Originally Posted On: https://www.marconitech.com/2026/10/08/what-do-fdny-arcs-actually-do-during-a-high-rise-fire-in-nyc/
Handheld radios die in steel—and—concrete stairwells. That's the whole problem, and it's why FDNY ARCS exist. Picture a 60-story tower in Midtown Manhattan, or one of the newer glass-and-steel buildings at Hudson Yards, with a fire on the 38th floor. The chief at the lobby command post can't raise the company working above the fire, because the building itself is eating the signal.
An ARCS (Auxiliary Radio Communication System) fixes that with dedicated channels, a repeater, and an antenna network that runs through the stairwells, the cellar, and the core. Simple on paper. Rough in practice.
Fire safety directors and life safety managers in NYC carry the burden when it doesn't work. Inspectors don't grade on effort. They test coverage, check the console at the command station, and walk away if something's off. So what does the system actually do when the alarm comes in, and what trips up buildings at acceptance testing? Start with what happens in those first few minutes.
A probationary firefighter climbs the stairwell of a Midtown Manhattan tower, three floors above the fire, and his handheld goes silent. No static. Nothing. That's what steel and concrete do, and it happens in Hudson Yards glass towers and Lower Manhattan pre-war high-rises alike.
Dense framing, fire-rated shafts, and low-E glass swallow radio signal. Inspectors saw it for decades. FDNY ARCS exist to fix exactly this.
ARCS stands for Auxiliary Radio Communication System. It's a building-installed setup that gives the fire command post a dedicated, reliable radio link to crews in stairwells and on upper floors. Unlike a BDA system, which most cities require, NYC wants its own approach. Properly designed ARCS systems use dedicated channels and a console at the lobby command station.
This section is written for fire safety directors and life safety managers who have to pass FDNY inspection the first time. Not the second. Not after a re-test fee and a lost month.
So what does the system actually do in a fire? What does the code demand? And what gets a submission rejected?
Plain answers follow.
What Is an FDNY ARCS and What Does It Do During a High-Rise Fire?
An FDNY ARCS is a dedicated, FDNY-mandated radio system that keeps firefighters in contact inside a high-rise when normal handheld radio signals can't get through. That's the whole job. Here's how it plays out. First-arriving companies hit the lobby of a Midtown tower, and the chief sets up the command post beside the fire command station. Crews then climb the stairwells toward the fire floor, and every report back to the lobby runs through the system.
Physically, it's a repeater, a dedicated set of channels, and an antenna network wired through the stairs and floors. A Dedicated Radio Console sits at the command post. Any ARC building in NYC needs all of those pieces working together.
Blunt note: it's not a phone system.
It's not a scanner feed. And it's not the same as an arc fire alarm panel, which only signals the fire. Owners should also vet FDNY approved ARCS companies before buying anything.
How Firefighters Use ARCS Channels at the Command Post
The chief at the lobby command station works from the console, often a touchscreen unit, to talk with operating units on upper floors. The channels are reserved for fire department use. No tenant chatter, no crowded airwaves. Only fire ground traffic.
What ARCS Does That Handheld Radios Alone Can't
Steel, concrete, elevator shafts — shielded stairwells swallow handheld signals. Below-grade levels and core areas are worse. Realistically, that's where a mayday can get lost.
People who listen to FDNY radio on live scanners across Manhattan, Brooklyn, and Queens hear public citywide chatter. That isn't an in-building system. ARCS works inside the structure, where scanners and handhelds go quiet.
Why Does NYC Require ARCS Instead of a BDA or ERCES System?
Why does a city that borrows so much from the national fire code walk away from it on radio coverage? NYC uses ARCS because FDNY wants a dedicated, fire-department-controlled radio system rather than the signal-booster approach most U.S. jurisdictions accept.
Here's the plain difference.
A bi-directional amplifier grabs a donor signal off a rooftop antenna and rebroadcasts it inside. Most of the country relies on that model, and a bda fire alarm interface is a familiar piece of that setup. FDNY doesn't trust a booster to carry its traffic through steel-and-concrete canyons. So the city requires its own repeater-based system, arcs nyc style, with channels the department controls.
The paperwork lives in the NYC Fire Code and FDNY rules, and FDNY technology management oversees the requirements. Equipment must carry UL 2524A-related listing, and the antenna monitoring language matters. Inspectors read it closely.
