Ohio Rooftop Tower PE report
Budget: $3,000 – $5,000 USD
I have an ATC control tower with a flat roof where I am mounting a new piece of surveillance equipment. The payload—including mounting hardware—comes in under 600 lbs and will sit on a gravity-base platform built from steel with concrete blocks as ballast.
The drawing set attached to this posting shows the exact layout, member sizes, anchoring details and the location of the ballast blocks. What I need now is a formal structural review, sealed by an Ohio-licensed Professional Engineer, confirming two things: that the ballast mass and distribution are adequate to resist wind, seismic and overturning forces, and that both the gravity base and the existing tower structure can carry the resulting loads without overstressing the roof slab or supporting members.
All calculations must reference current Ohio Building Code, ASCE 7 wind load provisions and any FAA guidance that applies to control-tower rooftop appurtenances. Please incorporate the wind exposure category indicated on the drawings.
The ATC tower is located in Springfield Ohio and the roof ( where this is to be installed ) is 86 feet above ground level.
These are the Rohn components used:
(1) 25GBRM 25G series gravity base
(1) 10ft 25G tower segment
(1) 5ft 25G tower segment
(1) BPL25G Top Section
https://www.dxengineering.com/search/part-type/tower-top-plates/product-line/rohn-bpl25g-tower-bearing-plates
(1) Lighthouse Avionics Camera Assembly
Deliverables (PDF):
• PE-stamped calculation package and summary letter
• Mark-ups or brief memo noting any required field verifications or minor drawing tweaks
I will provide the full drawing file (DWG and PDF) plus manufacturer cut-sheets once we start. A quick turnaround is appreciated so I can keep the installation on schedule.
The drawing set attached to this posting shows the exact layout, member sizes, anchoring details and the location of the ballast blocks. What I need now is a formal structural review, sealed by an Ohio-licensed Professional Engineer, confirming two things: that the ballast mass and distribution are adequate to resist wind, seismic and overturning forces, and that both the gravity base and the existing tower structure can carry the resulting loads without overstressing the roof slab or supporting members.
All calculations must reference current Ohio Building Code, ASCE 7 wind load provisions and any FAA guidance that applies to control-tower rooftop appurtenances. Please incorporate the wind exposure category indicated on the drawings.
The ATC tower is located in Springfield Ohio and the roof ( where this is to be installed ) is 86 feet above ground level.
These are the Rohn components used:
(1) 25GBRM 25G series gravity base
(1) 10ft 25G tower segment
(1) 5ft 25G tower segment
(1) BPL25G Top Section
https://www.dxengineering.com/search/part-type/tower-top-plates/product-line/rohn-bpl25g-tower-bearing-plates
(1) Lighthouse Avionics Camera Assembly
Deliverables (PDF):
• PE-stamped calculation package and summary letter
• Mark-ups or brief memo noting any required field verifications or minor drawing tweaks
I will provide the full drawing file (DWG and PDF) plus manufacturer cut-sheets once we start. A quick turnaround is appreciated so I can keep the installation on schedule.