[Scan-DC] Firefighter radios did not work in tunne l du r ing Metro smoke incident ·

[Andrew Clegg]

I'll be surprised if the NTSB investigation includes any investigation of radio issues.
> Date: Wed, 14 Jan 2015 17:32:57 -0500
> To: edtobias at comcast.net
> From: jeff at krauss.ws
> CC: scan-dc at mailman.qth.net
> Subject: [Scan-DC]  Re:  Firefighter radios did not work in tunne l du r ing Metro smoke incident ·
> 
> Tunnel antenna systems are complicated things.
> See 
> http://www.researchgate.net/publication/3156527_Measurements_and_Modeling_of_Distributed_Antenna_Systems_in_Railway_Tunnels
> Maybe the antenna system was poorly designed, with large coverage gaps.
> Maybe the antenna system introduces phase noise or group delay 
> distortion that affects decryption capability.
> Just saying "not working" may be insufficient.
> Those are issues for the NTSB investigation.
> 
> 
> At 04:53 PM 1/14/2015, Ed Tobias wrote:
> >Yes, that's been reported by a number of news organizations. 
> >However, if the tunnel repeaters weren't working, as has also been 
> >reported, there would be a lack of comms to the command post, 
> >whether encrypted or not.
> >
> >I spent 40 years in the DC news media and have been listening to 
> >public safety radio for 50+ years. I firmly oppose encryption on 
> >routine public safety channels. However, I have to wonder whether 
> >news reports that are focusing on encrypted radios as a possible 
> >cause of the comms problems are doing so because media members are 
> >unhappy about the encryption and they're trying to make a case against it.
> >
> >The question that should be asked is "did the repeaters fail and, if 
> >so, why?"  Maybe encryption is a factor, maybe not.
> >
> >Ed
> >
> >Sent from my iPhone
> >
> > > On Jan 14, 2015, at 3:34 PM, "Thomas J. Dalrymple" 
> > <tjdalrymple at gmail.com> wrote:
> > >
> > > I heard this on WTOP around 2pm, but have not found it on their 
> > website yet.
> > >
> > > Encrypted radios were not working in the tunnels, and firefighters
> > > resorted to runners to deliver communications from the site to
> > > firefighters outside.
> > >
> > > Tom D.
> > >
> > >> On Wed, Jan 14, 2015 at 10:02 AM, Ed Tobias <edtobias at comcast.net> wrote:
> > >> The problem, (at least one of them), seems to have been that the 
> > in-tunnel repeaters were out of service. That would have made it 
> > difficult, if not impossible, to communicate from tunnel to command 
> > post or along long stretches of tunnel.
> > >>
> > >> Montgomery used to send a Btl Chief to the Command Center at 
> > Metro Hq to help coordinate incidents. Not sure if they still do or 
> > if DC does that.
> > >>
> > >> The Rail70x units are, I believe, MCFD officers with specialized 
> > training for Metro incidents.   Don't confuse them with NCR70x 
> > units, who carry radio caches for use in major incidents involving 
> > multiple jurisdictions.
> > >>
> > >> Ed
> > >>
> > >> Sent from my iPhone
> > >>
> > >>> On Jan 13, 2015, at 10:29 PM, Jeff Krauss <jeff at krauss.ws> wrote:
> > >>>
> > >>> After viewing the Fox5 piece by Paul Wagner, I'm sure you're correct.
> > >>> He said that the units in the tunnel couldn't communicate with 
> > the incident commander at street level.
> > >>>
> > >>> Which means that the DCFD command structure was deficient.
> > >>>
> > >>> If I recall, the Montgomery County FD procedure is to assign a 
> > "Forward Incident Commander" (they don't use that term) at the 
> > stationmaster's kiosk, whose job includes communications between 
> > units in the tunnel and the command post upstairs.
> > >>>
> > >>> Also, when Montgomery County has a Metro incident, I hear units 
> > come up on the air identifying themselves as "Rail 704" and similar 
> > callsigns.  Not clear whether they are County FD employees or WMATA 
> > employees.  At least some of them seem to carry caches of radios to 
> > assist in radio communications between the fire department and 
> > Metro dispatchers.
> > >>>
> > >>>
> > >>>
> > >>> At 08:07 PM 1/13/2015, djoneses wrote:
> > >>>> I would think that this quote from the Fox5 story answers your question:
> > >>>> "firefighters used line of sight communication in the 
> > tunnel."  Presumably
> > >>>> that means that simplex i.e. line of sight channels were used.
> > >>>>
> > >>>> -----Original Message-----
> > >>>> From: Scan-DC [mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of Jeff
> > >>>> Krauss
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