Which Buildings Get Pulled In?
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New high-rises that meet the code's height threshold
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Existing buildings that trigger the requirement through major alterations or upgrades
Don't assume a grandfathered building stays exempt. Check before the work starts.
What About Yonkers and New Rochelle?
Nearby municipalities run their own variations. Yonkers and New Rochelle both have local fire department radio setups, so a design that clears FDNY won't automatically clear them.
What Are the FDNY ARCS Requirements, Forms, and Approval Steps for a NYC Building?
Roughly one in three first-time ARCS submissions comes back with comments, and most of them are paperwork. ARCS approval in NYC runs through FDNY plan review, installation by qualified personnel, and acceptance testing witnessed or verified by FDNY. Here's the order that works:
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Design and propagation study of the building's steel and concrete.
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Shop drawings and as-builts.
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FDNY submission with the ARCS agreement and required forms.
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Installation by qualified personnel.
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Commissioning of the radio, antennas, and console.
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Acceptance test with FDNY.
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Ongoing testing on the schedule FDNY sets.
As for forms, the TM-1, TM-2, and TM-4 are generally the technology management filings tied to this work. Each covers a different stage, so don't guess. Pull the current FDNY manual documents from FDNY's official site and confirm the version before you file. Outdated forms get bounced. Every time.
Who Can Design, Install, and Test an ARCS?
Only people holding the right FDNY certifications should test and commission. Ask for the certificate, not a promise. A manufacturer with in-house engineering shortens the chain, and a NYC ARCS built by Marconi Technologies is UL Listed, with FDNY-certified testing and commissioning. The plug-n-play, non-proprietary design lets qualified contractors commission without waiting on third-party technicians.
What Fails ARCS Inspection the First Time?
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Weak or unmonitored antenna runs
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Dead coverage in stairwells and cellar levels
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Wrong or missing documentation
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Mislabeled equipment
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Dead backup power
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A console that won't work at the command post
That antenna failure is the sneaky one. The RC-108A uses active antenna monitoring, UL-Listed for 2524A, so a broken antenna shows up before the inspector finds it. Compare that with a basic BDA system fire alarm setup, which won't tell you much until test day.
How Do You Keep an ARCS Working and Ready for the Next FDNY Inspection?
Keep an ARCS inspection-ready by testing it on a schedule, monitoring antennas and power continuously, and fixing faults before FDNY finds them. Passing once doesn't mean you're done. That's the myth that sinks buildings.
The approval is the starting line. A good arcs system still drifts over time, and the inspector will test it as it is today, not as it was at sign-off.
The routine that works
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Coverage checks: walk the stairwells and test radio talk-through from the lobby up to the roof.
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Battery and power: test the backup supply under load, and log the date and result.
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Antenna monitoring alarms: never silence one without a ticket and a fix date.
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Log book: keep every test, fault, and repair in one binder at the fire command station.
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2 a.m. contact: post the 24/7 number where the overnight staff can see it.
Renewal and recurring test intervals change, so confirm the current schedule with FDNY before you plan your year.
Plan for buildouts
Tenant buildouts move walls, add steel, and block signal paths. Re-test coverage after any major floor change. Many owners also ask how an ARCS differs from a BDA fire system. In NYC, FDNY expects the ARCS.
Don't wait for the inspector.
Schedule an engineering consultation or call the 24/7 line at (212) 376-4548 for a site review before the inspector shows up.
A high-rise fire in NYC doesn't wait for a system to be ready. When the first companies climb into a steel-and-concrete stairwell, FDNY ARCS is the only thing standing between a working command post and silence. That's the whole job. Dedicated channels, a repeater, and a monitored antenna network keep the lobby talking to the floors above.
Fire safety directors who pass on the first try tend to share one habit: they find problems before the inspector does. A dead battery, a cut antenna cable, a mislabeled component, a console that won't power up at the command station. Each one is a failed inspection waiting to happen, and each one is cheap to catch early. Continuous antenna monitoring and a routine test schedule do most of that work.
The code, the forms, and the approval steps are fixed. The only open question is whether the building is ready when FDNY arrives.
Don't leave that to chance.
Call Marconi Technologies' 24/7 line at (212) 376-4548 or book an engineering consultation to get a site review done before the inspection date is on the calendar.
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