanded, if an equipment building or associated equipment needs to be placed outside the structure owner’s current lease area, or if the parent parcel of the existing site has been divided since the most recent survey. Wireless site developers rely upon site acquisition consultants and project attorneys to raise a flag and speak up to indicate that a new final survey may be needed. For more about requirements for collocation site drawings and reports see Module 23 Collocation Agreements.
The final survey represents a combination of the professional surveyor’s research, fieldwork, and drafting to accurately characterize legal descriptions and drawings for the following:
The beauty of merging survey work with title research is documented in national standards between surveyors and title companies, as discussed in Module 18 Title Insurance Commitment.1 The surveyor evaluates the title report for the rights of others to easements and property encumbrances and then advises if each easement or encumbrance will or won’t impact the construction or operation of a proposed facility. In some cases, such as the case of blanket easements, the surveyor won’t have enough information to make this determination.
As discussed in Module 6 Search Area Design, one goal of RF engineering in designing a search area that might require a new structure is to avoid conflicts with air traffic navigation. In Module 16 Project Initiation, I discussed the preparation of an FAA 7460-1 form that is submitted to the FAA for a determination either approving or denying the height of a new structure at a given set of coordinates (latitude and longitude) and ground elevation above mean sea level (AMSL).1
Upon completion of a final survey, a lease exhibit (LE) can be created by the A&E firm. The lease exhibit is a formal site sketch attached to the site agreement. It indicates the proposed lease space referred to in the agreement. Beware: if the final survey is revised, the lease exhibit may need revision as well.
The initial version of construction drawings (CDs) is merely a starting point for developing comprehensive revisions of the plans. CDs are commonly developed in computer-aided design (CAD) software and printed on 11 × 17–inch sheets convenient for reproduction. It is common to originate drawings on 24 × 36–inch sheets for a clear display of details and to print plans on 8.5 × 11–inch sheets to conveniently file hard copies.
The initial CDs typically include a cover sheet with the following information: read more…
Architectural drawings depict overhead and side views (known as elevations) of the plans. A wide angle or overall site plan, a detailed site plan, foundation plans, and elevations from the ground to the top of the antenna structure and the equipment shelter (or outdoor associated equipment) characterize architectural drawings.
All aspects of cable routing, equipment placement, interconnection with the local service provider including locations of the telecom demarcation boxes, electrical plan specifications including the location of the power transfer switch and cut-off switch, and notes to the electrical contractor are specified in the electrical drawings.
Road design is subject to review by property owners and jurisdictions where compliance with road development standards is regulated, such as with driveway or highway approach permits. A driveway or highway approach permit may be required from a state or local agency for new access from a public right-of-way.
Grounding plans are designed to divert the energy lightning strikes can impose to damage expensive and sensitive electronic radio equipment within wireless facilities. Wide-ranging geographical subsurface soil contents affect the grounding design implemented from one project location to another. Grounding materials are specified to match site-specific soil conditions. The resource for response to inquiries or questions that arise (from property owners or building officials or in zoning hearings) about the grounding design is here in the plan drawings.
A soil test is one of the final due diligence tasks performed by a specialty (geological) engineer on a property prior to the construction of a new antenna structure. Subsurface soils vary greatly across America’s landscape. Some soils present more challenges than others when designing an antenna structure subsurface foundation. In most situations, structural design engineers can plan and implement a structurally sound foundation design. On two extremes, I’ve worked on a project where the tower was designed in sand and one where the subsurface was bedrock. The subsurface may impact grounding plans. Foundation design is usually unnecessary for collocations on existing structures.
A structural engineer generates tower drawings and calculations on behalf of the structure fabricator. These drawings and calculations explain the engineering design required for the structure to support the proposed loading during and after the erection of the structure. Specifically, the design goal is to accommodate the proposed and future antenna system loading, as well as the loading required to construct the structure.
Most wireless structures are designed to accommodate, in one way or another, the loading of multiple carriers. This is commonly a condition of local permit rights approval.
Structural engineering is the engineering specialty engaged in structural analysis. Structural engineering firms and individuals exist that perform services exclusively for wireless facilities. Some site management firms assert their preference as to which structural engineer is contracted to perform structural studies on their owned or managed sites. Others may allow the carrier, at its own expense, to contract a structural engineer directly to perform the analysis. The engineer who performed the latest analysis on a structure or originally performed calculations and designed a structure’s tower drawings may be ideal for future studies.
There are times when a wireless carrier proposes adding antenna loading to a structure or member of a structure (such as the catwalk railing of a water tower) such that a full-blown structural analysis may not be necessary. If the proposed loading isn’t significant, a professional engineer (PE) may be willing to simply draft a letter to that effect and sign it. The cost of a PE letter is a fraction of the cost of a full structural analysis.
CDs are used in the early stages of construction management to provide the project details to contractors receiving requests for quotations (RFQs). Construction contractors develop bids for specific facility locations based solely on what they know about each site as represented in the CDs. Details remaining to be implemented in site construction, as documented in space rights agreements and local permit rights approvals along with facility developer assurances, need to be included in the CDs or notes provided with the RFQ distribution.
© 2024 · John M. Rowe/Communications Real Estate, Inc./Telecom Birddogs, LLC